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  1. Hi

    I have some AVI clips which I am converting to DVD format.

    I have been using Nero Express 2 and the first few worked fine, but now I am getting audio sync problems. . The clips work fine on the PC but not when converted to DVD format. I have tried extracted the audio to a wav file using VirtualDub and then encoded the file with TMPEG using the wav file as an audio source, but this doesn't solve the problem. The audio on the MPEG file created by this method is even out of sync on the PC.

    I read somewhere ages ago that the timeline of the audio file may need to be stretched or shortened to match the timeline of the video file, but I can't find this article now. Has anyone heard of this, and would it solve the problem. If so, how would I carry out this process.

    Cheers
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  2. Member
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    I have heard of it. First get the time of the video. Virtual Dub works okay for this. Next get the time for the audio. Try Gold Wave for this. If the audio does not match the video, select Effects-->Time Warp, adjust the Time to match the video time, Save it as a wave, and mux them back together.
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  3. I'm a Super Moderator johns0's Avatar
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    A way to calculate the time difference is to load the file into virtualdubmod and set audio to full processing and set the audio delay in interleaving to what you figure the clip will be out of sync near the end so if its 4 seconds set it to that and then play the clip near the end in virtualdub and play/output and see if it matches and adjust so its back in sync near the end,then use the delay number you figured out and use this for the time stretch or shrink difference for the audio in goldwave.
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  4. Thanks for replying.

    This is wierd. I have run DivFix and it comes up with no errors.

    All of the clips play perfectly in Windows Media Player, but the audio of all of them seems to be out when played in Virtual dub. The first few that I burned to DVD worked fine, the audio is out of sync in the rest.

    When opening any of the files in VirtualDub, a "VBR audio strem detected" message is displayed.

    Any ideas?

    Cheers
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  5. Member ZippyP.'s Avatar
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    Originally Posted by garyevs
    Any ideas?
    Try scanning for bad frames with Virtualdub, see link below.

    Try extracting a wav file with Goldwave, just load the avi then save.
    "Art is making something out of nothing and selling it." - Frank Zappa
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  6. I downloaded the latest version of VirtualDub (V1.5.10) and ran the "scan video strem for errors" option.

    After it had finished, there was no log file on the C: drive, or anywhere else called "badframes.log". I searched for all the .log files on the PC but it wan't there, or anything close to it.
    There were no .log files created or modified anywhere near the time I ran the process.

    Sorry to be a pain, but is there a setting in VirtulDub which needs to be enabled for this log to be created? I have looked but cannot find anything relevent to this process.

    Cheers
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  7. garyevs,

    Try TMPGEnc to convert it.

    It really sounds however like you are dropping video frames while encoding, which happens on a bad source like video tape. There is an option in VirtualDub you need to use when capping that will drop audio frames when a video frame is dropped so everything comes out ok. Fixing a gradually out of sync file is nearly impossible is it's more than about 1/2 second out of sync. A file that's out of sync by the same amount can be fixed pretty easy once you know how far to offset the video from the audio.
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  8. Member ZippyP.'s Avatar
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    Originally Posted by garyevs
    I downloaded the latest version of VirtualDub (V1.5.10) and ran the "scan video strem for errors" option.
    Virtualdub MP3 Freeze or regular Vdub? You need the MP3 version.
    "Art is making something out of nothing and selling it." - Frank Zappa
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  9. I did have the wrong version of VirtualDub.

    I now have the MP3 version and ran it against the AVI's I have which were out of sync. No bad frames were found at all in any of the AVI's.
    I watched one AVI which I had burned onto DVD, tonight and it was fine for a while and then jumped out of sync, which would indicate a bad frame but none were found.

    If there were bad frames, shouldn't the audio be out of sync when watching the original AVI on the PC too, as this plays perfectly? So could it be an encoding problem, rather than a problem with the original AVI?

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  10. Member ZippyP.'s Avatar
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    Originally Posted by garyevs
    .... it was fine for a while and then jumped out of sync, which would indicate a bad frame but none were found.

    If there were bad frames, shouldn't the audio be out of sync when watching the original AVI on the PC too, as this plays perfectly?
    Unfortuantely Vdub does not always catch all bad frames. Playback sync is not affected by bad frames, sometimes all you see is a few blocks or green squares when playing the avi. If you know where it goes out of sync then open the avi using virtualdub (any version) and edit that part out.

    Good luck.
    "Art is making something out of nothing and selling it." - Frank Zappa
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