when using virtualdub i can not get the audio to match the video after about the first 10mins of the video it goes askew. at the start i get a warning saying this is going to happen and to use a constant bitrate encoder to fix this. have seen posting on this site to correct this but none work. also i can not find a constant bitrate encoder
OK...What is wrong is that your AVI file has VBR Mp3 audio and when decoded the Length changes because the Bit stream is not constant because of the Variable Bitrate...What needs to happen is the Audio needs to be Fully Decompressed and then re-compressed useing a CBR Compression method Or it doesn"t even have to be re-compressed you can leave it uncompressed but the File size will be Much bigger because of the Uncompressed audio...The best way to uncompressed the audio is to use a Little utility called "Decompress.exe" , It comes with an old crappy encoder called AVI2VCD, which can be downloaded here: http://home.cogeco.ca/~avi2vcd/rq4dl/avi2vcd_ver1_4_2.zip Just take the "Decompress.exe" file out and you can get rid of the rest..Just load your AVI file into it and then click "Decompress" and it will make a copy of your AVI file but with Uncompressed audio..Now you can take the New AVI file and do whatever you want with it in Virtual-Dub, and if you want to output it with compressed audio you just set the "Video" to "Direct Stream Copy" and set the audio to "Full Proscessing Mode" then under "Audio" go to "Compression" and choose an "Mp3" codec and choose the Bitrate you want to use like 128kbs, then close the compression dialog and to go "file" to "save Avi" and give the File a Name and then save it, Now the new file with be an AVI with Mp3 audio that will stay in sync....Cheers
Aha I've just stumbled on to this thread and you may have dealt with my problem Minion. I'm having a similar problem too, and I posted a thread please refer to http://forums.afterdawn.com/thread_view.cfm/52844 Is this what I should do as well? Decompress the audio in both of the AVIs, then append the two segments then recompress. Then voila? If so I will give it a try. Thanks
Ya Minion same problem here, thanks for the info and decompress program, but.... I have another movie that I ammended in virtDub, and File Information shows audio as AC-3 ACM decompressor. Now the complete joined movie is perfect in audio/video matching, but my file size is 1400mb. Usually I reduce files like these in DrDivx they come out fine but this one always mismatches the audio alignment(when the viewing comes into the second part) in my finished product of 850mb. I used DrDivx and change the audio to 128/44hz and have never had this problem on 2nd time runs of divx compression(original was a divx, then I run it again thru DrDivx to make smaller after joining parts). I also tried running the complete movie above thru virtDub(audio compression) which reduced the file size to 1100mb, but again this finished product has mismatched audio in the second half of the movie, any ideas....
I recently discovered, that when resampling from 48 kHz to 44.1 kHz, VirtualDubbing goes slowly out of sync, which becomes notable after half an hour or more of video. The same happens when compressing on-the-fly with for instance FlaskMpeg. To avoid problems you could try to use a codec that supports 48 kHz. This gives better results. Alternatively, you could cut out 50 ms of sound every 20 minutes or so before dubbing.
