Page 1 of 1

vdpau blockiness

Posted: Sun Dec 16, 2018 7:05 pm
by mcmoyer
I've been battling blocks appearing during playback on my machines lately.
IMG_0080.jpg (101.64 KiB) Viewed 654 times
It happens most in fast sideways action so sports are kind of a pain to watch right now. I'm using VDPAU with a GeForce GT 730. This started happening a while back, after some system update. I almost think it was an NVIDIA driver update.

My system is:

Mythbuntu 16.04
GeForce GT 730 (1 GB ram)
4 GB ram
Intel(R) Core(TM)2 CPU 4300 @ 1.80GHz x 2

I'm currently running 0.29, but it was also happening with 0.28.

I've tried setting `vdpaubuffercount=50` but that didn't make a difference.

Anything else I can try?

Re: vdpau blockiness

Posted: Sun Dec 16, 2018 7:10 pm
by mcmoyer
I forgot, I'm currently on version 410.78 of the NVIDIA driver, but I swear I've tried ever version from 340 on up.

..and I can watch the same recording with Kodi running on my Mac and there are no blocks in the video. It's completely smooth.

Re: vdpau blockiness

Posted: Sun Dec 16, 2018 7:25 pm
by pgbennett
There is a bug in VDPAU mpeg2 decoding where many TV stations are showing this problem, because of "unexpectedly long motion vectors". If you only notice it on certain local channels, that is likely the problem. It is showing up more often now because recently more broadcast stations are sharing the same frequency, requiring higher compression rates. NVidia are aware of the problem and have no plan to fix it. It is in the hardware so could not be fixed for exsiting cards anyway. The solution is to use standard (software) decoding for mpeg2. You can update your playback profile to use standard decoding with OpenGL for mpeg2 and VDPAU for the rest. Alternatively switch to an OpenGL profile for everything.

Re: vdpau blockiness

Posted: Mon Dec 17, 2018 12:30 am
by mcmoyer

I can't believe the fix was that quick...granted there's a bit more CPU usage now, but wow...the picture looks great again.

Thanks for the quick reply!

Re: vdpau blockiness

Posted: Mon Dec 24, 2018 3:11 pm
by mcmoyer
I decided I can live with the blockiness given how much CPU the openGL modes seem to use with my card.