audio not in sync

Discussion in 'Video - Software discussion' started by redwings, Mar 1, 2004.

  1. redwings

    redwings Member

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    is there a software to fix audio not in sync with the video ?
     
  2. Minion

    Minion Senior member

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    Well a Little more information would have been helpfull to properly answer your Question..Like What Type of Files are you talking about?? Did you Create these Files yourself or are they files you downloaded?? If you did download these files were they out of Sync when you downloaded them or after you converted them to another format??? What type of Sync Problem is it?? Does the File start out in Sync but gradually goes out of sync as the Movie Progresses?? Or is it out of Sync at the Beginning and it stays the Same ammount out of Sync through the whole File???
     
  3. jimbusse

    jimbusse Member

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    I have the loss of sync as well. The files have been captured from VHS (another forum, I read all that). The original capture was 44.1K 16-bit stereo audio. The "mp2" files that are created play back perfectly with Media Player, no loss of sync. The video is MPEG2, I frammes only using the ATI AllInWonderPro. The report says <.1% frame drop.

    I used TMPGenc 2.5 to encode it I bought DVDit, but that wouldn't read the "mp2" files. I tried DVD Lab, but that gave me an error "This file has an encrypted video stream--it can't be demuxed". But TMPGenc will split it, and I can make a DVD, but the audio's out of sync. I'm pretty sure TMPGenc can't adjust the 44.1K into 48K so well and where ther is frame drop, the encoding software can't possibly know where it happened. So loss of sync must be fixed by hand, not software.

    TMPGenc has a feature that will let you adjust the audio offset, but it's only one time and applied for the whole file, so you're behind at the start, but ahead at the end. Not good enough.

    Is there any softwre that will let you take the encoded DVD file (the output of TMPGenc) and either cut frames or add duplicate frames? Then I could play back the output, simply adjusting the sync as I go.

    Jim
     
  4. Minion

    Minion Senior member

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    The Dropped Frames are what is Most likely causeing the Sync Problem...What you can do is demux the audio and Video and then Find out the exact length of the Video File and write it down, and then take the audio file and Load it into a Audio editor Like "Goldwave" and use it"s "Time Warp" feature to Stretch/Shrink the audio file to the exact same Length as the Video File and then export the audio as a 48000hz Wav file and then encode the wav file to Mp2 with tmpgenc or some other tool and then author the Files to DVD...
    You must have a Fairly slow PC if you have to capture useing I Frames and you still drop Frames..Maybe an upgrade would be a Good Idea as you can upgrade to a 2ghz+ CPU and Motherboard for about $100...Cheers
     
  5. jimbusse

    jimbusse Member

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    Ah, good tip, I'll try that next. I tried cutting the scenes using TMPGenc's start and stop frame cutting method, then using TMPGEnc's DVD authoring software to put them together. It was a lot of work and took a lot of time but was only mildly successful: some of the segments "froze". The DVD played to the end, but 3/8 segments were silent and stationary. I guess TMPGenc's software isn't ready for Prime Time yet. I'm grateful for their "try-before-you-buy" attitude; I had to buy DVDit before I could find out it didn't work.

    A reason to capture I-frames only: The resulting video can have no software-generated artifacts, only hardware bit-errors. Having designed and coded an MPEG-2 audio codec, I completely understand what can happen, and how the software can generate artifacts. And reviewing the I frame only version compared with the TEMPGenc encoded version, I can definitely pick out artifacts. And my vision's poor.

    My capture device would not capture 48K audio, so some of the codecs (DVDit, DVD-lab, ulead Media Studio Pro) complained. If your idea about stretching the audio works for me, I will buy TEMPGenc because at least it will split the AV streams.

    Thanks for the tip!

    Jim
     

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