[mythtv-users] video playback profile for Intel graphics

Ben Healy melben1001 at yahoo.com.au
Wed Oct 26 00:40:30 UTC 2016


>________________________________
> From: Hamish Moffatt <hamish at cloud.net.au>
>To: mythtv-users at mythtv.org 
>Sent: Saturday, 22 October 2016, 18:18
>Subject: Re: [mythtv-users] video playback profile for Intel graphics
> 
>
>On 22/10/16 16:47, Hamish Moffatt wrote:
>>
>>
>> 2. Crashing on certain videos. I've got a series of videos in 720p 25 
>> fps which I've been watching lately. I can watch one, but starting any 
>> of those videos a second time causes Mythfrontend to crash. The last 
>> line in the log is:
>>
>> Oct 21 21:26:19 bandicoot mythfrontend.real: mythfrontend[29899]: I 
>> CoreContext mythrender_vdpau.cpp:615 (CheckOutputSurfaces) VDPAU: 
>> Added 2 output surfaces (total 4, max 4)
>
>This seems to be related to MP4 HEVC videos. My VAAPI can't do it (Intel 
>Haswell), so Myth falls back to VDPAU even though VAAPI is selected as 
>the profile. The VDPAU works fine on the first run but crashes on the 
>next run.
>
>Oct 22 17:28:46 bandicoot mythfrontend.real: mythfrontend[5446]: I 
>CoreContext mythrender_vdpau.cpp:1796 (CheckHardwareSupport) VDPAU: 
>Information OpenGL/VAAPI/libswscale
>  backend for VDPAU
>
>... which is from libvdpau-va-gl1, not the mesa package I mentioned before.
>
>I removed libvdpau-va-gl1 and now it can't fall back to VDPAU, and it 
>doesn't crash. Will need a bit of time to determine if the overall 
>performance/quality is acceptable now though.
>
>

>Hamish

Hi Hamish

I also have a Haswell Chromebox. I'm running Mythbuntu 14.04 and used the Tear Free option to get rid of tearing. I think there's also a hardware cursor option in there too to as I think I had an issue with the cursor showing up sometimes.


I have settled on a modification to the VAAPI profile, so that VAAPI is only used for videos >= 1920*1080. Lower than that and OpenGL will be used. (I could probably change that to >= 1280*720, but some channels here transmit 1920*1440 and the CPU can just handle it)


I do this because the deinterlacing is fairly poor in the current MythTV VAAPI implementation. It doesn't look too bad on HD TV, but is quite poor on SD so Open GL looks better. Even though the profile is set to use bob deinterlacing, I think it's only using Onefield and I have never been able to work out why.


I also updated to the Xenial kernel yesterday and that seems to have improved performance a bit, but if you're on 16.04 that's not relevant.

I have KODI installed that I launch from a menu item if I really want to use good deinterlacing or if MythTV is struggling with something as the KODI implementation of VAAPI is currently much better, with very good deinterlacers.

Overall it's a nice, little, quiet, cheap box that has been working well for me as a combined backend/frontend for quite some time now.

Ben


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