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Changing audio from 29.97 fps to 23.976 fps?

Discussion in 'Audio' started by 3rdstrike, Jul 5, 2009.

  1. 3rdstrike

    3rdstrike Member

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    Hello everyone,

    I know audio does not have a framerate, however I hope someone can help. I have a video source that runs at 23.976 that I need to sync with an audio track that was taken from a video source that runs at 29.97 fps. The video and audio are from different releases of the same film. Is there a way to change the audio track's length to fit the video source without changing pitch? I've tried BeSweet but it changes the pitch drastically.

    By the way, the audio is mono (and I intend to keep it in mono) so I don't need to worry about any conversion issues (that BeSweet seems to run into).

    Thanks for reading,
    Regards.
     
  2. attar

    attar Senior member

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    Try Audacity to see if it does what you need..
    Load the audio and click 'Effect' > 'Pitch and Tempo' > 'Change Tempo'
    Insert the running time of the video.
    The pitch should not change.


    [​IMG]
     
  3. davexnet

    davexnet Active member

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    Also, often the 23.976 and the 29.97 version can have the same
    running length - but different frame rates due to the way they
    were ripped. What are the lengths you're talking about?
    (in hours, minutes and seconds?)
     
  4. 3rdstrike

    3rdstrike Member

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    The video goes for 01:30:59
    The audio from the video has the same running time.
    The audio that I want to add goes for 01:27::15.

    However, the video source contains a film company logo and ending credits that the mono audio source lacks. I'm planning to add a delay to compensate for the missing audio for the logo and not worry about the ending credits. So in reality, I'd need to have the audio run at about 01:29:45 (including the 19 second delay, it would come to roughly 01:29:26).
     
  5. davexnet

    davexnet Active member

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    Sync it up at the beginning, as you suggest.
    Then see if it's still good as the film progresses.

    There may well be some stretching as attar suggested.

    Usually PAL sourced files are shorter because of the 4% speedup
    done in the film>video conversion .

    I once tried adding an alternate audio as you are doing .
    For the life of me I couldn't get it right. It was only after I
    painstakingly went through minute by minute, did I realize that
    the video I was working with had a whole extra scene, about
    3 minutes, that had been cut in the version my preferred audio
    had been sourced from!

    I gave up on it and bought the DVD.
     
  6. 3rdstrike

    3rdstrike Member

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    I'm in a similar situation, it just so happens that the dvd release with the better quality video has horrible audio compared to the older release (not to mention the logo and credits).
     

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