Using MKVmerge from the

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November 21, 2011 at 8:49 pm #6505
RehabMan

    Using MKVmerge from the mkvtoolnix suite… so same as you.  I got my Harry Potter series in a box set (HD-DVD) and backed them up last summer, so I was using “4.2.0”… I’m thinking of remuxing with the current version and seeing what happens.  I definitely know about the FPS issue…  But these are VC-1 and MediaInfo correctly shows 23.976.  I probably did have to set it to 24000/1001 when I originally ran mmg (mkvmerge GUI).

    My thoughts on it so far:

    Since it is TrueHD and I’m bitstreaming, it seems to me the player needs to keep the video in sync with the audio (because the audio is being handled externally bit-for-bit… there is no opportunity to slow down or speed up (stretch or shrink) the audio to match the video frame).

    I’m not really sure how the media pipeline works in DirectShow, but either the splitter component or the video decoder component has to be responsible for skipping a video frame should the video start falling behind the audio.

    I wonder if this problem isn’t related to the SNB clock being not quite exact with respect to 23.967 (well actually, 24000/1001).

    I may try recoding the video as h264 just to see if I have similar issues with drift (keep the TrueHD audio untouched).

    I really don’t think there is a muxing problem w/ respect to sync because when I seek into the movie at any point, the sync problem corrects itself (then later falls behind).  If there was some kind of sync problem from the get-go (say if the video really was 24fps on disc), you would think that as you seek further and further into the movie, the AV-sync would get more and more off…

    But heck… I’m just an old washed up C++ programmer who has not had any real media programming experience, so I’m just guessing…

    I haven’t had time to look at this issue, so really haven’t tried a lot of the suggestions and ideas of my own, but I hope to soon.