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View Full Version : vdub uncompressed audio is suddenly out of sync?


scottchicken
14th June 2003, 08:38
Hi all,

I've been using VirtualDub to fix VBR mp3 audio in AVI files before converting them to SVCD with the AVI2SVCD component of DVD2SVCD.

Have been doing it by doing a direct stream copy of video, and doing audio->full processing mode, audio->compression->no compression PCM. Of couse after removing any bad frames if they exist, using the vdub-vbr-mp3-freeze mod first, and direct stream copy of both video and audio.

This has worked perfect for the last year or so, nothing but praise for the authors of vdub and the vbrmp3freeze mod, and dvd2svcd.

But in the last week something has happened to cause my AVIs saved with WAV audio to be out of sync with the video. I cannot figure out for the life of me what is different as I am doing everything the same. Even the old vdub versions I have do it, and vdubmod. Downloaded a new copy and ran it fresh from a different location, still the same.

What steps should I take to try and track down the cause?

Any suggestions would be appreciated.

I have some examples of what is working and what isn't:

Example1 - The Source file with VBR audio:
(Audio is in sync, but cannot be converted to SVCD)
http://blah.scottchicken.com/x1.source-vbr.jpg

Example1 - After saving with no compression, no conversion:
(Audio is out of sync)
http://blah.scottchicken.com/x1.48wav-sync.jpg

Example1 - After saving with no compression, conversion to 44.1hz:
(Audio is out of sync)
http://blah.scottchicken.com/x1.441wav-sync.jpg


Example2 - The Source file with VBR audio:
(Audio is in sync, but cannot be converted to SVCD)
http://blah.scottchicken.com/x2.source-vbr.jpg

Example2 - After saving with no compression, conversion to 44.1hz:
(Audio is in sync!)
http://blah.scottchicken.com/x2.wav-ok.jpg


Example3 - The Source file with CBR audio:
(Audio is in sync!)
http://blah.scottchicken.com/x3.cbr-ok.jpg

Now, why is example1 out of sync????????

scottchicken
20th June 2003, 16:44
It also seems to make no difference whether the source audio is 5 channel or 2 channel i.e. I have had no trouble using vdub to uncompress 5 channel audio to WAV and then use DVD2SVCD to convert successfully.

????? Still in the dark.....