Why can’t audacity load mp4 with pcm audio?

Audacity 3 Help Forum
1

hi guys

i’m not sure why audacity fail to load an mp4 file with mutliple pcm audio layers. here’s the full context guys:

  1. i recorded an mkv file in obs that contains video and multiple pcm audio layers. audacity can import this mkv without any issues. i installed ffmpeg for audacity 3.2.0, so the mkv works perfectly.

  2. when i remux the mkv to an mp4 (no transcoding, just changing the container), audacity won’t load it. instead, i get this error:

“[filename].mp4 is an advanced audio coding file. without the optional ffmpeg library, audacity cannot open this type of file.”

  1. I know the mp4 file is fine because video editing software recognizes both the video layer and the audio layers without any issues. the metadata for the mp4 also confirms the audio is pcm.
    This is an audacity or ffmpeg issue where pcm audio in an mp4 container is being misinterpreted or unsupported, I already instaleld ffmpeg for audiactiy and been working fine, but for this situation it fails and I cant understand why …

  2. Does audacity not support pcm in mp4, or is this a bug? if audacity doesn’t support it, why does the mp4 metadata confirm pcm and other video editing software handles it correctly?

Btw here is the metadata of the mp4 file: