CasparCG's bundled FFMPEG/HLS consumer muxes a broken audio track
(aac sample_rate=0, time_base 1/0) into the preview, and silently drops
every arg that would remove it (-an, -codec:a, -g, -r all "Unused
option"). That corrupt audio black-screens the browser preview because
neither ffmpeg nor hls.js can decode the playlist.
Re-architect the preview path: CasparCG now STREAMs plain mpegts to a
UDP loopback port, and a Node-spawned STANDALONE ffmpeg (where -an
actually works) re-muxes it to clean, video-only HLS with -c:v copy.
The child process is tracked, auto-respawned while running, and killed
in stopChannel(). The PRIMARY SRT/RTMP/SDI/NDI output (with program
audio) is untouched.
Also fix the Dockerfile to match the working image: ubuntu:22.04 base +
CasparCG 2.4.0 ubuntu22 zip + NodeSource Node 20, and add a standalone
ffmpeg CLI. The old 2.3.3 tarball URL 404s. entrypoint.sh updated for
the 2.4.x bin/casparcg layout + bundled lib/ LD_LIBRARY_PATH.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Zac Gaetano
27a868aa5c