[FEATURE] Transcoding capability for a reworked Player

[GlassedSilver]

Blocks #544

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Is your feature request related to a problem? Please describe.
Transcoding capabilities would allow everyone (who has workable hardware) to always get the best video at their desired specs and use transcoding whenever the connection or client codec capabilities necessitate it.

Lots of storage saved and less quality wasted in many cases on already typically very lossy compressed videos. :)

Also, Apple is a special snowflake ignoring common codecs used in the real world. (and I don't see that changing anytime soon)

Describe the solution you'd like
See title, maybe we can take inspiration from projects like Jellyfin.

Additional context
Probably blocked by a rework of the Player component in general. Not sure. (there'd be some hot ideas around that one can think of easily as well, but I think the player in general right now is a lesser important part in early 2022)