Support raw h264 and vp8 input streams over tcp/udp/unix without transcoding

[spigelli]

[davidzhao]

We do support bypass transcoding with WHIP, and that's what I'd suggest. A few issues that we can see with raw streams:

• elementary streams may not contain timing information, so it'd be challenging to synchronize playback speed
• similar to the above, A/V sync will be an issue when ingesting a video with sound as they would be two separate tracks
• with TCP, you have head-of-line blocking, potentially producing a choppy translation to real-time
• with UDP, there is no standard to recover/retransmit lost packets (this is the benefit of WebRTC/WHIP here)

Due to the above, we do not see this as a viable path for ingest.