fc_pipe now muxes video + that frame's embedded audio into ONE streaming AVI
container on stdout, so ffmpeg reads a SINGLE input (-f avi -i pipe:0) instead
of a raw video pipe + a separate live audio FIFO. The two-live-pipe design
deadlocked ffmpeg (it stalled forever probing input 0); a single interleaved
stream removes that failure mode entirely.
fc_pipe.c:
- New AVI mode (argv[3] == "--avi"/"avi"). Writes RIFF('AVI ') + LIST(hdrl)
{ avih + strl(vids: strh+BITMAPINFOHEADER UYVY 16bpp) + strl(auds:
strh+WAVEFORMATEX PCM s16le 48k 2ch) } + LIST(movi) once, then per ring
entry a '00dc' video chunk followed by a '01wb' audio chunk (LE sizes,
even-pad). RIFF/movi sizes use the 0x7FFFFFFF streaming sentinel (pipe is
unseekable); dwFlags has NO index bits. Frame-coupled by construction: both
chunks come from the SAME ring entry in one read-loop iteration.
- dwScale/dwRate = fps_den/fps_num (video) and nBlockAlign/nAvgBytesPerSec
(audio). If a frame has audio_size 0, emits one frame-interval of silence
(round(48000*fps_den/fps_num) samples) so the audio timeline tracks video
and ffmpeg never starves on the audio demuxer.
- Legacy raw video-only mode retained when no avi flag is given. The old
split-stdout/audio-FIFO threaded path is removed (it was the deadlock).
fc_client.{h,c}:
- Add fc_consumer_info() / fc_stream_info_t to expose the slot header's
width/height/fps/audio params to fc_pipe for the AVI header.
capture-manager.js (_buildInputArgs deltacast/sdi framecache branch):
- Spawn fc_pipe with "--avi" (no audio FIFO). Remove the mkfifo + audio-FIFO
creation for this path.
- inputArgs: ONE input -thread_queue_size 512 -f avi [AUDIO_OFFSET_MS] -i pipe:0
(was: -f rawvideo -i pipe:0 AND -f s16le -ar 48000 -ac 2 -i <fifo>).
- audioInputIndex 0, audioFifo null. Growing VC-3/HEVC builders already map
[0:v] and audioMap 0🅰️0?; with one AVI input that resolves to 0:v / 0:a.
Validated on zampp3 against the LIVE deltacast-0-0 slot: fc_pipe --avi | ffmpeg
-f avi -i pipe:0 -> dnxhd/pcm_s24le MXF gives 360 video / 360 audio packets in
6.006s (no stall at 2 frames). A synthetic 1 kHz sine slot through the same
path yields mean_volume -9 dB / max -6 dB, proving the muxer carries real audio
end-to-end (the live SDI input currently carries no embedded audio, so the
bridge's silence fallback reads -91 dB — upstream of the muxer).