High CPU usage with HW transcoding

[Mike5123 1]

I'm on 3.6.0.56 on Ubuntu 18.04 using VAAPI (have to, since the non-beta version wouldn't use HW transcoding at all) and I'm having some high CPU usage with hardware transcoding.

 

Converting x265 10bit 1080p to x264 at max settings gives me a 35% GPU load during buffer and 70% of a core at the same time. This is with an Intel i7-8700.

 

Plex did not have this CPU overhead. But I switched to Emby for a number of reasons, including how plex wouldn't play my movies on my fire tv stick.

 

And sure, assuming the Intel 630 GPU could even support 12 users there would still be 3.6 cores free. But that's still a rather high load considering the whole point of hw transcoding is to not use the CPU.

 

Is there a setting I need to change to remove the CPU overhead? audio? subtitle (not that it was playing), etc?

 

CPU is set to performance mode and clocking in at 4.4Ghz.

[Luke 42078]

Hi there @@Mike5123, can we look at an example? Please attach the information requested in how to report a media playback issue. thanks !

[Mike5123 1]

So, I take it back. Subtitles cause the 70% CPU usage and with them disabled its around 40% and only for the buffering to finish. So about what i'd expect.

 

Still not sure why subtitles use so much CPU on plex & emby, I take it they can't be put on the GPU?

[Happy2Play 9780]

I assume your are referring to psg subtitle burn in, is that correct?  If so there are multiple topic about issues this issues.  And they all recommend using external subtitles (srt).

[Mike5123 1]

Is there a way to force download open subtitles for existing files?

[Mike5123 1]

For some reason it only shows one of my streams playing in the admin panel when I'm running 4 for testing.

[Luke 42078]

Is there a way to force download open subtitles for existing files?

 

Just configure the download settings and the downloads will occur with the next run of the subtitle download scheduled task.