[AUDIO] Support playing of startup WAV file or hardcoded 'jingle'

kernel/audio/OutputAudioDevice.cpp

@@ -2,7 +2,7 @@
 #include "memory/page_allocator.h"
 
 //TODO: We should allocate at least 40 pages, possibly 64 to have more than a second at once
-#define BUF_SIZE PAGE_SIZE * 10
+#define BUF_SIZE PAGE_SIZE * 20
 
 void OutputAudioDevice::populate(){
     buffer = (uintptr_t)palloc(BUF_SIZE, MEM_PRIV_KERNEL, MEM_RW, true);

kernel/audio/audio.cpp

@@ -4,8 +4,9 @@
 #include "console/kio.h"
 #include "math/math.h"
 #include "audio/cuatro.h"
-#include "graph/graphics.h"
+#include "audio/wav.h"
 #include "theme/theme.h"
+#include "syscalls/syscalls.h"
 
 VirtioAudioDriver *audio_driver;
 
@@ -26,53 +27,100 @@ void audio_submit_buffer(){
     audio_driver->out_dev->submit_buffer(audio_driver);
 }
 
-void make_wave(WAVE_TYPE type, float freq, float seconds, uint32_t amplitude){
-    gpu_clear(0x1fb03f);
-    uint32_t period = 441/((freq/100.f) * 2);//TODO: improve this formula
-    kprintf("Period %i",period);
-    uint32_t accumulator = 0;
-    uint32_t increment = (uint32_t)(freq * (float)UINT32_MAX / 44100.0);
-    gpu_size size = gpu_get_screen_size();
-    uint32_t previous_pixel = UINT32_MAX;
-
-    //TODO: distorsion
-    //size of the buffer should be bigger, 
-    //palloc should be 64 pages
-    //in the virtio driver, cmd_index is waiting for the device to catch up
-
-    for (int i = 0; i < seconds * 100; i++){
+// TODO: get sample rate, channels etc. from audio driver. 
+//       Currently ASSUMES output stream has two channels in U32 format.
+const float SAMPLE_RATE = 44100.f;
+
+
+void play_wave(WAVE_TYPE type, float freq, float seconds, uint32_t amplitude){
+    uint32_t phase = 0;
+    // TODO: validate freqency to ensure phase_incr is sensible value.
+    uint32_t phase_incr = (uint32_t)(freq * (float)PHASE_MAX / SAMPLE_RATE);
+    uint32_t samples_remaining = ceil(SAMPLE_RATE * seconds);
+
+    while (samples_remaining > 0){
+        sizedptr buf = audio_request_buffer(audio_driver->out_dev->stream_id);
+        uint32_t* buffer = (uint32_t*)buf.ptr;
+        uint32_t samples_in_buffer = (uint32_t)min(buf.size/2, samples_remaining);
+        uint32_t sample = 0;
+        size_t slot = 0;
+        while (sample++ < samples_in_buffer){
+            float wave = sample_raw_wave(type, phase) * amplitude;
+            buffer[slot++] = wave;      // Left ch.
+            buffer[slot++] = wave;      // Right ch.
+            phase = (phase + phase_incr) & PHASE_MASK;
+        }
+        while (slot < buf.size){
+            buffer[slot++] = WAVE_MID_VALUE;
+        }
+        audio_submit_buffer();
+        samples_remaining -= samples_in_buffer;
+    }
+}
+
+void play_silence(float seconds){
+    if (seconds < 0.01) return;
+    sizedptr buf = audio_request_buffer(audio_driver->out_dev->stream_id);
+    uint32_t buffer_count = (uint32_t)ceil(SAMPLE_RATE * seconds * 2 / buf.size);
+    do{
+        uint32_t* buffer = (uint32_t*)buf.ptr;
+        size_t slot = 0;
+        while (slot < buf.size){
+            buffer[slot++] = WAVE_MID_VALUE;
+        }
+        audio_submit_buffer();
+        buf = audio_request_buffer(audio_driver->out_dev->stream_id);
+    } while (--buffer_count > 0);
+}
+
+static inline uint32_t int16_to_uint32(int16_t sample, uint32_t amplitude){
+    return (uint64_t)(((int64_t)sample * amplitude) >> 16) + WAVE_MID_VALUE;
+}
+
+void play_int16_samples(int16_t *samples, size_t smpl_per_channel, size_t channels, uint32_t amplitude){
+    size_t samples_remaining = smpl_per_channel * channels;
+    while (samples_remaining > 0){
         sizedptr buf = audio_request_buffer(audio_driver->out_dev->stream_id);
-
-        uint32_t num_samples = buf.size;
-        uint32_t *buffer = (uint32_t*)buf.ptr;
-        for (uint32_t sample = 0; sample < num_samples; sample++){
-            float wave = sample_raw_wave(type, accumulator, period);
-            uint32_t min = 64 * num_samples;
-            buffer[sample] = wave * amplitude;
-
-            accumulator += increment;
-            if (accumulator >= min && accumulator < min + size.width){
-                gpu_point p = (gpu_point){ accumulator - min, 100-(uint32_t)(100*wave)};
-                if (previous_pixel != UINT32_MAX && abs(p.y-previous_pixel) > 10){
-                    gpu_draw_line({ p.x - 1, previous_pixel}, p, 0xFFB4DD13);
-                }
-                previous_pixel = p.y;
-                gpu_draw_pixel(p, 0xFFB4DD13);
-            }
+        uint32_t* buffer = (uint32_t*)buf.ptr;
+        size_t samples_in_buffer = (size_t)min(buf.size, samples_remaining);
+        size_t slot = 0;
+        while (slot < samples_in_buffer){
+            uint32_t sample = int16_to_uint32(*samples++, amplitude);
+            buffer[slot++] = sample;        // Left ch.
+            buffer[slot++] = (channels == 1) ? sample : int16_to_uint32(*samples++, amplitude);  // Right ch.
+        }
+        while (slot < buf.size){
+            buffer[slot++] = WAVE_MID_VALUE;
         }
         audio_submit_buffer();
+        samples_remaining -= samples_in_buffer;
+    }
+}
+
+void play_startup(){
+    wav_data wav = {};
+    if (wav_load("/boot/redos/startup.wav", &wav)){
+        // TODO: other WAV formats are available
+        play_int16_samples(wav.samples, wav.smpls_per_channel, wav.channels, AUDIO_LEVEL_MAX/2);
+        free((void*)wav.file_content.ptr, wav.file_content.size);
+    }else{
+        play_wave(WAVE_SAW, 440, 0.1, AUDIO_LEVEL_MAX/2);
+        play_silence(0.05);
+        play_wave(WAVE_SAW, 494, 0.1, AUDIO_LEVEL_MAX/2);
+        play_silence(0.05);
+        play_wave(WAVE_SAW, 523, 0.3, AUDIO_LEVEL_MAX/2);
+        play_silence(0.5);
     }
-    gpu_flush();
-    while(1);
 }
 
-int play_test_audio(int argc, char* argv[]){      
-    // make_wave(WAVE_SAW, 440, 3, UINT32_MAX/4);
+int audio_mixer(int argc, char* argv[]){
+    play_startup();
+    while (1) sleep(1000);  // Idle sound process for time(!) being
     return 0;
 }
 
 process_t* init_audio_mixer(){
-    return create_kernel_process("audiotest", play_test_audio, 0, 0);
+    return create_kernel_process("Audio out", audio_mixer, 0, 0);
 }
 
 driver_module audio_module = (driver_module){

kernel/audio/virtio_audio_pci.cpp

@@ -3,6 +3,7 @@
 #include "console/kio.h"
 #include "memory/page_allocator.h"
 #include "std/memory_access.h"
+#include "syscalls/syscalls.h"
 #include "audio.h"
 #include "std/memory.h"
 #include "OutputAudioDevice.hpp"
@@ -26,7 +27,8 @@
 #define VIRTIO_SND_PCM_RATE_44100   6
 #define VIRTIO_SND_PCM_RATE_48000   7
 
-#define SND_44100_BUFFER_SIZE 441
+#define SND_44100_BUFFER_SIZE 256
+static_assert((SND_44100_BUFFER_SIZE & 0x01) == 0x00, "Audio buffer size must be even.");
 #define SND_U32_BYTES 4
 #define SND_PERIOD 1
 #define TOTAL_PERIOD_SIZE SND_44100_BUFFER_SIZE * SND_U32_BYTES * channels
@@ -83,7 +85,7 @@ typedef struct virtio_snd_event {
 bool VirtioAudioDriver::init(){
     uint64_t addr = find_pci_device(VIRTIO_VENDOR, VIRTIO_AUDIO_ID);
     if (!addr){ 
-        kprintf("Disk device not found");
+        kprintf("Audio device not found");
         return false;
     }
 
@@ -107,15 +109,15 @@ bool VirtioAudioDriver::init(){
     pci_enable_device(addr);
 
     if (!virtio_init_device(&audio_dev)){
-        kprintf("Failed disk initialization");
+        kprintf("[VIRTIO_AUDIO] Failed initialization");
         return false;
     }
 
     select_queue(&audio_dev, EVENT_QUEUE);
 
     audio_dev.common_cfg->queue_msix_vector = 0;
     if (audio_dev.common_cfg->queue_msix_vector != 0){
-        kprintf("[VIRTIO_AUDIO error] failed to setup interrupts for event queue");
+        kprintf("[VIRTIO_AUDIO] failed to setup interrupts for event queue");
         return false;
     }
     //TODO: This should (probably) be for input devices only
@@ -181,7 +183,7 @@ bool VirtioAudioDriver::config_streams(uint32_t streams){
         kprintf("[VIRTIO_AUDIO] Stream %i (%s): Features %x. Format %x. Sample %x. Channels %i-%i",stream, (uintptr_t)(stream_info[stream].direction ? "IN" : "OUT"), stream_info[stream].features, format, rate, stream_info->channels_min, stream_info->channels_max);
 
         if (!(format & (1 << VIRTIO_SND_PCM_FMT_U32))){
-            kprintf("[VIRTIO_AUDIO implementation error] stream does not support Float32 format");
+            kprintf("[VIRTIO_AUDIO implementation error] stream does not support Uint32 format");
             return false;
         }
 
@@ -191,7 +193,7 @@ bool VirtioAudioDriver::config_streams(uint32_t streams){
         }
 
         //TODO: Stereo
-        uint8_t channels = 1;//stream_info->channels_max;
+        uint8_t channels = 2; // 1;//stream_info->channels_max;
 
         if (!stream_set_params(stream, stream_info[stream].features, VIRTIO_SND_PCM_FMT_U32, VIRTIO_SND_PCM_RATE_44100, channels)){
             kprintf("[VIRTIO_AUDIO error] Failed to configure stream %i",stream);
@@ -215,6 +217,7 @@ void VirtioAudioDriver::send_buffer(sizedptr buf){
     virtio_add_buffer(&audio_dev, cmd_index % audio_dev.common_cfg->queue_size, buf.ptr, buf.size, true);
     struct virtq_used* u = (struct virtq_used*)(uintptr_t)audio_dev.common_cfg->queue_device;
     if (u->idx < cmd_index-20){
+//sleep(1);
         while (u->idx < cmd_index-5);
     }
     cmd_index++;
@@ -286,7 +289,6 @@ void VirtioAudioDriver::handle_interrupt(){
     select_queue(&audio_dev, EVENT_QUEUE);
     struct virtq_used* used = (struct virtq_used*)(uintptr_t)audio_dev.common_cfg->queue_device;
     struct virtq_avail* avail = (struct virtq_avail*)(uintptr_t)audio_dev.common_cfg->queue_driver;
-
     uint16_t new_idx = used->idx;
     if (new_idx != last_used_idx) {
         uint16_t used_ring_index = last_used_idx % 128;

shared/audio/cuatro.c

@@ -1,21 +1,21 @@
 #include "cuatro.h"
 #include "math/math.h"
 
-float sample_raw_wave(WAVE_TYPE type, uint32_t accumulator, uint32_t period){
-    float t = ((float)accumulator/(float)UINT32_MAX);
+float sample_raw_wave(WAVE_TYPE type, uint32_t phase){
     switch (type) {
         case WAVE_TRIG: {
-            float trig = 2*(absf(t-floor(t + 0.5)));
+            float t = ((float)phase/(float)PHASE_MAX);
+            float trig = 2*(absf(t-floor(t + 0.5f)));
             return trig;
         }
         case WAVE_SAW:
-            return ((t-floor(t + 0.5)) + 0.5f);
+            return (float)(PHASE_MAX - phase) / (float)PHASE_MAX;
         case WAVE_SQUARE:
-            return (accumulator < UINT32_MAX/2) ? 0 : 1;
+            return (phase < PHASE_MID) ? 0.f : 1.f;
     }
     return 0;
 }
 
-uint32_t sample_wave(WAVE_TYPE type, uint32_t accumulator, uint32_t period, uint32_t amplitude){
-    return sample_raw_wave(type, accumulator, period) * amplitude;
+uint32_t sample_wave(WAVE_TYPE type, uint32_t phase, uint32_t amplitude){
+    return sample_raw_wave(type, phase) * amplitude;
 }

shared/audio/cuatro.h

@@ -8,11 +8,20 @@ typedef enum WAVE_TYPE {
     WAVE_SAW,
 } WAVE_TYPE;
 
+#define PHASE_MASK 0x00FFFFFF
+#define PHASE_MAX  PHASE_MASK
+#define PHASE_MID  (PHASE_MAX >> 1)
+
+#define WAVE_MID_VALUE 0x80000000
+
+#define AUDIO_LEVEL_MAX UINT32_MAX
+
+
 #ifdef __cplusplus
 extern "C" {
 #endif
-float sample_raw_wave(WAVE_TYPE type, uint32_t accumulator, uint32_t period);
-uint32_t sample_wave(WAVE_TYPE type, uint32_t accumulator, uint32_t period, uint32_t amplitude);
+float sample_raw_wave(WAVE_TYPE type, uint32_t phase);
+uint32_t sample_wave(WAVE_TYPE type, uint32_t phase, uint32_t amplitude);
 // void make_wave(WAVE_TYPE type, float freq, float seconds);
 #ifdef __cplusplus
 }

shared/types.h

@@ -61,6 +61,8 @@ typedef signed long intptr_t;
 typedef signed short int16_t;
 typedef signed char int8_t;
 
+#define INT16_MAX 0x7FFF
+
 typedef struct sizedptr {
     uintptr_t ptr;
     size_t size;