Edit: We now have a good half dozen people reporting identical behavior. It has been this way for over six months. This sure sounds like a bug yet I see zero responses from anyone that can actually fix this.
Problem: H.264 mkv files get transcoded on iOS no matter what the settings are for playback quality. Converting these files to an mp4 container allows for direct play, indicating that the issue is not with the encoding of the file itself or the bandwidth of the connection or the cpu strength of the player.
Expectation: H.264 mkv files should direct play if the same file can direct play when converted to an mp4 wrapper (no re-encoding, direct copy of streams).
I just moved to an iPad Pro from an android tablet for plex playback and noticed many files that should be able to be direct streamed are being transcoded by Plex. Selecting "original quality" in the drop down does nothing. Several times, transcoded bitrates are higher than the original bitrate! What the hell is going on? This is the core functionality of Plex and it appears to be broken on iOS.
There was a post with this exact same issue from May and it was shown as "answered" despite it obviously being a bug.
Before you ask:
- H.264 encoding, Level 4.0, Stereo AAC Audio
- No subtitles being used
- Server is set to "maximum" playback quality
- There is plenty of network bandwidth to do a direct stream (my lowly Nexus 5 and my Pixel C tablet can play these same files at original quality)
- Encodes using the exact same settings at slightly lower bitrates direct play just fine on the iPad (as in this likely isn't some "compatibility issue" with the files)
As near as I can tell, any file with a bitrate above 10.0 MBps (or perhaps a threshold on the file size itself?) gets transcoded on iOS. Are you trying to tell me an iPad Pro can't play a 1080p 10.5 MBps H.264 stream when a 3 year old android phone can? BS. This is a bug with Plex on iOS and it was shrugged off previously, so here I am trying to bring more attention to it.
I can provide sample files if necessary.