Video preview thumbnail generation only using one thread

Server Version#: 1.22.2.4282 (On Ubuntu 20.04)
Player Version#: N/A

I had a Pentium Gold G5420 (2 cores with hyperthreading) in my Plex server, but video preview thumbnail generation was taking a while, among a few other issues under CPU load. I saw a deal on an I7-9700K (8 cores, no hyperthreading) so just replaced that in the server.

I imported a couple of files into the library to see what kind of difference it made with the additional cores, but it looks like Plex Transcoder generating the thumbnails is only using a single core.

Is there a way to change this behavior to utilize more cores?

Unfortunately - - No.

Engineering deemed it to be a Background task.

I’m sure they would change that if there were enough Feature Request votes to support it.

Alright, I guess its not critical. I think the issue I was having before is that I would get a bluray collection in the mail and import 26-52 episodes of a show, and then have to wait for the thumbnail previews to be done generating to start watching it when using the Pentium Gold (because subtitle and audio transcoding during playback were still happening on the CPU depending on which client I was using).

So with the i7 it will take about as long, but I can start watching immediately and let them run in the background on that single core - so I get where they are coming from.

Curious what happens if you start an episode while video preview thumbnails are still being generated? Are they available immediately in the playback session as they are generated?

I am still noticing other improvements. The media library is on the same SSD from before but thumbnails in menus are showing up quicker, and playing / fast forwarding / rewinding etc. is happening smoother & snappier.

I also have a lot of 480i content from older DVD’s with subtitles, and they were having issues playing back and especially seeking on certain clients due to the subtitle generation and deinterlacing using the CPU, all of those issues are resolved too (which was another main goal).

Originally thought all I needed was the Intel Quicksync and no other CPU horsepower, glad the upgrade was worth it.

Once PMS has done its cursory analysis (knows the bit rates and stream info), you can play the file.

You don’t need to wait for the rest to be generated. It will catch up.

Quicksync + some CPU power is still needed. The CPU itself is needed for adio conversions, subtitle burning, preview image generation, and detailed profiling (for remote access streaming).

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