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Audio and video out of sync

Discussion in 'MPEG-1 and MPEG-2 encoding (AVI to DVD)' started by Karvedys, Oct 16, 2003.

  1. Karvedys

    Karvedys Member

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    I have a problem and two questions:

    PROBLEM: encoded a movie onto two mpeg-2 files and the audio in both is about .5 seconds ahead of the video. Another symptom: the video file is only 48:33 long, while the audio file is 48:39 for the first CD. The synchronization is off with what appears a constant value, though.

    Tons of discussion about these issues with .avi files, but can't find help on fixing this .mpeg.

    So,
    1. Is there a way to find out EXACTLY what the delay in video is? I judge it by hand/eye/ear with a chronometer and get values of around .5-.6 sec. I don't think this is a very acurate way to do this.

    2. How do I fix this? I do have the separate audio and video streams and I think I should re-mux this over. What program would allow me to delay audio by .5 or so?

    Thanks,
    Haris
     
  2. Minion

    Minion Senior member

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    The only way to fix this is to stretch or Shrink the Audio file so that it is exacly the same length as the Video file then Mux them together and they should be in sync...You will need a Good audio editor Like Sound forge or Goldwave to do this but I have done this Quite a few times and it works about 90% of the time....Cheers
     
  3. Karvedys

    Karvedys Member

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    I'mm trying to do that. Just opened the file in AudioEdit Deluxe and this program only allows you to change the length in whole percent values. As my audio/video difference is only .21% (48:39 and 48:33) I am SOL with this one.

    The question remains for me, however, what happened that caused this synchronization problem? I've burned many SVCDs before and this is the first time. The only difference, I used DVD Decrypter rather than Smart Ripper.

    Can anyone shed light on this question, please!
     
  4. Minion

    Minion Senior member

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    Well Maybe the Problem isn"t DVD Decrypter But maybe DVD2AVI (If that is what you used to extract the audio from the Vob files) cuz it has been known to cause simular problems when decodeing AC3 to Wav..If you Demux the AC3 instead of decodeing it then used an audio encoder like Headac3he to decode the AC3 maybe the sync problem would go away....If you used a different audio editor like Goldwave or Sound forge you will be able to fix the audio....
     
  5. Karvedys

    Karvedys Member

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    Thanks for your input, Minion. I'll try and post the results. In the meantime, I've been time warping my audio with Goldwave. It takes forever!!! I am running PIII 1GB with 1GB of PC-133 and a 5400 hard drive. Just opening a 77MB mp2 file takes over 30 minutes! I am not sure how long it took to time warp and then recompress into a mp3 and finally save. I am sure well over an hour. Is that normal or am I off somehow?!

    Thanks again,
    Haris
     
  6. Minion

    Minion Senior member

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    I have never used Goldwave for this so I don"t know how long it should take ,I usually use Vegas Video 4 for this and the Actual Stretching or shrinking of the audio is instant but the Rendering of the File takes about 2 minutes for a Audio file about 90 minutes long then Again I use a P-4 2.53ghz PC..And if you are makeing a VCD or SVCD you don"t output the audio file as MP3 cuz that is not the correct format you need to use MP2 and for DVD you will need MP2 or AC3 or WAV.....
     

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