Things become strange when your videos are in x265 10bit. Plex definition of bitrate is not straight what you see from the video itself. It is like Plex does everything in x264 but to me it does not make sense, I have no idea how it works, but it is not straight forward. You might be playing a x265 video with 5mbs bit rate and Plex says it is 12mbs or something weird like that.
At the moment transcoding thresholds based on bitrate do not make sense anyway when you have a mix of x264 and x265 because Plex is implementing something wrong there. You have to increase the transcoding threshold to something really high to avoid x265 videos to be transcoded, but then that threshold is too high for x264.
If the video cannot be direct played on the client for whatever reason it’s going to get transcoded, and for video that generally results in a stream larger than the source (to maintain quality). It’s also possible you’re looking at the video bitrate and forgetting the audio bitrate has to be included in the total, too.
Do you have any examples to back up this idea that Plex is being untruthful in calculating bitrate of HEVC video verses AVC? Bitrate is a measure of data flow. The type of data doesn’t even enter the equation.
Of course I know that, that’s not the problem. It is clear that if a x265 video is transcoded the result will be a much bigger video because it will be transcoded to x264.
The problem is when you are defining transcoding thresholds i.e. do not transcode under 1080 8mbs. This works very clear when the original video is x264. But when it is x265 weird things happen. A video that is lets say 6mbs will trigger transcoding, and to me that does not make sense. The whole “transcoding threshold” is due to bandwidth limits, so if I want to have a 8mbs limit then a video that is 6mbs should not be transcoded, but it is transcoded.
Look, I have zero interest in winning Internet discussions. I just saw that some users were not understanding what @AmpedSilence said and I was trying to clarify his point, because he is totally correct. I experience problems with this basically every single week because I have most or my recent TV series in x265 and I stream from outside my house during my launch breaks and every time the Internet speed is fiddly I have to play around with this nonsense.
I have never seen this happen when the target device fully support the file in question. I have however seen that an unsupported audio track can result in Plex transcoding both audio and video, for some stupid reason, on some devices.
Its a really simple, easily reproduced test, so i dont see why there is so much discussion.
Find a x265 10bit 1080p file in your server that is below 4mbps (animated shows are the most dramatic… i.e. Archer on fx, which typically has a total bitrate of 800kbps).
Set the play quality to 4 mbps 720p…
Watch the server encode the 800kbps 1080p file to 4 mbps 720p…
Switch it back to maximum, watch file direct play…
Its common for me and all my users and now is bigger becuase the 12 mbps 1080p limit will transcode 4k 6mbps hdr files down to 12 mbps 1080p sdr.
Maybe the transcode limit should be defined only by bitrate and not by resolution. Or at least an option to not transcode videos in higher resolution if the bitrate is still under the threshold.
According to you that would transcode because 480p < 1080p.
What are we doing differently to see different results?
I tested using Plex for Windows Version 1.76.2.3951-15712eae. I also tried Plex Web Version 4.116.1 in Chrome and got similar results except it direct streamed instead of direct played, but still didn’t transcode.
I also just tested it on an iPhone (Plex for iOS 8.26) with the same test file as above and it direct plays at original quality but the server transcodes when reducing the quality.
However, I also tested it on Android (Plex for Android 10.2.0.4374) and it still direct plays with a lower quality selected.
At this point Plex is behaving as I expect (direct playing) on more platforms than not. So I am leaning towards a bug or limitation specifically with iOS rather than a general issue.
Do you have Settings > Quality > Remote streaming quality > ‘Play smaller videos at original quality’ set? Also, I don’t know if the limit applies to the average bitrate, or Plex’s peak bitrate calculations done during deep analysis. If you go to View XML in the Get Info screen, are there requiredBandwidths entries, and if so, are they higher than the bandwidth limit?
I think in this particular case the issue is that Plex is rounding up the bitrate and somehow deciding it should be transcoded. I think there is as well some issue in the way Plex decides the bitrate of x265, because I’ve seen weird things like files with let’s say 6mbs and Plex reporting it as 10mbs during playback. I tried to explain that before but someone started to mock me to I decided to let it go.
If that is your theory (rounding up), then does it make a difference if you select 1080p 8 Mbps? What if you try a file with a slightly lower bitrate so it is well below 4 Mbps?
With very low bitrate it won’t transcode. For example 1.2mbs will be reported as 2mbs and it will be direct played. I assume because 2 is still lower than 4.
But the “rounding up” is sometimes not just to the next whole unit. For example, this 3.4mbs file is reported as 5mbs during playback:
