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  #1  
09-17-2004, 09:18 AM
Jimblob Jimblob is offline
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Hi

Occasionally I convert a pal dvd to ntsc. I use AssumeFPS to change the video framerate and BeSweet to stretch the audio.
Often the resulting audio and video are out of sync. To solve this, I mux the two and use media player classic to determine the offset. MP classic has an option to offset the audio. I adjust the offset untill I have sync. Then I remux using the offset determined in MP classic.
I am interested in knowing if someone can suggest a better way to achieve A/V sync.
BTW. Most of the sync problems occur even when VobEdit says the original pal source has no offset.

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09-17-2004, 09:23 AM
Dialhot Dialhot is offline
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For me this has nothing to do with the fact you convert from PAL to NTSC.
I mean even if you had encoding directly in PAL, you would have had the same problem.
(synch problems due to PAL->NTSC are generally sliding delay, not offset delay).

You probably face to some strange behaviour we already noticed on some DVD : the audio track is shorter than the video track and if you encode and mux directly the audio is sometimes SEVERAL SECONDS away !
(see there : http://www.kvcd.net/forum/viewtopic.php?p=87437 )

I don't remember somone has an explanation on this and how to detect it before to encode.
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09-17-2004, 10:48 PM
Jimblob Jimblob is offline
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Firstly, I agree, the sync problem has nothing to do with the conversion process.
Here is what I have done so far. Originally I was using dvd2avi 1.77.3 to create my d2v project file. After converting video and audio, I had a sync difference of 160 mSec.
Next I tried dvd2avi 1.76.1.5 which left me with a sync difference of 120mSec.
Finally I tried DGIndex which resulted in perfect A/V sync. I wonder now if the 2 versions of dvd2avi have been dropping frames. What do you think?
Also, after reading the thread you pointed me to, I now know why I once encountered an approx 17 sec difference in A/V sync. That 17 sec was a portion of the intro from the default audio track that was not present in the track I was working with.
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