[mythtv-users] HD playback does not work well

[HP-mini]

On Sun, 2013-02-24 at 14:28 +0000, Marius Bjørnstad wrote:
> Hi,
> 
> I have mythtv on a computer which I use to watch TV, but also for other
> things. I have some trouble watching HD channels encoded in H.264, from
> DVB2. The video frequently starts going in slow motion, and after a few
> seconds it skips to the right position. It also sometimes skips back and
> forth quickly. I get these errors in the mythfrontend output:
> 2013-02-24 14:07:45.090126 E  GetNextFreeFrame() unable to lock frame
> 100 times. Discarding Frames.
> 
> It worked well before, but sadly I changed two things before I noticed
> it was broken: (1) Upgraded from 0.25 to 0.26 (2) Upgraded the CPU.
> I'm running now: mythtv  0.26.0-6
> CPU: Xeon E3-1270 v2 -- I have tried with hyperthreading disabled
> GPU: Radeon 6770 -- Open source driver
> 
> My monitor can only run at 60 Hz (sometimes it says 59.9 Hz), and the HD
> channels typically have 50fps interlaced, which should produce some
> jerky-ness, but not as extreme as what I'm seeing. I have a second
> monitor which supports 75 Hz and see the same there. The video files
> look great when I open them in VLC or mplayer instead. I have tried all
> settings for renderer and deinterlacer, without success. I don't think I
> can try 0.25 again after I've upgraded. Does anyone have any ideas of
> what I can do?

There was a ffmpeg commit (early in 0.26+fixes) that caused gross
jittering/mixed up frame order..
That commit was required for certain BBC-HD channels.
This was reversed some weeks later.
A later commit fixed BBC-HD without breaking every other H264 recording.

Can you fix (temporarily) by pause-play or seek-back-forward or
bookmark-exit-play ?

What have do you use for recording?.

There have been lots of commits in master by Jim Stichnoth (& patchable
into 0.26+fixes) tagged with HD-PVR & Keyframe/I frame detection,
missing packets etc.
All those commits were very relevant to my H264 dvb-t recordings &
cutlist editor functionality.

25/50Hz playback on 60Hz refresh rate became jittery with myth0.25 on..
VLC, mplayer & XBMC don't have this problem (XBMC has a menu setting).
There is a simple 5-6 line patch to revert to 0.24 behaviour..