Server Version#: 1.19.1.2701-6327e27bf
Player Version#: 4.32.1
When transcoding in general, plex does not offer any choices to transcode to a higher bitrate than the source. This is not limited to HEVC, but it is most egregious an issue when it comes to HEVC.
Why would I want to transcode to a higher bitrate? Generally speaking, transcoding is lossy, so going to a higher bitrate will likely introduce fewer artifacts and quality loss. The place where this is relevant is not when transcoding to account for slower networks, but it is very important for transcoding when the reason is simply player compatibility.
When it comes to HEVC, you can generally expect to get the same quality at half the bitrate. With that in mind, whenever plex transcodes from a HEVC source, it should ALWAYS consider the source to be twice its actual bitrate. This issue is especially bad because PMS assumes that 4mbps is 720p. I have plenty of 4-5mbps 1080p HEVC that looks far better than h.264 at even 10mbps. So when I try to watch one of these videos on a player that can’t do HEVC decoding, plex is not only killing it by going to h.264 at only 4mbps, it is also usually shrinking the frame to 720p.
This is also a huge issue for players that need to burn subs…
The easy fix here is to just allow the user to choose higher bitrates than the source when transcoding, always just allow that, because it is actually useful even for h.264 -> h.264. But it is not just useful, but required for transcoding HEVC without ruining it.
