[mythtv-users] 2005 laptop stutters after upgrade from 0.27 to 0.28

[Peter Bennett]

On 06/06/2017 06:39 PM, faginbagin wrote:
> Yep, I've still got a few old laptops that have been working quite 
> well as frontends. But one isn't performing quite as well with mythtv 
> 0.28 and mythbuntu 16.04 as it is with mythtv 0.27 and mythbuntu 
> 12.04. So, I'm trying to understand why, and whether there's anything 
> I can do to get it to perform running 0.28 as well as it does running 
> 0.27. The laptop and the master backend have multiple boot partitions, 
> so that's how I switch back and forth between 0.27 and 0.28
>
> I see slight but noticeable stuttering during panning scenes when I 
> playback standard definition H.264 video on 0.28 but not when I play 
> back the same video on 0.27. It's not CPU bound, the CPU hovers around 
> 30% to 35% on both versions and might be using a tad less CPU on 0.28 
> as it does on 0.27.
>
> The laptop is a Dell Inspiron B130 with an Intel Celeron M 1.5 GHz CPU 
> and an Intel Mobile 915GM/GMS/910GML Express Graphics Controller. The 
> display is 1280x800 resolution. It's configured to use the Slim 
> playback profile on both 0.27 and 0.28, as defined in the database 
> migrated from 0.27 to 0.28.
>
> I have compared mythfrontend logs using -v general,playback at the 
> default info level. I can see no meaningful difference in the log 
> output. I've hesitated to try the debug level, for fear that might 
> push the CPU and/or disk to work too hard, although maybe that should 
> be my next step?
>
> I have compared Xorg.0.log on both OSs, and only see slight 
> differences like version numbers, and a handful of different messages 
> that I suspect are due to logging changes in source and not meaningful.
>
> FWIW, the laptop can play 720p and 1080i MPEG2 transport streams 
> smoothly in both 0.27 and 0.28. But it cannot play high definition 
> H.264 content on either, where it's definitely CPU bound. I've also 
> got a couple of circa 2004 thinkpads with Pentium M CPUs and Radeon 
> GPUs that CAN handle the SD H.264 in both 0.27 and 0.28 environments. 
> It's just this Dell that's keeping me from cutting over to 0.28.
>
> Has anyone else noticed a degradation in performance on older hardware 
> after upgrading?
>
> Any suggestions on how to identify the cause, e.g. OS module, X driver 
> or mythtv?
>
> _______________________________________________

Does your laptop setup support OpenGL? You could try an OpenGL playback 
profile, that may be smoother. (if it works - I had a Dell laptop from 
2007 with Nvidia and turning on OpenGL caused the entire system to 
freeze.). Note that if you turn on OpenGL playback profile you must also 
select OpenGL for the Theme Painter.

It may be the same problem as https://code.mythtv.org/trac/ticket/12907 
. That is on Raspberry Pi, but I think the problem will happen with 
systems with less power. I think it is caused by the amount of 
processing between frames. I plan to look into whether this cam be 
reduced so as to minimize the jumpiness.

Peter