`Orum
4th August 2008, 03:11
This is a very strange playback problem I've been having. This particular file I have (H.264 video, AAC audio, MKV container) does not play back well when opened in Media Player Classic. The frames are played back with "jerky" motion in scenes where the camera pans. And, to make matters more complicated, the CPU usage doesn't look abnormally high (stays around 30% in pans and high motion scenes). However, if I create a AviSynth script to play it via DirectShowSource(), the video plays back just fine! In both cases, the audio plays back just fine. I have also tested direct playback of the file in graphedit, and it has the same issue as MPC.
I've tried changing every setting I thought might have an impact on this in MPC, including splitter selection, with no avail. Frustrated, I thought the problem might be with ffdshow, but again, this was not the case. When the AVS script is loaded with MPC, it still uses ffdshow to play back the video/audio (actually, MPC doesn't use ffdshow for audio playback, but graphedit does and that displays the same issue).
The only thing I can think of that might be causing this is the fact that the video is anamorphic (pixel aspect ratio that's not 1:1). AviSynth ignores PAR, and thus I needed to include a Spline36Resize() to get the video to play back at the correct aspect ratio.
Now, my questions... Could the fact that the video is anamorphic be causing the problem, and how would I tell? If so, why, and how would I go about fixing it? If not, what could be the problem, and how would I go about diagnosing something like this?
Any advice is greatly appreciated, as I haven't seen anything like this before.
I've tried changing every setting I thought might have an impact on this in MPC, including splitter selection, with no avail. Frustrated, I thought the problem might be with ffdshow, but again, this was not the case. When the AVS script is loaded with MPC, it still uses ffdshow to play back the video/audio (actually, MPC doesn't use ffdshow for audio playback, but graphedit does and that displays the same issue).
The only thing I can think of that might be causing this is the fact that the video is anamorphic (pixel aspect ratio that's not 1:1). AviSynth ignores PAR, and thus I needed to include a Spline36Resize() to get the video to play back at the correct aspect ratio.
Now, my questions... Could the fact that the video is anamorphic be causing the problem, and how would I tell? If so, why, and how would I go about fixing it? If not, what could be the problem, and how would I go about diagnosing something like this?
Any advice is greatly appreciated, as I haven't seen anything like this before.