[mythtv-users] .25 on mac-mini

[Jean-Yves Avenard]

On 25 April 2012 00:09, Sean Whitney <sean.whitney at gmail.com> wrote:
> 1) HDPVR 1080 playback on mac-mini using 0.24 with the quartz-blit or
> xv-blit profile was functional.
> 2) Upgrades to 0.25 has introduced a new performance bug that is
> affecting all profiles available.  This bug is manifests as stuttering
> audio/video.  Other types of 1080 encoded playback works great (ie, the
> HD test video)
>
> What can we do to help troubleshoot/fix this bug?

I actually don't think it's myth 0.25 per-say that introduced a problem.

There has been so many changes on how the application is built.
First, Qt was updated. Which version of Qt is used depends on what the
person who build your package decided to use. Myth can be built
against 4.6, 4.7 or 4.8
There could very well have been a regression in Qt that introduced a
new problem. It wouldn't be the first time it happens.

Quartz is only available using the Carbon framework which is a 32 bits
only framework. If your application is 64 bits, you can't use Quartz.

It was actually my intention to remove any Carbon related code from
the mythtv code. I don't think it's the problem...

The HD-PVR videos are known to be compressed with a highly complex
h264 profile, much more complex than what the test video use

We need to do some profiling to find out where the CPU cycles are used.

In the mean time, try the OpenGL normal video profile  (Setup ->
Videos -> Playback), make sure the painter is also OpenGL (Setup ->
Appearances).
Edit the OpenGL Normal profile and make sure that the number of CPU is
at least 2.
You can also try the "Normal" playback profile.

mythtv uses the newer ffmpeg which can make use of the multi-core CPU.

When playing the video, what is the CPU usage? is it more than 100% or below ?

Finally, can you make a sample of that video available somewhere?

Thanks.

We'll get to the bottom of this
Jean-Yves