Adding a "force audio only" option

[Sp3r4z]

Describe the problem to be solved

In the new v6.3 release, it is possible to stream audio only on client side, but not possible to just force, from server/admin side to just have audio only without any video content.

Describe the solution you would like

If we can have an audio only content, forced by server/admin side, it would be a good idea. This can helps to create podcast player. Maybe an URL parameter, to get an embed with only audio content.

[FediVideos]

Yes, would love this. Would like option of audio files to be automatically presented as audio files at the other end. This would encourage people to set up audio-themed instances to use for podcasts, as podcast RSS compatibility and ActivityPub following is already there.