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View Full Version : Serious asynch with MPEG2 cut and merge


DarkMatter
26th October 2004, 02:08
I have been trying to convert 5 MPEG2 files that are each 3 hours long with VirtualDub Mod. I have been importing the MPEG2's in, then removing commercials, and deviding them into the 3 hour-long shows I originally captured. I have then been compressing them with the Xvid and Lame codecs. Each resulting 1 hour .avi has non-consistent audio asynchronicity. That is, when I fix the synch so that the audio and video are in synch at the bigining and the end, the middle is out of synch. Sometimes the audio is fast, some times it's slow. So, it isn't just a framerate problem. It appears that each cut commercial throws it out of synch a little. I have caught short blips of audio that belonged to video that is no longer in the final file. It seems that VDub Mod is not cutting the audio and video equally. Or, it isn't joining the segment's audio and video correctly. I've had some success with using delay and framerate control to fix each between-commercial segment then joining them in another program. But, you can guess how much time and aggrevation that entails. The synch is fine in the original MPEG. It reduces the degree to divide the files into 1 hour avi's then cut commercials, but the synch problems are still there. When I do the cutting and merging in TMPGEnc then simply use VDub to compress and convert to avi, it does fine. Is there some obscure setting I've missed?

DarkMatter
27th October 2004, 20:28
I've uninstalled and reinstalled, switched versions, and various other things without resolution. I finished the files by using TMPGEnc to cut and merge the trancoded in VDub Mod, but this is a mystery. Should/can I report this a bug. It may be specific to the files I have, in which case, the bug report is useless.

eb
28th October 2004, 05:30
I am 99.99% sure that there are audio and/or video dropouts.
To have good synchro use DVD2AVIT3 and mux video and audio with VirtualDubMod /setting DELAY as pointed in audio header.
If there is need to use filters then at first process mpegs in ProjectX