Add RFC: Add notion of protocol

[tytan652]

RFC 45: Add notion of protocol

Summary

• Add notion of service protocol in libobs and OBS Studio
• Outputs for streaming are registered with their compatible protocol and codecs
• Only codecs compatible with the output and the service are shown
• Audio encoder can be choosen if various compatible
• Will be extended with RFC Add RFC: Service Overhaul #39

Motivation and Context

Create a better management of outputs, encoders and services with an approach focused on protocols.

Link to RFC

[henke37]

It seems like a needless feature to let users select which implementation of a protocol they want. And that's the only feature here that can't trivially be moved to the output objects.

[tytan652]

Big rewrite of the RFC, thank you @henke37 for the (maybe wrong word) spur.

I was stuck thinking about protocol and output being separate thing but having them together is better and more lightweight codewise.

[tytan652]

Maybe not enough "complete" but I begin to need reviews.

[derrod]

In addition to codec compatibility, we might want to have a flag in the services file to indicate compatibility with HDR (None/PQ/HLG/Both).

Services may support HEVC or AV1 codecs for improved compression, but do support HDR delivery or tonemapping to SDR, which would result in viewers receiving a clipped version of the video. Furthermore they may support only one of the HDR formats (e.g. PQ but not HLG).

While the number of services supporting HLS or SRT/RIST ingest is currently limited, in the future there may also be outputs such as WHIP or MoQ/WARP that support more than H.264.

[tytan652]

In addition to codec compatibility, we might want to have a flag in the services file to indicate compatibility with HDR (None/PQ/HLG/Both).

Services may support HEVC or AV1 codecs for improved compression, but do support HDR delivery or tonemapping to SDR, which would result in viewers receiving a clipped version of the video. Furthermore they may support only one of the HDR formats (e.g. PQ but not HLG).

While the number of services supporting HLS or SRT/RIST ingest is currently limited, in the future there may also be outputs such as WHIP or MoQ/WARP that support more than H.264.

All of this is out of scope of this RFC, it is more related to RFC #39 but selecting a color format is literally a trial and error in OBS as it always was, the user can apply unusable settings in advanced video. This needs a major refactor of settings that can only be done after (maybe while) RFC #53 which is after 39.

[RytoEX]

Some further questions.

[Fenrirthviti]

Entering FCP. We've merged the initial PRs, but any further adjustments necessary are still welcome. Once the open conversations are resolved, we will merge this.

[tytan652]

I just squashed all the commit together.

[RytoEX]

My concerns were resolved. The implementing PRs have been merged anyway, so my approval is more a formality at this point.