[mythtv-users] MythTV Raspberry Pi2 frontend testers

[Patrick Ouellette]

On Mon, Nov 30, 2015 at 07:02:34PM +0000, Lawrence Rust wrote:
> Date: Mon, 30 Nov 2015 19:02:34 +0000
> From: Lawrence Rust <lvr at softsystem.co.uk>
> Subject: Re: [mythtv-users] MythTV Raspberry Pi2 frontend testers
> To: Discussion about MythTV <mythtv-users at mythtv.org>
> X-Mailer: Evolution 3.2.3-0ubuntu6 
> 
> On Sat, 2015-11-28 at 11:39 -0500, Peter Bennett (cats22) wrote:
> > On 11/27/2015 03:46 PM, Lawrence Rust wrote:
> > > I'm missing something. I've tested a number of videos, monitors &
> > > resolutions and haven't see any jerkiness with eglfs playback. So a
> > > small favour, would you run a test with the most jerky video that you
> > > have and post me the mythfrontend log with '-v playback --loglevel
> > > debug' args. It would also be extremely useful to test a video that
> > > causes problems so is it possible to download it from somewhere?
> > 
> > Mythfrontend log with those parameters is here
> > https://dl.dropboxusercontent.com/u/45325311/mythfrontend.log
> > This is on the 1280x1280 DVI screen and analog audio. First build (I did
> > not yet install the new build from today).
> > In that log, I played the recording from timestamp 11:22:52 to 11:23:22.
> > During that 30 seconds the audio is choppy and the video jerky.
> > 
> > The recording is many Gigabytes, so I extracted the first 2 minutes
> > using ffmpeg. This only extracts video and one audio track, no sub
> > titles. Playing this 2 minute video through Mythtv Videos gives the same
> > jerkiness.
> > The file is here
> > https://dl.dropboxusercontent.com/u/45325311/News_Extract_2min.mpg
> 
> Peter,
> 
> Many thanks for the logfile and recording.  I can now reproduce the
> jerkiness that you describe.
> 
> Unfortunately, it would appear that the problem is largely h/w related.
> The recording is MPEG2 1920x1080i 30Hz which is saturating the GPU.  The
> key point is the log lines 'Waiting for video buffers' which indicate
> GPU overload.
>

This doesn't explain why the same MPEG2 video renders perfectly with other
applications or in xcb. I would think if it was overloading the GPU it would
happen anytime you wanted to play 1920x1080 30Hz MPEG2 video but it doesn't
with other software. OpenElec/Kodi works just fine with such video with full 
advanced hardware deinterlacing enabled.

I appreciate the work you've put into this, and I hope you can find out why
this happens. 

Thanks for the hard work!

Pat