configure

#!/bin/sh
#
# FFmpeg configure script
#
# Copyright (c) 2000-2002 Fabrice Bellard
# Copyright (c) 2005-2008 Diego Biurrun
# Copyright (c) 2005-2008 Mans Rullgard
#

# Prevent locale nonsense from breaking basic text processing.
LC_ALL=C
export LC_ALL

# make sure we are running under a compatible shell
# try to make this part work with most shells

try_exec(){
    echo "Trying shell $1"
    type "$1" > /dev/null 2>&1 && exec "$@"
}

unset foo
(: ${foo%%bar}) 2> /dev/null
E1="$?"

(: ${foo?}) 2> /dev/null
E2="$?"

if test "$E1" != 0 || test "$E2" = 0; then
    echo "Broken shell detected.  Trying alternatives."
    export FF_CONF_EXEC
    if test "0$FF_CONF_EXEC" -lt 1; then
        FF_CONF_EXEC=1
        try_exec bash "$0" "$@"
    fi
    if test "0$FF_CONF_EXEC" -lt 2; then
        FF_CONF_EXEC=2
        try_exec ksh "$0" "$@"
    fi
    if test "0$FF_CONF_EXEC" -lt 3; then
        FF_CONF_EXEC=3
        try_exec /usr/xpg4/bin/sh "$0" "$@"
    fi
    echo "No compatible shell script interpreter found."
    echo "This configure script requires a POSIX-compatible shell"
    echo "such as bash or ksh."
    echo "THIS IS NOT A BUG IN FFMPEG, DO NOT REPORT IT AS SUCH."
    echo "Instead, install a working POSIX-compatible shell."
    echo "Disabling this configure test will create a broken FFmpeg."
    if test "$BASH_VERSION" = '2.04.0(1)-release'; then
        echo "This bash version ($BASH_VERSION) is broken on your platform."
        echo "Upgrade to a later version if available."
    fi
    exit 1
fi

test -d /usr/xpg4/bin && PATH=/usr/xpg4/bin:$PATH

show_help(){
    cat <<EOF
Usage: configure [options]
Options: [defaults in brackets after descriptions]

Help options:
  --help                   print this message
  --list-decoders          show all available decoders
  --list-encoders          show all available encoders
  --list-hwaccels          show all available hardware accelerators
  --list-demuxers          show all available demuxers
  --list-muxers            show all available muxers
  --list-parsers           show all available parsers
  --list-protocols         show all available protocols
  --list-bsfs              show all available bitstream filters
  --list-indevs            show all available input devices
  --list-outdevs           show all available output devices
  --list-filters           show all available filters

Standard options:
  --logfile=FILE           log tests and output to FILE [config.log]
  --disable-logging        do not log configure debug information
  --fatal-warnings         fail if any configure warning is generated
  --prefix=PREFIX          install in PREFIX [$prefix]
  --bindir=DIR             install binaries in DIR [PREFIX/bin]
  --datadir=DIR            install data files in DIR [PREFIX/share/ffmpeg]
  --docdir=DIR             install documentation in DIR [PREFIX/share/doc/ffmpeg]
  --libdir=DIR             install libs in DIR [PREFIX/lib]
  --shlibdir=DIR           install shared libs in DIR [LIBDIR]
  --incdir=DIR             install includes in DIR [PREFIX/include]
  --mandir=DIR             install man page in DIR [PREFIX/share/man]
  --enable-rpath           use rpath to allow installing libraries in paths
                           not part of the dynamic linker search path
                           use rpath when linking programs [USE WITH CARE]

Licensing options:
  --enable-gpl             allow use of GPL code, the resulting libs
                           and binaries will be under GPL [no]
  --enable-version3        upgrade (L)GPL to version 3 [no]
  --enable-nonfree         allow use of nonfree code, the resulting libs
                           and binaries will be unredistributable [no]

Configuration options:
  --disable-static         do not build static libraries [no]
  --enable-shared          build shared libraries [no]
  --enable-small           optimize for size instead of speed
  --disable-runtime-cpudetect disable detecting cpu capabilities at runtime (smaller binary)
  --enable-gray            enable full grayscale support (slower color)
  --disable-swscale-alpha  disable alpha channel support in swscale
  --disable-all            disable building components, libraries and programs
  --enable-incompatible-libav-abi enable incompatible Libav fork ABI [no]
  --enable-raise-major     increase major version numbers in sonames [no]

Program options:
  --disable-programs       do not build command line programs
  --disable-ffmpeg         disable ffmpeg build
  --disable-ffplay         disable ffplay build
  --disable-ffprobe        disable ffprobe build
  --disable-ffserver       disable ffserver build

Documentation options:
  --disable-doc            do not build documentation
  --disable-htmlpages      do not build HTML documentation pages
  --disable-manpages       do not build man documentation pages
  --disable-podpages       do not build POD documentation pages
  --disable-txtpages       do not build text documentation pages

Component options:
  --disable-avdevice       disable libavdevice build
  --disable-avcodec        disable libavcodec build
  --disable-avformat       disable libavformat build
  --disable-avutil         disable libavutil build
  --disable-swresample     disable libswresample build
  --disable-swscale        disable libswscale build
  --disable-postproc       disable libpostproc build
  --disable-avfilter       disable libavfilter build
  --enable-avresample      enable libavresample build [no]
  --disable-pthreads       disable pthreads [autodetect]
  --disable-w32threads     disable Win32 threads [autodetect]
  --disable-os2threads     disable OS/2 threads [autodetect]
  --disable-network        disable network support [no]
  --disable-dct            disable DCT code
  --disable-dwt            disable DWT code
  --disable-error-resilience disable error resilience code
  --disable-lsp            disable LSP code
  --disable-lzo            disable LZO decoder code
  --disable-mdct           disable MDCT code
  --disable-rdft           disable RDFT code
  --disable-fft            disable FFT code
  --disable-faan           disable floating point AAN (I)DCT code
  --disable-pixelutils     disable pixel utils in libavutil

Hardware accelerators:
  --disable-dxva2          disable DXVA2 code [autodetect]
  --disable-vaapi          disable VAAPI code [autodetect]
  --disable-vda            disable VDA code [autodetect]
  --disable-vdpau          disable VDPAU code [autodetect]

Individual component options:
  --disable-everything     disable all components listed below
  --disable-encoder=NAME   disable encoder NAME
  --enable-encoder=NAME    enable encoder NAME
  --disable-encoders       disable all encoders
  --disable-decoder=NAME   disable decoder NAME
  --enable-decoder=NAME    enable decoder NAME
  --disable-decoders       disable all decoders
  --disable-hwaccel=NAME   disable hwaccel NAME
  --enable-hwaccel=NAME    enable hwaccel NAME
  --disable-hwaccels       disable all hwaccels
  --disable-muxer=NAME     disable muxer NAME
  --enable-muxer=NAME      enable muxer NAME
  --disable-muxers         disable all muxers
  --disable-demuxer=NAME   disable demuxer NAME
  --enable-demuxer=NAME    enable demuxer NAME
  --disable-demuxers       disable all demuxers
  --enable-parser=NAME     enable parser NAME
  --disable-parser=NAME    disable parser NAME
  --disable-parsers        disable all parsers
  --enable-bsf=NAME        enable bitstream filter NAME
  --disable-bsf=NAME       disable bitstream filter NAME
  --disable-bsfs           disable all bitstream filters
  --enable-protocol=NAME   enable protocol NAME
  --disable-protocol=NAME  disable protocol NAME
  --disable-protocols      disable all protocols
  --enable-indev=NAME      enable input device NAME
  --disable-indev=NAME     disable input device NAME
  --disable-indevs         disable input devices
  --enable-outdev=NAME     enable output device NAME
  --disable-outdev=NAME    disable output device NAME
  --disable-outdevs        disable output devices
  --disable-devices        disable all devices
  --enable-filter=NAME     enable filter NAME
  --disable-filter=NAME    disable filter NAME
  --disable-filters        disable all filters

External library support:
  --enable-avisynth        enable reading of AviSynth script files [no]
  --disable-bzlib          disable bzlib [autodetect]
  --enable-fontconfig      enable fontconfig, useful for drawtext filter [no]
  --enable-frei0r          enable frei0r video filtering [no]
  --enable-gnutls          enable gnutls, needed for https support
                           if openssl is not used [no]
  --disable-iconv          disable iconv [autodetect]
  --enable-ladspa          enable LADSPA audio filtering [no]
  --enable-libaacplus      enable AAC+ encoding via libaacplus [no]
  --enable-libass          enable libass subtitles rendering,
                           needed for subtitles and ass filter [no]
  --enable-libbluray       enable BluRay reading using libbluray [no]
  --enable-libbs2b         enable bs2b DSP library [no]
  --enable-libcaca         enable textual display using libcaca [no]
  --enable-libcelt         enable CELT decoding via libcelt [no]
  --enable-libcdio         enable audio CD grabbing with libcdio [no]
  --enable-libdc1394       enable IIDC-1394 grabbing using libdc1394
                           and libraw1394 [no]
  --enable-libfaac         enable AAC encoding via libfaac [no]
  --enable-libfdk-aac      enable AAC de/encoding via libfdk-aac [no]
  --enable-libflite        enable flite (voice synthesis) support via libflite [no]
  --enable-libfreetype     enable libfreetype, needed for drawtext filter [no]
  --enable-libfribidi      enable libfribidi, improves drawtext filter [no]
  --enable-libgme          enable Game Music Emu via libgme [no]
  --enable-libgsm          enable GSM de/encoding via libgsm [no]
  --enable-libiec61883     enable iec61883 via libiec61883 [no]
  --enable-libilbc         enable iLBC de/encoding via libilbc [no]
  --enable-libmfx          enable HW acceleration through libmfx
  --enable-libmodplug      enable ModPlug via libmodplug [no]
  --enable-libmp3lame      enable MP3 encoding via libmp3lame [no]
  --enable-libnut          enable NUT (de)muxing via libnut,
                           native (de)muxer exists [no]
  --enable-libopencore-amrnb enable AMR-NB de/encoding via libopencore-amrnb [no]
  --enable-libopencore-amrwb enable AMR-WB decoding via libopencore-amrwb [no]
  --enable-libopencv       enable video filtering via libopencv [no]
  --enable-libopenh264     enable H.264 encoding via OpenH264 [no]
  --enable-libopenjpeg     enable JPEG 2000 de/encoding via OpenJPEG [no]
  --enable-libopus         enable Opus de/encoding via libopus [no]
  --enable-libpulse        enable Pulseaudio input via libpulse [no]
  --enable-libquvi         enable quvi input via libquvi [no]
  --enable-librtmp         enable RTMP[E] support via librtmp [no]
  --enable-libschroedinger enable Dirac de/encoding via libschroedinger [no]
  --enable-libshine        enable fixed-point MP3 encoding via libshine [no]
  --enable-libsmbclient    enable Samba protocol via libsmbclient [no]
  --enable-libsoxr         enable Include libsoxr resampling [no]
  --enable-libspeex        enable Speex de/encoding via libspeex [no]
  --enable-libssh          enable SFTP protocol via libssh [no]
  --enable-libstagefright-h264  enable H.264 decoding via libstagefright [no]
  --enable-libtheora       enable Theora encoding via libtheora [no]
  --enable-libtwolame      enable MP2 encoding via libtwolame [no]
  --enable-libutvideo      enable Ut Video encoding and decoding via libutvideo [no]
  --enable-libv4l2         enable libv4l2/v4l-utils [no]
  --enable-libvidstab      enable video stabilization using vid.stab [no]
  --enable-libvo-aacenc    enable AAC encoding via libvo-aacenc [no]
  --enable-libvo-amrwbenc  enable AMR-WB encoding via libvo-amrwbenc [no]
  --enable-libvorbis       enable Vorbis en/decoding via libvorbis,
                           native implementation exists [no]
  --enable-libvpx          enable VP8 and VP9 de/encoding via libvpx [no]
  --enable-libwavpack      enable wavpack encoding via libwavpack [no]
  --enable-libwebp         enable WebP encoding via libwebp [no]
  --enable-libx264         enable H.264 encoding via x264 [no]
  --enable-libx265         enable HEVC encoding via x265 [no]
  --enable-libxavs         enable AVS encoding via xavs [no]
  --enable-libxcb          enable X11 grabbing using XCB [autodetect]
  --enable-libxcb-shm      enable X11 grabbing shm communication [autodetect]
  --enable-libxcb-xfixes   enable X11 grabbing mouse rendering [autodetect]
  --enable-libxcb-shape    enable X11 grabbing shape rendering [autodetect]
  --enable-libxvid         enable Xvid encoding via xvidcore,
                           native MPEG-4/Xvid encoder exists [no]
  --enable-libzmq          enable message passing via libzmq [no]
  --enable-libzvbi         enable teletext support via libzvbi [no]
  --disable-lzma           disable lzma [autodetect]
  --enable-decklink        enable Blackmagick DeckLink I/O support [no]
  --enable-nvenc           enable NVIDIA NVENC support [no]
  --enable-openal          enable OpenAL 1.1 capture support [no]
  --enable-opencl          enable OpenCL code
  --enable-opengl          enable OpenGL rendering [no]
  --enable-openssl         enable openssl, needed for https support
                           if gnutls is not used [no]
  --disable-sdl            disable sdl [autodetect]
  --enable-x11grab         enable X11 grabbing (legacy) [no]
  --disable-xlib           disable xlib [autodetect]
  --disable-zlib           disable zlib [autodetect]

Toolchain options:
  --arch=ARCH              select architecture [$arch]
  --cpu=CPU                select the minimum required CPU (affects
                           instruction selection, may crash on older CPUs)
  --cross-prefix=PREFIX    use PREFIX for compilation tools [$cross_prefix]
  --progs-suffix=SUFFIX    program name suffix []
  --enable-cross-compile   assume a cross-compiler is used
  --sysroot=PATH           root of cross-build tree
  --sysinclude=PATH        location of cross-build system headers
  --target-os=OS           compiler targets OS [$target_os]
  --target-exec=CMD        command to run executables on target
  --target-path=DIR        path to view of build directory on target
  --target-samples=DIR     path to samples directory on target
  --tempprefix=PATH        force fixed dir/prefix instead of mktemp for checks
  --toolchain=NAME         set tool defaults according to NAME
  --nm=NM                  use nm tool NM [$nm_default]
  --ar=AR                  use archive tool AR [$ar_default]
  --as=AS                  use assembler AS [$as_default]
  --windres=WINDRES        use windows resource compiler WINDRES [$windres_default]
  --yasmexe=EXE            use yasm-compatible assembler EXE [$yasmexe_default]
  --cc=CC                  use C compiler CC [$cc_default]
  --cxx=CXX                use C compiler CXX [$cxx_default]
  --dep-cc=DEPCC           use dependency generator DEPCC [$cc_default]
  --ld=LD                  use linker LD [$ld_default]
  --pkg-config=PKGCONFIG   use pkg-config tool PKGCONFIG [$pkg_config_default]
  --pkg-config-flags=FLAGS pass additional flags to pkgconf []
  --ranlib=RANLIB          use ranlib RANLIB [$ranlib_default]
  --doxygen=DOXYGEN        use DOXYGEN to generate API doc [$doxygen_default]
  --host-cc=HOSTCC         use host C compiler HOSTCC
  --host-cflags=HCFLAGS    use HCFLAGS when compiling for host
  --host-cppflags=HCPPFLAGS use HCPPFLAGS when compiling for host
  --host-ld=HOSTLD         use host linker HOSTLD
  --host-ldflags=HLDFLAGS  use HLDFLAGS when linking for host
  --host-libs=HLIBS        use libs HLIBS when linking for host
  --host-os=OS             compiler host OS [$target_os]
  --extra-cflags=ECFLAGS   add ECFLAGS to CFLAGS [$CFLAGS]
  --extra-cxxflags=ECFLAGS add ECFLAGS to CXXFLAGS [$CXXFLAGS]
  --extra-ldflags=ELDFLAGS add ELDFLAGS to LDFLAGS [$LDFLAGS]
  --extra-ldexeflags=ELDFLAGS add ELDFLAGS to LDEXEFLAGS [$LDEXEFLAGS]
  --extra-libs=ELIBS       add ELIBS [$ELIBS]
  --extra-version=STRING   version string suffix []
  --optflags=OPTFLAGS      override optimization-related compiler flags
  --build-suffix=SUFFIX    library name suffix []
  --enable-pic             build position-independent code
  --enable-thumb           compile for Thumb instruction set
  --enable-lto             use link-time optimization

Advanced options (experts only):
  --malloc-prefix=PREFIX   prefix malloc and related names with PREFIX
  --disable-symver         disable symbol versioning
  --enable-hardcoded-tables use hardcoded tables instead of runtime generation
  --disable-safe-bitstream-reader
                           disable buffer boundary checking in bitreaders
                           (faster, but may crash)
  --enable-memalign-hack   emulate memalign, interferes with memory debuggers
  --sws-max-filter-size=N  the max filter size swscale uses [$sws_max_filter_size_default]

Optimization options (experts only):
  --disable-asm            disable all assembly optimizations
  --disable-altivec        disable AltiVec optimizations
  --disable-amd3dnow       disable 3DNow! optimizations
  --disable-amd3dnowext    disable 3DNow! extended optimizations
  --disable-mmx            disable MMX optimizations
  --disable-mmxext         disable MMXEXT optimizations
  --disable-sse            disable SSE optimizations
  --disable-sse2           disable SSE2 optimizations
  --disable-sse3           disable SSE3 optimizations
  --disable-ssse3          disable SSSE3 optimizations
  --disable-sse4           disable SSE4 optimizations
  --disable-sse42          disable SSE4.2 optimizations
  --disable-avx            disable AVX optimizations
  --disable-xop            disable XOP optimizations
  --disable-fma3           disable FMA3 optimizations
  --disable-fma4           disable FMA4 optimizations
  --disable-avx2           disable AVX2 optimizations
  --disable-armv5te        disable armv5te optimizations
  --disable-armv6          disable armv6 optimizations
  --disable-armv6t2        disable armv6t2 optimizations
  --disable-vfp            disable VFP optimizations
  --disable-neon           disable NEON optimizations
  --disable-inline-asm     disable use of inline assembly
  --disable-yasm           disable use of nasm/yasm assembly
  --disable-mipsdspr1      disable MIPS DSP ASE R1 optimizations
  --disable-mipsdspr2      disable MIPS DSP ASE R2 optimizations
  --disable-mipsfpu        disable floating point MIPS optimizations
  --disable-fast-unaligned consider unaligned accesses slow

Developer options (useful when working on FFmpeg itself):
  --disable-debug          disable debugging symbols
  --enable-debug=LEVEL     set the debug level [$debuglevel]
  --disable-optimizations  disable compiler optimizations
  --enable-extra-warnings  enable more compiler warnings
  --disable-stripping      disable stripping of executables and shared libraries
  --assert-level=level     0(default), 1 or 2, amount of assertion testing,
                           2 causes a slowdown at runtime.
  --enable-memory-poisoning fill heap uninitialized allocated space with arbitrary data
  --valgrind=VALGRIND      run "make fate" tests through valgrind to detect memory
                           leaks and errors, using the specified valgrind binary.
                           Cannot be combined with --target-exec
  --enable-ftrapv          Trap arithmetic overflows
  --samples=PATH           location of test samples for FATE, if not set use
                           \$FATE_SAMPLES at make invocation time.
  --enable-neon-clobber-test check NEON registers for clobbering (should be
                           used only for debugging purposes)
  --enable-xmm-clobber-test check XMM registers for clobbering (Win64-only;
                           should be used only for debugging purposes)
  --enable-random          randomly enable/disable components
  --disable-random
  --enable-random=LIST     randomly enable/disable specific components or
  --disable-random=LIST    component groups. LIST is a comma-separated list
                           of NAME[:PROB] entries where NAME is a component
                           (group) and PROB the probability associated with
                           NAME (default 0.5).
  --random-seed=VALUE      seed value for --enable/disable-random

NOTE: Object files are built at the place where configure is launched.
EOF
  exit 0
}

quotes='""'

log(){
    echo "$@" >> $logfile
}

log_file(){
    log BEGIN $1
    pr -n -t $1 >> $logfile
    log END $1
}

echolog(){
    log "$@"
    echo "$@"
}

warn(){
    log "WARNING: $*"
    WARNINGS="${WARNINGS}WARNING: $*\n"
}

die(){
    echolog "$@"
    cat <<EOF

If you think configure made a mistake, make sure you are using the latest
version from Git.  If the latest version fails, report the problem to the
ffmpeg-user@ffmpeg.org mailing list or IRC #ffmpeg on irc.freenode.net.
EOF
    if disabled logging; then
        cat <<EOF
Rerun configure with logging enabled (do not use --disable-logging), and
include the log this produces with your report.
EOF
    else
        cat <<EOF
Include the log file "$logfile" produced by configure as this will help
solve the problem.
EOF
    fi
    exit 1
}

# Avoid locale weirdness, besides we really just want to translate ASCII.
toupper(){
    echo "$@" | tr abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLMNOPQRSTUVWXYZ
}

tolower(){
    echo "$@" | tr ABCDEFGHIJKLMNOPQRSTUVWXYZ abcdefghijklmnopqrstuvwxyz
}

c_escape(){
    echo "$*" | sed 's/["\\]/\\\0/g'
}

sh_quote(){
    v=$(echo "$1" | sed "s/'/'\\\\''/g")
    test "x$v" = "x${v#*[!A-Za-z0-9_/.+-]}" || v="'$v'"
    echo "$v"
}

cleanws(){
    echo "$@" | sed 's/^ *//;s/  */ /g;s/ *$//;s/\\r//g'
}

filter(){
    pat=$1
    shift
    for v; do
        eval "case $v in $pat) echo $v ;; esac"
    done
}

filter_out(){
    pat=$1
    shift
    for v; do
        eval "case $v in $pat) ;; *) echo $v ;; esac"
    done
}

map(){
    m=$1
    shift
    for v; do eval $m; done
}

add_suffix(){
    suffix=$1
    shift
    for v; do echo ${v}${suffix}; done
}

set_all(){
    value=$1
    shift
    for var in $*; do
        eval $var=$value
    done
}

set_weak(){
    value=$1
    shift
    for var; do
        eval : \${$var:=$value}
    done
}

sanitize_var_name(){
    echo $@ | sed 's/[^A-Za-z0-9_]/_/g'
}

set_safe(){
    var=$1
    shift
    eval $(sanitize_var_name "$var")='$*'
}

get_safe(){
    eval echo \$$(sanitize_var_name "$1")
}

pushvar(){
    for pvar in $*; do
        eval level=\${${pvar}_level:=0}
        eval ${pvar}_${level}="\$$pvar"
        eval ${pvar}_level=$(($level+1))
    done
}

popvar(){
    for pvar in $*; do
        eval level=\${${pvar}_level:-0}
        test $level = 0 && continue
        eval level=$(($level-1))
        eval $pvar="\${${pvar}_${level}}"
        eval ${pvar}_level=$level
        eval unset ${pvar}_${level}
    done
}

enable(){
    set_all yes $*
}

disable(){
    set_all no $*
}

enable_weak(){
    set_weak yes $*
}

disable_weak(){
    set_weak no $*
}

enable_safe(){
    for var; do
        enable $(echo "$var" | sed 's/[^A-Za-z0-9_]/_/g')
    done
}

disable_safe(){
    for var; do
        disable $(echo "$var" | sed 's/[^A-Za-z0-9_]/_/g')
    done
}

do_enable_deep(){
    for var; do
        enabled $var && continue
        eval sel="\$${var}_select"
        eval sgs="\$${var}_suggest"
        pushvar var sgs
        enable_deep $sel
        popvar sgs
        enable_deep_weak $sgs
        popvar var
    done
}

enable_deep(){
    do_enable_deep $*
    enable $*
}

enable_deep_weak(){
    for var; do
        disabled $var && continue
        pushvar var
        do_enable_deep $var
        popvar var
        enable_weak $var
    done
}

enabled(){
    test "${1#!}" = "$1" && op== || op=!=
    eval test "x\$${1#!}" $op "xyes"
}

disabled(){
    test "${1#!}" = "$1" && op== || op=!=
    eval test "x\$${1#!}" $op "xno"
}

enabled_all(){
    for opt; do
        enabled $opt || return 1
    done
}

disabled_all(){
    for opt; do
        disabled $opt || return 1
    done
}

enabled_any(){
    for opt; do
        enabled $opt && return 0
    done
}

disabled_any(){
    for opt; do
        disabled $opt && return 0
    done
    return 1
}

set_default(){
    for opt; do
        eval : \${$opt:=\$${opt}_default}
    done
}

is_in(){
    value=$1
    shift
    for var in $*; do
        [ $var = $value ] && return 0
    done
    return 1
}

do_check_deps(){
    for cfg; do
        cfg="${cfg#!}"
        enabled ${cfg}_checking && die "Circular dependency for $cfg."
        disabled ${cfg}_checking && continue
        enable ${cfg}_checking
        append allopts $cfg

        eval dep_all="\$${cfg}_deps"
        eval dep_any="\$${cfg}_deps_any"
        eval dep_sel="\$${cfg}_select"
        eval dep_sgs="\$${cfg}_suggest"
        eval dep_ifa="\$${cfg}_if"
        eval dep_ifn="\$${cfg}_if_any"

        pushvar cfg dep_all dep_any dep_sel dep_sgs dep_ifa dep_ifn
        do_check_deps $dep_all $dep_any $dep_sel $dep_sgs $dep_ifa $dep_ifn
        popvar cfg dep_all dep_any dep_sel dep_sgs dep_ifa dep_ifn

        [ -n "$dep_ifa" ] && { enabled_all $dep_ifa && enable_weak $cfg; }
        [ -n "$dep_ifn" ] && { enabled_any $dep_ifn && enable_weak $cfg; }
        enabled_all  $dep_all || disable $cfg
        enabled_any  $dep_any || disable $cfg
        disabled_any $dep_sel && disable $cfg

        if enabled $cfg; then
            enable_deep $dep_sel
            enable_deep_weak $dep_sgs
        fi

        disable ${cfg}_checking
    done
}

check_deps(){
    unset allopts

    do_check_deps "$@"

    for cfg in $allopts; do
        enabled $cfg || continue
        eval dep_extralibs="\$${cfg}_extralibs"
        test -n "$dep_extralibs" && add_extralibs $dep_extralibs
    done
}

print_config(){
    pfx=$1
    files=$2
    shift 2
    map 'eval echo "$v \${$v:-no}"' "$@" |
    awk "BEGIN { split(\"$files\", files) }
        {
            c = \"$pfx\" toupper(\$1);
            v = \$2;
            sub(/yes/, 1, v);
            sub(/no/,  0, v);
            for (f in files) {
                file = files[f];
                if (file ~ /\\.h\$/) {
                    printf(\"#define %s %d\\n\", c, v) >>file;
                } else if (file ~ /\\.asm\$/) {
                    printf(\"%%define %s %d\\n\", c, v) >>file;
                } else if (file ~ /\\.mak\$/) {
                    n = -v ? \"\" : \"!\";
                    printf(\"%s%s=yes\\n\", n, c) >>file;
                } else if (file ~ /\\.texi\$/) {
                    pre = -v ? \"\" : \"@c \";
                    yesno = \$2;
                    c2 = tolower(c);
                    gsub(/_/, \"-\", c2);
                    printf(\"%s@set %s %s\\n\", pre, c2, yesno) >>file;
                }
            }
        }"
}

print_enabled(){
    suf=$1
    shift
    for v; do
        enabled $v && printf "%s\n" ${v%$suf};
    done
}

append(){
    var=$1
    shift
    eval "$var=\"\$$var $*\""
}

prepend(){
    var=$1
    shift
    eval "$var=\"$* \$$var\""
}

unique(){
    var=$1
    uniq_list=""
    for tok in $(eval echo \$$var); do
        uniq_list="$(filter_out $tok $uniq_list) $tok"
    done
    eval "$var=\"${uniq_list}\""
}

add_cppflags(){
    append CPPFLAGS "$@"
}

add_cflags(){
    append CFLAGS $($cflags_filter "$@")
}

add_cxxflags(){
    append CXXFLAGS $($cflags_filter "$@")
}

add_asflags(){
    append ASFLAGS $($asflags_filter "$@")
}

add_ldflags(){
    append LDFLAGS $($ldflags_filter "$@")
}

add_ldexeflags(){
    append LDEXEFLAGS $($ldflags_filter "$@")
}

add_stripflags(){
    append ASMSTRIPFLAGS "$@"
}

add_extralibs(){
    prepend extralibs $($ldflags_filter "$@")
}

add_host_cppflags(){
    append host_cppflags "$@"
}

add_host_cflags(){
    append host_cflags $($host_cflags_filter "$@")
}

add_host_ldflags(){
    append host_ldflags $($host_ldflags_filter "$@")
}

add_compat(){
    append compat_objs $1
    shift
    map 'add_cppflags -D$v' "$@"
}

check_cmd(){
    log "$@"
    "$@" >> $logfile 2>&1
}

check_stat(){
    log check_stat "$@"
    stat "$1" >> $logfile 2>&1
}

cc_o(){
    eval printf '%s\\n' $CC_O
}

cc_e(){
    eval printf '%s\\n' $CC_E
}

check_cc(){
    log check_cc "$@"
    cat > $TMPC
    log_file $TMPC
    check_cmd $cc $CPPFLAGS $CFLAGS "$@" $CC_C $(cc_o $TMPO) $TMPC
}

check_cxx(){
    log check_cxx "$@"
    cat > $TMPCPP
    log_file $TMPCPP
    check_cmd $cxx $CPPFLAGS $CFLAGS $CXXFLAGS "$@" $CXX_C -o $TMPO $TMPCPP
}

check_oc(){
    log check_oc "$@"
    cat > $TMPM
    log_file $TMPM
    check_cmd $cc -Werror=missing-prototypes $CPPFLAGS $CFLAGS "$@" $CC_C $(cc_o $TMPO) $TMPM
}

check_cpp(){
    log check_cpp "$@"
    cat > $TMPC
    log_file $TMPC
    check_cmd $cc $CPPFLAGS $CFLAGS "$@" $(cc_e $TMPO) $TMPC
}

as_o(){
    eval printf '%s\\n' $AS_O
}

check_as(){
    log check_as "$@"
    cat > $TMPS
    log_file $TMPS
    check_cmd $as $CPPFLAGS $ASFLAGS "$@" $AS_C $(as_o $TMPO) $TMPS
}

check_inline_asm(){
    log check_inline_asm "$@"
    name="$1"
    code="$2"
    shift 2
    disable $name
    check_cc "$@" <<EOF && enable $name
void foo(void){ __asm__ volatile($code); }
EOF
}

check_insn(){
    log check_insn "$@"
    check_inline_asm ${1}_inline "\"$2\""
    echo "$2" | check_as && enable ${1}_external || disable ${1}_external
}

check_yasm(){
    log check_yasm "$@"
    echo "$1" > $TMPS
    log_file $TMPS
    shift 1
    check_cmd $yasmexe $YASMFLAGS -Werror "$@" -o $TMPO $TMPS
}

ld_o(){
    eval printf '%s\\n' $LD_O
}

check_ld(){
    log check_ld "$@"
    type=$1
    shift 1
    flags=$(filter_out '-l*|*.so' $@)
    libs=$(filter '-l*|*.so' $@)
    check_$type $($cflags_filter $flags) || return
    flags=$($ldflags_filter $flags)
    libs=$($ldflags_filter $libs)
    check_cmd $ld $LDFLAGS $flags $(ld_o $TMPE) $TMPO $libs $extralibs
}

print_include(){
    hdr=$1
    test "${hdr%.h}" = "${hdr}" &&
        echo "#include $hdr"    ||
        echo "#include <$hdr>"
}

check_code(){
    log check_code "$@"
    check=$1
    headers=$2
    code=$3
    shift 3
    {
        for hdr in $headers; do
            print_include $hdr
        done
        echo "int main(void) { $code; return 0; }"
    } | check_$check "$@"
}

check_cppflags(){
    log check_cppflags "$@"
    check_cc "$@" <<EOF && append CPPFLAGS "$@"
int x;
EOF
}

test_cflags(){
    log test_cflags "$@"
    set -- $($cflags_filter "$@")
    check_cc "$@" <<EOF
int x;
EOF
}

check_cflags(){
    log check_cflags "$@"
    test_cflags "$@" && add_cflags "$@"
}

check_cxxflags(){
    log check_cxxflags "$@"
    set -- $($cflags_filter "$@")
    check_cxx "$@" <<EOF && append CXXFLAGS "$@"
int x;
EOF
}

test_ldflags(){
    log test_ldflags "$@"
    check_ld "cc" "$@" <<EOF
int main(void){ return 0; }
EOF
}

check_ldflags(){
    log check_ldflags "$@"
    test_ldflags "$@" && add_ldflags "$@"
}

test_stripflags(){
    log test_stripflags "$@"
    # call check_cc to get a fresh TMPO
    check_cc <<EOF
int main(void) { return 0; }
EOF
    check_cmd $strip $ASMSTRIPFLAGS "$@" $TMPO
}

check_stripflags(){
    log check_stripflags "$@"
    test_stripflags "$@" && add_stripflags "$@"
}

check_header(){
    log check_header "$@"
    header=$1
    shift
    disable_safe $header
    check_cpp "$@" <<EOF && enable_safe $header
#include <$header>
int x;
EOF
}

check_header_oc(){
    log check_header_oc "$@"
    rm -f -- "$TMPO"
    header=$1
    shift
    disable_safe $header
    {
       echo "#include <$header>"
       echo "int main(void) { return 0; }"
    } | check_oc && check_stat "$TMPO" && enable_safe $headers
}

check_func(){
    log check_func "$@"
    func=$1
    shift
    disable $func
    check_ld "cc" "$@" <<EOF && enable $func
extern int $func();
int main(void){ $func(); }
EOF
}

check_mathfunc(){
    log check_mathfunc "$@"
    func=$1
    narg=$2
    shift 2
    test $narg = 2 && args="f, g" || args="f"
    disable $func
    check_ld "cc" "$@" <<EOF && enable $func
#include <math.h>
float foo(float f, float g) { return $func($args); }
int main(void){ return (int) foo; }
EOF
}

check_func_headers(){
    log check_func_headers "$@"
    headers=$1
    funcs=$2
    shift 2
    {
        for hdr in $headers; do
            print_include $hdr
        done
        for func in $funcs; do
            echo "long check_$func(void) { return (long) $func; }"
        done
        echo "int main(void) { return 0; }"
    } | check_ld "cc" "$@" && enable $funcs && enable_safe $headers
}

check_class_headers_cpp(){
    log check_class_headers_cpp "$@"
    headers=$1
    classes=$2
    shift 2
    {
        for hdr in $headers; do
            echo "#include <$hdr>"
        done
        echo "int main(void) { "
        i=1
        for class in $classes; do
            echo "$class obj$i;"
            i=$(expr $i + 1)
        done
        echo "return 0; }"
    } | check_ld "cxx" "$@" && enable $funcs && enable_safe $headers
}

check_cpp_condition(){
    log check_cpp_condition "$@"
    header=$1
    condition=$2
    shift 2
    check_cpp "$@" <<EOF
#include <$header>
#if !($condition)
#error "unsatisfied condition: $condition"
#endif
EOF
}

check_lib(){
    log check_lib "$@"
    header="$1"
    func="$2"
    shift 2
    check_header $header && check_func $func "$@" && add_extralibs "$@"
}

check_lib2(){
    log check_lib2 "$@"
    headers="$1"
    funcs="$2"
    shift 2
    check_func_headers "$headers" "$funcs" "$@" && add_extralibs "$@"
}

check_lib_cpp(){
    log check_lib_cpp "$@"
    headers="$1"
    classes="$2"
    shift 2
    check_class_headers_cpp "$headers" "$classes" "$@" && add_extralibs "$@"
}

check_pkg_config(){
    log check_pkg_config "$@"
    pkgandversion="$1"
    pkg="${1%% *}"
    headers="$2"
    funcs="$3"
    shift 3
    check_cmd $pkg_config --exists --print-errors $pkgandversion || return
    pkg_cflags=$($pkg_config --cflags $pkg_config_flags $pkg)
    pkg_libs=$($pkg_config --libs $pkg_config_flags $pkg)
    check_func_headers "$headers" "$funcs" $pkg_cflags $pkg_libs "$@" &&
        set_safe ${pkg}_cflags $pkg_cflags   &&
        set_safe ${pkg}_libs   $pkg_libs
}

check_exec(){
    check_ld "cc" "$@" && { enabled cross_compile || $TMPE >> $logfile 2>&1; }
}

check_exec_crash(){
    code=$(cat)

    # exit() is not async signal safe.  _Exit (C99) and _exit (POSIX)
    # are safe but may not be available everywhere.  Thus we use
    # raise(SIGTERM) instead.  The check is run in a subshell so we
    # can redirect the "Terminated" message from the shell.  SIGBUS
    # is not defined by standard C so it is used conditionally.

    (check_exec "$@") >> $logfile 2>&1 <<EOF
#include <signal.h>
static void sighandler(int sig){
    raise(SIGTERM);
}
int foo(void){
    $code
}
int (*func_ptr)(void) = foo;
int main(void){
    signal(SIGILL, sighandler);
    signal(SIGFPE, sighandler);
    signal(SIGSEGV, sighandler);
#ifdef SIGBUS
    signal(SIGBUS, sighandler);
#endif
    return func_ptr();
}
EOF
}

check_type(){
    log check_type "$@"
    headers=$1
    type=$2
    shift 2
    disable_safe "$type"
    check_code cc "$headers" "$type v" "$@" && enable_safe "$type"
}

check_struct(){
    log check_struct "$@"
    headers=$1
    struct=$2
    member=$3
    shift 3
    disable_safe "${struct}_${member}"
    check_code cc "$headers" "const void *p = &(($struct *)0)->$member" "$@" &&
        enable_safe "${struct}_${member}"
}

check_builtin(){
    log check_builtin "$@"
    name=$1
    headers=$2
    builtin=$3
    shift 3
    disable "$name"
    check_code ld "$headers" "$builtin" "cc" "$@" && enable "$name"
}

check_compile_assert(){
    log check_compile_assert "$@"
    name=$1
    headers=$2
    condition=$3
    shift 3
    disable "$name"
    check_code cc "$headers" "char c[2 * !!($condition) - 1]" "$@" && enable "$name"
}

require(){
    name="$1"
    header="$2"
    func="$3"
    shift 3
    check_lib $header $func "$@" || die "ERROR: $name not found"
}

require2(){
    name="$1"
    headers="$2"
    func="$3"
    shift 3
    check_lib2 "$headers" $func "$@" || die "ERROR: $name not found"
}

require_cpp(){
    name="$1"
    headers="$2"
    classes="$3"
    shift 3
    check_lib_cpp "$headers" "$classes" "$@" || die "ERROR: $name not found"
}

use_pkg_config(){
    pkg="$1"
    check_pkg_config "$@" || return 1
    add_cflags    $(get_safe ${pkg}_cflags)
    add_extralibs $(get_safe ${pkg}_libs)
}

require_pkg_config(){
    use_pkg_config "$@" || die "ERROR: $pkg not found using pkg-config$pkg_config_fail_message"
}

require_libfreetype(){
    log require_libfreetype "$@"
    pkg="freetype2"
    check_cmd $pkg_config --exists --print-errors $pkg \
      || die "ERROR: $pkg not found"
    pkg_cflags=$($pkg_config --cflags $pkg_config_flags $pkg)
    pkg_libs=$($pkg_config --libs $pkg_config_flags $pkg)
    {
        echo "#include <ft2build.h>"
        echo "#include FT_FREETYPE_H"
        echo "long check_func(void) { return (long) FT_Init_FreeType; }"
        echo "int main(void) { return 0; }"
    } | check_ld "cc" $pkg_cflags $pkg_libs \
      && set_safe ${pkg}_cflags $pkg_cflags \
      && set_safe ${pkg}_libs   $pkg_libs \
      || die "ERROR: $pkg not found"
    add_cflags    $(get_safe ${pkg}_cflags)
    add_extralibs $(get_safe ${pkg}_libs)
}

hostcc_e(){
    eval printf '%s\\n' $HOSTCC_E
}

hostcc_o(){
    eval printf '%s\\n' $HOSTCC_O
}

check_host_cc(){
    log check_host_cc "$@"
    cat > $TMPC
    log_file $TMPC
    check_cmd $host_cc $host_cflags "$@" $HOSTCC_C $(hostcc_o $TMPO) $TMPC
}

check_host_cpp(){
    log check_host_cpp "$@"
    cat > $TMPC
    log_file $TMPC
    check_cmd $host_cc $host_cppflags $host_cflags "$@" $(hostcc_e $TMPO) $TMPC
}

check_host_cppflags(){
    log check_host_cppflags "$@"
    check_host_cc "$@" <<EOF && append host_cppflags "$@"
int x;
EOF
}

check_host_cflags(){
    log check_host_cflags "$@"
    set -- $($host_cflags_filter "$@")
    check_host_cc "$@" <<EOF && append host_cflags "$@"
int x;
EOF
}

check_host_cpp_condition(){
    log check_host_cpp_condition "$@"
    header=$1
    condition=$2
    shift 2
    check_host_cpp "$@" <<EOF
#include <$header>
#if !($condition)
#error "unsatisfied condition: $condition"
#endif
EOF
}

apply(){
    file=$1
    shift
    "$@" < "$file" > "$file.tmp" && mv "$file.tmp" "$file" || rm "$file.tmp"
}

cp_if_changed(){
    cmp -s "$1" "$2" && echo "$2 is unchanged" && return
    mkdir -p "$(dirname $2)"
    $cp_f "$1" "$2"
}

# CONFIG_LIST contains configurable options, while HAVE_LIST is for
# system-dependent things.

COMPONENT_LIST="
    bsfs
    decoders
    demuxers
    encoders
    filters
    hwaccels
    indevs
    muxers
    outdevs
    parsers
    protocols
"

EXAMPLE_LIST="
    avio_reading_example
    decoding_encoding_example
    demuxing_decoding_example
    extract_mvs_example
    filter_audio_example
    filtering_audio_example
    filtering_video_example
    metadata_example
    muxing_example
    qsvdec_example
    remuxing_example
    resampling_audio_example
    scaling_video_example
    transcode_aac_example
    transcoding_example
"

EXTERNAL_LIBRARY_LIST="
    avisynth
    bzlib
    crystalhd
    decklink
    frei0r
    gnutls
    iconv
    ladspa
    libaacplus
    libass
    libbluray
    libbs2b
    libcaca
    libcdio
    libcelt
    libdc1394
    libfaac
    libfdk_aac
    libflite
    libfontconfig
    libfreetype
    libfribidi
    libgme
    libgsm
    libiec61883
    libilbc
    libmfx
    libmodplug
    libmp3lame
    libnut
    libopencore_amrnb
    libopencore_amrwb
    libopencv
    libopenh264
    libopenjpeg
    libopus
    libpulse
    libquvi
    librtmp
    libschroedinger
    libshine
    libsmbclient
    libsoxr
    libspeex
    libssh
    libstagefright_h264
    libtheora
    libtwolame
    libutvideo
    libv4l2
    libvidstab
    libvo_aacenc
    libvo_amrwbenc
    libvorbis
    libvpx
    libwavpack
    libwebp
    libx264
    libx265
    libxavs
    libxcb
    libxcb_shm
    libxcb_shape
    libxcb_xfixes
    libxvid
    libzmq
    libzvbi
    lzma
    nvenc
    openal
    opencl
    opengl
    openssl
    sdl
    x11grab
    xlib
    zlib
"

DOCUMENT_LIST="
    doc
    htmlpages
    manpages
    podpages
    txtpages
"

FEATURE_LIST="
    ftrapv
    gray
    hardcoded_tables
    runtime_cpudetect
    safe_bitstream_reader
    shared
    small
    static
    swscale_alpha
"

HWACCEL_LIST="
    dxva2
    vaapi
    vda
    vdpau
    xvmc
"

LIBRARY_LIST="
    avcodec
    avdevice
    avfilter
    avformat
    avresample
    avutil
    postproc
    swresample
    swscale
"

LICENSE_LIST="
    gpl
    nonfree
    version3
"

PROGRAM_LIST="
    ffplay
    ffprobe
    ffserver
    ffmpeg
"

SUBSYSTEM_LIST="
    dct
    dwt
    error_resilience
    faan
    fast_unaligned
    fft
    lsp
    lzo
    mdct
    pixelutils
    network
    qsv
    rdft
"

CONFIG_LIST="
    $COMPONENT_LIST
    $DOCUMENT_LIST
    $EXAMPLE_LIST
    $EXTERNAL_LIBRARY_LIST
    $FEATURE_LIST
    $HWACCEL_LIST
    $LICENSE_LIST
    $LIBRARY_LIST
    $PROGRAM_LIST
    $SUBSYSTEM_LIST
    fontconfig
    incompatible_libav_abi
    memalign_hack
    memory_poisoning
    neon_clobber_test
    pic
    pod2man
    raise_major
    thumb
    xmm_clobber_test
"

THREADS_LIST="
    pthreads
    os2threads
    w32threads
"

ATOMICS_LIST="
    atomics_gcc
    atomics_suncc
    atomics_win32
"

ARCH_LIST="
    aarch64
    alpha
    arm
    avr32
    avr32_ap
    avr32_uc
    bfin
    ia64
    m68k
    mips
    mips64
    parisc
    ppc
    ppc64
    s390
    sh4
    sparc
    sparc64
    tilegx
    tilepro
    tomi
    x86
    x86_32
    x86_64
"

ARCH_EXT_LIST_ARM="
    armv5te
    armv6
    armv6t2
    armv8
    neon
    vfp
    vfpv3
    setend
"

ARCH_EXT_LIST_MIPS="
    mipsfpu
    mips32r2
    mipsdspr1
    mipsdspr2
"

ARCH_EXT_LIST_X86_SIMD="
    amd3dnow
    amd3dnowext
    avx
    avx2
    fma3
    fma4
    mmx
    mmxext
    sse
    sse2
    sse3
    sse4
    sse42
    ssse3
    xop
"

ARCH_EXT_LIST_PPC="
    altivec
    dcbzl
    ldbrx
    ppc4xx
    vsx
"

ARCH_EXT_LIST_X86="
    $ARCH_EXT_LIST_X86_SIMD
    cpunop
    i686
"

ARCH_EXT_LIST="
    $ARCH_EXT_LIST_ARM
    $ARCH_EXT_LIST_PPC
    $ARCH_EXT_LIST_X86
    $ARCH_EXT_LIST_MIPS
    loongson
"

ARCH_FEATURES="
    aligned_stack
    fast_64bit
    fast_clz
    fast_cmov
    local_aligned_8
    local_aligned_16
    local_aligned_32
    simd_align_16
"

BUILTIN_LIST="
    atomic_cas_ptr
    atomic_compare_exchange
    machine_rw_barrier
    MemoryBarrier
    mm_empty
    rdtsc
    sarestart
    sync_val_compare_and_swap
"
HAVE_LIST_CMDLINE="
    inline_asm
    symver
    yasm
"

HAVE_LIST_PUB="
    bigendian
    fast_unaligned
    incompatible_libav_abi
"

HEADERS_LIST="
    alsa_asoundlib_h
    altivec_h
    arpa_inet_h
    asm_types_h
    cdio_paranoia_h
    cdio_paranoia_paranoia_h
    dev_bktr_ioctl_bt848_h
    dev_bktr_ioctl_meteor_h
    dev_ic_bt8xx_h
    dev_video_bktr_ioctl_bt848_h
    dev_video_meteor_ioctl_meteor_h
    direct_h
    dlfcn_h
    dxva_h
    ES2_gl_h
    gsm_h
    io_h
    mach_mach_time_h
    machine_ioctl_bt848_h
    machine_ioctl_meteor_h
    malloc_h
    openjpeg_1_5_openjpeg_h
    OpenGL_gl3_h
    poll_h
    sndio_h
    soundcard_h
    sys_mman_h
    sys_param_h
    sys_resource_h
    sys_select_h
    sys_soundcard_h
    sys_time_h
    sys_un_h
    sys_videoio_h
    termios_h
    udplite_h
    unistd_h
    windows_h
    winsock2_h
"

INTRINSICS_LIST="
    intrinsics_neon
"

MATH_FUNCS="
    atanf
    atan2f
    cbrt
    cbrtf
    cosf
    exp2
    exp2f
    expf
    isinf
    isnan
    ldexpf
    llrint
    llrintf
    log2
    log2f
    log10f
    lrint
    lrintf
    powf
    rint
    round
    roundf
    sinf
    trunc
    truncf
"

SYSTEM_FUNCS="
    access
    aligned_malloc
    clock_gettime
    closesocket
    CommandLineToArgvW
    CoTaskMemFree
    CryptGenRandom
    dlopen
    fcntl
    flt_lim
    fork
    getaddrinfo
    gethrtime
    getopt
    GetProcessAffinityMask
    GetProcessMemoryInfo
    GetProcessTimes
    getrusage
    getservbyport
    GetSystemTimeAsFileTime
    gettimeofday
    glob
    glXGetProcAddress
    gmtime_r
    inet_aton
    isatty
    jack_port_get_latency_range
    kbhit
    localtime_r
    lzo1x_999_compress
    mach_absolute_time
    MapViewOfFile
    memalign
    mkstemp
    mmap
    mprotect
    nanosleep
    PeekNamedPipe
    posix_memalign
    pthread_cancel
    sched_getaffinity
    SetConsoleTextAttribute
    setmode
    setrlimit
    Sleep
    strerror_r
    sysconf
    sysctl
    usleep
    VirtualAlloc
    wglGetProcAddress
"

TOOLCHAIN_FEATURES="
    as_dn_directive
    as_func
    as_object_arch
    asm_mod_q
    attribute_may_alias
    attribute_packed
    ebp_available
    ebx_available
    gnu_as
    gnu_windres
    ibm_asm
    inline_asm_labels
    inline_asm_nonlocal_labels
    inline_asm_direct_symbol_refs
    pragma_deprecated
    rsync_contimeout
    symver_asm_label
    symver_gnu_asm
    vfp_args
    xform_asm
    xmm_clobbers
"

TYPES_LIST="
    CONDITION_VARIABLE_Ptr
    DXVA_PicParams_HEVC
    socklen_t
    struct_addrinfo
    struct_group_source_req
    struct_ip_mreq_source
    struct_ipv6_mreq
    struct_pollfd
    struct_rusage_ru_maxrss
    struct_sctp_event_subscribe
    struct_sockaddr_in6
    struct_sockaddr_sa_len
    struct_sockaddr_storage
    struct_stat_st_mtim_tv_nsec
    struct_v4l2_frmivalenum_discrete
"

HAVE_LIST="
    $ARCH_EXT_LIST
    $(add_suffix _external $ARCH_EXT_LIST)
    $(add_suffix _inline   $ARCH_EXT_LIST)
    $ARCH_FEATURES
    $ATOMICS_LIST
    $BUILTIN_LIST
    $HAVE_LIST_CMDLINE
    $HAVE_LIST_PUB
    $HEADERS_LIST
    $INTRINSICS_LIST
    $MATH_FUNCS
    $SYSTEM_FUNCS
    $THREADS_LIST
    $TOOLCHAIN_FEATURES
    $TYPES_LIST
    atomics_native
    dos_paths
    dxva2api_cobj
    dxva2_lib
    libc_msvcrt
    libdc1394_1
    libdc1394_2
    makeinfo
    makeinfo_html
    perl
    pod2man
    sdl
    section_data_rel_ro
    texi2html
    threads
    vaapi_x11
    vdpau_x11
    xlib
"

# options emitted with CONFIG_ prefix but not available on the command line
CONFIG_EXTRA="
    aandcttables
    ac3dsp
    audio_frame_queue
    audiodsp
    blockdsp
    bswapdsp
    cabac
    dvprofile
    exif
    faandct
    faanidct
    fdctdsp
    fmtconvert
    frame_thread_encoder
    gcrypt
    golomb
    gplv3
    h263dsp
    h264chroma
    h264dsp
    h264pred
    h264qpel
    hpeldsp
    huffman
    huffyuvdsp
    huffyuvencdsp
    idctdsp
    iirfilter
    imdct15
    intrax8
    lgplv3
    llauddsp
    llviddsp
    lpc
    me_cmp
    mpeg_er
    mpegaudio
    mpegaudiodsp
    mpegvideo
    mpegvideoenc
    nettle
    pixblockdsp
    qpeldsp
    rangecoder
    riffdec
    riffenc
    rtpdec
    rtpenc_chain
    sinewin
    startcode
    tpeldsp
    videodsp
    vp3dsp
    wma_freqs
"

CMDLINE_SELECT="
    $ARCH_EXT_LIST
    $CONFIG_LIST
    $HAVE_LIST_CMDLINE
    $THREADS_LIST
    asm
    cross_compile
    debug
    extra_warnings
    logging
    lto
    optimizations
    rpath
    stripping
"

PATHS_LIST="
    bindir
    datadir
    docdir
    incdir
    libdir
    mandir
    prefix
    shlibdir
"

CMDLINE_SET="
    $PATHS_LIST
    ar
    arch
    as
    assert_level
    build_suffix
    cc
    cpu
    cross_prefix
    cxx
    dep_cc
    doxygen
    extra_version
    gas
    host_cc
    host_cflags
    host_ld
    host_ldflags
    host_libs
    host_os
    install
    ld
    logfile
    malloc_prefix
    nm
    optflags
    pkg_config
    pkg_config_flags
    progs_suffix
    random_seed
    ranlib
    samples
    strip
    sws_max_filter_size
    sysinclude
    sysroot
    target_exec
    target_os
    target_path
    target_samples
    tempprefix
    toolchain
    valgrind
    yasmexe
"

CMDLINE_APPEND="
    extra_cflags
    extra_cxxflags
    host_cppflags
"

# code dependency declarations

# architecture extensions

armv5te_deps="arm"
armv6_deps="arm"
armv6t2_deps="arm"
armv8_deps="aarch64"
neon_deps_any="aarch64 arm"
intrinsics_neon_deps="neon"
vfp_deps_any="aarch64 arm"
vfpv3_deps="vfp"
setend_deps="arm"

map 'eval ${v}_inline_deps=inline_asm' $ARCH_EXT_LIST_ARM

mipsfpu_deps="mips"
mipsdspr1_deps="mips"
mipsdspr2_deps="mips"

altivec_deps="ppc"
ppc4xx_deps="ppc"
vsx_deps="ppc"

cpunop_deps="i686"
x86_64_select="i686"
x86_64_suggest="fast_cmov"

amd3dnow_deps="mmx"
amd3dnowext_deps="amd3dnow"
i686_deps="x86"
mmx_deps="x86"
mmxext_deps="mmx"
sse_deps="mmxext"
sse2_deps="sse"
sse3_deps="sse2"
ssse3_deps="sse3"
sse4_deps="ssse3"
sse42_deps="sse4"
avx_deps="sse42"
xop_deps="avx"
fma3_deps="avx"
fma4_deps="avx"
avx2_deps="avx"

mmx_external_deps="yasm"
mmx_inline_deps="inline_asm"
mmx_suggest="mmx_external mmx_inline"

for ext in $(filter_out mmx $ARCH_EXT_LIST_X86_SIMD); do
    eval dep=\$${ext}_deps
    eval ${ext}_external_deps='"${dep}_external"'
    eval ${ext}_inline_deps='"${dep}_inline"'
    eval ${ext}_suggest='"${ext}_external ${ext}_inline"'
done

aligned_stack_if_any="aarch64 ppc x86"
fast_64bit_if_any="aarch64 alpha ia64 mips64 parisc64 ppc64 sparc64 x86_64"
fast_clz_if_any="aarch64 alpha avr32 mips ppc x86"
fast_unaligned_if_any="aarch64 ppc x86"
simd_align_16_if_any="altivec neon sse"

# system capabilities

symver_if_any="symver_asm_label symver_gnu_asm"

# threading support
atomics_gcc_if_any="sync_val_compare_and_swap atomic_compare_exchange"
atomics_suncc_if="atomic_cas_ptr machine_rw_barrier"
atomics_win32_if="MemoryBarrier"
atomics_native_if_any="$ATOMICS_LIST"
w32threads_deps="atomics_native"
threads_if_any="$THREADS_LIST"

# subsystems
dct_select="rdft"
error_resilience_select="me_cmp"
faandct_deps="faan fdctdsp"
faanidct_deps="faan idctdsp"
frame_thread_encoder_deps="encoders threads"
intrax8_select="error_resilience"
mdct_select="fft"
rdft_select="fft"
me_cmp_select="fdctdsp idctdsp pixblockdsp"
mpeg_er_select="error_resilience"
mpegaudio_select="mpegaudiodsp"
mpegaudiodsp_select="dct"
mpegvideo_select="blockdsp h264chroma hpeldsp idctdsp me_cmp videodsp"
mpegvideoenc_select="me_cmp mpegvideo pixblockdsp qpeldsp"

# decoders / encoders
aac_decoder_select="imdct15 mdct sinewin"
aac_encoder_select="audio_frame_queue iirfilter mdct sinewin"
aac_latm_decoder_select="aac_decoder aac_latm_parser"
ac3_decoder_select="ac3_parser ac3dsp bswapdsp fmtconvert mdct"
ac3_fixed_decoder_select="ac3_parser ac3dsp bswapdsp mdct"
ac3_encoder_select="ac3dsp audiodsp mdct me_cmp"
ac3_fixed_encoder_select="ac3dsp audiodsp mdct me_cmp"
aic_decoder_select="golomb idctdsp"
alac_encoder_select="lpc"
als_decoder_select="bswapdsp"
amrnb_decoder_select="lsp"
amrwb_decoder_select="lsp"
amv_decoder_select="sp5x_decoder exif"
amv_encoder_select="aandcttables mpegvideoenc"
ape_decoder_select="bswapdsp llauddsp"
apng_decoder_select="zlib"
asv1_decoder_select="blockdsp bswapdsp idctdsp"
asv1_encoder_select="bswapdsp fdctdsp pixblockdsp"
asv2_decoder_select="blockdsp bswapdsp idctdsp"
asv2_encoder_select="bswapdsp fdctdsp pixblockdsp"
atrac1_decoder_select="mdct sinewin"
atrac3_decoder_select="mdct"
atrac3p_decoder_select="mdct sinewin"
avrn_decoder_select="exif"
bink_decoder_select="blockdsp hpeldsp"
binkaudio_dct_decoder_select="mdct rdft dct sinewin wma_freqs"
binkaudio_rdft_decoder_select="mdct rdft sinewin wma_freqs"
cavs_decoder_select="blockdsp golomb h264chroma idctdsp qpeldsp videodsp"
cllc_decoder_select="bswapdsp"
comfortnoise_encoder_select="lpc"
cook_decoder_select="audiodsp mdct sinewin"
cscd_decoder_select="lzo"
cscd_decoder_suggest="zlib"
dca_decoder_select="fmtconvert mdct"
dirac_decoder_select="dwt golomb videodsp mpegvideoenc"
dnxhd_decoder_select="blockdsp idctdsp"
dnxhd_encoder_select="aandcttables blockdsp fdctdsp idctdsp mpegvideoenc pixblockdsp"
dvvideo_decoder_select="dvprofile idctdsp"
dvvideo_encoder_select="dvprofile fdctdsp me_cmp pixblockdsp"
dxa_decoder_select="zlib"
eac3_decoder_select="ac3_decoder"
eac3_encoder_select="ac3_encoder"
eamad_decoder_select="aandcttables blockdsp bswapdsp idctdsp mpegvideo"
eatgq_decoder_select="aandcttables"
eatqi_decoder_select="aandcttables blockdsp bswapdsp idctdsp mpeg1video_decoder"
exr_decoder_select="zlib"
ffv1_decoder_select="golomb rangecoder"
ffv1_encoder_select="rangecoder"
ffvhuff_decoder_select="huffyuv_decoder"
ffvhuff_encoder_select="huffyuv_encoder"
fic_decoder_select="golomb"
flac_decoder_select="golomb"
flac_encoder_select="bswapdsp golomb lpc"
flashsv_decoder_select="zlib"
flashsv_encoder_select="zlib"
flashsv2_encoder_select="zlib"
flashsv2_decoder_select="zlib"
flv_decoder_select="h263_decoder"
flv_encoder_select="h263_encoder"
fourxm_decoder_select="blockdsp bswapdsp"
fraps_decoder_select="bswapdsp huffman"
g2m_decoder_select="blockdsp idctdsp zlib"
g729_decoder_select="audiodsp"
h261_decoder_select="mpeg_er mpegvideo"
h261_encoder_select="aandcttables mpegvideoenc"
h263_decoder_select="error_resilience h263_parser h263dsp mpeg_er mpegvideo qpeldsp"
h263_encoder_select="aandcttables h263dsp mpegvideoenc"
h263i_decoder_select="h263_decoder"
h263p_encoder_select="h263_encoder"
h264_decoder_select="cabac golomb h264chroma h264dsp h264pred h264qpel startcode videodsp"
h264_decoder_suggest="error_resilience"
h264_qsv_decoder_deps="libmfx"
h264_qsv_decoder_select="h264_mp4toannexb_bsf h264_parser qsv h264_qsv_hwaccel"
hevc_decoder_select="bswapdsp cabac golomb videodsp"
huffyuv_decoder_select="bswapdsp huffyuvdsp llviddsp"
huffyuv_encoder_select="bswapdsp huffman huffyuvencdsp llviddsp"
iac_decoder_select="imc_decoder"
imc_decoder_select="bswapdsp fft mdct sinewin"
indeo3_decoder_select="hpeldsp"
interplay_video_decoder_select="hpeldsp"
jpegls_decoder_select="golomb mjpeg_decoder"
jpegls_encoder_select="golomb"
jv_decoder_select="blockdsp"
lagarith_decoder_select="huffyuvdsp"
ljpeg_encoder_select="aandcttables idctdsp"
loco_decoder_select="golomb"
mdec_decoder_select="blockdsp idctdsp mpegvideo"
metasound_decoder_select="lsp mdct sinewin"
mimic_decoder_select="blockdsp bswapdsp hpeldsp idctdsp"
mjpeg_decoder_select="blockdsp hpeldsp exif idctdsp"
mjpeg_encoder_select="aandcttables mpegvideoenc"
mjpegb_decoder_select="mjpeg_decoder"
mlp_decoder_select="mlp_parser"
motionpixels_decoder_select="bswapdsp"
mp1_decoder_select="mpegaudio"
mp1float_decoder_select="mpegaudio"
mp2_decoder_select="mpegaudio"
mp2float_decoder_select="mpegaudio"
mp3_decoder_select="mpegaudio"
mp3adu_decoder_select="mpegaudio"
mp3adufloat_decoder_select="mpegaudio"
mp3float_decoder_select="mpegaudio"
mp3on4_decoder_select="mpegaudio"
mp3on4float_decoder_select="mpegaudio"
mpc7_decoder_select="bswapdsp mpegaudiodsp"
mpc8_decoder_select="mpegaudiodsp"
mpeg_xvmc_decoder_deps="X11_extensions_XvMClib_h"
mpeg_xvmc_decoder_select="mpeg2video_decoder"
mpegvideo_decoder_select="error_resilience mpeg_er mpegvideo"
mpeg1video_decoder_select="error_resilience mpeg_er mpegvideo"
mpeg1video_encoder_select="aandcttables mpegvideoenc h263dsp"
mpeg2video_decoder_select="error_resilience mpeg_er mpegvideo"
mpeg2video_encoder_select="aandcttables mpegvideoenc h263dsp"
mpeg4_decoder_select="h263_decoder mpeg4video_parser"
mpeg4_encoder_select="h263_encoder"
msmpeg4v1_decoder_select="h263_decoder"
msmpeg4v2_decoder_select="h263_decoder"
msmpeg4v2_encoder_select="h263_encoder"
msmpeg4v3_decoder_select="h263_decoder"
msmpeg4v3_encoder_select="h263_encoder"
mss2_decoder_select="error_resilience mpeg_er qpeldsp vc1_decoder"
mxpeg_decoder_select="mjpeg_decoder"
nellymoser_decoder_select="mdct sinewin"
nellymoser_encoder_select="audio_frame_queue mdct sinewin"
nuv_decoder_select="idctdsp lzo"
on2avc_decoder_select="mdct"
opus_decoder_deps="swresample"
opus_decoder_select="imdct15"
png_decoder_select="zlib"
png_encoder_select="huffyuvencdsp zlib"
prores_decoder_select="blockdsp idctdsp"
prores_encoder_select="fdctdsp"
qcelp_decoder_select="lsp"
qdm2_decoder_select="mdct rdft mpegaudiodsp"
ra_144_encoder_select="audio_frame_queue lpc audiodsp"
ra_144_decoder_select="audiodsp"
ralf_decoder_select="golomb"
rawvideo_decoder_select="bswapdsp"
rtjpeg_decoder_select="me_cmp"
rv10_decoder_select="error_resilience h263_decoder h263dsp mpeg_er"
rv10_encoder_select="h263_encoder"
rv20_decoder_select="error_resilience h263_decoder h263dsp mpeg_er"
rv20_encoder_select="h263_encoder"
rv30_decoder_select="error_resilience golomb h264chroma h264pred h264qpel mpeg_er mpegvideo videodsp"
rv40_decoder_select="error_resilience golomb h264chroma h264pred h264qpel mpeg_er mpegvideo videodsp"
shorten_decoder_select="golomb"
sipr_decoder_select="lsp"
snow_decoder_select="dwt h264qpel hpeldsp me_cmp rangecoder videodsp"
snow_encoder_select="aandcttables dwt h264qpel hpeldsp me_cmp mpegvideoenc rangecoder"
sonic_decoder_select="golomb rangecoder"
sonic_encoder_select="golomb rangecoder"
sonic_ls_encoder_select="golomb rangecoder"
sp5x_decoder_select="mjpeg_decoder"
svq1_decoder_select="hpeldsp"
svq1_encoder_select="aandcttables hpeldsp me_cmp mpegvideoenc"
svq3_decoder_select="h264_decoder hpeldsp tpeldsp"
svq3_decoder_suggest="zlib"
tak_decoder_select="audiodsp"
theora_decoder_select="vp3_decoder"
thp_decoder_select="mjpeg_decoder"
tiff_decoder_suggest="zlib lzma"
tiff_encoder_suggest="zlib"
truehd_decoder_select="mlp_parser"
truemotion2_decoder_select="bswapdsp"
truespeech_decoder_select="bswapdsp"
tscc_decoder_select="zlib"
twinvq_decoder_select="mdct lsp sinewin"
utvideo_decoder_select="bswapdsp"
utvideo_encoder_select="bswapdsp huffman huffyuvencdsp"
vble_decoder_select="huffyuvdsp"
vc1_decoder_select="blockdsp error_resilience h263_decoder h264chroma h264qpel intrax8 mpeg_er qpeldsp startcode"
vc1image_decoder_select="vc1_decoder"
vorbis_decoder_select="mdct"
vorbis_encoder_select="mdct"
vp3_decoder_select="hpeldsp vp3dsp videodsp"
vp5_decoder_select="h264chroma hpeldsp videodsp vp3dsp"
vp6_decoder_select="h264chroma hpeldsp huffman videodsp vp3dsp"
vp6a_decoder_select="vp6_decoder"
vp6f_decoder_select="vp6_decoder"
vp7_decoder_select="h264pred videodsp"
vp8_decoder_select="h264pred videodsp"
vp9_decoder_select="videodsp vp9_parser"
webp_decoder_select="vp8_decoder"
wmalossless_decoder_select="llauddsp"
wmapro_decoder_select="mdct sinewin wma_freqs"
wmav1_decoder_select="mdct sinewin wma_freqs"
wmav1_encoder_select="mdct sinewin wma_freqs"
wmav2_decoder_select="mdct sinewin wma_freqs"
wmav2_encoder_select="mdct sinewin wma_freqs"
wmavoice_decoder_select="lsp rdft dct mdct sinewin"
wmv1_decoder_select="h263_decoder"
wmv1_encoder_select="h263_encoder"
wmv2_decoder_select="blockdsp h263_decoder idctdsp intrax8 videodsp"
wmv2_encoder_select="h263_encoder"
wmv3_decoder_select="vc1_decoder"
wmv3image_decoder_select="wmv3_decoder"
zerocodec_decoder_select="zlib"
zlib_decoder_select="zlib"
zlib_encoder_select="zlib"
zmbv_decoder_select="zlib"
zmbv_encoder_select="zlib"

# hardware accelerators
crystalhd_deps="libcrystalhd_libcrystalhd_if_h"
dxva2_deps="dxva2api_h"
vaapi_deps="va_va_h"
vda_deps="VideoDecodeAcceleration_VDADecoder_h pthreads"
vda_extralibs="-framework CoreFoundation -framework VideoDecodeAcceleration -framework QuartzCore"
vdpau_deps="vdpau_vdpau_h vdpau_vdpau_x11_h"
xvmc_deps="X11_extensions_XvMClib_h"

h263_vaapi_hwaccel_deps="vaapi"
h263_vaapi_hwaccel_select="h263_decoder"
h263_vdpau_hwaccel_deps="vdpau"
h263_vdpau_hwaccel_select="h263_decoder"
h264_crystalhd_decoder_select="crystalhd h264_mp4toannexb_bsf h264_parser"
h264_dxva2_hwaccel_deps="dxva2"
h264_dxva2_hwaccel_select="h264_decoder"
h264_qsv_hwaccel_deps="libmfx"
h264_vaapi_hwaccel_deps="vaapi"
h264_vaapi_hwaccel_select="h264_decoder"
h264_vda_decoder_deps="vda"
h264_vda_decoder_select="h264_decoder"
h264_vda_hwaccel_deps="vda"
h264_vda_hwaccel_select="h264_decoder"
h264_vda_old_hwaccel_deps="vda"
h264_vda_old_hwaccel_select="h264_decoder"
h264_vdpau_decoder_deps="vdpau"
h264_vdpau_decoder_select="h264_decoder"
h264_vdpau_hwaccel_deps="vdpau"
h264_vdpau_hwaccel_select="h264_decoder"
hevc_dxva2_hwaccel_deps="dxva2 DXVA_PicParams_HEVC"
hevc_dxva2_hwaccel_select="hevc_decoder"
mpeg_vdpau_decoder_deps="vdpau"
mpeg_vdpau_decoder_select="mpeg2video_decoder"
mpeg_xvmc_hwaccel_deps="xvmc"
mpeg_xvmc_hwaccel_select="mpeg2video_decoder"
mpeg1_vdpau_decoder_deps="vdpau"
mpeg1_vdpau_decoder_select="mpeg1video_decoder"
mpeg1_vdpau_hwaccel_deps="vdpau"
mpeg1_vdpau_hwaccel_select="mpeg1video_decoder"
mpeg1_xvmc_hwaccel_deps="xvmc"
mpeg1_xvmc_hwaccel_select="mpeg1video_decoder"
mpeg2_crystalhd_decoder_select="crystalhd"
mpeg2_dxva2_hwaccel_deps="dxva2"
mpeg2_dxva2_hwaccel_select="mpeg2video_decoder"
mpeg2_vaapi_hwaccel_deps="vaapi"
mpeg2_vaapi_hwaccel_select="mpeg2video_decoder"
mpeg2_vdpau_hwaccel_deps="vdpau"
mpeg2_vdpau_hwaccel_select="mpeg2video_decoder"
mpeg2_xvmc_hwaccel_deps="xvmc"
mpeg2_xvmc_hwaccel_select="mpeg2video_decoder"
mpeg4_crystalhd_decoder_select="crystalhd"
mpeg4_vaapi_hwaccel_deps="vaapi"
mpeg4_vaapi_hwaccel_select="mpeg4_decoder"
mpeg4_vdpau_decoder_deps="vdpau"
mpeg4_vdpau_decoder_select="mpeg4_decoder"
mpeg4_vdpau_hwaccel_deps="vdpau"
mpeg4_vdpau_hwaccel_select="mpeg4_decoder"
msmpeg4_crystalhd_decoder_select="crystalhd"
vc1_crystalhd_decoder_select="crystalhd"
vc1_dxva2_hwaccel_deps="dxva2"
vc1_dxva2_hwaccel_select="vc1_decoder"
vc1_vaapi_hwaccel_deps="vaapi"
vc1_vaapi_hwaccel_select="vc1_decoder"
vc1_vdpau_decoder_deps="vdpau"
vc1_vdpau_decoder_select="vc1_decoder"
vc1_vdpau_hwaccel_deps="vdpau"
vc1_vdpau_hwaccel_select="vc1_decoder"
wmv3_crystalhd_decoder_select="crystalhd"
wmv3_dxva2_hwaccel_select="vc1_dxva2_hwaccel"
wmv3_vaapi_hwaccel_select="vc1_vaapi_hwaccel"
wmv3_vdpau_decoder_select="vc1_vdpau_decoder"
wmv3_vdpau_hwaccel_select="vc1_vdpau_hwaccel"

# parsers
h264_parser_select="h264_decoder"
hevc_parser_select="hevc_decoder"
mpegvideo_parser_select="mpegvideo"
mpeg4video_parser_select="error_resilience h263dsp mpeg_er mpegvideo qpeldsp"
vc1_parser_select="mpegvideo startcode vc1_decoder"

# external libraries
libaacplus_encoder_deps="libaacplus"
libcelt_decoder_deps="libcelt"
libfaac_encoder_deps="libfaac"
libfaac_encoder_select="audio_frame_queue"
libfdk_aac_decoder_deps="libfdk_aac"
libfdk_aac_encoder_deps="libfdk_aac"
libfdk_aac_encoder_select="audio_frame_queue"
libgme_demuxer_deps="libgme"
libgsm_decoder_deps="libgsm"
libgsm_encoder_deps="libgsm"
libgsm_ms_decoder_deps="libgsm"
libgsm_ms_encoder_deps="libgsm"
libilbc_decoder_deps="libilbc"
libilbc_encoder_deps="libilbc"
libmodplug_demuxer_deps="libmodplug"
libmp3lame_encoder_deps="libmp3lame"
libmp3lame_encoder_select="audio_frame_queue"
libopencore_amrnb_decoder_deps="libopencore_amrnb"
libopencore_amrnb_encoder_deps="libopencore_amrnb"
libopencore_amrnb_encoder_select="audio_frame_queue"
libopencore_amrwb_decoder_deps="libopencore_amrwb"
libopenh264_encoder_deps="libopenh264"
libopenjpeg_decoder_deps="libopenjpeg"
libopenjpeg_encoder_deps="libopenjpeg"
libopus_decoder_deps="libopus"
libopus_encoder_deps="libopus"
libopus_encoder_select="audio_frame_queue"
libquvi_demuxer_deps="libquvi"
libschroedinger_decoder_deps="libschroedinger"
libschroedinger_encoder_deps="libschroedinger"
libshine_encoder_deps="libshine"
libshine_encoder_select="audio_frame_queue"
libspeex_decoder_deps="libspeex"
libspeex_encoder_deps="libspeex"
libspeex_encoder_select="audio_frame_queue"
libstagefright_h264_decoder_deps="libstagefright_h264"
libtheora_encoder_deps="libtheora"
libtwolame_encoder_deps="libtwolame"
libvo_aacenc_encoder_deps="libvo_aacenc"
libvo_aacenc_encoder_select="audio_frame_queue"
libvo_amrwbenc_encoder_deps="libvo_amrwbenc"
libvorbis_decoder_deps="libvorbis"
libvorbis_encoder_deps="libvorbis"
libvorbis_encoder_select="audio_frame_queue"
libvpx_vp8_decoder_deps="libvpx"
libvpx_vp8_encoder_deps="libvpx"
libvpx_vp9_decoder_deps="libvpx"
libvpx_vp9_encoder_deps="libvpx"
libwavpack_encoder_deps="libwavpack"
libwebp_encoder_deps="libwebp"
libx264_encoder_deps="libx264"
libx264rgb_encoder_deps="libx264"
libx264rgb_encoder_select="libx264_encoder"
libx265_encoder_deps="libx265"
libxavs_encoder_deps="libxavs"
libxvid_encoder_deps="libxvid"
libutvideo_decoder_deps="libutvideo"
libutvideo_encoder_deps="libutvideo"
libzvbi_teletext_decoder_deps="libzvbi"
nvenc_encoder_deps="nvenc"

# demuxers / muxers
ac3_demuxer_select="ac3_parser"
asf_demuxer_select="riffdec"
asf_muxer_select="riffenc"
asf_stream_muxer_select="asf_muxer"
avi_demuxer_select="riffdec exif"
avi_muxer_select="riffenc"
avisynth_demuxer_deps="avisynth"
avisynth_demuxer_select="riffdec"
caf_demuxer_select="riffdec"
dash_muxer_select="mp4_muxer"
dirac_demuxer_select="dirac_parser"
dts_demuxer_select="dca_parser"
dtshd_demuxer_select="dca_parser"
dv_demuxer_select="dvprofile"
dv_muxer_select="dvprofile"
dxa_demuxer_select="riffdec"
eac3_demuxer_select="ac3_parser"
f4v_muxer_select="mov_muxer"
flac_demuxer_select="flac_parser"
hds_muxer_select="flv_muxer"
hls_muxer_select="mpegts_muxer"
image2_alias_pix_demuxer_select="image2_demuxer"
image2_brender_pix_demuxer_select="image2_demuxer"
ipod_muxer_select="mov_muxer"
ismv_muxer_select="mov_muxer"
libnut_demuxer_deps="libnut"
libnut_muxer_deps="libnut"
matroska_audio_muxer_select="matroska_muxer"
matroska_demuxer_select="riffdec"
matroska_demuxer_suggest="bzlib lzo zlib"
matroska_muxer_select="riffenc"
mmf_muxer_select="riffenc"
mov_demuxer_select="riffdec"
mov_demuxer_suggest="zlib"
mov_muxer_select="riffenc rtpenc_chain"
mp3_demuxer_select="mpegaudio_parser"
mp4_muxer_select="mov_muxer"
mpegts_muxer_select="adts_muxer latm_muxer"
mpegtsraw_demuxer_select="mpegts_demuxer"
mxf_d10_muxer_select="mxf_muxer"
mxf_opatom_muxer_select="mxf_muxer"
nut_muxer_select="riffenc"
nuv_demuxer_select="riffdec"
oga_muxer_select="ogg_muxer"
ogg_demuxer_select="golomb"
opus_muxer_select="ogg_muxer"
psp_muxer_select="mov_muxer"
rtp_demuxer_select="sdp_demuxer"
rtpdec_select="asf_demuxer rm_demuxer rtp_protocol mpegts_demuxer mov_demuxer"
rtsp_demuxer_select="http_protocol rtpdec"
rtsp_muxer_select="rtp_muxer http_protocol rtp_protocol rtpenc_chain"
sap_demuxer_select="sdp_demuxer"
sap_muxer_select="rtp_muxer rtp_protocol rtpenc_chain"
sdp_demuxer_select="rtpdec"
smoothstreaming_muxer_select="ismv_muxer"
spdif_muxer_select="aac_parser"
spx_muxer_select="ogg_muxer"
tak_demuxer_select="tak_parser"
tg2_muxer_select="mov_muxer"
tgp_muxer_select="mov_muxer"
vobsub_demuxer_select="mpegps_demuxer"
w64_demuxer_select="wav_demuxer"
w64_muxer_select="wav_muxer"
wav_demuxer_select="riffdec"
wav_muxer_select="riffenc"
webm_muxer_select="riffenc"
wtv_demuxer_select="riffdec"
wtv_muxer_select="riffenc"
xmv_demuxer_select="riffdec"
xwma_demuxer_select="riffdec"

# indevs / outdevs
alsa_indev_deps="alsa_asoundlib_h snd_pcm_htimestamp"
alsa_outdev_deps="alsa_asoundlib_h"
avfoundation_indev_extralibs="-framework CoreVideo -framework Foundation -framework AVFoundation -framework CoreMedia"
avfoundation_indev_select="avfoundation"
bktr_indev_deps_any="dev_bktr_ioctl_bt848_h machine_ioctl_bt848_h dev_video_bktr_ioctl_bt848_h dev_ic_bt8xx_h"
caca_outdev_deps="libcaca"
decklink_outdev_deps="decklink pthreads"
decklink_outdev_extralibs="-lstdc++"
decklink_indev_deps="decklink pthreads"
decklink_indev_extralibs="-lstdc++"
dshow_indev_deps="IBaseFilter"
dshow_indev_extralibs="-lpsapi -lole32 -lstrmiids -luuid -loleaut32"
dv1394_indev_deps="dv1394"
dv1394_indev_select="dv_demuxer"
fbdev_indev_deps="linux_fb_h"
fbdev_outdev_deps="linux_fb_h"
gdigrab_indev_deps="CreateDIBSection"
gdigrab_indev_extralibs="-lgdi32"
gdigrab_indev_select="bmp_decoder"
iec61883_indev_deps="libiec61883"
jack_indev_deps="jack_jack_h sem_timedwait"
lavfi_indev_deps="avfilter"
libcdio_indev_deps="libcdio"
libdc1394_indev_deps="libdc1394"
libv4l2_indev_deps="libv4l2"
openal_indev_deps="openal"
opengl_outdev_deps="opengl"
oss_indev_deps_any="soundcard_h sys_soundcard_h"
oss_outdev_deps_any="soundcard_h sys_soundcard_h"
pulse_indev_deps="libpulse"
pulse_outdev_deps="libpulse"
qtkit_indev_extralibs="-framework QTKit -framework Foundation -framework QuartzCore"
qtkit_indev_select="qtkit"
sdl_outdev_deps="sdl"
sndio_indev_deps="sndio_h"
sndio_outdev_deps="sndio_h"
v4l_indev_deps="linux_videodev_h"
v4l2_indev_deps_any="linux_videodev2_h sys_videoio_h"
v4l2_outdev_deps_any="linux_videodev2_h sys_videoio_h"
vfwcap_indev_deps="capCreateCaptureWindow vfwcap_defines"
vfwcap_indev_extralibs="-lavicap32"
xv_outdev_deps="X11_extensions_Xvlib_h XvGetPortAttribute"
xv_outdev_extralibs="-lXv -lX11 -lXext"
x11grab_indev_deps="x11grab"
x11grab_xcb_indev_deps="libxcb"

# protocols
bluray_protocol_deps="libbluray"
ffrtmpcrypt_protocol_deps="!librtmp_protocol"
ffrtmpcrypt_protocol_deps_any="gcrypt nettle openssl"
ffrtmpcrypt_protocol_select="tcp_protocol"
ffrtmphttp_protocol_deps="!librtmp_protocol"
ffrtmphttp_protocol_select="http_protocol"
ftp_protocol_select="tcp_protocol"
gopher_protocol_select="network"
http_protocol_select="tcp_protocol"
httpproxy_protocol_select="tcp_protocol"
https_protocol_select="tls_protocol"
icecast_protocol_select="http_protocol"
librtmp_protocol_deps="librtmp"
librtmpe_protocol_deps="librtmp"
librtmps_protocol_deps="librtmp"
librtmpt_protocol_deps="librtmp"
librtmpte_protocol_deps="librtmp"
libsmbclient_protocol_deps="libsmbclient gplv3"
libssh_protocol_deps="libssh"
mmsh_protocol_select="http_protocol"
mmst_protocol_select="network"
rtmp_protocol_deps="!librtmp_protocol"
rtmp_protocol_select="tcp_protocol"
rtmpe_protocol_select="ffrtmpcrypt_protocol"
rtmps_protocol_deps="!librtmp_protocol"
rtmps_protocol_select="tls_protocol"
rtmpt_protocol_select="ffrtmphttp_protocol"
rtmpte_protocol_select="ffrtmpcrypt_protocol ffrtmphttp_protocol"
rtmpts_protocol_select="ffrtmphttp_protocol https_protocol"
rtp_protocol_select="udp_protocol"
sctp_protocol_deps="struct_sctp_event_subscribe"
sctp_protocol_select="network"
srtp_protocol_select="rtp_protocol"
tcp_protocol_select="network"
tls_protocol_deps_any="openssl gnutls"
tls_protocol_select="tcp_protocol"
udp_protocol_select="network"
udplite_protocol_select="network"
unix_protocol_deps="sys_un_h"
unix_protocol_select="network"

# filters
amovie_filter_deps="avcodec avformat"
aresample_filter_deps="swresample"
ass_filter_deps="libass"
asyncts_filter_deps="avresample"
atempo_filter_deps="avcodec"
atempo_filter_select="rdft"
azmq_filter_deps="libzmq"
blackframe_filter_deps="gpl"
boxblur_filter_deps="gpl"
bs2b_filter_deps="libbs2b"
colormatrix_filter_deps="gpl"
cropdetect_filter_deps="gpl"
delogo_filter_deps="gpl"
deshake_filter_select="pixelutils"
drawtext_filter_deps="libfreetype"
ebur128_filter_deps="gpl"
eq_filter_deps="gpl"
fftfilt_filter_deps="avcodec"
fftfilt_filter_select="rdft"
flite_filter_deps="libflite"
frei0r_filter_deps="frei0r dlopen"
frei0r_src_filter_deps="frei0r dlopen"
fspp_filter_deps="gpl"
geq_filter_deps="gpl"
histeq_filter_deps="gpl"
hqdn3d_filter_deps="gpl"
interlace_filter_deps="gpl"
kerndeint_filter_deps="gpl"
ladspa_filter_deps="ladspa dlopen"
mcdeint_filter_deps="avcodec gpl"
movie_filter_deps="avcodec avformat"
mpdecimate_filter_deps="gpl"
mpdecimate_filter_select="pixelutils"
mptestsrc_filter_deps="gpl"
negate_filter_deps="lut_filter"
perspective_filter_deps="gpl"
pp7_filter_deps="gpl"
ocv_filter_deps="libopencv"
owdenoise_filter_deps="gpl"
pan_filter_deps="swresample"
phase_filter_deps="gpl"
pp_filter_deps="gpl postproc"
pullup_filter_deps="gpl"
removelogo_filter_deps="avcodec avformat swscale"
repeatfields_filter_deps="gpl"
resample_filter_deps="avresample"
sab_filter_deps="gpl swscale"
scale_filter_deps="swscale"
select_filter_select="pixelutils"
smartblur_filter_deps="gpl swscale"
showspectrum_filter_deps="avcodec"
showspectrum_filter_select="rdft"
spp_filter_deps="gpl avcodec"
spp_filter_select="fft idctdsp fdctdsp me_cmp pixblockdsp"
stereo3d_filter_deps="gpl"
subtitles_filter_deps="avformat avcodec libass"
super2xsai_filter_deps="gpl"
tinterlace_filter_deps="gpl"
vidstabdetect_filter_deps="libvidstab"
vidstabtransform_filter_deps="libvidstab"
pixfmts_super2xsai_test_deps="super2xsai_filter"
tinterlace_merge_test_deps="tinterlace_filter"
tinterlace_pad_test_deps="tinterlace_filter"
uspp_filter_deps="gpl avcodec"
zmq_filter_deps="libzmq"
zoompan_filter_deps="swscale"

# examples
avio_reading="avformat avcodec avutil"
avcodec_example_deps="avcodec avutil"
decoding_encoding_example_deps="avcodec avformat avutil"
demuxing_decoding_example_deps="avcodec avformat avutil"
extract_mvs_example_deps="avcodec avformat avutil"
filter_audio_example_deps="avfilter avutil"
filtering_audio_example_deps="avfilter avcodec avformat avutil"
filtering_video_example_deps="avfilter avcodec avformat avutil"
metadata_example_deps="avformat avutil"
muxing_example_deps="avcodec avformat avutil swscale"
qsvdec_example_deps="avcodec avutil libmfx h264_qsv_decoder vaapi_x11"
remuxing_example_deps="avcodec avformat avutil"
resampling_audio_example_deps="avutil swresample"
scaling_video_example_deps="avutil swscale"
transcode_aac_example_deps="avcodec avformat swresample"
transcoding_example_deps="avfilter avcodec avformat avutil"

# libraries, in linking order
avcodec_deps="avutil"
avdevice_deps="avformat avcodec avutil"
avfilter_deps="avutil"
avformat_deps="avcodec avutil"
avresample_deps="avutil"
postproc_deps="avutil gpl"
swresample_deps="avutil"
swscale_deps="avutil"

# programs
ffmpeg_deps="avcodec avfilter avformat swresample"
ffmpeg_select="aformat_filter anull_filter atrim_filter format_filter
               null_filter
               setpts_filter trim_filter"
ffplay_deps="avcodec avformat swscale swresample sdl"
ffplay_libs='$sdl_libs'
ffplay_select="rdft crop_filter transpose_filter hflip_filter vflip_filter rotate_filter"
ffprobe_deps="avcodec avformat"
ffserver_deps="avformat fork sarestart"
ffserver_select="ffm_muxer rtp_protocol rtsp_demuxer"

# documentation
podpages_deps="perl"
manpages_deps="perl pod2man"
htmlpages_deps="perl"
htmlpages_deps_any="makeinfo_html texi2html"
txtpages_deps="perl makeinfo"
doc_deps_any="manpages htmlpages podpages txtpages"

# default parameters

logfile="config.log"

# installation paths
prefix_default="/usr/local"
bindir_default='${prefix}/bin'
datadir_default='${prefix}/share/ffmpeg'
docdir_default='${prefix}/share/doc/ffmpeg'
incdir_default='${prefix}/include'
libdir_default='${prefix}/lib'
mandir_default='${prefix}/share/man'

# toolchain
ar_default="ar"
cc_default="gcc"
cxx_default="g++"
host_cc_default="gcc"
cp_f="cp -f"
doxygen_default="doxygen"
install="install"
ln_s="ln -s -f"
nm_default="nm -g"
objformat="elf"
pkg_config_default=pkg-config
if ranlib 2>&1 | grep -q "\-D "; then
    ranlib_default="ranlib -D"
else
    ranlib_default="ranlib"
fi
strip_default="strip"
yasmexe_default="yasm"
windres_default="windres"

# OS
target_os_default=$(tolower $(uname -s))
host_os=$target_os_default

# machine
if test "$target_os_default" = aix; then
    arch_default=$(uname -p)
    strip_default="strip -X32_64"
else
    arch_default=$(uname -m)
fi
cpu="generic"
intrinsics="none"

# configurable options
enable $PROGRAM_LIST
enable $DOCUMENT_LIST
enable $EXAMPLE_LIST
enable $(filter_out avresample $LIBRARY_LIST)
enable stripping

enable asm
enable debug
enable doc
enable faan faandct faanidct
enable optimizations
enable runtime_cpudetect
enable safe_bitstream_reader
enable static
enable swscale_alpha

sws_max_filter_size_default=256
set_default sws_max_filter_size

# Enable hwaccels by default.
enable dxva2 vaapi vda vdpau xvmc
enable xlib

# build settings
SHFLAGS='-shared -Wl,-soname,$$(@F)'
LIBPREF="lib"
LIBSUF=".a"
FULLNAME='$(NAME)$(BUILDSUF)'
LIBNAME='$(LIBPREF)$(FULLNAME)$(LIBSUF)'
SLIBPREF="lib"
SLIBSUF=".so"
SLIBNAME='$(SLIBPREF)$(FULLNAME)$(SLIBSUF)'
SLIBNAME_WITH_VERSION='$(SLIBNAME).$(LIBVERSION)'
SLIBNAME_WITH_MAJOR='$(SLIBNAME).$(LIBMAJOR)'
LIB_INSTALL_EXTRA_CMD='$$(RANLIB) "$(LIBDIR)/$(LIBNAME)"'
SLIB_INSTALL_NAME='$(SLIBNAME_WITH_VERSION)'
SLIB_INSTALL_LINKS='$(SLIBNAME_WITH_MAJOR) $(SLIBNAME)'

asflags_filter=echo
cflags_filter=echo
ldflags_filter=echo

AS_C='-c'
AS_O='-o $@'
CC_C='-c'
CC_E='-E -o $@'
CC_O='-o $@'
CXX_C='-c'
CXX_O='-o $@'
LD_O='-o $@'
LD_LIB='-l%'
LD_PATH='-L'
HOSTCC_C='-c'
HOSTCC_E='-E -o $@'
HOSTCC_O='-o $@'
HOSTLD_O='-o $@'

host_libs='-lm'
host_cflags_filter=echo
host_ldflags_filter=echo

target_path='$(CURDIR)'

# since the object filename is not given with the -MM flag, the compiler
# is only able to print the basename, and we must add the path ourselves
DEPCMD='$(DEP$(1)) $(DEP$(1)FLAGS) $($(1)DEP_FLAGS) $< | sed -e "/^\#.*/d" -e "s,^[[:space:]]*$(*F)\\.o,$(@D)/$(*F).o," > $(@:.o=.d)'
DEPFLAGS='-MM'

# find source path
if test -f configure; then
    source_path=.
else
    source_path=$(cd $(dirname "$0"); pwd)
    echo "$source_path" | grep -q '[[:blank:]]' &&
        die "Out of tree builds are impossible with whitespace in source path."
    test -e "$source_path/config.h" &&
        die "Out of tree builds are impossible with config.h in source dir."
fi

for v in "$@"; do
    r=${v#*=}
    l=${v%"$r"}
    r=$(sh_quote "$r")
    FFMPEG_CONFIGURATION="${FFMPEG_CONFIGURATION# } ${l}${r}"
done

find_things(){
    thing=$1
    pattern=$2
    file=$source_path/$3
    sed -n "s/^[^#]*$pattern.*([^,]*, *\([^,]*\)\(,.*\)*).*/\1_$thing/p" "$file"
}

ENCODER_LIST=$(find_things  encoder  ENC      libavcodec/allcodecs.c)
DECODER_LIST=$(find_things  decoder  DEC      libavcodec/allcodecs.c)
HWACCEL_LIST=$(find_things  hwaccel  HWACCEL  libavcodec/allcodecs.c)
PARSER_LIST=$(find_things   parser   PARSER   libavcodec/allcodecs.c)
BSF_LIST=$(find_things      bsf      BSF      libavcodec/allcodecs.c)
MUXER_LIST=$(find_things    muxer    _MUX     libavformat/allformats.c)
DEMUXER_LIST=$(find_things  demuxer  DEMUX    libavformat/allformats.c)
OUTDEV_LIST=$(find_things   outdev   OUTDEV   libavdevice/alldevices.c)
INDEV_LIST=$(find_things    indev    _IN      libavdevice/alldevices.c)
PROTOCOL_LIST=$(find_things protocol PROTOCOL libavformat/allformats.c)
FILTER_LIST=$(find_things   filter   FILTER   libavfilter/allfilters.c)

ALL_COMPONENTS="
    $BSF_LIST
    $DECODER_LIST
    $DEMUXER_LIST
    $ENCODER_LIST
    $FILTER_LIST
    $HWACCEL_LIST
    $INDEV_LIST
    $MUXER_LIST
    $OUTDEV_LIST
    $PARSER_LIST
    $PROTOCOL_LIST
"

for n in $COMPONENT_LIST; do
    v=$(toupper ${n%s})_LIST
    eval enable \$$v
    eval ${n}_if_any="\$$v"
done

enable $ARCH_EXT_LIST

die_unknown(){
    echo "Unknown option \"$1\"."
    echo "See $0 --help for available options."
    exit 1
}

print_3_columns() {
    cat | tr ' ' '\n' | sort | pr -r -3 -t
}

show_list() {
    suffix=_$1
    shift
    echo $* | sed s/$suffix//g | print_3_columns
    exit 0
}

rand_list(){
    IFS=', '
    set -- $*
    unset IFS
    for thing; do
        comp=${thing%:*}
        prob=${thing#$comp}
        prob=${prob#:}
        is_in ${comp} $COMPONENT_LIST && eval comp=\$$(toupper ${comp%s})_LIST
        echo "prob ${prob:-0.5}"
        printf '%s\n' $comp
    done
}

do_random(){
    action=$1
    shift
    random_seed=$(awk "BEGIN { srand($random_seed); print srand() }")
    $action $(rand_list "$@" | awk "BEGIN { srand($random_seed) } \$1 == \"prob\" { prob = \$2; next } rand() < prob { print }")
}

for opt do
    optval="${opt#*=}"
    case "$opt" in
        --extra-ldflags=*)
            add_ldflags $optval
        ;;
        --extra-ldexeflags=*)
            add_ldexeflags $optval
        ;;
        --extra-libs=*)
            add_extralibs $optval
        ;;
        --disable-devices)
            disable $INDEV_LIST $OUTDEV_LIST
        ;;
        --enable-debug=*)
            debuglevel="$optval"
        ;;
        --disable-programs)
            disable $PROGRAM_LIST
        ;;
        --disable-everything)
            map 'eval unset \${$(toupper ${v%s})_LIST}' $COMPONENT_LIST
        ;;
        --disable-all)
            map 'eval unset \${$(toupper ${v%s})_LIST}' $COMPONENT_LIST
            disable $LIBRARY_LIST $PROGRAM_LIST doc
        ;;
        --enable-random|--disable-random)
            action=${opt%%-random}
            do_random ${action#--} $COMPONENT_LIST
        ;;
        --enable-random=*|--disable-random=*)
            action=${opt%%-random=*}
            do_random ${action#--} $optval
        ;;
        --enable-*=*|--disable-*=*)
            eval $(echo "${opt%%=*}" | sed 's/--/action=/;s/-/ thing=/')
            is_in "${thing}s" $COMPONENT_LIST || die_unknown "$opt"
            eval list=\$$(toupper $thing)_LIST
            name=$(echo "${optval}" | sed "s/,/_${thing}|/g")_${thing}
            list=$(filter "$name" $list)
            [ "$list" = "" ] && warn "Option $opt did not match anything"
            $action $list
        ;;
        --enable-?*|--disable-?*)
            eval $(echo "$opt" | sed 's/--/action=/;s/-/ option=/;s/-/_/g')
            if is_in $option $COMPONENT_LIST; then
                test $action = disable && action=unset
                eval $action \$$(toupper ${option%s})_LIST
            elif is_in $option $CMDLINE_SELECT; then
                $action $option
            else
                die_unknown $opt
            fi
        ;;
        --list-*)
            NAME="${opt#--list-}"
            is_in $NAME $COMPONENT_LIST || die_unknown $opt
            NAME=${NAME%s}
            eval show_list $NAME \$$(toupper $NAME)_LIST
        ;;
        --help|-h) show_help
        ;;
        --fatal-warnings) enable fatal_warnings
        ;;
        *)
            optname="${opt%%=*}"
            optname="${optname#--}"
            optname=$(echo "$optname" | sed 's/-/_/g')
            if is_in $optname $CMDLINE_SET; then
                eval $optname='$optval'
            elif is_in $optname $CMDLINE_APPEND; then
                append $optname "$optval"
            else
                die_unknown $opt
            fi
        ;;
    esac
done

disabled logging && logfile=/dev/null

echo "# $0 $FFMPEG_CONFIGURATION" > $logfile
set >> $logfile

test -n "$cross_prefix" && enable cross_compile

if enabled cross_compile; then
    test -n "$arch" && test -n "$target_os" ||
        die "Must specify target arch and OS when cross-compiling"
fi

test -n "$valgrind" && toolchain="valgrind-memcheck"

case "$toolchain" in
    clang-asan)
        cc_default="clang"
        add_cflags  -fsanitize=address
        add_ldflags -fsanitize=address
    ;;
    clang-tsan)
        cc_default="clang"
        add_cflags  -fsanitize=thread -pie
        add_ldflags -fsanitize=thread -pie
    ;;
    clang-usan)
        cc_default="clang"
        add_cflags  -fsanitize=undefined
        add_ldflags -fsanitize=undefined
    ;;
    gcc-asan)
        cc_default="gcc"
        add_cflags  -fsanitize=address
        add_ldflags -fsanitize=address
    ;;
    gcc-tsan)
        cc_default="gcc"
        add_cflags  -fsanitize=thread -pie -fPIC
        add_ldflags -fsanitize=thread -pie -fPIC
    ;;
    gcc-usan)
        cc_default="gcc"
        add_cflags  -fsanitize=undefined
        add_ldflags -fsanitize=undefined
    ;;
    valgrind-massif)
        target_exec_default=${valgrind:-"valgrind"}
        target_exec_args="--tool=massif --alloc-fn=av_malloc --alloc-fn=av_mallocz --alloc-fn=av_calloc --alloc-fn=av_fast_padded_malloc --alloc-fn=av_fast_malloc --alloc-fn=av_realloc_f --alloc-fn=av_fast_realloc --alloc-fn=av_realloc"
    ;;
    valgrind-memcheck)
        target_exec_default=${valgrind:-"valgrind"}
        target_exec_args="--error-exitcode=1 --malloc-fill=0x2a --track-origins=yes --leak-check=full --gen-suppressions=all --suppressions=$source_path/tests/fate-valgrind.supp"
    ;;
    msvc)
        # Check whether the current MSVC version needs the C99 converter.
        # From MSVC 2013 (compiler major version 18) onwards, it does actually
        # support enough of C99 to build ffmpeg. Default to the new
        # behaviour if the regexp was unable to match anything, since this
        # successfully parses the version number of existing supported
        # versions that require the converter (MSVC 2010 and 2012).
        cl_major_ver=$(cl 2>&1 | sed -n 's/.*Version \([[:digit:]]\{1,\}\)\..*/\1/p')
        if [ -z "$cl_major_ver" ] || [ $cl_major_ver -ge 18 ]; then
            cc_default="cl"
        else
            cc_default="c99wrap cl"
        fi
        ld_default="link"
        nm_default="dumpbin -symbols"
        ar_default="lib"
        target_os_default="win32"
        # Use a relative path for TMPDIR. This makes sure all the
        # ffconf temp files are written with a relative path, avoiding
        # issues with msys/win32 path conversion for MSVC parameters
        # such as -Fo<file> or -out:<file>.
        TMPDIR=.
    ;;
    icl)
        cc_default="icl"
        ld_default="xilink"
        nm_default="dumpbin -symbols"
        ar_default="xilib"
        target_os_default="win32"
        TMPDIR=.
    ;;
    gcov)
        add_cflags  -fprofile-arcs -ftest-coverage
        add_ldflags -fprofile-arcs -ftest-coverage
    ;;
    hardened)
        add_cppflags -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2
        add_cflags   -fno-strict-overflow -fstack-protector-all
        add_ldflags  -Wl,-z,relro -Wl,-z,now
    ;;
    ?*)
        die "Unknown toolchain $toolchain"
    ;;
esac

ar_default="${cross_prefix}${ar_default}"
cc_default="${cross_prefix}${cc_default}"
cxx_default="${cross_prefix}${cxx_default}"
nm_default="${cross_prefix}${nm_default}"
pkg_config_default="${cross_prefix}${pkg_config_default}"
ranlib_default="${cross_prefix}${ranlib_default}"
strip_default="${cross_prefix}${strip_default}"
windres_default="${cross_prefix}${windres_default}"

sysinclude_default="${sysroot}/usr/include"

set_default arch cc cxx doxygen pkg_config ranlib strip sysinclude \
    target_exec target_os yasmexe
enabled cross_compile || host_cc_default=$cc
set_default host_cc

pkg_config_fail_message=""
if ! $pkg_config --version >/dev/null 2>&1; then
    warn "$pkg_config not found, library detection may fail."
    pkg_config=false
elif is_in -static $cc $LDFLAGS && ! is_in --static $pkg_config $pkg_config_flags; then
    pkg_config_fail_message="
Note: When building a static binary, add --pkg-config-flags=\"--static\"."
fi

if test $doxygen != $doxygen_default && \
  ! $doxygen --version >/dev/null 2>&1; then
    warn "Specified doxygen \"$doxygen\" not found, API documentation will fail to build."
fi

exesuf() {
    case $1 in
        mingw32*|win32|win64|cygwin*|*-dos|freedos|opendos|os/2*|symbian) echo .exe ;;
    esac
}

EXESUF=$(exesuf $target_os)
HOSTEXESUF=$(exesuf $host_os)

# set temporary file name
: ${TMPDIR:=$TEMPDIR}
: ${TMPDIR:=$TMP}
: ${TMPDIR:=/tmp}

if [ -n "$tempprefix" ] ; then
    mktemp(){
        echo $tempprefix.${HOSTNAME}.${UID}
    }
elif ! check_cmd mktemp -u XXXXXX; then
    # simple replacement for missing mktemp
    # NOT SAFE FOR GENERAL USE
    mktemp(){
        echo "${2%%XXX*}.${HOSTNAME}.${UID}.$$"
    }
fi

tmpfile(){
    tmp=$(mktemp -u "${TMPDIR}/ffconf.XXXXXXXX")$2 &&
        (set -C; exec > $tmp) 2>/dev/null ||
        die "Unable to create temporary file in $TMPDIR."
    append TMPFILES $tmp
    eval $1=$tmp
}

trap 'rm -f -- $TMPFILES' EXIT

tmpfile TMPASM .asm
tmpfile TMPC   .c
tmpfile TMPCPP .cpp
tmpfile TMPE   $EXESUF
tmpfile TMPH   .h
tmpfile TMPM   .m
tmpfile TMPO   .o
tmpfile TMPS   .S
tmpfile TMPSH  .sh
tmpfile TMPV   .ver

unset -f mktemp

chmod +x $TMPE

# make sure we can execute files in $TMPDIR
cat > $TMPSH 2>> $logfile <<EOF
#! /bin/sh
EOF
chmod +x $TMPSH >> $logfile 2>&1
if ! $TMPSH >> $logfile 2>&1; then
    cat <<EOF
Unable to create and execute files in $TMPDIR.  Set the TMPDIR environment
variable to another directory and make sure that it is not mounted noexec.
EOF
    die "Sanity test failed."
fi

armasm_flags(){
    for flag; do
        case $flag in
            # Filter out MSVC cl.exe options from cflags that shouldn't
            # be passed to gas-preprocessor
            -M[TD]*)                                            ;;
            *)                  echo $flag                      ;;
        esac
   done
}

ccc_flags(){
    for flag; do
        case $flag in
            -std=c99)           echo -c99                       ;;
            -mcpu=*)            echo -arch ${flag#*=}           ;;
            -mieee)             echo -ieee                      ;;
            -O*|-fast)          echo $flag                      ;;
            -fno-math-errno)    echo -assume nomath_errno       ;;
            -g)                 echo -g3                        ;;
            -Wall)              echo -msg_enable level2         ;;
            -Wno-pointer-sign)  echo -msg_disable ptrmismatch1  ;;
            -Wl,*)              echo $flag                      ;;
            -f*|-W*)                                            ;;
            *)                  echo $flag                      ;;
        esac
   done
}

cparser_flags(){
    for flag; do
        case $flag in
            -Wno-switch)             echo -Wno-switch-enum ;;
            -Wno-format-zero-length) ;;
            -Wdisabled-optimization) ;;
            -Wno-pointer-sign)       echo -Wno-other ;;
            *)                       echo $flag ;;
        esac
    done
}

msvc_common_flags(){
    for flag; do
        case $flag in
            # In addition to specifying certain flags under the compiler
            # specific filters, they must be specified here as well or else the
            # generic catch all at the bottom will print the original flag.
            -Wall)                ;;
            -std=c99)             ;;
            # Common flags
            -fomit-frame-pointer) ;;
            -g)                   echo -Z7 ;;
            -fno-math-errno)      ;;
            -fno-common)          ;;
            -fno-signed-zeros)    ;;
            -fPIC)                ;;
            -mthumb)              ;;
            -march=*)             ;;
            -lz)                  echo zlib.lib ;;
            -lavifil32)           echo vfw32.lib ;;
            -lavicap32)           echo vfw32.lib user32.lib ;;
            -l*)                  echo ${flag#-l}.lib ;;
            -L*)                  echo -libpath:${flag#-L} ;;
            *)                    echo $flag ;;
        esac
    done
}

msvc_flags(){
    msvc_common_flags "$@"
    for flag; do
        case $flag in
            -Wall)                echo -W4 -wd4244 -wd4127 -wd4018 -wd4389     \
                                       -wd4146 -wd4057 -wd4204 -wd4706 -wd4305 \
                                       -wd4152 -wd4324 -we4013 -wd4100 -wd4214 \
                                       -wd4554 \
                                       -wd4273 -wd4701 ;;
        esac
    done
}

icl_flags(){
    msvc_common_flags "$@"
    for flag; do
        case $flag in
            # Despite what Intel's documentation says -Wall, which is supported
            # on Windows, does enable remarks so disable them here.
            -Wall)                echo $flag -Qdiag-disable:remark ;;
            -std=c99)             echo -Qstd=c99 ;;
            -flto)                echo -ipo ;;
        esac
    done
}

icc_flags(){
    for flag; do
        case $flag in
            -flto)                echo -ipo ;;
            *)                    echo $flag ;;
        esac
    done
}

pgi_flags(){
    for flag; do
        case $flag in
            -flto)                echo -Mipa=fast,libopt,libinline,vestigial ;;
            -fomit-frame-pointer) echo -Mnoframe ;;
            -g)                   echo -gopt ;;
            *)                    echo $flag ;;
        esac
    done
}

suncc_flags(){
    for flag; do
        case $flag in
            -march=*|-mcpu=*)
                case "${flag#*=}" in
                    native)                   echo -xtarget=native       ;;
                    v9|niagara)               echo -xarch=sparc          ;;
                    ultrasparc)               echo -xarch=sparcvis       ;;
                    ultrasparc3|niagara2)     echo -xarch=sparcvis2      ;;
                    i586|pentium)             echo -xchip=pentium        ;;
                    i686|pentiumpro|pentium2) echo -xtarget=pentium_pro  ;;
                    pentium3*|c3-2)           echo -xtarget=pentium3     ;;
                    pentium-m)          echo -xarch=sse2 -xchip=pentium3 ;;
                    pentium4*)          echo -xtarget=pentium4           ;;
                    prescott|nocona)    echo -xarch=sse3 -xchip=pentium4 ;;
                    *-sse3)             echo -xarch=sse3                 ;;
                    core2)              echo -xarch=ssse3 -xchip=core2   ;;
                    bonnell)                   echo -xarch=ssse3         ;;
                    corei7|nehalem)            echo -xtarget=nehalem     ;;
                    westmere)                  echo -xtarget=westmere    ;;
                    silvermont)                echo -xarch=sse4_2        ;;
                    corei7-avx|sandybridge)    echo -xtarget=sandybridge ;;
                    core-avx*|ivybridge|haswell|broadwell)
                                               echo -xarch=avx           ;;
                    amdfam10|barcelona)        echo -xtarget=barcelona   ;;
                    btver1)                    echo -xarch=amdsse4a      ;;
                    btver2|bdver*)             echo -xarch=avx           ;;
                    athlon-4|athlon-[mx]p)     echo -xarch=ssea          ;;
                    k8|opteron|athlon64|athlon-fx)
                                               echo -xarch=sse2a         ;;
                    athlon*)                   echo -xarch=pentium_proa  ;;
                esac
                ;;
            -std=c99)             echo -xc99              ;;
            -fomit-frame-pointer) echo -xregs=frameptr    ;;
            -fPIC)                echo -KPIC -xcode=pic32 ;;
            -W*,*)                echo $flag              ;;
            -f*-*|-W*|-mimpure-text)                      ;;
            -shared)              echo -G                 ;;
            *)                    echo $flag              ;;
        esac
    done
}

tms470_flags(){
    for flag; do
        case $flag in
            -march=*|-mcpu=*)
                case "${flag#*=}" in
                    armv7-a|cortex-a*)      echo -mv=7a8 ;;
                    armv7-r|cortex-r*)      echo -mv=7r4 ;;
                    armv7-m|cortex-m*)      echo -mv=7m3 ;;
                    armv6*|arm11*)          echo -mv=6   ;;
                    armv5*e|arm[79]*e*|arm9[24]6*|arm96*|arm102[26])
                                            echo -mv=5e  ;;
                    armv4*|arm7*|arm9[24]*) echo -mv=4   ;;
                esac
                ;;
            -mfpu=neon)     echo --float_support=vfpv3 --neon ;;
            -mfpu=vfp)      echo --float_support=vfpv2        ;;
            -mfpu=vfpv3)    echo --float_support=vfpv3        ;;
            -mfpu=vfpv3-d16) echo --float_support=vfpv3d16    ;;
            -msoft-float)   echo --float_support=vfplib       ;;
            -O[0-3]|-mf=*)  echo $flag                        ;;
            -g)             echo -g -mn                       ;;
            -pds=*)         echo $flag                        ;;
            -D*|-I*)        echo $flag                        ;;
            --gcc|--abi=*)  echo $flag                        ;;
            -me)            echo $flag                        ;;
        esac
    done
}

probe_cc(){
    pfx=$1
    _cc=$2

    unset _type _ident _cc_c _cc_e _cc_o _flags _cflags
    unset _ld_o _ldflags _ld_lib _ld_path
    unset _depflags _DEPCMD _DEPFLAGS
    _flags_filter=echo

    if $_cc --version 2>&1 | grep -q '^GNU assembler'; then
        true # no-op to avoid reading stdin in following checks
    elif $_cc -v 2>&1 | grep -q '^gcc.*LLVM'; then
        _type=llvm_gcc
        gcc_extra_ver=$(expr "$($_cc --version | head -n1)" : '.*\((.*)\)')
        _ident="llvm-gcc $($_cc -dumpversion) $gcc_extra_ver"
        _depflags='-MMD -MF $(@:.o=.d) -MT $@'
        _cflags_speed='-O3'
        _cflags_size='-Os'
    elif $_cc -v 2>&1 | grep -qi ^gcc; then
        _type=gcc
        gcc_version=$($_cc --version | head -n1)
        gcc_basever=$($_cc -dumpversion)
        gcc_pkg_ver=$(expr "$gcc_version" : '[^ ]* \(([^)]*)\)')
        gcc_ext_ver=$(expr "$gcc_version" : ".*$gcc_pkg_ver $gcc_basever \\(.*\\)")
        _ident=$(cleanws "gcc $gcc_basever $gcc_pkg_ver $gcc_ext_ver")
        if ! $_cc -dumpversion | grep -q '^2\.'; then
            _depflags='-MMD -MF $(@:.o=.d) -MT $@'
        fi
        _cflags_speed='-O3'
        _cflags_size='-Os'
    elif $_cc --version 2>/dev/null | grep -q ^icc; then
        _type=icc
        _ident=$($_cc --version | head -n1)
        _depflags='-MMD'
        _cflags_speed='-O3'
        _cflags_size='-Os'
        _cflags_noopt='-O1'
        _flags_filter=icc_flags
    elif $_cc -v 2>&1 | grep -q xlc; then
        _type=xlc
        _ident=$($_cc -qversion 2>/dev/null | head -n1)
        _cflags_speed='-O5'
        _cflags_size='-O5 -qcompact'
    elif $_cc -V 2>/dev/null | grep -q Compaq; then
        _type=ccc
        _ident=$($_cc -V | head -n1 | cut -d' ' -f1-3)
        _DEPFLAGS='-M'
        _cflags_speed='-fast'
        _cflags_size='-O1'
        _flags_filter=ccc_flags
    elif $_cc --vsn 2>/dev/null | grep -Eq "ARM (C/C\+\+ )?Compiler"; then
        test -d "$sysroot" || die "No valid sysroot specified."
        _type=armcc
        _ident=$($_cc --vsn | grep -i build | head -n1 | sed 's/.*: //')
        armcc_conf="$PWD/armcc.conf"
        $_cc --arm_linux_configure                 \
             --arm_linux_config_file="$armcc_conf" \
             --configure_sysroot="$sysroot"        \
             --configure_cpp_headers="$sysinclude" >>$logfile 2>&1 ||
             die "Error creating armcc configuration file."
        $_cc --vsn | grep -q RVCT && armcc_opt=rvct || armcc_opt=armcc
        _flags="--arm_linux_config_file=$armcc_conf --translate_gcc"
        as_default="${cross_prefix}gcc"
        _depflags='-MMD'
        _cflags_speed='-O3'
        _cflags_size='-Os'
    elif $_cc -version 2>/dev/null | grep -Eq 'TMS470|TI ARM'; then
        _type=tms470
        _ident=$($_cc -version | head -n1 | tr -s ' ')
        _flags='--gcc --abi=eabi -me'
        _cc_e='-ppl -fe=$@'
        _cc_o='-fe=$@'
        _depflags='-ppa -ppd=$(@:.o=.d)'
        _cflags_speed='-O3 -mf=5'
        _cflags_size='-O3 -mf=2'
        _flags_filter=tms470_flags
    elif $_cc -v 2>&1 | grep -q clang; then
        _type=clang
        _ident=$($_cc --version | head -n1)
        _depflags='-MMD -MF $(@:.o=.d) -MT $@'
        _cflags_speed='-O3'
        _cflags_size='-Os'
    elif $_cc -V 2>&1 | grep -q Sun; then
        _type=suncc
        _ident=$($_cc -V 2>&1 | head -n1 | cut -d' ' -f 2-)
        _DEPCMD='$(DEP$(1)) $(DEP$(1)FLAGS) $($(1)DEP_FLAGS) $< | sed -e "1s,^.*: ,$@: ," -e "\$$!s,\$$, \\\," -e "1!s,^.*: , ," > $(@:.o=.d)'
        _DEPFLAGS='-xM1 -xc99'
        _ldflags='-std=c99'
        _cflags_speed='-O5'
        _cflags_size='-O5 -xspace'
        _flags_filter=suncc_flags
    elif $_cc -v 2>&1 | grep -q 'PathScale\|Path64'; then
        _type=pathscale
        _ident=$($_cc -v 2>&1 | head -n1 | tr -d :)
        _depflags='-MMD -MF $(@:.o=.d) -MT $@'
        _cflags_speed='-O2'
        _cflags_size='-Os'
        _flags_filter='filter_out -Wdisabled-optimization'
    elif $_cc -v 2>&1 | grep -q Open64; then
        _type=open64
        _ident=$($_cc -v 2>&1 | head -n1 | tr -d :)
        _depflags='-MMD -MF $(@:.o=.d) -MT $@'
        _cflags_speed='-O2'
        _cflags_size='-Os'
        _flags_filter='filter_out -Wdisabled-optimization|-Wtype-limits|-fno-signed-zeros'
    elif $_cc -V 2>&1 | grep -q Portland; then
        _type=pgi
        _ident="PGI $($_cc -V 2>&1 | awk '/^pgcc/ { print $2; exit }')"
        opt_common='-alias=ansi -Mdse -Mlre -Mpre'
        _cflags_speed="-O3 -Mautoinline -Munroll=c:4 $opt_common"
        _cflags_size="-O2 -Munroll=c:1 $opt_common"
        _cflags_noopt="-O"
        _flags_filter=pgi_flags
    elif $_cc 2>&1 | grep -q 'Microsoft.*ARM.*Assembler'; then
        _type=armasm
        _ident=$($_cc | head -n1)
        # 4509: "This form of conditional instruction is deprecated"
        _flags="-nologo -ignore 4509"
        _flags_filter=armasm_flags
    elif $_cc 2>&1 | grep -q Intel; then
        _type=icl
        _ident=$($cc 2>&1 | head -n1)
        _depflags='-QMMD -QMF$(@:.o=.d) -QMT$@'
        # Not only is O3 broken on 13.x+ but it is slower on all previous
        # versions (tested) as well.
        _cflags_speed="-O2"
        _cflags_size="-O1 -Oi" # -O1 without -Oi miscompiles stuff
        if $_cc 2>&1 | grep -q Linker; then
            _ld_o='-out:$@'
        else
            _ld_o='-Fe$@'
        fi
        _cc_o='-Fo$@'
        _cc_e='-P'
        _flags_filter=icl_flags
        _ld_lib='lib%.a'
        _ld_path='-libpath:'
        # -Qdiag-error to make icl error when seeing certain unknown arguments
        _flags='-nologo -Qdiag-error:4044,10157'
        # -Qvec- -Qsimd- to prevent miscompilation, -GS, fp:precise for consistency
        # with MSVC which enables it by default.
        _cflags='-D_USE_MATH_DEFINES -FIstdlib.h -Dstrtoll=_strtoi64 -Qms0 -Qvec- -Qsimd- -GS -fp:precise'
        if [ $pfx = hostcc ]; then
            append _cflags -Dsnprintf=_snprintf
        fi
        disable stripping
    elif $_cc 2>&1 | grep -q Microsoft; then
        _type=msvc
        _ident=$($cc 2>&1 | head -n1)
        _DEPCMD='$(DEP$(1)) $(DEP$(1)FLAGS) $($(1)DEP_FLAGS) $< 2>&1 | awk '\''/including/ { sub(/^.*file: */, ""); gsub(/\\/, "/"); if (!match($$0, / /)) print "$@:", $$0 }'\'' > $(@:.o=.d)'
        _DEPFLAGS='$(CPPFLAGS) $(CFLAGS) -showIncludes -Zs'
        _cflags_speed="-O2"
        _cflags_size="-O1"
        if $_cc 2>&1 | grep -q Linker; then
            _ld_o='-out:$@'
        else
            _ld_o='-Fe$@'
        fi
        _cc_o='-Fo$@'
        _cc_e='-P -Fi$@'
        _flags_filter=msvc_flags
        _ld_lib='lib%.a'
        _ld_path='-libpath:'
        _flags='-nologo'
        _cflags='-D_USE_MATH_DEFINES -D_CRT_SECURE_NO_WARNINGS -Dinline=__inline -FIstdlib.h -Dstrtoll=_strtoi64'
        if [ $pfx = hostcc ]; then
            append _cflags -Dsnprintf=_snprintf
        fi
        disable stripping
    elif $_cc --version 2>/dev/null | grep -q ^cparser; then
        _type=cparser
        _ident=$($_cc --version | head -n1)
        _depflags='-MMD'
        _cflags_speed='-O4'
        _cflags_size='-O2'
        _flags_filter=cparser_flags
    fi

    eval ${pfx}_type=\$_type
    eval ${pfx}_ident=\$_ident
}

set_ccvars(){
    eval ${1}_C=\${_cc_c-\${${1}_C}}
    eval ${1}_E=\${_cc_e-\${${1}_E}}
    eval ${1}_O=\${_cc_o-\${${1}_O}}

    if [ -n "$_depflags" ]; then
        eval ${1}_DEPFLAGS=\$_depflags
    else
        eval ${1}DEP=\${_DEPCMD:-\$DEPCMD}
        eval ${1}DEP_FLAGS=\${_DEPFLAGS:-\$DEPFLAGS}
        eval DEP${1}FLAGS=\$_flags
    fi
}

probe_cc cc "$cc"
cflags_filter=$_flags_filter
cflags_speed=$_cflags_speed
cflags_size=$_cflags_size
cflags_noopt=$_cflags_noopt
add_cflags $_flags $_cflags
cc_ldflags=$_ldflags
set_ccvars CC

probe_cc hostcc "$host_cc"
host_cflags_filter=$_flags_filter
add_host_cflags  $_flags $_cflags
set_ccvars HOSTCC

test -n "$cc_type" && enable $cc_type ||
    warn "Unknown C compiler $cc, unable to select optimal CFLAGS"

: ${as_default:=$cc}
: ${dep_cc_default:=$cc}
: ${ld_default:=$cc}
: ${host_ld_default:=$host_cc}
set_default ar as dep_cc ld host_ld windres

probe_cc as "$as"
asflags_filter=$_flags_filter
add_asflags $_flags $_cflags
set_ccvars AS

probe_cc ld "$ld"
ldflags_filter=$_flags_filter
add_ldflags $_flags $_ldflags
test "$cc_type" != "$ld_type" && add_ldflags $cc_ldflags
LD_O=${_ld_o-$LD_O}
LD_LIB=${_ld_lib-$LD_LIB}
LD_PATH=${_ld_path-$LD_PATH}

probe_cc hostld "$host_ld"
host_ldflags_filter=$_flags_filter
add_host_ldflags $_flags $_ldflags
HOSTLD_O=${_ld_o-$HOSTLD_O}

if [ -z "$CC_DEPFLAGS" ] && [ "$dep_cc" != "$cc" ]; then
    probe_cc depcc "$dep_cc"
    CCDEP=${_DEPCMD:-$DEPCMD}
    CCDEP_FLAGS=${_DEPFLAGS:=$DEPFLAGS}
    DEPCCFLAGS=$_flags
fi

if $ar 2>&1 | grep -q Microsoft; then
    arflags="-nologo"
    ar_o='-out:$@'
elif $ar 2>&1 | grep -q 'Texas Instruments'; then
    arflags="rq"
    ar_o='$@'
elif $ar 2>&1 | grep -q 'Usage: ar.*-X.*any'; then
    arflags='-Xany -r -c'
    ar_o='$@'
elif $ar 2>&1 | grep -q "\[D\] "; then
    arflags="rcD"
    ar_o='$@'
else
    arflags="rc"
    ar_o='$@'
fi

add_cflags $extra_cflags
add_cxxflags $extra_cxxflags
add_asflags $extra_cflags

if test -n "$sysroot"; then
    case "$cc_type" in
        gcc|llvm_gcc|clang)
            add_cppflags --sysroot="$sysroot"
            add_ldflags --sysroot="$sysroot"
# On Darwin --sysroot may be ignored, -isysroot always affects headers and linking
            add_cppflags -isysroot "$sysroot"
            add_ldflags -isysroot "$sysroot"
        ;;
        tms470)
            add_cppflags -I"$sysinclude"
            add_ldflags  --sysroot="$sysroot"
        ;;
    esac
fi

if test "$cpu" = host; then
    enabled cross_compile &&
        die "--cpu=host makes no sense when cross-compiling."

    case "$cc_type" in
        gcc|llvm_gcc)
            check_native(){
                $cc $1=native -v -c -o $TMPO $TMPC >$TMPE 2>&1 || return
                sed -n "/cc1.*$1=/{
                            s/.*$1=\\([^ ]*\\).*/\\1/
                            p
                            q
                        }" $TMPE
            }
            cpu=$(check_native -march || check_native -mcpu)
        ;;
    esac

    test "${cpu:-host}" = host &&
        die "--cpu=host not supported with compiler $cc"
fi

# Deal with common $arch aliases
case "$arch" in
    aarch64|arm64)
        arch="aarch64"
    ;;
    arm*|iPad*|iPhone*)
        arch="arm"
    ;;
    mips*|IP*)
        arch="mips"
    ;;
    parisc*|hppa*)
        arch="parisc"
    ;;
    "Power Macintosh"|ppc*|powerpc*)
        arch="ppc"
    ;;
    s390|s390x)
        arch="s390"
    ;;
    sh4|sh)
        arch="sh4"
    ;;
    sun4u|sparc*)
        arch="sparc"
    ;;
    tilegx|tile-gx)
        arch="tilegx"
    ;;
    i[3-6]86*|i86pc|BePC|x86pc|x86_64|x86_32|amd64)
        arch="x86"
    ;;
esac

is_in $arch $ARCH_LIST || warn "unknown architecture $arch"
enable $arch

# Add processor-specific flags
if enabled aarch64; then

    case $cpu in
        armv*)
            cpuflags="-march=$cpu"
        ;;
        *)
            cpuflags="-mcpu=$cpu"
        ;;
    esac

elif enabled alpha; then

    cpuflags="-mcpu=$cpu"

elif enabled arm; then

    check_arm_arch() {
        check_cpp_condition stddef.h \
            "defined __ARM_ARCH_${1}__ || defined __TARGET_ARCH_${2:-$1}" \
            $cpuflags
    }

    probe_arm_arch() {
        if   check_arm_arch 4;        then echo armv4;
        elif check_arm_arch 4T;       then echo armv4t;
        elif check_arm_arch 5;        then echo armv5;
        elif check_arm_arch 5E;       then echo armv5e;
        elif check_arm_arch 5T;       then echo armv5t;
        elif check_arm_arch 5TE;      then echo armv5te;
        elif check_arm_arch 5TEJ;     then echo armv5te;
        elif check_arm_arch 6;        then echo armv6;
        elif check_arm_arch 6J;       then echo armv6j;
        elif check_arm_arch 6K;       then echo armv6k;
        elif check_arm_arch 6Z;       then echo armv6z;
        elif check_arm_arch 6ZK;      then echo armv6zk;
        elif check_arm_arch 6T2;      then echo armv6t2;
        elif check_arm_arch 7;        then echo armv7;
        elif check_arm_arch 7A  7_A;  then echo armv7-a;
        elif check_arm_arch 7R  7_R;  then echo armv7-r;
        elif check_arm_arch 7M  7_M;  then echo armv7-m;
        elif check_arm_arch 7EM 7E_M; then echo armv7-m;
        elif check_arm_arch 8A  8_A;  then echo armv8-a;
        fi
    }

    [ "$cpu" = generic ] && cpu=$(probe_arm_arch)

    case $cpu in
        armv*)
            cpuflags="-march=$cpu"
            subarch=$(echo $cpu | sed 's/[^a-z0-9]//g')
        ;;
        *)
            cpuflags="-mcpu=$cpu"
            case $cpu in
                cortex-a*)                               subarch=armv7a  ;;
                cortex-r*)                               subarch=armv7r  ;;
                cortex-m*)                 enable thumb; subarch=armv7m  ;;
                arm11*)                                  subarch=armv6   ;;
                arm[79]*e*|arm9[24]6*|arm96*|arm102[26]) subarch=armv5te ;;
                armv4*|arm7*|arm9[24]*)                  subarch=armv4   ;;
                *)                             subarch=$(probe_arm_arch) ;;
            esac
        ;;
    esac

    case "$subarch" in
        armv5t*)    enable fast_clz                ;;
        armv[6-8]*)
            enable fast_clz
            disabled fast_unaligned || enable fast_unaligned
            ;;
    esac

elif enabled avr32; then

    case $cpu in
        ap7[02]0[0-2])
            subarch="avr32_ap"
            cpuflags="-mpart=$cpu"
        ;;
        ap)
            subarch="avr32_ap"
            cpuflags="-march=$cpu"
        ;;
        uc3[ab]*)
            subarch="avr32_uc"
            cpuflags="-mcpu=$cpu"
        ;;
        uc)
            subarch="avr32_uc"
            cpuflags="-march=$cpu"
        ;;
    esac

elif enabled bfin; then

    cpuflags="-mcpu=$cpu"

elif enabled mips; then

    cpuflags="-march=$cpu"

    case $cpu in
        24kc)
            disable mipsfpu
            disable mipsdspr1
            disable mipsdspr2
        ;;
        24kf*)
            disable mipsdspr1
            disable mipsdspr2
        ;;
        24kec|34kc|1004kc)
            disable mipsfpu
            disable mipsdspr2
        ;;
        24kef*|34kf*|1004kf*)
            disable mipsdspr2
        ;;
        74kc)
            disable mipsfpu
        ;;
    esac

elif enabled ppc; then

    disable ldbrx
    disable vsx

    case $(tolower $cpu) in
        601|ppc601|powerpc601)
            cpuflags="-mcpu=601"
            disable altivec
        ;;
        603*|ppc603*|powerpc603*)
            cpuflags="-mcpu=603"
            disable altivec
        ;;
        604*|ppc604*|powerpc604*)
            cpuflags="-mcpu=604"
            disable altivec
        ;;
        g3|75*|ppc75*|powerpc75*)
            cpuflags="-mcpu=750"
            disable altivec
        ;;
        g4|745*|ppc745*|powerpc745*)
            cpuflags="-mcpu=7450"
        ;;
        74*|ppc74*|powerpc74*)
            cpuflags="-mcpu=7400"
        ;;
        g5|970|ppc970|powerpc970)
            cpuflags="-mcpu=970"
        ;;
        power[3-8]*)
            cpuflags="-mcpu=$cpu"
        ;;
        cell)
            cpuflags="-mcpu=cell"
            enable ldbrx
        ;;
        e500mc)
            cpuflags="-mcpu=e500mc"
            disable altivec
        ;;
        e500v2)
            cpuflags="-mcpu=8548 -mhard-float -mfloat-gprs=double"
            disable altivec
            disable dcbzl
        ;;
        e500)
            cpuflags="-mcpu=8540 -mhard-float"
            disable altivec
            disable dcbzl
        ;;
    esac

elif enabled sparc; then

    case $cpu in
        cypress|f93[04]|tsc701|sparcl*|supersparc|hypersparc|niagara|v[789])
            cpuflags="-mcpu=$cpu"
        ;;
        ultrasparc*|niagara[234])
            cpuflags="-mcpu=$cpu"
        ;;
    esac

elif enabled x86; then

    case $cpu in
        i[345]86|pentium)
            cpuflags="-march=$cpu"
            disable i686
            disable mmx
        ;;
        # targets that do NOT support nopl and conditional mov (cmov)
        pentium-mmx|k6|k6-[23]|winchip-c6|winchip2|c3)
            cpuflags="-march=$cpu"
            disable i686
        ;;
        # targets that do support nopl and conditional mov (cmov)
        i686|pentiumpro|pentium[23]|pentium-m|athlon|athlon-tbird|athlon-4|athlon-[mx]p|athlon64*|k8*|opteron*|athlon-fx\
        |core*|atom|bonnell|nehalem|westmere|silvermont|sandybridge|ivybridge|haswell|broadwell|amdfam10|barcelona|b[dt]ver*)
            cpuflags="-march=$cpu"
            enable i686
            enable fast_cmov
        ;;
        # targets that do support conditional mov but on which it's slow
        pentium4|pentium4m|prescott|nocona)
            cpuflags="-march=$cpu"
            enable i686
            disable fast_cmov
        ;;
    esac

fi

if [ "$cpu" != generic ]; then
    add_cflags  $cpuflags
    add_asflags $cpuflags
fi

# compiler sanity check
check_exec <<EOF
int main(void){ return 0; }
EOF
if test "$?" != 0; then
    echo "$cc is unable to create an executable file."
    if test -z "$cross_prefix" && ! enabled cross_compile ; then
        echo "If $cc is a cross-compiler, use the --enable-cross-compile option."
        echo "Only do this if you know what cross compiling means."
    fi
    die "C compiler test failed."
fi

add_cppflags -D_ISOC99_SOURCE
add_cxxflags -D__STDC_CONSTANT_MACROS
check_cflags -std=c99
check_cc -D_FILE_OFFSET_BITS=64 <<EOF && add_cppflags -D_FILE_OFFSET_BITS=64
#include <stdlib.h>
EOF
check_cc -D_LARGEFILE_SOURCE <<EOF && add_cppflags -D_LARGEFILE_SOURCE
#include <stdlib.h>
EOF

add_host_cppflags -D_ISOC99_SOURCE
check_host_cflags -std=c99
check_host_cflags -Wall
check_host_cflags -O3

check_64bit(){
    arch32=$1
    arch64=$2
    expr=$3
    check_code cc "" "int test[2*($expr) - 1]" &&
        subarch=$arch64 || subarch=$arch32
}

case "$arch" in
    aarch64|alpha|ia64)
        spic=$shared
    ;;
    mips)
        check_64bit mips mips64 '_MIPS_SIM > 1'
        spic=$shared
    ;;
    parisc)
        check_64bit parisc parisc64 'sizeof(void *) > 4'
        spic=$shared
    ;;
    ppc)
        check_64bit ppc ppc64 'sizeof(void *) > 4'
        spic=$shared
    ;;
    s390)
        check_64bit s390 s390x 'sizeof(void *) > 4'
        spic=$shared
    ;;
    sparc)
        check_64bit sparc sparc64 'sizeof(void *) > 4'
        spic=$shared
    ;;
    x86)
        check_64bit x86_32 x86_64 'sizeof(void *) > 4'
        # Treat x32 as x64 for now. Note it also needs spic=$shared
        test "$subarch" = "x86_32" && check_cpp_condition stddef.h 'defined(__x86_64__)' &&
            subarch=x86_64
        if test "$subarch" = "x86_64"; then
            spic=$shared
        fi
    ;;
    ppc)
        check_cc <<EOF && subarch="ppc64"
        int test[(int)sizeof(char*) - 7];
EOF
    ;;
esac

enable $subarch
enabled spic && enable_weak pic

# OS specific
case $target_os in
    aix)
        SHFLAGS=-shared
        add_cppflags '-I\$(SRC_PATH)/compat/aix'
        enabled shared && add_ldflags -Wl,-brtl
        ;;
    android)
        disable symver
        enable section_data_rel_ro
        SLIB_INSTALL_NAME='$(SLIBNAME)'
        SLIB_INSTALL_LINKS=
        # soname not set on purpose
        SHFLAGS=-shared
        ;;
    haiku)
        prefix_default="/boot/common"
        network_extralibs="-lnetwork"
        host_libs=
        ;;
    sunos)
        SHFLAGS='-shared -Wl,-h,$$(@F)'
        enabled x86 && SHFLAGS="-mimpure-text $SHFLAGS"
        network_extralibs="-lsocket -lnsl"
        # When using suncc to build, the Solaris linker will mark
        # an executable with each instruction set encountered by
        # the Solaris assembler.  As our libraries contain their own
        # guards for processor-specific code, instead suppress
        # generation of the HWCAPS ELF section on Solaris x86 only.
        enabled_all suncc x86 &&
            echo "hwcap_1 = OVERRIDE;" > mapfile &&
            add_ldflags -Wl,-M,mapfile
        nm_default='nm -P -g'
        ;;
    netbsd)
        disable symver
        oss_indev_extralibs="-lossaudio"
        oss_outdev_extralibs="-lossaudio"
        enabled gcc || check_ldflags -Wl,-zmuldefs
        ;;
    openbsd|bitrig)
        disable symver
        SHFLAGS='-shared'
        SLIB_INSTALL_NAME='$(SLIBNAME).$(LIBMAJOR).$(LIBMINOR)'
        SLIB_INSTALL_LINKS=
        oss_indev_extralibs="-lossaudio"
        oss_outdev_extralibs="-lossaudio"
        ;;
    dragonfly)
        disable symver
        ;;
    freebsd)
        ;;
    bsd/os)
        add_extralibs -lpoll -lgnugetopt
        strip="strip -d"
        ;;
    darwin)
        enabled ppc && add_asflags -force_cpusubtype_ALL
        SHFLAGS='-dynamiclib -Wl,-single_module -Wl,-install_name,$(SHLIBDIR)/$(SLIBNAME_WITH_MAJOR),-current_version,$(LIBVERSION),-compatibility_version,$(LIBMAJOR)'
        enabled x86_32 && append SHFLAGS -Wl,-read_only_relocs,suppress
        strip="${strip} -x"
        add_ldflags -Wl,-dynamic,-search_paths_first
        SLIBSUF=".dylib"
        SLIBNAME_WITH_VERSION='$(SLIBPREF)$(FULLNAME).$(LIBVERSION)$(SLIBSUF)'
        SLIBNAME_WITH_MAJOR='$(SLIBPREF)$(FULLNAME).$(LIBMAJOR)$(SLIBSUF)'
        objformat="macho"
        enabled x86_64 && objformat="macho64"
        enabled_any pic shared x86_64 ||
            { check_cflags -mdynamic-no-pic && add_asflags -mdynamic-no-pic; }
        ;;
    mingw32*)
        if test $target_os = "mingw32ce"; then
            disable network
        else
            target_os=mingw32
        fi
        LIBTARGET=i386
        if enabled x86_64; then
            LIBTARGET="i386:x86-64"
        elif enabled arm; then
            LIBTARGET=arm-wince
        fi
        enabled shared && ! enabled small && check_cmd $windres --version && enable gnu_windres
        check_ldflags -Wl,--nxcompat
        check_ldflags -Wl,--dynamicbase
        enabled x86_32 && check_ldflags -Wl,--large-address-aware
        shlibdir_default="$bindir_default"
        SLIBPREF=""
        SLIBSUF=".dll"
        SLIBNAME_WITH_VERSION='$(SLIBPREF)$(FULLNAME)-$(LIBVERSION)$(SLIBSUF)'
        SLIBNAME_WITH_MAJOR='$(SLIBPREF)$(FULLNAME)-$(LIBMAJOR)$(SLIBSUF)'
        dlltool="${cross_prefix}dlltool"
        if check_cmd lib.exe -list; then
            SLIB_EXTRA_CMD=-'sed -e "s/ @[^ ]*//" $$(@:$(SLIBSUF)=.orig.def) > $$(@:$(SLIBSUF)=.def); lib.exe /machine:$(LIBTARGET) /def:$$(@:$(SLIBSUF)=.def) /out:$(SUBDIR)$(SLIBNAME:$(SLIBSUF)=.lib)'
            if enabled x86_64; then
                LIBTARGET=x64
            fi
        elif check_cmd $dlltool --version; then
            SLIB_EXTRA_CMD=-'sed -e "s/ @[^ ]*//" $$(@:$(SLIBSUF)=.orig.def) > $$(@:$(SLIBSUF)=.def); $(DLLTOOL) -m $(LIBTARGET) -d $$(@:$(SLIBSUF)=.def) -l $(SUBDIR)$(SLIBNAME:$(SLIBSUF)=.lib) -D $(SLIBNAME_WITH_MAJOR)'
        fi
        SLIB_INSTALL_NAME='$(SLIBNAME_WITH_MAJOR)'
        SLIB_INSTALL_LINKS=
        SLIB_INSTALL_EXTRA_SHLIB='$(SLIBNAME:$(SLIBSUF)=.lib)'
        SLIB_INSTALL_EXTRA_LIB='lib$(SLIBNAME:$(SLIBSUF)=.dll.a) $(SLIBNAME_WITH_MAJOR:$(SLIBSUF)=.def)'
        SHFLAGS='-shared -Wl,--output-def,$$(@:$(SLIBSUF)=.orig.def) -Wl,--out-implib,$(SUBDIR)lib$(SLIBNAME:$(SLIBSUF)=.dll.a) -Wl,--enable-runtime-pseudo-reloc -Wl,--enable-auto-image-base'
        objformat="win32"
        ranlib=:
        enable dos_paths
        ;;
    win32|win64)
        disable symver
        if enabled shared; then
            # Link to the import library instead of the normal static library
            # for shared libs.
            LD_LIB='%.lib'
            # Cannot build both shared and static libs with MSVC or icl.
            disable static
        fi
        enabled x86_32 && check_ldflags -LARGEADDRESSAWARE
        shlibdir_default="$bindir_default"
        SLIBPREF=""
        SLIBSUF=".dll"
        SLIBNAME_WITH_VERSION='$(SLIBPREF)$(FULLNAME)-$(LIBVERSION)$(SLIBSUF)'
        SLIBNAME_WITH_MAJOR='$(SLIBPREF)$(FULLNAME)-$(LIBMAJOR)$(SLIBSUF)'
        SLIB_CREATE_DEF_CMD='$(SRC_PATH)/compat/windows/makedef $(SUBDIR)lib$(NAME).ver $(OBJS) > $$(@:$(SLIBSUF)=.def)'
        SLIB_INSTALL_NAME='$(SLIBNAME_WITH_MAJOR)'
        SLIB_INSTALL_LINKS=
        SLIB_INSTALL_EXTRA_SHLIB='$(SLIBNAME:$(SLIBSUF)=.lib)'
        SLIB_INSTALL_EXTRA_LIB='$(SLIBNAME_WITH_MAJOR:$(SLIBSUF)=.def)'
        SHFLAGS='-dll -def:$$(@:$(SLIBSUF)=.def) -implib:$(SUBDIR)$(SLIBNAME:$(SLIBSUF)=.lib)'
        objformat="win32"
        ranlib=:
        enable dos_paths
        ;;
    cygwin*)
        target_os=cygwin
        shlibdir_default="$bindir_default"
        SLIBPREF="cyg"
        SLIBSUF=".dll"
        SLIBNAME_WITH_VERSION='$(SLIBPREF)$(FULLNAME)-$(LIBVERSION)$(SLIBSUF)'
        SLIBNAME_WITH_MAJOR='$(SLIBPREF)$(FULLNAME)-$(LIBMAJOR)$(SLIBSUF)'
        SLIB_INSTALL_NAME='$(SLIBNAME_WITH_MAJOR)'
        SLIB_INSTALL_LINKS=
        SLIB_INSTALL_EXTRA_LIB='lib$(FULLNAME).dll.a'
        SHFLAGS='-shared -Wl,--out-implib,$(SUBDIR)lib$(FULLNAME).dll.a'
        objformat="win32"
        enable dos_paths
        enabled shared && ! enabled small && check_cmd $windres --version && enable gnu_windres
        ;;
    *-dos|freedos|opendos)
        network_extralibs="-lsocket"
        objformat="coff"
        enable dos_paths
        add_cppflags -U__STRICT_ANSI__
        ;;
    linux)
        enable dv1394
        enable section_data_rel_ro
        ;;
    irix*)
        target_os=irix
        ranlib="echo ignoring ranlib"
        ;;
    os/2*)
        strip="lxlite -CS"
        ln_s="cp -f"
        objformat="aout"
        add_cppflags -D_GNU_SOURCE
        add_ldflags -Zomf -Zbin-files -Zargs-wild -Zmap
        SHFLAGS='$(SUBDIR)$(NAME).def -Zdll -Zomf'
        LIBSUF="_s.a"
        SLIBPREF=""
        SLIBSUF=".dll"
        SLIBNAME_WITH_VERSION='$(SLIBPREF)$(NAME)-$(LIBVERSION)$(SLIBSUF)'
        SLIBNAME_WITH_MAJOR='$(SLIBPREF)$(shell echo $(NAME) | cut -c1-6)$(LIBMAJOR)$(SLIBSUF)'
        SLIB_CREATE_DEF_CMD='echo LIBRARY $(SLIBNAME_WITH_MAJOR) INITINSTANCE TERMINSTANCE > $(SUBDIR)$(NAME).def; \
            echo PROTMODE >> $(SUBDIR)$(NAME).def; \
            echo CODE PRELOAD MOVEABLE DISCARDABLE >> $(SUBDIR)$(NAME).def; \
            echo DATA PRELOAD MOVEABLE MULTIPLE NONSHARED >> $(SUBDIR)$(NAME).def; \
            echo EXPORTS >> $(SUBDIR)$(NAME).def; \
            emxexp -o $(OBJS) >> $(SUBDIR)$(NAME).def'
        SLIB_EXTRA_CMD='emximp -o $(SUBDIR)$(LIBPREF)$(NAME)_dll.a $(SUBDIR)$(NAME).def; \
            emximp -o $(SUBDIR)$(LIBPREF)$(NAME)_dll.lib $(SUBDIR)$(NAME).def;'
        SLIB_INSTALL_EXTRA_LIB='$(LIBPREF)$(NAME)_dll.a $(LIBPREF)$(NAME)_dll.lib'
        enable dos_paths
        enable_weak os2threads
        ;;
    gnu/kfreebsd)
        add_cppflags -D_BSD_SOURCE
        ;;
    gnu)
        ;;
    qnx)
        add_cppflags -D_QNX_SOURCE
        network_extralibs="-lsocket"
        ;;
    symbian)
        SLIBSUF=".dll"
        enable dos_paths
        add_cflags --include=$sysinclude/gcce/gcce.h -fvisibility=default
        add_cppflags -D__GCCE__ -D__SYMBIAN32__ -DSYMBIAN_OE_POSIX_SIGNALS
        add_ldflags -Wl,--target1-abs,--no-undefined \
                    -Wl,-Ttext,0x80000,-Tdata,0x1000000 -shared \
                    -Wl,--entry=_E32Startup -Wl,-u,_E32Startup
        add_extralibs -l:eexe.lib -l:usrt2_2.lib -l:dfpaeabi.dso \
                      -l:drtaeabi.dso -l:scppnwdl.dso -lsupc++ -lgcc \
                      -l:libc.dso -l:libm.dso -l:euser.dso -l:libcrt0.lib
        ;;
    osf1)
        add_cppflags -D_OSF_SOURCE -D_POSIX_PII -D_REENTRANT
        ;;
    minix)
        ;;
    plan9)
        add_cppflags -D_C99_SNPRINTF_EXTENSION  \
                     -D_REENTRANT_SOURCE        \
                     -D_RESEARCH_SOURCE         \
                     -DFD_SETSIZE=96            \
                     -DHAVE_SOCK_OPTS
        add_compat strtod.o strtod=avpriv_strtod
        network_extralibs='-lbsd'
        exeobjs=compat/plan9/main.o
        disable ffserver
        cp_f='cp'
        ;;
    none)
        ;;
    *)
        die "Unknown OS '$target_os'."
        ;;
esac

# determine libc flavour

probe_libc(){
    pfx=$1
    pfx_no_=${pfx%_}
    # uclibc defines __GLIBC__, so it needs to be checked before glibc.
    if check_${pfx}cpp_condition features.h "defined __UCLIBC__"; then
        eval ${pfx}libc_type=uclibc
        add_${pfx}cppflags -D_POSIX_C_SOURCE=200112 -D_XOPEN_SOURCE=600
    elif check_${pfx}cpp_condition features.h "defined __GLIBC__"; then
        eval ${pfx}libc_type=glibc
        add_${pfx}cppflags -D_POSIX_C_SOURCE=200112 -D_XOPEN_SOURCE=600
    # MinGW headers can be installed on Cygwin, so check for newlib first.
    elif check_${pfx}cpp_condition newlib.h "defined _NEWLIB_VERSION"; then
        eval ${pfx}libc_type=newlib
        add_${pfx}cppflags -U__STRICT_ANSI__
    # MinGW64 is backwards compatible with MinGW32, so check for it first.
    elif check_${pfx}cpp_condition _mingw.h "defined __MINGW64_VERSION_MAJOR"; then
        eval ${pfx}libc_type=mingw64
        if check_${pfx}cpp_condition _mingw.h "__MINGW64_VERSION_MAJOR < 3"; then
            add_compat msvcrt/snprintf.o
            add_cflags "-include $source_path/compat/msvcrt/snprintf.h"
        fi
        add_${pfx}cppflags -U__STRICT_ANSI__ -D__USE_MINGW_ANSI_STDIO=1
        eval test \$${pfx_no_}cc_type = "gcc" &&
            add_${pfx}cppflags -D__printf__=__gnu_printf__
    elif check_${pfx}cpp_condition _mingw.h "defined __MINGW_VERSION"  ||
         check_${pfx}cpp_condition _mingw.h "defined __MINGW32_VERSION"; then
        eval ${pfx}libc_type=mingw32
        check_${pfx}cpp_condition _mingw.h "__MINGW32_MAJOR_VERSION > 3 || \
            (__MINGW32_MAJOR_VERSION == 3 && __MINGW32_MINOR_VERSION >= 15)" ||
            die "ERROR: MinGW32 runtime version must be >= 3.15."
        add_${pfx}cppflags -U__STRICT_ANSI__ -D__USE_MINGW_ANSI_STDIO=1
        eval test \$${pfx_no_}cc_type = "gcc" &&
            add_${pfx}cppflags -D__printf__=__gnu_printf__
    elif check_${pfx}cpp_condition crtversion.h "defined _VC_CRT_MAJOR_VERSION"; then
        eval ${pfx}libc_type=msvcrt
        # The MSVC 2010 headers (Win 7.0 SDK) set _WIN32_WINNT to
        # 0x601 by default unless something else is set by the user.
        # This can easily lead to us detecting functions only present
        # in such new versions and producing binaries requiring windows 7.0.
        # Therefore explicitly set the default to XP unless the user has
        # set something else on the command line.
        check_${pfx}cpp_condition stdlib.h "defined(_WIN32_WINNT)" ||
            add_${pfx}cppflags -D_WIN32_WINNT=0x0502
    elif check_${pfx}cpp_condition stddef.h "defined __KLIBC__"; then
        eval ${pfx}libc_type=klibc
    elif check_${pfx}cpp_condition sys/cdefs.h "defined __BIONIC__"; then
        eval ${pfx}libc_type=bionic
    elif check_${pfx}cpp_condition sys/brand.h "defined LABELED_BRAND_NAME"; then
        eval ${pfx}libc_type=solaris
        add_${pfx}cppflags -D__EXTENSIONS__ -D_XOPEN_SOURCE=600
    fi
    check_${pfx}cc <<EOF
#include <time.h>
void *v = localtime_r;
EOF
test "$?" != 0 && check_${pfx}cc -D_POSIX_C_SOURCE=200112 -D_XOPEN_SOURCE=600 <<EOF && add_${pfx}cppflags -D_POSIX_C_SOURCE=200112 -D_XOPEN_SOURCE=600
#include <time.h>
void *v = localtime_r;
EOF

}

probe_libc
test -n "$libc_type" && enable libc_$libc_type
probe_libc host_
test -n "$host_libc_type" && enable host_libc_$host_libc_type

case $libc_type in
    bionic)
        add_compat strtod.o strtod=avpriv_strtod
        ;;
    msvcrt)
        add_compat strtod.o strtod=avpriv_strtod
        add_compat msvcrt/snprintf.o snprintf=avpriv_snprintf   \
                                     _snprintf=avpriv_snprintf  \
                                     vsnprintf=avpriv_vsnprintf
        ;;
esac

# hacks for compiler/libc/os combinations

if enabled_all tms470 libc_glibc; then
    CPPFLAGS="-I${source_path}/compat/tms470 ${CPPFLAGS}"
    add_cppflags -D__USER_LABEL_PREFIX__=
    add_cppflags -D__builtin_memset=memset
    add_cppflags -D__gnuc_va_list=va_list -D_VA_LIST_DEFINED
    add_cflags   -pds=48    # incompatible redefinition of macro
fi

if enabled_all ccc libc_glibc; then
    add_ldflags -Wl,-z,now  # calls to libots crash without this
fi

check_compile_assert flt_lim "float.h limits.h" "DBL_MAX == (double)DBL_MAX" ||
    add_cppflags '-I\$(SRC_PATH)/compat/float'

esc(){
    echo "$*" | sed 's/%/%25/g;s/:/%3a/g'
}

echo "config:$arch:$subarch:$cpu:$target_os:$(esc $cc_ident):$(esc $FFMPEG_CONFIGURATION)" >config.fate

check_cpp_condition stdlib.h "defined(__PIC__) || defined(__pic__) || defined(PIC)" && enable_weak pic

set_default libdir
: ${shlibdir_default:="$libdir"}

set_default $PATHS_LIST
set_default nm

# we need to build at least one lib type
if ! enabled_any static shared; then
    cat <<EOF
At least one library type must be built.
Specify --enable-static to build the static libraries or --enable-shared to
build the shared libraries as well. To only build the shared libraries specify
--disable-static in addition to --enable-shared.
EOF
    exit 1;
fi

die_license_disabled() {
    enabled $1 || { enabled $2 && die "$2 is $1 and --enable-$1 is not specified."; }
}

die_license_disabled_gpl() {
    enabled $1 || { enabled $2 && die "$2 is incompatible with the gpl and --enable-$1 is not specified."; }
}

die_license_disabled gpl frei0r
die_license_disabled gpl libcdio
die_license_disabled gpl libsmbclient
die_license_disabled gpl libutvideo
die_license_disabled gpl libvidstab
die_license_disabled gpl libx264
die_license_disabled gpl libx265
die_license_disabled gpl libxavs
die_license_disabled gpl libxvid
die_license_disabled gpl libzvbi
die_license_disabled gpl x11grab

die_license_disabled nonfree libaacplus
die_license_disabled nonfree libfaac
die_license_disabled nonfree nvenc
enabled gpl && die_license_disabled_gpl nonfree libfdk_aac
enabled gpl && die_license_disabled_gpl nonfree openssl

die_license_disabled version3 libopencore_amrnb
die_license_disabled version3 libopencore_amrwb
die_license_disabled version3 libsmbclient
die_license_disabled version3 libvo_aacenc
die_license_disabled version3 libvo_amrwbenc

enabled version3 && { enabled gpl && enable gplv3 || enable lgplv3; }

disabled optimizations || check_cflags -fomit-frame-pointer

enable_weak_pic() {
    disabled pic && return
    enable pic
    add_cppflags -DPIC
    case "$target_os" in
    mingw*|cygwin*)
        ;;
    *)
        add_cflags -fPIC
        ;;
    esac
    add_asflags  -fPIC
}

enabled pic && enable_weak_pic

check_cc <<EOF || die "Symbol mangling check failed."
int ff_extern;
EOF
sym=$($nm $TMPO | awk '/ff_extern/{ print substr($0, match($0, /[^ \t]*ff_extern/)) }')
extern_prefix=${sym%%ff_extern*}

check_cc <<EOF && enable_weak inline_asm
void foo(void) { __asm__ volatile ("" ::); }
EOF

_restrict=
for restrict_keyword in restrict __restrict__ __restrict; do
    check_cc <<EOF && _restrict=$restrict_keyword && break
void foo(char * $restrict_keyword p);
EOF
done

check_cc <<EOF && enable pragma_deprecated
void foo(void) { _Pragma("GCC diagnostic ignored \"-Wdeprecated-declarations\"") }
EOF

check_cc <<EOF && enable attribute_packed
struct { int x; } __attribute__((packed)) x;
EOF

check_cc <<EOF && enable attribute_may_alias
union { int x; } __attribute__((may_alias)) x;
EOF

check_cc <<EOF || die "endian test failed"
unsigned int endian = 'B' << 24 | 'I' << 16 | 'G' << 8 | 'E';
EOF
od -t x1 $TMPO | grep -q '42 *49 *47 *45' && enable bigendian

if  [ "$cpu" = "power7" ] || [ "$cpu" = "power8" ] || enabled ppc64; then
    if ! enabled bigendian && enabled altivec ;then
        enable vsx
    fi
fi

check_gas() {
    log "check_gas using '$as' as AS"
    # :vararg is used on aarch64, arm and ppc altivec
    check_as <<EOF || return 1
.macro m n, y:vararg=0
\n: .int \y
.endm
m x
EOF
    # .altmacro is only used in arm asm
    ! enabled arm || check_as <<EOF || return 1
.altmacro
EOF
    enable gnu_as
    return 0
}

if enabled_any arm aarch64 || enabled_all ppc altivec && enabled asm; then
    nogas=:
    enabled_any arm aarch64 && nogas=die
    enabled_all ppc altivec && [ $target_os_default != aix ] && nogas=warn
    as_noop=-v

    case $as_type in
        arm*) gaspp_as_type=armasm; as_noop=-h ;;
        gcc)  gaspp_as_type=gas ;;
        *)    gaspp_as_type=$as_type ;;
    esac

    [ $target_os = "darwin" ] && gaspp_as_type="apple-$gaspp_as_type"

    test "${as#*gas-preprocessor.pl}" != "$as" ||
    check_cmd gas-preprocessor.pl -arch $arch -as-type $gaspp_as_type -- ${as:=$cc} $as_noop &&
        gas="${gas:=gas-preprocessor.pl} -arch $arch -as-type $gaspp_as_type -- ${as:=$cc}"

    if ! check_gas ; then
        as=${gas:=$as}
        check_gas || \
            $nogas "GNU assembler not found, install/update gas-preprocessor"
    fi

    check_as <<EOF && enable as_func
.func test
.endfunc
EOF
fi

check_inline_asm inline_asm_labels '"1:\n"'

check_inline_asm inline_asm_nonlocal_labels '"Label:\n"'

if enabled aarch64; then
    enabled armv8 && check_insn armv8 'prfm   pldl1strm, [x0]'
    # internal assembler in clang 3.3 does not support this instruction
    enabled neon && check_insn neon 'ext   v0.8B, v0.8B, v1.8B, #1'
    enabled vfp  && check_insn vfp  'fmadd d0,    d0,    d1,    d2'

    map 'enabled_any ${v}_external ${v}_inline || disable $v' $ARCH_EXT_LIST_ARM

elif enabled alpha; then

    check_cflags -mieee

elif enabled arm; then

    check_cpp_condition stddef.h "defined __thumb__" && check_cc <<EOF && enable_weak thumb
float func(float a, float b){ return a+b; }
EOF

    enabled thumb && check_cflags -mthumb || check_cflags -marm

    if     check_cpp_condition stddef.h "defined __ARM_PCS_VFP"; then
        enable vfp_args
    elif ! check_cpp_condition stddef.h "defined __ARM_PCS || defined __SOFTFP__"; then
        case "${cross_prefix:-$cc}" in
            *hardfloat*)         enable vfp_args;   fpabi=vfp ;;
            *) check_ld "cc" <<EOF && enable vfp_args && fpabi=vfp || fpabi=soft ;;
__asm__ (".eabi_attribute 28, 1");
int main(void) { return 0; }
EOF
        esac
        warn "Compiler does not indicate floating-point ABI, guessing $fpabi."
    fi

    enabled armv5te && check_insn armv5te 'qadd r0, r0, r0'
    enabled armv6   && check_insn armv6   'sadd16 r0, r0, r0'
    enabled armv6t2 && check_insn armv6t2 'movt r0, #0'
    enabled neon    && check_insn neon    'vadd.i16 q0, q0, q0'
    enabled vfp     && check_insn vfp     'fadds s0, s0, s0'
    enabled vfpv3   && check_insn vfpv3   'vmov.f32 s0, #1.0'
    enabled setend  && check_insn setend  'setend be'

    [ $target_os = linux ] || [ $target_os = android ] ||
        map 'enabled_any ${v}_external ${v}_inline || disable $v' \
            $ARCH_EXT_LIST_ARM

    check_inline_asm asm_mod_q '"add r0, %Q0, %R0" :: "r"((long long)0)'

    check_as <<EOF && enable as_dn_directive
ra .dn d0.i16
.unreq ra
EOF

    # llvm's integrated assembler supports .object_arch from llvm 3.5
    [ "$objformat" = elf ] && check_as <<EOF && enable as_object_arch
.object_arch armv4
EOF

    [ $target_os != win32 ] && enabled_all armv6t2 shared !pic && enable_weak_pic

elif enabled mips; then

    check_inline_asm loongson '"dmult.g $1, $2, $3"'

    # Enable minimum ISA based on selected options
    if enabled mips64 && (enabled mipsdspr1 || enabled mipsdspr2); then
        add_cflags "-mips64r2"
        add_asflags "-mips64r2"
    elif enabled mips64 && enabled mipsfpu; then
        add_cflags "-mips64"
        add_asflags "-mips64"
    elif enabled mipsfpu || enabled mipsdspr1 || enabled mipsdspr2; then
        add_cflags "-mips32r2"
        add_asflags "-mips32r2"
    fi

    enabled mipsdspr1 && add_cflags "-mdsp" && add_asflags "-mdsp" &&
     check_inline_asm mipsdspr1 '"addu.qb $t0, $t1, $t2"'
    enabled mipsdspr2 && add_cflags "-mdspr2" && add_asflags "-mdspr2" &&
     check_inline_asm mipsdspr2 '"absq_s.qb $t0, $t1"'
    enabled mipsfpu   && add_cflags "-mhard-float" && add_asflags "-mhard-float" &&
     check_inline_asm mipsfpu   '"madd.d $f0, $f2, $f4, $f6"'

elif enabled parisc; then

    if enabled gcc; then
        case $($cc -dumpversion) in
            4.[3-9].*) check_cflags -fno-optimize-sibling-calls ;;
        esac
    fi

elif enabled ppc; then

    enable local_aligned_8 local_aligned_16 local_aligned_32

    check_inline_asm dcbzl     '"dcbzl 0, %0" :: "r"(0)'
    check_inline_asm ibm_asm   '"add 0, 0, 0"'
    check_inline_asm ppc4xx    '"maclhw r10, r11, r12"'
    check_inline_asm xform_asm '"lwzx %1, %y0" :: "Z"(*(int*)0), "r"(0)'

    # AltiVec flags: The FSF version of GCC differs from the Apple version
    if enabled altivec; then
        check_cflags -maltivec -mabi=altivec &&
        { check_header altivec.h && inc_altivec_h="#include <altivec.h>" ; } ||
        check_cflags -faltivec

        # check if our compiler supports Motorola AltiVec C API
        check_cc <<EOF || disable altivec
$inc_altivec_h
int main(void) {
    vector signed int v1 = (vector signed int) { 0 };
    vector signed int v2 = (vector signed int) { 1 };
    v1 = vec_add(v1, v2);
    return 0;
}
EOF

        enabled altivec || warn "Altivec disabled, possibly missing --cpu flag"
    fi

    if enabled vsx; then
        check_cflags -mvsx
    fi
elif enabled x86; then

    check_builtin rdtsc    intrin.h   "__rdtsc()"
    check_builtin mm_empty mmintrin.h "_mm_empty()"

    enable local_aligned_8 local_aligned_16 local_aligned_32

    # check whether EBP is available on x86
    # As 'i' is stored on the stack, this program will crash
    # if the base pointer is used to access it because the
    # base pointer is cleared in the inline assembly code.
    check_exec_crash <<EOF && enable ebp_available
volatile int i=0;
__asm__ volatile ("xorl %%ebp, %%ebp" ::: "%ebp");
return i;
EOF

    # check whether EBX is available on x86
    check_inline_asm ebx_available '""::"b"(0)' &&
        check_inline_asm ebx_available '"":::"%ebx"'

    # check whether xmm clobbers are supported
    check_inline_asm xmm_clobbers '"":::"%xmm0"'

    check_inline_asm inline_asm_direct_symbol_refs '"movl '$extern_prefix'test, %eax"' ||
        check_inline_asm inline_asm_direct_symbol_refs '"movl '$extern_prefix'test(%rip), %eax"'

    # check whether binutils is new enough to compile SSSE3/MMXEXT
    enabled ssse3  && check_inline_asm ssse3_inline  '"pabsw %xmm0, %xmm0"'
    enabled mmxext && check_inline_asm mmxext_inline '"pmaxub %mm0, %mm1"'

    if ! disabled_any asm mmx yasm; then
        if check_cmd $yasmexe --version; then
            enabled x86_64 && yasm_extra="-m amd64"
            yasm_debug="-g dwarf2"
        elif check_cmd nasm -v; then
            yasmexe=nasm
            yasm_debug="-g -F dwarf"
            if enabled x86_64; then
                case "$objformat" in
                    elf)   objformat=elf64 ;;
                    win32) objformat=win64 ;;
                esac
            fi
        fi

        YASMFLAGS="-f $objformat $yasm_extra"
        enabled pic               && append YASMFLAGS "-DPIC"
        test -n "$extern_prefix"  && append YASMFLAGS "-DPREFIX"
        case "$objformat" in
            elf*) enabled debug && append YASMFLAGS $yasm_debug ;;
        esac

        check_yasm "movbe ecx, [5]" && enable yasm ||
            die "yasm/nasm not found or too old. Use --disable-yasm for a crippled build."
        check_yasm "vextracti128 xmm0, ymm0, 0"      || disable avx2_external
        check_yasm "vpmacsdd xmm0, xmm1, xmm2, xmm3" || disable xop_external
        check_yasm "vfmaddps ymm0, ymm1, ymm2, ymm3" || disable fma4_external
        check_yasm "CPU amdnop" || disable cpunop
    fi

    case "$cpu" in
        athlon*|opteron*|k8*|pentium|pentium-mmx|prescott|nocona|atom|geode)
            disable fast_clz
        ;;
    esac

fi

check_code cc arm_neon.h "int16x8_t test = vdupq_n_s16(0)" && enable intrinsics_neon

check_ldflags -Wl,--as-needed
check_ldflags -Wl,-z,noexecstack

if check_func dlopen; then
    ldl=
elif check_func dlopen -ldl; then
    ldl=-ldl
fi

frei0r_filter_extralibs='$ldl'
frei0r_src_filter_extralibs='$ldl'
ladspa_filter_extralibs='$ldl'
nvenc_encoder_extralibs='$ldl'

if ! disabled network; then
    check_func getaddrinfo $network_extralibs
    check_func getservbyport $network_extralibs
    check_func inet_aton $network_extralibs

    check_type netdb.h "struct addrinfo"
    check_type netinet/in.h "struct group_source_req" -D_BSD_SOURCE
    check_type netinet/in.h "struct ip_mreq_source" -D_BSD_SOURCE
    check_type netinet/in.h "struct ipv6_mreq" -D_DARWIN_C_SOURCE
    check_type poll.h "struct pollfd"
    check_type netinet/sctp.h "struct sctp_event_subscribe"
    check_struct "sys/types.h sys/socket.h" "struct sockaddr" sa_len
    check_type netinet/in.h "struct sockaddr_in6"
    check_type "sys/types.h sys/socket.h" "struct sockaddr_storage"
    check_type "sys/types.h sys/socket.h" socklen_t

    # Prefer arpa/inet.h over winsock2
    if check_header arpa/inet.h ; then
        check_func closesocket
    elif check_header winsock2.h ; then
        check_func_headers winsock2.h closesocket -lws2 &&
            network_extralibs="-lws2" ||
        { check_func_headers winsock2.h closesocket -lws2_32 &&
            network_extralibs="-lws2_32"; } || disable winsock2_h network
        check_func_headers ws2tcpip.h getaddrinfo $network_extralibs

        check_type ws2tcpip.h socklen_t
        check_type ws2tcpip.h "struct addrinfo"
        check_type ws2tcpip.h "struct group_source_req"
        check_type ws2tcpip.h "struct ip_mreq_source"
        check_type ws2tcpip.h "struct ipv6_mreq"
        check_type winsock2.h "struct pollfd"
        check_struct winsock2.h "struct sockaddr" sa_len
        check_type ws2tcpip.h "struct sockaddr_in6"
        check_type ws2tcpip.h "struct sockaddr_storage"
    else
        disable network
    fi
fi

check_builtin atomic_cas_ptr atomic.h "void **ptr; void *oldval, *newval; atomic_cas_ptr(ptr, oldval, newval)"
check_builtin atomic_compare_exchange "" "int *ptr, *oldval; int newval; __atomic_compare_exchange_n(ptr, oldval, newval, 0, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)"
check_builtin machine_rw_barrier mbarrier.h "__machine_rw_barrier()"
check_builtin MemoryBarrier windows.h "MemoryBarrier()"
check_builtin sarestart signal.h "SA_RESTART"
check_builtin sync_val_compare_and_swap "" "int *ptr; int oldval, newval; __sync_val_compare_and_swap(ptr, oldval, newval)"

check_func_headers malloc.h _aligned_malloc     && enable aligned_malloc
check_func  ${malloc_prefix}memalign            && enable memalign
check_func  ${malloc_prefix}posix_memalign      && enable posix_memalign

check_func  access
check_func_headers time.h clock_gettime || { check_func_headers time.h clock_gettime -lrt && add_extralibs -lrt && LIBRT="-lrt"; }
check_func  fcntl
check_func  fork
check_func  gethrtime
check_func  getopt
check_func  getrusage
check_func  gettimeofday
check_func  gmtime_r
check_func  isatty
check_func  localtime_r
check_func  mach_absolute_time
check_func  mkstemp
check_func  mmap
check_func  mprotect
# Solaris has nanosleep in -lrt, OpenSolaris no longer needs that
check_func_headers time.h nanosleep || { check_func_headers time.h nanosleep -lrt && add_extralibs -lrt && LIBRT="-lrt"; }
check_func  sched_getaffinity
check_func  setrlimit
check_struct "sys/stat.h" "struct stat" st_mtim.tv_nsec -D_BSD_SOURCE
check_func  strerror_r
check_func  sysconf
check_func  sysctl
check_func  usleep

check_func_headers conio.h kbhit
check_func_headers io.h setmode
check_func_headers lzo/lzo1x.h lzo1x_999_compress
check_func_headers stdlib.h getenv

check_func_headers windows.h CoTaskMemFree -lole32
check_func_headers windows.h GetProcessAffinityMask
check_func_headers windows.h GetProcessTimes
check_func_headers windows.h GetSystemTimeAsFileTime
check_func_headers windows.h MapViewOfFile
check_func_headers windows.h PeekNamedPipe
check_func_headers windows.h SetConsoleTextAttribute
check_func_headers windows.h Sleep
check_func_headers windows.h VirtualAlloc
check_struct windows.h "CONDITION_VARIABLE" Ptr
check_func_headers glob.h glob
enabled xlib &&
    check_func_headers "X11/Xlib.h X11/extensions/Xvlib.h" XvGetPortAttribute -lXv -lX11 -lXext

check_header direct.h
check_header dlfcn.h
check_header dxva.h
check_header dxva2api.h -D_WIN32_WINNT=0x0600
check_header io.h
check_header libcrystalhd/libcrystalhd_if.h
check_header mach/mach_time.h
check_header malloc.h
check_header net/udplite.h
check_header poll.h
check_header sys/mman.h
check_header sys/param.h
check_header sys/resource.h
check_header sys/select.h
check_header sys/time.h
check_header sys/un.h
check_header termios.h
check_header unistd.h
check_header vdpau/vdpau.h
check_header vdpau/vdpau_x11.h
check_header VideoDecodeAcceleration/VDADecoder.h
check_header windows.h
check_header X11/extensions/XvMClib.h
check_header asm/types.h

check_lib2 "windows.h shellapi.h" CommandLineToArgvW -lshell32
check_lib2 "windows.h wincrypt.h" CryptGenRandom -ladvapi32
check_lib2 "windows.h psapi.h" GetProcessMemoryInfo -lpsapi

check_struct "sys/time.h sys/resource.h" "struct rusage" ru_maxrss

check_type "windows.h dxva.h" "DXVA_PicParams_HEVC"

if ! disabled w32threads && ! enabled pthreads; then
    check_func_headers "windows.h process.h" _beginthreadex &&
        enable w32threads || disable w32threads
fi

# check for some common methods of building with pthread support
# do this before the optional library checks as some of them require pthreads
if ! disabled pthreads && ! enabled w32threads && ! enabled os2threads; then
    enable pthreads
    if check_func pthread_join -pthread && check_func pthread_create -pthread; then
        add_cflags -pthread
        add_extralibs -pthread
    elif check_func pthread_join -pthreads && check_func pthread_create -pthreads; then
        add_cflags -pthreads
        add_extralibs -pthreads
    elif check_func pthread_join -ldl -pthread && check_func pthread_create -ldl -pthread; then
        add_cflags -ldl -pthread
        add_extralibs -ldl -pthread
    elif check_func pthread_join -lpthreadGC2 && check_func pthread_create -lpthreadGC2; then
        add_extralibs -lpthreadGC2
    elif check_lib pthread.h pthread_join -lpthread && check_lib pthread.h pthread_create -lpthread; then
        :
    elif ! check_func pthread_join && ! check_func pthread_create; then
        disable pthreads
    fi
    check_code cc "pthread.h" "static pthread_mutex_t atomic_lock = PTHREAD_MUTEX_INITIALIZER" || disable pthreads
fi


if enabled pthreads; then
  check_func pthread_cancel
fi

disabled  zlib || check_lib   zlib.h      zlibVersion -lz   || disable  zlib
disabled bzlib || check_lib2 bzlib.h BZ2_bzlibVersion -lbz2 || disable bzlib
disabled  lzma || check_lib2  lzma.h lzma_version_number -llzma || disable lzma

check_lib math.h sin -lm && LIBM="-lm"
disabled crystalhd || check_lib libcrystalhd/libcrystalhd_if.h DtsCrystalHDVersion -lcrystalhd || disable crystalhd

atan2f_args=2
ldexpf_args=2
powf_args=2

for func in $MATH_FUNCS; do
    eval check_mathfunc $func \${${func}_args:-1}
done

# these are off by default, so fail if requested and not available
enabled avfoundation_indev && { check_header_oc AVFoundation/AVFoundation.h || disable avfoundation_indev; }
enabled avfoundation_indev && { check_lib2 CoreGraphics/CoreGraphics.h CGGetActiveDisplayList -framework CoreGraphics ||
                                check_lib2 ApplicationServices/ApplicationServices.h CGGetActiveDisplayList -framework ApplicationServices; }
enabled avisynth          && { { check_lib2 "windows.h" LoadLibrary; } ||
                               { check_lib2 "dlfcn.h" dlopen -ldl; } ||
                               die "ERROR: LoadLibrary/dlopen not found for avisynth"; }
enabled decklink          && { check_header DeckLinkAPI.h || die "ERROR: DeckLinkAPI.h header not found"; }
enabled frei0r            && { check_header frei0r.h || die "ERROR: frei0r.h header not found"; }
enabled gnutls            && require_pkg_config gnutls gnutls/gnutls.h gnutls_global_init
enabled ladspa            && { check_header ladspa.h || die "ERROR: ladspa.h header not found"; }
enabled libiec61883       && require libiec61883 libiec61883/iec61883.h iec61883_cmp_connect -lraw1394 -lavc1394 -lrom1394 -liec61883
enabled libaacplus        && require "libaacplus >= 2.0.0" aacplus.h aacplusEncOpen -laacplus
enabled libass            && require_pkg_config libass ass/ass.h ass_library_init
enabled libbluray         && require_pkg_config libbluray libbluray/bluray.h bd_open
enabled libbs2b           && require_pkg_config libbs2b bs2b.h bs2b_open
enabled libcelt           && require libcelt celt/celt.h celt_decode -lcelt0 &&
                             { check_lib celt/celt.h celt_decoder_create_custom -lcelt0 ||
                               die "ERROR: libcelt must be installed and version must be >= 0.11.0."; }
enabled libcaca           && require_pkg_config caca caca.h caca_create_canvas
enabled libfaac           && require2 libfaac "stdint.h faac.h" faacEncGetVersion -lfaac
enabled libfdk_aac        && require libfdk_aac fdk-aac/aacenc_lib.h aacEncOpen -lfdk-aac
flite_libs="-lflite_cmu_time_awb -lflite_cmu_us_awb -lflite_cmu_us_kal -lflite_cmu_us_kal16 -lflite_cmu_us_rms -lflite_cmu_us_slt -lflite_usenglish -lflite_cmulex -lflite"
enabled libflite          && require2 libflite "flite/flite.h" flite_init $flite_libs
enabled fontconfig        && enable libfontconfig
enabled libfontconfig     && require_pkg_config fontconfig "fontconfig/fontconfig.h" FcInit
enabled libfreetype       && require_libfreetype
enabled libfribidi        && require_pkg_config fribidi fribidi.h fribidi_version_info
enabled libgme            && require  libgme gme/gme.h gme_new_emu -lgme -lstdc++
enabled libgsm            && { for gsm_hdr in "gsm.h" "gsm/gsm.h"; do
                                   check_lib "${gsm_hdr}" gsm_create -lgsm && break;
                               done || die "ERROR: libgsm not found"; }
enabled libilbc           && require libilbc ilbc.h WebRtcIlbcfix_InitDecode -lilbc
enabled libmfx            && require_pkg_config libmfx "mfx/mfxvideo.h" MFXInit
enabled libmodplug        && require_pkg_config libmodplug libmodplug/modplug.h ModPlug_Load
enabled libmp3lame        && require "libmp3lame >= 3.98.3" lame/lame.h lame_set_VBR_quality -lmp3lame
enabled libnut            && require libnut libnut.h nut_demuxer_init -lnut
enabled libopencore_amrnb && require libopencore_amrnb opencore-amrnb/interf_dec.h Decoder_Interface_init -lopencore-amrnb
enabled libopencore_amrwb && require libopencore_amrwb opencore-amrwb/dec_if.h D_IF_init -lopencore-amrwb
enabled libopencv         && require_pkg_config opencv opencv/cxcore.h cvCreateImageHeader
enabled libopenh264       && require_pkg_config openh264 wels/codec_api.h WelsGetCodecVersion
enabled libopenjpeg       && { check_lib openjpeg.h opj_version -lopenmj2 -DOPJ_STATIC ||
                               check_lib openjpeg-1.5/openjpeg.h opj_version -lopenjpeg -DOPJ_STATIC ||
                               check_lib openjpeg.h opj_version -lopenjpeg -DOPJ_STATIC ||
                               die "ERROR: libopenjpeg not found"; }
enabled libopus           && require_pkg_config opus opus_multistream.h opus_multistream_decoder_create
enabled libpulse          && require_pkg_config libpulse pulse/pulseaudio.h pa_context_new
enabled libquvi           && require_pkg_config libquvi quvi/quvi.h quvi_init
enabled librtmp           && require_pkg_config librtmp librtmp/rtmp.h RTMP_Socket
enabled libschroedinger   && require_pkg_config schroedinger-1.0 schroedinger/schro.h schro_init
enabled libshine          && require_pkg_config shine shine/layer3.h shine_encode_buffer
enabled libsmbclient      && { use_pkg_config smbclient libsmbclient.h smbc_init ||
                               require smbclient libsmbclient.h smbc_init -lsmbclient; }
enabled libsoxr           && require libsoxr soxr.h soxr_create -lsoxr
enabled libssh            && require_pkg_config libssh libssh/sftp.h sftp_init
enabled libspeex          && require_pkg_config speex speex/speex.h speex_decoder_init -lspeex
enabled libstagefright_h264 && require_cpp libstagefright_h264 "binder/ProcessState.h media/stagefright/MetaData.h
    media/stagefright/MediaBufferGroup.h media/stagefright/MediaDebug.h media/stagefright/MediaDefs.h
    media/stagefright/OMXClient.h media/stagefright/OMXCodec.h" android::OMXClient -lstagefright -lmedia -lutils -lbinder -lgnustl_static
enabled libtheora         && require libtheora theora/theoraenc.h th_info_init -ltheoraenc -ltheoradec -logg
enabled libtwolame        && require libtwolame twolame.h twolame_init -ltwolame &&
                             { check_lib twolame.h twolame_encode_buffer_float32_interleaved -ltwolame ||
                               die "ERROR: libtwolame must be installed and version must be >= 0.3.10"; }
enabled libutvideo        && require_cpp utvideo "stdint.h stdlib.h utvideo/utvideo.h utvideo/Codec.h" 'CCodec*' -lutvideo -lstdc++
enabled libv4l2           && require_pkg_config libv4l2 libv4l2.h v4l2_ioctl
enabled libvidstab        && require_pkg_config "vidstab >= 0.98" vid.stab/libvidstab.h vsMotionDetectInit
enabled libvo_aacenc      && require libvo_aacenc vo-aacenc/voAAC.h voGetAACEncAPI -lvo-aacenc
enabled libvo_amrwbenc    && require libvo_amrwbenc vo-amrwbenc/enc_if.h E_IF_init -lvo-amrwbenc
enabled libvorbis         && require libvorbis vorbis/vorbisenc.h vorbis_info_init -lvorbisenc -lvorbis -logg
enabled libvpx            && {
    enabled libvpx_vp8_decoder && { check_lib2 "vpx/vpx_decoder.h vpx/vp8dx.h" vpx_codec_dec_init_ver -lvpx ||
                                    die "ERROR: libvpx decoder version must be >=0.9.1"; }
    enabled libvpx_vp8_encoder && { check_lib2 "vpx/vpx_encoder.h vpx/vp8cx.h" "vpx_codec_enc_init_ver VP8E_SET_MAX_INTRA_BITRATE_PCT" -lvpx ||
                                    die "ERROR: libvpx encoder version must be >=0.9.7"; }
    enabled libvpx_vp9_decoder && { check_lib2 "vpx/vpx_decoder.h vpx/vp8dx.h" "vpx_codec_vp9_dx" -lvpx || disable libvpx_vp9_decoder; }
    enabled libvpx_vp9_encoder && { check_lib2 "vpx/vpx_encoder.h vpx/vp8cx.h" "vpx_codec_vp9_cx VP9E_SET_AQ_MODE" -lvpx || disable libvpx_vp9_encoder; } }
enabled libwavpack        && require libwavpack wavpack/wavpack.h WavpackOpenFileOutput  -lwavpack
enabled libwebp           && require_pkg_config "libwebp >= 0.2.0" webp/encode.h WebPGetEncoderVersion
enabled libx264           && { use_pkg_config x264 "stdint.h x264.h" x264_encoder_encode ||
                               { require libx264 x264.h x264_encoder_encode -lx264 &&
                                 warn "using libx264 without pkg-config"; } } &&
                             { check_cpp_condition x264.h "X264_BUILD >= 118" ||
                               die "ERROR: libx264 must be installed and version must be >= 0.118."; }
enabled libx265           && require_pkg_config x265 x265.h x265_encoder_encode &&
                             { check_cpp_condition x265.h "X265_BUILD >= 17" ||
                               die "ERROR: libx265 version must be >= 17."; }
enabled libxavs           && require libxavs xavs.h xavs_encoder_encode -lxavs
enabled libxvid           && require libxvid xvid.h xvid_global -lxvidcore
enabled libzmq            && require_pkg_config libzmq zmq.h zmq_ctx_new
enabled libzvbi           && require libzvbi libzvbi.h vbi_decoder_new -lzvbi
enabled nvenc             && { check_header nvEncodeAPI.h || die "ERROR: nvEncodeAPI.h not found."; } &&
                             { [ $target_os != cygwin ] || die "ERROR: NVENC is not supported on Cygwin currently."; }
enabled openal            && { { for al_libs in "${OPENAL_LIBS}" "-lopenal" "-lOpenAL32"; do
                               check_lib 'AL/al.h' alGetError "${al_libs}" && break; done } ||
                               die "ERROR: openal not found"; } &&
                             { check_cpp_condition "AL/al.h" "defined(AL_VERSION_1_1)" ||
                               die "ERROR: openal must be installed and version must be 1.1 or compatible"; }
enabled opencl            && { check_lib2 OpenCL/cl.h clEnqueueNDRangeKernel -Wl,-framework,OpenCL ||
                               check_lib2 CL/cl.h clEnqueueNDRangeKernel -lOpenCL ||
                               die "ERROR: opencl not found"; } &&
                             { check_cpp_condition "OpenCL/cl.h" "defined(CL_VERSION_1_2)" ||
                               check_cpp_condition "CL/cl.h" "defined(CL_VERSION_1_2)" ||
                               die "ERROR: opencl must be installed and version must be 1.2 or compatible"; }
enabled opengl            && { check_lib GL/glx.h glXGetProcAddress "-lGL" ||
                               check_lib2 windows.h wglGetProcAddress "-lopengl32 -lgdi32" ||
                               check_lib2 OpenGL/gl3.h glGetError "-Wl,-framework,OpenGL" ||
                               check_lib2 ES2/gl.h glGetError "-isysroot=${sysroot} -Wl,-framework,OpenGLES" ||
                               die "ERROR: opengl not found."
                             }
enabled openssl           && { check_lib openssl/ssl.h SSL_library_init -lssl -lcrypto ||
                               check_lib openssl/ssl.h SSL_library_init -lssl32 -leay32 ||
                               check_lib openssl/ssl.h SSL_library_init -lssl -lcrypto -lws2_32 -lgdi32 ||
                               die "ERROR: openssl not found"; }
enabled qtkit_indev      && { check_header_oc QTKit/QTKit.h || disable qtkit_indev; }

if enabled gnutls; then
    { check_lib nettle/bignum.h nettle_mpz_get_str_256 -lnettle -lhogweed -lgmp && enable nettle; } ||
    { check_lib gcrypt.h gcry_mpi_new -lgcrypt && enable gcrypt; }
fi

# libdc1394 check
if enabled libdc1394; then
    { require_pkg_config libdc1394-2 dc1394/dc1394.h dc1394_new &&
        enable libdc1394_2; } ||
    { check_lib libdc1394/dc1394_control.h dc1394_create_handle -ldc1394_control -lraw1394 &&
        enable libdc1394_1; } ||
    die "ERROR: No version of libdc1394 found "
fi
if ! disabled sdl; then
    SDL_CONFIG="${cross_prefix}sdl-config"
    if check_pkg_config sdl SDL_events.h SDL_PollEvent; then
        check_cpp_condition SDL.h "(SDL_MAJOR_VERSION<<16 | SDL_MINOR_VERSION<<8 | SDL_PATCHLEVEL) >= 0x010201" $sdl_cflags &&
        check_cpp_condition SDL.h "(SDL_MAJOR_VERSION<<16 | SDL_MINOR_VERSION<<8 | SDL_PATCHLEVEL) < 0x010300" $sdl_cflags &&
        enable sdl
    else
        if "${SDL_CONFIG}" --version > /dev/null 2>&1; then
            sdl_cflags=$("${SDL_CONFIG}" --cflags)
            sdl_libs=$("${SDL_CONFIG}" --libs)
            check_func_headers SDL_version.h SDL_Linked_Version $sdl_cflags $sdl_libs &&
            check_cpp_condition SDL.h "(SDL_MAJOR_VERSION<<16 | SDL_MINOR_VERSION<<8 | SDL_PATCHLEVEL) >= 0x010201" $sdl_cflags &&
            check_cpp_condition SDL.h "(SDL_MAJOR_VERSION<<16 | SDL_MINOR_VERSION<<8 | SDL_PATCHLEVEL) < 0x010300" $sdl_cflags &&
            enable sdl
        elif enabled sdl ; then
            die "ERROR: SDL not found"
        else
            disable sdl
        fi
    fi
fi
enabled sdl && add_cflags $sdl_cflags && add_extralibs $sdl_libs

makeinfo --version > /dev/null 2>&1 && enable makeinfo  || disable makeinfo
enabled makeinfo && (makeinfo --version | \
                     grep -q 'makeinfo (GNU texinfo) 5' > /dev/null 2>&1) \
    && enable makeinfo_html || disable makeinfo_html
disabled makeinfo_html && texi2html --help 2> /dev/null | grep -q 'init-file' && enable texi2html || disable texi2html
perl -v            > /dev/null 2>&1 && enable perl      || disable perl
pod2man --help     > /dev/null 2>&1 && enable pod2man   || disable pod2man
rsync --help 2> /dev/null | grep -q 'contimeout' && enable rsync_contimeout || disable rsync_contimeout

check_header linux/fb.h
check_header linux/videodev.h
check_header linux/videodev2.h
check_code cc linux/videodev2.h "struct v4l2_frmsizeenum vfse; vfse.discrete.width = 0;" && enable_safe struct_v4l2_frmivalenum_discrete

check_header sys/videoio.h
check_code cc sys/videoio.h "struct v4l2_frmsizeenum vfse; vfse.discrete.width = 0;" && enable_safe struct_v4l2_frmivalenum_discrete

check_func_headers "windows.h vfw.h" capCreateCaptureWindow "$vfwcap_indev_extralibs"
# check that WM_CAP_DRIVER_CONNECT is defined to the proper value
# w32api 3.12 had it defined wrong
check_cpp_condition vfw.h "WM_CAP_DRIVER_CONNECT > WM_USER" && enable vfwcap_defines

check_type "dshow.h" IBaseFilter

# check for ioctl_meteor.h, ioctl_bt848.h and alternatives
{ check_header dev/bktr/ioctl_meteor.h &&
  check_header dev/bktr/ioctl_bt848.h; } ||
{ check_header machine/ioctl_meteor.h &&
  check_header machine/ioctl_bt848.h; } ||
{ check_header dev/video/meteor/ioctl_meteor.h &&
  check_header dev/video/bktr/ioctl_bt848.h; } ||
check_header dev/ic/bt8xx.h

check_header sndio.h
if check_struct sys/soundcard.h audio_buf_info bytes; then
    enable_safe sys/soundcard.h
else
    check_cc -D__BSD_VISIBLE -D__XSI_VISIBLE <<EOF && add_cppflags -D__BSD_VISIBLE -D__XSI_VISIBLE && enable_safe sys/soundcard.h
    #include <sys/soundcard.h>
    audio_buf_info abc;
EOF
fi
check_header soundcard.h

enabled_any alsa_indev alsa_outdev &&
    check_lib2 alsa/asoundlib.h snd_pcm_htimestamp -lasound

enabled jack_indev && check_lib2 jack/jack.h jack_client_open -ljack && check_func sem_timedwait &&
    check_func jack_port_get_latency_range -ljack

enabled_any sndio_indev sndio_outdev && check_lib2 sndio.h sio_open -lsndio

if enabled libcdio; then
    check_lib2 "cdio/cdda.h cdio/paranoia.h" cdio_cddap_open -lcdio_paranoia -lcdio_cdda -lcdio ||
    check_lib2 "cdio/paranoia/cdda.h cdio/paranoia/paranoia.h" cdio_cddap_open -lcdio_paranoia -lcdio_cdda -lcdio ||
    die "ERROR: No usable libcdio/cdparanoia found"
fi

enabled xlib &&
    check_lib X11/Xlib.h XOpenDisplay -lX11 || disable xlib

if ! disabled libxcb; then
    check_pkg_config "xcb >= 1.4" xcb/xcb.h xcb_connect || {
        enabled libxcb && die "ERROR: libxcb >= 1.4 not found";
    } && disable x11grab && enable libxcb

if enabled libxcb; then
    disabled libxcb_shm || {
        check_pkg_config xcb-shm xcb/shm.h xcb_shm_attach || {
            enabled libxcb_shm && die "ERROR: libxcb_shm not found";
        } && check_header sys/shm.h && enable libxcb_shm; }

    disabled libxcb_xfixes || {
        check_pkg_config xcb-xfixes xcb/xfixes.h xcb_xfixes_get_cursor_image || {
            enabled libxcb_xfixes && die "ERROR: libxcb_xfixes not found";
        } && enable libxcb_xfixes; }

    disabled libxcb_shape || {
        check_pkg_config xcb-shape xcb/shape.h xcb_shape_get_rectangles || {
            enabled libxcb_shape && die "ERROR: libxcb_shape not found";
        } && enable libxcb_shape; }

    add_cflags $xcb_cflags $xcb_shm_cflags $xcb_xfixes_cflags $xcb_shape_cflags
    add_extralibs $xcb_libs $xcb_shm_libs $xcb_xfixes_libs $xcb_shape_libs
fi
fi

if enabled x11grab; then
    enabled xlib || die "ERROR: Xlib not found"
    require Xext X11/extensions/XShm.h XShmCreateImage -lXext
    require Xfixes X11/extensions/Xfixes.h XFixesGetCursorImage -lXfixes
fi

check_func_headers "windows.h" CreateDIBSection "$gdigrab_indev_extralibs"

enabled dxva2api_h &&
    check_cc <<EOF && enable dxva2api_cobj
#define _WIN32_WINNT 0x0600
#define COBJMACROS
#include <windows.h>
#include <d3d9.h>
#include <dxva2api.h>
int main(void) { IDirectXVideoDecoder *o = NULL; IDirectXVideoDecoder_Release(o); return 0; }
EOF

enabled vaapi &&
    check_lib va/va.h vaInitialize -lva ||
    disable vaapi

enabled vaapi && enabled xlib &&
    check_lib2 "va/va.h va/va_x11.h" vaGetDisplay -lva -lva-x11 &&
    enable vaapi_x11

enabled vdpau &&
    check_cpp_condition vdpau/vdpau.h "defined VDP_DECODER_PROFILE_MPEG4_PART2_ASP" ||
    disable vdpau

enabled vdpau && enabled xlib &&
    check_func_headers "vdpau/vdpau.h vdpau/vdpau_x11.h" vdp_device_create_x11 -lvdpau &&
    prepend ffmpeg_libs $($ldflags_filter "-lvdpau") &&
    enable vdpau_x11

# Funny iconv installations are not unusual, so check it after all flags have been set
disabled iconv || check_func_headers iconv.h iconv || check_lib2 iconv.h iconv -liconv || disable iconv

enabled debug && add_cflags -g"$debuglevel" && add_asflags -g"$debuglevel"

# add some useful compiler flags if supported
check_cflags -Wdeclaration-after-statement
check_cflags -Wall
check_cflags -Wdisabled-optimization
check_cflags -Wpointer-arith
check_cflags -Wredundant-decls
check_cflags -Wwrite-strings
check_cflags -Wtype-limits
check_cflags -Wundef
check_cflags -Wmissing-prototypes
check_cflags -Wno-pointer-to-int-cast
check_cflags -Wstrict-prototypes
check_cflags -Wempty-body
enabled extra_warnings && check_cflags -Winline

check_disable_warning(){
    warning_flag=-W${1#-Wno-}
    test_cflags $warning_flag && add_cflags $1
}

check_disable_warning -Wno-parentheses
check_disable_warning -Wno-switch
check_disable_warning -Wno-format-zero-length
check_disable_warning -Wno-pointer-sign

# add some linker flags
check_ldflags -Wl,--warn-common
check_ldflags -Wl,-rpath-link=libpostproc:libswresample:libswscale:libavfilter:libavdevice:libavformat:libavcodec:libavutil:libavresample
enabled rpath && add_ldexeflags -Wl,-rpath,$libdir
test_ldflags -Wl,-Bsymbolic && append SHFLAGS -Wl,-Bsymbolic

# add some strip flags
# -wN '..@*' is more selective than -x, but not available everywhere.
check_stripflags -wN \'..@*\' || check_stripflags -x

enabled neon_clobber_test &&
    check_ldflags -Wl,--wrap,avcodec_open2              \
                  -Wl,--wrap,avcodec_decode_audio4      \
                  -Wl,--wrap,avcodec_decode_video2      \
                  -Wl,--wrap,avcodec_decode_subtitle2   \
                  -Wl,--wrap,avcodec_encode_audio2      \
                  -Wl,--wrap,avcodec_encode_video2      \
                  -Wl,--wrap,avcodec_encode_subtitle    \
                  -Wl,--wrap,swr_convert                \
                  -Wl,--wrap,avresample_convert ||
    disable neon_clobber_test

enabled xmm_clobber_test &&
    check_ldflags -Wl,--wrap,avcodec_open2              \
                  -Wl,--wrap,avcodec_decode_audio4      \
                  -Wl,--wrap,avcodec_decode_video2      \
                  -Wl,--wrap,avcodec_decode_subtitle2   \
                  -Wl,--wrap,avcodec_encode_audio2      \
                  -Wl,--wrap,avcodec_encode_video       \
                  -Wl,--wrap,avcodec_encode_video2      \
                  -Wl,--wrap,avcodec_encode_subtitle    \
                  -Wl,--wrap,swr_convert                \
                  -Wl,--wrap,avresample_convert         \
                  -Wl,--wrap,sws_scale ||
    disable xmm_clobber_test

echo "X{};" > $TMPV
if test_ldflags -Wl,--version-script,$TMPV; then
    append SHFLAGS '-Wl,--version-script,\$(SUBDIR)lib\$(NAME).ver'
    check_cc <<EOF && enable symver_asm_label
void ff_foo(void) __asm__ ("av_foo@VERSION");
void ff_foo(void) { ${inline_asm+__asm__($quotes);} }
EOF
    check_cc <<EOF && enable symver_gnu_asm
__asm__(".symver ff_foo,av_foo@VERSION");
void ff_foo(void) {}
EOF
fi

if [ -z "$optflags" ]; then
    if enabled small; then
        optflags=$cflags_size
    elif enabled optimizations; then
        optflags=$cflags_speed
    else
        optflags=$cflags_noopt
    fi
fi

check_optflags(){
    check_cflags "$@"
    enabled lto && check_ldflags "$@"
}


if enabled lto; then
    test "$cc_type" != "$ld_type" && die "LTO requires same compiler and linker"
    check_cflags  -flto
    check_ldflags -flto $cpuflags
    disable inline_asm_direct_symbol_refs
fi

check_optflags $optflags
check_optflags -fno-math-errno
check_optflags -fno-signed-zeros

enabled ftrapv && check_cflags -ftrapv

check_cc -mno-red-zone <<EOF && noredzone_flags="-mno-red-zone"
int x;
EOF


if enabled icc; then
    # Just warnings, no remarks
    check_cflags -w1
    # -wd: Disable following warnings
    # 144, 167, 556: -Wno-pointer-sign
    # 188: enumerated type mixed with another type
    # 1292: attribute "foo" ignored
    # 1419: external declaration in primary source file
    # 10006: ignoring unknown option -fno-signed-zeros
    # 10148: ignoring unknown option -Wno-parentheses
    # 10156: ignoring option '-W'; no argument required
    check_cflags -wd144,167,188,556,1292,1419,10006,10148,10156
    # 11030: Warning unknown option --as-needed
    # 10156: ignoring option '-export'; no argument required
    check_ldflags -wd10156,11030
    # icc 11.0 and 11.1 work with ebp_available, but don't pass the test
    enable ebp_available
    # The test above does not test linking
    enabled lto && disable symver_asm_label
    if enabled x86_32; then
        icc_version=$($cc -dumpversion)
        test ${icc_version%%.*} -ge 11 &&
            check_cflags -falign-stack=maintain-16-byte ||
            disable aligned_stack
    fi
elif enabled ccc; then
    # disable some annoying warnings
    add_cflags -msg_disable bitnotint
    add_cflags -msg_disable mixfuncvoid
    add_cflags -msg_disable nonstandcast
    add_cflags -msg_disable unsupieee
elif enabled gcc; then
    check_optflags -fno-tree-vectorize
    check_cflags -Werror=format-security
    check_cflags -Werror=implicit-function-declaration
    check_cflags -Werror=missing-prototypes
    check_cflags -Werror=return-type
    check_cflags -Werror=vla
    check_cflags -Wformat
    enabled extra_warnings || check_disable_warning -Wno-maybe-uninitialized
elif enabled llvm_gcc; then
    check_cflags -mllvm -stack-alignment=16
elif enabled clang; then
    check_cflags -mllvm -stack-alignment=16
    check_cflags -Qunused-arguments
    check_cflags -Werror=implicit-function-declaration
    check_cflags -Werror=missing-prototypes
    check_cflags -Werror=return-type
elif enabled cparser; then
    add_cflags -Wno-missing-variable-declarations
    add_cflags -Wno-empty-statement
elif enabled armcc; then
    add_cflags -W${armcc_opt},--diag_suppress=4343 # hardfp compat
    add_cflags -W${armcc_opt},--diag_suppress=3036 # using . as system include dir
    # 2523: use of inline assembly is deprecated
    add_cflags -W${armcc_opt},--diag_suppress=2523
    add_cflags -W${armcc_opt},--diag_suppress=1207
    add_cflags -W${armcc_opt},--diag_suppress=1293 # assignment in condition
    add_cflags -W${armcc_opt},--diag_suppress=3343 # hardfp compat
    add_cflags -W${armcc_opt},--diag_suppress=167  # pointer sign
    add_cflags -W${armcc_opt},--diag_suppress=513  # pointer sign
elif enabled tms470; then
    add_cflags -pds=824 -pds=837
    disable inline_asm
elif enabled pathscale; then
    add_cflags -fstrict-overflow -OPT:wrap_around_unsafe_opt=OFF
elif enabled_any msvc icl; then
    enabled x86_32 && disable aligned_stack
    enabled_all x86_32 debug && add_cflags -Oy-
    enabled debug && add_ldflags -debug
    enable pragma_deprecated
    if enabled icl; then
        # -Qansi-alias is basically -fstrict-aliasing, but does not work
        # (correctly) on icl 13.x.
        check_cpp_condition "windows.h" "__ICL < 1300 || __ICL >= 1400" &&
            add_cflags -Qansi-alias
        # Some inline asm is not compilable in debug
        if enabled debug; then
            disable ebp_available
            disable ebx_available
        fi
    fi
    # msvcrt10 x64 incorrectly enables log2, only msvcrt12 onwards actually has log2.
    check_cpp_condition crtversion.h "_VC_CRT_MAJOR_VERSION >= 12" || disable log2
fi

case $as_type in
    clang)
        add_asflags -Qunused-arguments
    ;;
esac

case $ld_type in
    clang)
        check_ldflags -Qunused-arguments
    ;;
esac

case $target_os in
    osf1)
        enabled ccc && add_ldflags '-Wl,-expect_unresolved,*'
    ;;
    plan9)
        add_cppflags -Dmain=plan9_main
    ;;
esac

enable frame_thread_encoder

enabled asm || { arch=c; disable $ARCH_LIST $ARCH_EXT_LIST; }

check_deps $CONFIG_LIST       \
           $CONFIG_EXTRA      \
           $HAVE_LIST         \
           $ALL_COMPONENTS    \

enabled threads && ! enabled pthreads && ! enabled atomics_native && die "non pthread threading without atomics not supported, try adding --enable-pthreads or --cpu=i486 or higher if you are on x86"


if test $target_os = "haiku"; then
    disable memalign
    disable posix_memalign
fi

enabled_all dxva2 dxva2api_cobj CoTaskMemFree &&
    prepend ffmpeg_libs $($ldflags_filter "-lole32" "-luser32") &&
    enable dxva2_lib

! enabled_any memalign posix_memalign aligned_malloc &&
    enabled simd_align_16 && enable memalign_hack

# add_dep lib dep
# -> enable ${lib}_deps_${dep}
# -> add $dep to ${lib}_deps only once
add_dep() {
    lib=$1
    dep=$2
    enabled "${lib}_deps_${dep}" && return 0
    enable  "${lib}_deps_${dep}"
    prepend "${lib}_deps" $dep
}

# merge deps lib components
# merge all ${component}_deps into ${lib}_deps and ${lib}_deps_*
merge_deps() {
    lib=$1
    shift
    for comp in $*; do
        enabled $comp || continue
        eval "dep=\"\$${comp}_deps\""
        for d in $dep; do
            add_dep $lib $d
        done
    done
}

merge_deps libavfilter $FILTER_LIST

map 'enabled $v && intrinsics=${v#intrinsics_}' $INTRINSICS_LIST

for thread in $THREADS_LIST; do
    if enabled $thread; then
        test -n "$thread_type" &&
            die "ERROR: Only one thread type must be selected." ||
            thread_type="$thread"
    fi
done

enabled zlib && add_cppflags -DZLIB_CONST

# conditional library dependencies, in linking order
enabled amovie_filter       && prepend avfilter_deps "avformat avcodec"
enabled aresample_filter    && prepend avfilter_deps "swresample"
enabled asyncts_filter      && prepend avfilter_deps "avresample"
enabled atempo_filter       && prepend avfilter_deps "avcodec"
enabled ebur128_filter && enabled swresample && prepend avfilter_deps "swresample"
enabled elbg_filter         && prepend avfilter_deps "avcodec"
enabled fftfilt_filter      && prepend avfilter_deps "avcodec"
enabled mcdeint_filter      && prepend avfilter_deps "avcodec"
enabled movie_filter    && prepend avfilter_deps "avformat avcodec"
enabled pan_filter          && prepend avfilter_deps "swresample"
enabled pp_filter           && prepend avfilter_deps "postproc"
enabled removelogo_filter   && prepend avfilter_deps "avformat avcodec swscale"
enabled resample_filter && prepend avfilter_deps "avresample"
enabled sab_filter          && prepend avfilter_deps "swscale"
enabled scale_filter    && prepend avfilter_deps "swscale"
enabled showspectrum_filter && prepend avfilter_deps "avcodec"
enabled smartblur_filter    && prepend avfilter_deps "swscale"
enabled subtitles_filter    && prepend avfilter_deps "avformat avcodec"
enabled uspp_filter         && prepend avfilter_deps "avcodec"

enabled lavfi_indev         && prepend avdevice_deps "avfilter"

enabled opus_decoder    && prepend avcodec_deps "swresample"

expand_deps(){
    lib_deps=${1}_deps
    eval "deps=\$$lib_deps"
    append $lib_deps $(map 'eval echo \$${v}_deps' $deps)
    unique $lib_deps
}

#we have to remove gpl from the deps here as some code assumes all lib deps are libs
postproc_deps="$(filter_out 'gpl' $postproc_deps)"

map 'expand_deps $v' $LIBRARY_LIST

echo "install prefix            $prefix"
echo "source path               $source_path"
echo "C compiler                $cc"
echo "C library                 $libc_type"
if test "$host_cc" != "$cc"; then
    echo "host C compiler           $host_cc"
    echo "host C library            $host_libc_type"
fi
echo "ARCH                      $arch ($cpu)"
if test "$build_suffix" != ""; then
    echo "build suffix              $build_suffix"
fi
if test "$progs_suffix" != ""; then
    echo "progs suffix              $progs_suffix"
fi
if test "$extra_version" != ""; then
    echo "version string suffix     $extra_version"
fi
echo "big-endian                ${bigendian-no}"
echo "runtime cpu detection     ${runtime_cpudetect-no}"
if enabled x86; then
    echo "${yasmexe}                      ${yasm-no}"
    echo "MMX enabled               ${mmx-no}"
    echo "MMXEXT enabled            ${mmxext-no}"
    echo "3DNow! enabled            ${amd3dnow-no}"
    echo "3DNow! extended enabled   ${amd3dnowext-no}"
    echo "SSE enabled               ${sse-no}"
    echo "SSSE3 enabled             ${ssse3-no}"
    echo "AVX enabled               ${avx-no}"
    echo "XOP enabled               ${xop-no}"
    echo "FMA3 enabled              ${fma3-no}"
    echo "FMA4 enabled              ${fma4-no}"
    echo "i686 features enabled     ${i686-no}"
    echo "CMOV is fast              ${fast_cmov-no}"
    echo "EBX available             ${ebx_available-no}"
    echo "EBP available             ${ebp_available-no}"
fi
if enabled aarch64; then
    echo "NEON enabled              ${neon-no}"
    echo "VFP enabled               ${vfp-no}"
fi
if enabled arm; then
    echo "ARMv5TE enabled           ${armv5te-no}"
    echo "ARMv6 enabled             ${armv6-no}"
    echo "ARMv6T2 enabled           ${armv6t2-no}"
    echo "VFP enabled               ${vfp-no}"
    echo "NEON enabled              ${neon-no}"
    echo "THUMB enabled             ${thumb-no}"
fi
if enabled mips; then
    echo "MIPS FPU enabled          ${mipsfpu-no}"
    echo "MIPS DSP R1 enabled       ${mipsdspr1-no}"
    echo "MIPS DSP R2 enabled       ${mipsdspr2-no}"
fi
if enabled ppc; then
    echo "AltiVec enabled           ${altivec-no}"
    echo "PPC 4xx optimizations     ${ppc4xx-no}"
    echo "PPC VSX optimizations     ${vsx-no}"
    echo "dcbzl available           ${dcbzl-no}"
fi
echo "debug symbols             ${debug-no}"
echo "strip symbols             ${stripping-no}"
echo "optimize for size         ${small-no}"
echo "optimizations             ${optimizations-no}"
echo "static                    ${static-no}"
echo "shared                    ${shared-no}"
echo "postprocessing support    ${postproc-no}"
echo "new filter support        ${avfilter-no}"
echo "network support           ${network-no}"
echo "threading support         ${thread_type-no}"
echo "safe bitstream reader     ${safe_bitstream_reader-no}"
echo "SDL support               ${sdl-no}"
echo "opencl enabled            ${opencl-no}"
echo "texi2html enabled         ${texi2html-no}"
echo "perl enabled              ${perl-no}"
echo "pod2man enabled           ${pod2man-no}"
echo "makeinfo enabled          ${makeinfo-no}"
echo "makeinfo supports HTML    ${makeinfo_html-no}"
test -n "$random_seed" &&
    echo "random seed               ${random_seed}"
echo

echo "External libraries:"
print_enabled '' $EXTERNAL_LIBRARY_LIST | print_3_columns
echo

for type in decoder encoder hwaccel parser demuxer muxer protocol filter bsf indev outdev; do
    echo "Enabled ${type}s:"
    eval list=\$$(toupper $type)_LIST
    print_enabled '_*' $list | print_3_columns
    echo
done

license="LGPL version 2.1 or later"
if enabled nonfree; then
    license="nonfree and unredistributable"
elif enabled gplv3; then
    license="GPL version 3 or later"
elif enabled lgplv3; then
    license="LGPL version 3 or later"
elif enabled gpl; then
    license="GPL version 2 or later"
fi

echo "License: $license"

echo "Creating config.mak, config.h, and doc/config.texi..."

test -e Makefile || echo "include $source_path/Makefile" > Makefile

enabled stripping || strip="echo skipping strip"

config_files="$TMPH config.mak doc/config.texi"

cat > config.mak <<EOF
# Automatically generated by configure - do not modify!
ifndef FFMPEG_CONFIG_MAK
FFMPEG_CONFIG_MAK=1
FFMPEG_CONFIGURATION=$FFMPEG_CONFIGURATION
prefix=$prefix
LIBDIR=\$(DESTDIR)$libdir
SHLIBDIR=\$(DESTDIR)$shlibdir
INCDIR=\$(DESTDIR)$incdir
BINDIR=\$(DESTDIR)$bindir
DATADIR=\$(DESTDIR)$datadir
DOCDIR=\$(DESTDIR)$docdir
MANDIR=\$(DESTDIR)$mandir
SRC_PATH=$source_path
ifndef MAIN_MAKEFILE
SRC_PATH:=\$(SRC_PATH:.%=..%)
endif
CC_IDENT=$cc_ident
ARCH=$arch
INTRINSICS=$intrinsics
CC=$cc
CXX=$cxx
AS=$as
LD=$ld
DEPCC=$dep_cc
DEPCCFLAGS=$DEPCCFLAGS \$(CPPFLAGS)
DEPAS=$as
DEPASFLAGS=$DEPASFLAGS \$(CPPFLAGS)
YASM=$yasmexe
DEPYASM=$yasmexe
AR=$ar
ARFLAGS=$arflags
AR_O=$ar_o
RANLIB=$ranlib
STRIP=$strip
CP=cp -p
LN_S=$ln_s
CPPFLAGS=$CPPFLAGS
CFLAGS=$CFLAGS
CXXFLAGS=$CXXFLAGS
ASFLAGS=$ASFLAGS
AS_C=$AS_C
AS_O=$AS_O
CC_C=$CC_C
CC_E=$CC_E
CC_O=$CC_O
CXX_C=$CXX_C
CXX_O=$CXX_O
LD_O=$LD_O
LD_LIB=$LD_LIB
LD_PATH=$LD_PATH
DLLTOOL=$dlltool
WINDRES=$windres
DEPWINDRES=$dep_cc
DOXYGEN=$doxygen
LDFLAGS=$LDFLAGS
LDEXEFLAGS=$LDEXEFLAGS
SHFLAGS=$(echo $($ldflags_filter $SHFLAGS))
ASMSTRIPFLAGS=$ASMSTRIPFLAGS
YASMFLAGS=$YASMFLAGS
BUILDSUF=$build_suffix
PROGSSUF=$progs_suffix
FULLNAME=$FULLNAME
LIBPREF=$LIBPREF
LIBSUF=$LIBSUF
LIBNAME=$LIBNAME
SLIBPREF=$SLIBPREF
SLIBSUF=$SLIBSUF
EXESUF=$EXESUF
EXTRA_VERSION=$extra_version
CCDEP=$CCDEP
CXXDEP=$CXXDEP
CCDEP_FLAGS=$CCDEP_FLAGS
ASDEP=$ASDEP
ASDEP_FLAGS=$ASDEP_FLAGS
CC_DEPFLAGS=$CC_DEPFLAGS
AS_DEPFLAGS=$AS_DEPFLAGS
HOSTCC=$host_cc
HOSTLD=$host_ld
HOSTCFLAGS=$host_cflags
HOSTCPPFLAGS=$host_cppflags
HOSTEXESUF=$HOSTEXESUF
HOSTLDFLAGS=$host_ldflags
HOSTLIBS=$host_libs
DEPHOSTCC=$host_cc
DEPHOSTCCFLAGS=$DEPHOSTCCFLAGS \$(HOSTCCFLAGS)
HOSTCCDEP=$HOSTCCDEP
HOSTCCDEP_FLAGS=$HOSTCCDEP_FLAGS
HOSTCC_DEPFLAGS=$HOSTCC_DEPFLAGS
HOSTCC_C=$HOSTCC_C
HOSTCC_O=$HOSTCC_O
HOSTLD_O=$HOSTLD_O
TARGET_EXEC=$target_exec $target_exec_args
TARGET_PATH=$target_path
TARGET_SAMPLES=${target_samples:-\$(SAMPLES)}
CFLAGS-ffplay=$sdl_cflags
ZLIB=$($ldflags_filter -lz)
LIB_INSTALL_EXTRA_CMD=$LIB_INSTALL_EXTRA_CMD
EXTRALIBS=$extralibs
COMPAT_OBJS=$compat_objs
EXEOBJS=$exeobjs
INSTALL=$install
LIBTARGET=${LIBTARGET}
SLIBNAME=${SLIBNAME}
SLIBNAME_WITH_VERSION=${SLIBNAME_WITH_VERSION}
SLIBNAME_WITH_MAJOR=${SLIBNAME_WITH_MAJOR}
SLIB_CREATE_DEF_CMD=${SLIB_CREATE_DEF_CMD}
SLIB_EXTRA_CMD=${SLIB_EXTRA_CMD}
SLIB_INSTALL_NAME=${SLIB_INSTALL_NAME}
SLIB_INSTALL_LINKS=${SLIB_INSTALL_LINKS}
SLIB_INSTALL_EXTRA_LIB=${SLIB_INSTALL_EXTRA_LIB}
SLIB_INSTALL_EXTRA_SHLIB=${SLIB_INSTALL_EXTRA_SHLIB}
SAMPLES:=${samples:-\$(FATE_SAMPLES)}
NOREDZONE_FLAGS=$noredzone_flags
EOF

get_version(){
    lcname=lib${1}
    name=$(toupper $lcname)
    file=$source_path/$lcname/version.h
    eval $(awk "/#define ${name}_VERSION_M/ { print \$2 \"=\" \$3 }" "$file")
    enabled raise_major && eval ${name}_VERSION_MAJOR=$((${name}_VERSION_MAJOR+100))
    eval ${name}_VERSION=\$${name}_VERSION_MAJOR.\$${name}_VERSION_MINOR.\$${name}_VERSION_MICRO
    eval echo "${lcname}_VERSION=\$${name}_VERSION" >> config.mak
    eval echo "${lcname}_VERSION_MAJOR=\$${name}_VERSION_MAJOR" >> config.mak
    eval echo "${lcname}_VERSION_MINOR=\$${name}_VERSION_MINOR" >> config.mak
}

map 'get_version $v' $LIBRARY_LIST

map 'eval echo "${v}_FFLIBS=\$${v}_deps" >> config.mak' $LIBRARY_LIST

print_program_libs(){
    eval "program_libs=\$${1}_libs"
    eval echo "LIBS-${1}=${program_libs}" >> config.mak
}

map 'print_program_libs $v' $PROGRAM_LIST

cat > $TMPH <<EOF
/* Automatically generated by configure - do not modify! */
#ifndef FFMPEG_CONFIG_H
#define FFMPEG_CONFIG_H
#define FFMPEG_CONFIGURATION "$(c_escape $FFMPEG_CONFIGURATION)"
#define FFMPEG_LICENSE "$(c_escape $license)"
#define CONFIG_THIS_YEAR 2015
#define FFMPEG_DATADIR "$(eval c_escape $datadir)"
#define AVCONV_DATADIR "$(eval c_escape $datadir)"
#define CC_IDENT "$(c_escape ${cc_ident:-Unknown compiler})"
#define av_restrict $_restrict
#define EXTERN_PREFIX "${extern_prefix}"
#define EXTERN_ASM ${extern_prefix}
#define BUILDSUF "$build_suffix"
#define SLIBSUF "$SLIBSUF"
#define HAVE_MMX2 HAVE_MMXEXT
#define SWS_MAX_FILTER_SIZE $sws_max_filter_size
EOF

test -n "$assert_level" &&
    echo "#define ASSERT_LEVEL $assert_level" >>$TMPH

test -n "$malloc_prefix" &&
    echo "#define MALLOC_PREFIX $malloc_prefix" >>$TMPH

if enabled yasm; then
    append config_files $TMPASM
    printf '' >$TMPASM
fi

enabled getenv || echo "#define getenv(x) NULL" >> $TMPH


mkdir -p doc
mkdir -p tests
echo "@c auto-generated by configure" > doc/config.texi

print_config ARCH_   "$config_files" $ARCH_LIST
print_config HAVE_   "$config_files" $HAVE_LIST
print_config CONFIG_ "$config_files" $CONFIG_LIST       \
                                     $CONFIG_EXTRA      \
                                     $ALL_COMPONENTS    \

echo "#endif /* FFMPEG_CONFIG_H */" >> $TMPH
echo "endif # FFMPEG_CONFIG_MAK" >> config.mak

# Do not overwrite an unchanged config.h to avoid superfluous rebuilds.
cp_if_changed $TMPH config.h
touch .config

enabled yasm && cp_if_changed $TMPASM config.asm

cat > $TMPH <<EOF
/* Generated by ffconf */
#ifndef AVUTIL_AVCONFIG_H
#define AVUTIL_AVCONFIG_H
EOF

print_config AV_HAVE_ $TMPH $HAVE_LIST_PUB

echo "#endif /* AVUTIL_AVCONFIG_H */" >> $TMPH

cp_if_changed $TMPH libavutil/avconfig.h

if test -n "$WARNINGS"; then
    printf "\n$WARNINGS"
    enabled fatal_warnings && exit 1
fi

# build pkg-config files

lib_version(){
    eval printf "\"lib${1}${build_suffix} >= \$LIB$(toupper ${1})_VERSION, \""
}

pkgconfig_generate(){
    name=$1
    shortname=${name#lib}${build_suffix}
    comment=$2
    version=$3
    libs=$4
    requires=$(map 'lib_version $v' $(eval echo \$${name#lib}_deps))
    requires=${requires%, }
    enabled ${name#lib} || return 0
    mkdir -p $name
    cat <<EOF > $name/$name${build_suffix}.pc
prefix=$prefix
exec_prefix=\${prefix}
libdir=$libdir
includedir=$incdir

Name: $name
Description: $comment
Version: $version
Requires: $(enabled shared || echo $requires)
Requires.private: $(enabled shared && echo $requires)
Conflicts:
Libs: -L\${libdir} $(enabled rpath && echo "-Wl,-rpath,\${libdir}") -l${shortname} $(enabled shared || echo $libs)
Libs.private: $(enabled shared && echo $libs)
Cflags: -I\${includedir}
EOF

mkdir -p doc/examples/pc-uninstalled
includedir=${source_path}
[ "$includedir" = . ] && includedir="\${pcfiledir}/../../.."
    cat <<EOF > doc/examples/pc-uninstalled/$name.pc
prefix=
exec_prefix=
libdir=\${pcfiledir}/../../../$name
includedir=${includedir}

Name: $name
Description: $comment
Version: $version
Requires: $requires
Conflicts:
Libs: -L\${libdir} -Wl,-rpath,\${libdir} -l${shortname} $(enabled shared || echo $libs)
Cflags: -I\${includedir}
EOF
}

pkgconfig_generate libavutil     "FFmpeg utility library"               "$LIBAVUTIL_VERSION"     "$LIBRT $LIBM"
pkgconfig_generate libavcodec    "FFmpeg codec library"                 "$LIBAVCODEC_VERSION"    "$extralibs"
pkgconfig_generate libavformat   "FFmpeg container format library"      "$LIBAVFORMAT_VERSION"   "$extralibs"
pkgconfig_generate libavdevice   "FFmpeg device handling library"       "$LIBAVDEVICE_VERSION"   "$extralibs"
pkgconfig_generate libavfilter   "FFmpeg audio/video filtering library" "$LIBAVFILTER_VERSION"   "$extralibs"
pkgconfig_generate libpostproc   "FFmpeg postprocessing library"        "$LIBPOSTPROC_VERSION"   ""
pkgconfig_generate libavresample "Libav audio resampling library"       "$LIBAVRESAMPLE_VERSION" "$LIBM"
pkgconfig_generate libswscale    "FFmpeg image rescaling library"       "$LIBSWSCALE_VERSION"    "$LIBM"
pkgconfig_generate libswresample "FFmpeg audio resampling library"      "$LIBSWRESAMPLE_VERSION" "$LIBM"