I searched through the discussions but didn’t really find anything on this. I have multiple resolutions stored for the same video (480p, 720p, 1080p, 4k). In most cases when remote streaming, the optimal version of the film for no buffering is being selected automatically. However, when the server decides to transcode it is most often choosing to transcode down from the 4k file to a 720p format. Why is it doing this? Is there a way to stop this other than separating the 4k into a different library? Can I make a request to add an “if-then” scenario to Plex’s’ coding that if transcoding starts to select the closest source resolution to the target resolution?
As far as I am aware it should be using the one closest to the target without going under.
Would you mind sharing your server logs after it transcodes using the 4k version.
Plex Media Server Logs_2022-02-02_11-23-16.zip (7.0 MB)
I used the movie “Abominable” as a test but the issue occurs with almost every movie that has a 4k version loaded. Should be timestamped around 11:12 or so. Thanks in advance.
Check Settings → Scheduled Tasks.
Are Upgrade media analysis during maintenance and Perform extensive media analysis during maintenance selected?
Plex analyzes the files during scheduled tasks, including determining the bandwidth required to stream the file. Several of your files, including the 4K version of Abominable, are missing this analysis. This may be affecting Plex’s ability to select the proper file for transcoding.
The process shows up as “deep analysis” in the log files:
Feb 02, 2022 11:13:30.627 [10336] DEBUG - [Transcode] Streaming Resource: Required bandwidth unknown (media requires deep analysis) Changing decision parameters provided by client to fit bandwidth limit of 720kbps
Feb 02, 2022 11:13:30.627 [10336] DEBUG - [Transcode] Streaming Resource: Determining preferred transcode encoders through transcode only decision.
“Upgrade” was selected but “Extensive” was not. I have updated the settings. Thanks, I will update whether or not this fixes the issue.
The analysis will run during the scheduled tasks window.
You can tell if it ran by looking that the XML info for the movie.
You will see deepAnalysisVersion="6". Also, several entries with requiredBandwidths (for the overall movie, the video, and each audio & subtitle track).
No luck. deepanalysis has been run and is showing as “=6” in the XML info with the bandwidth info filled in, but it is still trying to convert from 4k to SD instead of choosing the 720p version.
I will include updated server logs and the XML info. I started the movie at 14:29
Abominable XML.txt (79.5 KB)
Plex Media Server Logs_2022-02-02_14-32-47.zip (8.4 MB)
The issue still persists. I notice that the server is also sometimes choosing 1080p versions to transcode down to SD instead of the 720p version. So, I guess there are no other solutions? Anything else to try?
I will say that it is genuinely frustrating to receive not so much as a “hey we are looking into this issue”. As a fairly long time Plex Pass holder and usually enthusiastic advertiser, to be ghosted on a legit issue stings a little.
Apologies for not getting back to you. Afaik I think it is choosing the 4k version because it is HDR and you have an HDR capable TV. I’m going to poke a dev again to confirm
Ok. I see that the server is choosing to transcode from 1080p to 720p even when I have a 720p version available. Can someone please explain why? If it is something I am doing wrong please let me know as I don’t want to be arbitrarily using more power than necessary. I included updated server logs as well as a screenshot of the two films transcoding. You can see in the logs that it shows both resolutions available and deepanalysis=6. Thanks
Plex Media Server Logs_2022-02-18_11-32-08.zip (6.9 MB)
Well never mind I guess. Just F me for asking a legit technical question…
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