<div dir="ltr">Hey guys, I've trawled the mailing list archive for this problem. I've found a few people talking about it, but no definitive fix.<div><br></div><div>My Problem:</div><div><br></div><div>I've got one channel (our local PBS affiliate) that is giving me grief. Every video I record off of it plays back as if it's trapped in slow motion. The video is slow, the audio is slow and crackly, and the log is filled with messages such as the following:</div>
<div><br></div><div><div>2008-07-30 23:34:00.259 NVP: Video is 3.44581 frames ahead of audio,</div><div> doubling video frame interval to slow down.</div><div>2008-07-30 23:34:00.259 Disabled deinterlacing</div>
<div>2008-07-30 23:34:00.309 NVP: Video is 6.10433 frames ahead of audio,</div><div> doubling video frame interval to slow down.</div><div>2008-07-30 23:34:00.359 NVP: Video is 8.05778 frames ahead of audio,</div>
<div> doubling video frame interval to slow down.</div><div>2008-07-30 23:34:00.408 NVP: Video is 9.48239 frames ahead of audio,</div><div><br></div><div>I've tried as many different combinations of settings as I could think of to no avail. Every video I record off of this channel exhibits this problem.</div>
<div><br></div><div>* "Audio Output Device: ALSA:default", jittery audio & video.</div><div>* "Audio Output Device: /dev/dsp", smooth video, no audio. The frontend complains that /dev/dsp is locked by another process, however, when I fuser /dev/dsp I see nobody using it.<br>
</div><div>* "Aggressive Sound Card Buffering: unchecked", no impact.</div><div>* "Resolution: 1280x768 @ 60Hz". Changing resolution has no impact.</div><div>* "Enable realtime priority threads: checked", no impact.</div>
<div>* "Extra audio buffering: unchecked", no impact.</div><div>* "Use video as timebase: unchecked", no impact.</div><div>* "Enable OpenGL vertical sync for timing: checked", no impact.</div>
<div>* "Decoder: Standard", no impact.<br></div><div><div>* "Video Renderer: xv-blit", no impact.</div><div>* "OSD Renderer: softblend", no impact.<br></div><div>* "OSD Fade: unchecked", no impact.</div>
<div>* "Primary Deinterlacer: None"</div><div>* "Fallback Deinterlacer: None"</div><div><div>* mythfrontend and mythbacked are chmod u+s</div><div>* cat /proc/sys/dev/rtc/max-user-freq = 1024</div><div>
* "xorg.conf:XvmcUsesTextures = 1", no impact.</div><div>* "xorg.conf:NVAGP = 2", no impact.</div><div>* "xorg.conf:UseEvents = true", no impact.</div><div></div></div></div><div><br></div><div>
I'm currently using OpenGL vsync and according to the mythfrontend output it appears to be working:</div><div><br></div><div><div>2008-07-30 23:33:59.939 OpenGLVideoSync()</div><div>2008-07-30 23:33:59.945 OpenGLVideoSync: x,y -> 800, 600</div>
<div>2008-07-30 23:34:00.173 Using OpenGLVideoSync</div><div><br></div><div>I also don't use a deinterlacer because I'm assuming the HD content I'm recording does not need to be deinterlaced. I may be wrong, however, changes to the deinterlacer do not fix this problem and often create new problems of their own.</div>
<div><br></div><div>Finally, some info about my computer:</div><div><br></div><div>* Ubuntu + Medibuntu 8.04</div><div>* MythTV TRUNK Build (updated this afternoon)<br></div></div></div><div>* Nvidia GeForce FX 5200</div>
<div>* Latest NVIDIA driver</div><div>* Pentium 4 3.2GHZ 1GB/ram, 500GB HD + 160GB HD </div><div>* PcHDTV 5500</div><div>* File Systems: XFS</div><div><br></div><div>I've uploaded some additional information. The first url below is a log of verbose mythfrontend output during playback of a problematic video. The second is a more detailed look at my system, including pci, cpu, and memory information, as well as a 3 second snapshot iostat output during playback that clearly shows that I/O and CPU are not an issue.</div>
<div><br></div><div><a href="http://pastebin.com/f36f319b3">http://pastebin.com/f36f319b3</a> (mythfrontend log)<br></div><div><a href="http://pastebin.com/f7fcd0b66">http://pastebin.com/f7fcd0b66</a> (system information)</div>
<div><br></div><div>Can anybody help? I've run out of ideas and I don't know where to look next.</div><div><br></div><div>Thanks,</div><div>Bryan</div></div>