[MPlayer-users] Jerky playback playing divx and mkv files

[Ismo Tanskanen]

  have been fighting with jerky playback a while. I use small minimyth 
distro in mythtv frontend. It includes mplayer to play matroska etc. 
files that myths internal player can't play

Minimyth includes nvidia 1.0-9746 drivers, 2.6.21.7 kernel, mplayer 
1.0rc1try3, alsa driver 1.0.14
I also have latest codecpack from mplayer website.

Situation:
I have strange playback problem when playing divx or matroska videos. 
Playback is jerky, and it picture sometimes stops for a half second or so.

Myth:s Internal player plays divx:s fine, but has those problems with 
matroska files. Mplayer is jerky with both filetypes. Audio is allways 
fine. It also seems not to have effect, if I play HD mkv file or normal 
DVD-resolution. Not a big difference, maybe HD is little worse, but not 
much. It also varies, sometimes picture is almost ok, but sometimes just 
unwatchable. I have two similar frontends, and both behavior just same.

MPG2 videos seems to play flawlessly, maybe they use xvmc?

Mythtv:s live tv and recordings are fine. Playing dvd:s from iso files 
with internal player is fine.

Hardware is AMD sempron 3200+, Asus M2PV-MX motherboard with NF6150 
chipset, 1GB ram, 1GB network.

Top shows only ~20-30% cpu usage when playing hd content. SD usage is 
under 10%.

Tricks i've tried so far:

- Tried different minimyth versions, oldest one (from march 2007) worked 
little better, but not good. Maybe it was only temporary, since behavior 
changes by time.

- Tried mplayer settings, all video drivers. xvmc does not work, maybe 
xv is the best. Sometimes it looks better without specifying video driver.

- Tried different video resolution, I normally use 1280x720, but I tried 
720x576, so mplayer does not need to do such much of scaling

- Disabled postprocessing in mplayer

- Tried mplayer -nosound to eliminate possible sound driver problems

- Copied mkv file to minimyth ram disk and played it from there to avoid 
possible network speed issues

- Tried with another display adapter (GF7600 256MB)

- Tried intel board and CoreDuo 2180 CPU. This worked much better, no 
stops, but still bit jerky. Unfortunately it had problems with network 
driver.

- Disabled X window manager and VNC server if they were taking too much 
resources.

- Tried xine, with same or worse symptoms.

- Tried AMD 5000+ X2 CPU, it was better, but still stops sometimes.

Does not anybody have same issue? Is there anything I could try anymore? 
I don't think it is CPU speed problem, because internal player plays 
xvid:s correctly.

  Is there any known problems with amd cpu:s or nvidia chipsets and 
xvid/matroska?

Matroska files are important to me, since I'm planning to encode all my 
dvd:s to mkv:s and put them on the hard drive. Matroska has chapter 
support and internal subtitles. Chapters are important to me, because I 
watch much music videos.

thanks at advance
-kane