Streams with audio and video muxed together aren't supported

[AxelDelmas]

This is probably a wontfix

[basketofsoftkittens]

I am curious as to why this is a wontfix. is it possible to do?

[AxelDelmas]

This is currently unsupported by the demuxer layer. We need to see if somebody has a use case for this, but we're primarily targeting MPEG-DASH support and muxed content is not very usual, although it is supported by the spec.
PRs are welcome of course