A file's CONTENT can tell ffmpeg to open other paths or URLs (HLS, concat
playlists). ffmpeg 7.0.2 refuses the ones tried, but that is version luck and
the image's ffmpeg is still to be chosen (#34). Pin protocol_whitelist to
file,pipe and format_whitelist to the demuxers real audio uses, before the input.
Red: audio.AllowedDemuxers is undefined.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Replaces whisper-server --convert. A zero exit that wrote nothing is an error.
Also fixes the red test's stub, which wrote an empty file and so (correctly)
tripped the no-output check.
Checked against real ffmpeg on iguana with the same argv: AAC .m4a in,
pcm_s16le 16000 Hz mono WAV out, duration preserved.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>