[mythtv] 50fps video playback on 30Hz display (4K on HDMI 1.4 output)

[Andreas Mayer]

On/Tue Oct 30 16:19:39 UTC 2018/  Peter Bennett <pb.mythtv at gmail.com <http://lists.mythtv.org/mailman/listinfo/mythtv-dev>> wrote: 

> I have added some checkboxes in the video playback advanced settings to
> disable certain pixel types. You can try disabling one or both of those
> to see if the results are any better. These are mainly useful for
> android and low powered systems but they may make a difference.
Disabling YV12(YUV 4:2:0) and UYVY(YUV 4:2:2) pixel format did not make 
any difference for VAAPI2.

> Please can you supply a sample video to test VAAPI and VAAPI2 issues. I
> will see if there is a way to improve the CPU requirements so that
> vaapi2 and avsync2 give a good result.
Will send PM ...

mythffmpeg -i hevc_test.ts
Input #0, mpegts, from 'hevc_test.ts':
         Duration: 00:02:47.65, start: 44350.528844, bitrate: 4602 kb/s
         Stream #0:0[0x1ff]: Video: hevc (Main 10), yuv420p10le(tv, 
bt2020nc/bt2020/arib-std-b67), 3840x2160 [SAR 1:1 DAR 16:9], 50 fps, 50 
tbr, 90k tbn, 50 tbc
         Stream #0:1[0x200](DEU): Audio: aac (LC), 48000 Hz, stereo, 
fltp, 192 kb/s

I'm using a playback profile with filters, OSD fading and deinterlacing 
disabled, avsync2 enabled and mythavtest for playback (on a 1920x1080 at 50 
display)

With VAAPI video and audio looks OK (although with -v playback you can 
see frames being dropped), intel_gpu_top shows 90-98%
With VAAPI2 only a few video frames are shown every few seconds, 
intel_gpu_top shows low gpu utilization.

Thank you,
Andreas