setup-ltc-loopback.sh

#!/bin/bash
# LTC Loopback using module-remap-source to create a proper input device
# This approach creates both a sink and a remapped source that Qt can see

set -e

case "$1" in
    start|"")
        echo "Creating LTC virtual audio cable..."

        # Create a null sink (output device)
        SINK_ID=$(pactl load-module module-null-sink \
            sink_name=ltc_cable_sink \
            sink_properties=device.description="LTC_Cable_Out")
        echo "Created output device: LTC_Cable_Out (module $SINK_ID)"

        # Create a remapped source from the null sink's monitor
        # This creates a proper input device (not just a monitor)
        SOURCE_ID=$(pactl load-module module-remap-source \
            master=ltc_cable_sink.monitor \
            source_name=ltc_cable_source \
            source_properties="device.description='LTC_Cable_In' device.class=audio/source")
        echo "Created input device: LTC_Cable_In (module $SOURCE_ID)"

        echo ""
        echo "Success! Virtual audio cable created."
        echo ""
        echo "In vtcgui:"
        echo "  Generator → Select 'LTC_Cable_Out' as output"
        echo "  Reader    → Select 'LTC_Cable_In' as input"
        echo ""
        echo "To remove: $0 stop"
        ;;

    stop)
        echo "Removing LTC virtual audio cable..."

        # Remove in reverse order
        pactl list short modules | grep ltc_cable_source | awk '{print $1}' | while read id; do
            pactl unload-module "$id" 2>/dev/null && echo "Removed source module $id" || true
        done

        pactl list short modules | grep ltc_cable_sink | awk '{print $1}' | while read id; do
            pactl unload-module "$id" 2>/dev/null && echo "Removed sink module $id" || true
        done

        echo "LTC virtual audio cable removed"
        ;;

    restart)
        $0 stop
        sleep 1
        $0 start
        ;;

    *)
        echo "Usage: $0 {start|stop|restart}"
        exit 1
        ;;
esac