Missing AC-4 stream

[DrSmith]

Hi,
I have an HDHomeRun Flex 4K that works great. Firmware 20250623, using HDHomeRun Windows software I can play all received, non-encrypted OTA channels. I am attempting to save AV streams to a file with a small program I wrote.
When I save from http://192.x.y.z:5004/auto/v15.1 (an ATSC 1.0 channel) I get a file with Stream 0: MPEG 2 video, Stream 1,2: AC3 audio, all good
When I save from http://192.x.y.z:5004/auto/v102.1 (an ATSC 3.0 unencrypted channel) I get a file with Stream 0: HEVC video, stream 1,2,3,4: Closed captions. Does anyone know why the AC-4 audio stream is not included or identified? I'm using the VLC player for windows for playback and codec reporting.

[kyl416]

VLC relies on FFmpeg which doesn't support AC-4, so it just ignores the AC-4 audio stream as unknown binary data

[DrSmith]

Good to know, thanks. I'll try some other players. I knew AC-4 decoding was patent-laden and probably not happening, but I figured the meta-data would at least acknowledge it existed.