- Audio map: the deltacast bridge delivers audio on a separate FIFO wired as
ffmpeg input 1, so the finalized master + HLS preview (and the growing
orchestrator) now map audio via `audioMap` (1🅰️0? for deltacast, 0🅰️0? for
DeckLink SDI / network) instead of an unconditional 0🅰️0?. Without this the
deltacast master/preview carried no audio.
- Channel/port: spawn the bridge with --device = board index (default 0) and
--port = source_config.port (falling back to the device index), so a recorder
can capture from any of the board's 8 channels. Adds `port`/`board` params to
start() and _buildInputArgs().
- Bridge stdin: the finalized-master ffmpeg reads the bridge's raw video from
pipe:0, so its stdin must be 'pipe' when a bridge is present (was 'ignore',
which made hiresProcess.stdin null and threw "Cannot read properties of null
(reading 'on')" at bridgeProcess.stdout.pipe(...)).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>