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Activity Forums Apple Final Cut Pro Legacy Audio drifting due to mixed frame rates. Please, advice….

  • Audio drifting due to mixed frame rates. Please, advice….

    Posted by Pete Camden on July 12, 2010 at 12:29 am

    I have a short film I am working on and most of it was shot with JVC HD250U.
    I was given folders with .m2t – files that I could not open with any software I was familiar with so I used MPEG streamclip and turn them into Apple ProRes. I came up with files that are 1280×720 with 59,94 frame rate. I have used in FCP the sequence settings 1280×720 / 59,94fps / square / none (field dominance).

    However, there was a pick up scene done with Canon DSLR. Original files H264 / 1080 / 23.98 that I just turn into ProRes without changing the frame rate. This scene I also edited with seq settings mentioned above… foolishly I must admit now.

    I exported OMF file to audio engineer and he came back with aiff-file which duration matches the sequence. BUT, the audio drifts in/out of sync during the scenes. Sure, this must have something to do with me not doing things in correct way in front.

    My main delivery will be to a film festival in US ie it’s going to be SD NTSC DVD. All a bit foreign to me who’s coming from Europe.

    What could be the most economical way to bring the project back on the track?
    Or, is it completely doomed due to my actions in front?
    If nothing else, this has been a learning experience, so I would warmly welcome any suggestions what I should’ve done differently.

    Viva el Espanol!

    It’s like what Lenin said… you look for the person who will benefit, and, uh, uh…

    Pete Camden replied 16 years, 1 month ago 1 Member · 6 Replies
  • 6 Replies
  • Pete Camden

    July 12, 2010 at 1:44 pm

    Anyone, anyone….

    I need get a NTSC DVD done this week and start to feel the pressure.

    a.) What would be the way forward to get around the audio drift issue.
    b.) Best practice to make the SD NTSC DVD from the sequence settings detailed above.

    Thanks heaps already!

    It’s like what Lenin said… you look for the person who will benefit, and, uh, uh…

  • Pete Camden

    July 12, 2010 at 11:25 pm

    Great news.

    TC won’t be a problem. It’s only a short scene (23.98fps) so the sync can be done manually.

    Any ideas why the audio keeps drifting. Is the mixed frame rates as i suspected?

    Thanks mate.

    It’s like what Lenin said… you look for the person who will benefit, and, uh, uh…

  • Pete Camden

    July 13, 2010 at 11:14 pm

    Yes. The audio is from a external recorder. I merged the audio and video files in FCP for editing purposes.

    So, are you suggesting that I would have to export the scene as individual clips and then re-edit?

    Cheers,

    It’s like what Lenin said… you look for the person who will benefit, and, uh, uh…

  • Pete Camden

    July 14, 2010 at 5:11 am

    Ok. Let me get my head around this.

    In the current full length Aiff-file from the audio engineer the things drifts out of sync gradually.
    This Aiff-file is based on exported audio tracks from the original 720 seq 59.94fps including the sequence shot with different format 1080/23.98, which I edited in. I didn’t edit that scene with the different format in seq with it’s native settings, but settings used in most of the film.

    So, I should now export the first sequence and import back to the project. Then re-export audio files to the audio engineer, right?
    Does this mean re-export audio for the engineer for the whole film or should the problem be solved if he re-does his work for the cafe scene only?

    I know I am after a short cut, but would appreciate your advice since you seem to have far greater knowledge regards to the matter.

    Thanks again,

    It’s like what Lenin said… you look for the person who will benefit, and, uh, uh…

  • Pete Camden

    July 14, 2010 at 9:52 pm

    Yes.

    That’s what I have been using, but apparently the sound engineer works 44.1kHz and then re-conforms everything back to 48 kHz.
    I have limited knowledge when it comes sound. Could this cause us the problems?

    What was wierd is that I made 2 QT exports. One of the first scene and then one of the rest of the film and then married them back together in FCP, exported audio to aiff and took to the audio engineer. He puts the track into Logic and everything is swell. We do 48k stereo Aiff- export and bring it back to FCP and the audio is out of sync. If worse comes to worse, I must ask him to give me the dialoq track separately and then try to sync it manually. Not a proper way, but time is closing in.

    Any suggerstions… anyone, anyone?

    Cheers,

    It’s like what Lenin said… you look for the person who will benefit, and, uh, uh…

  • Pete Camden

    July 14, 2010 at 10:32 pm

    All good now.

    Find the cure from this thread:
    https://forums.creativecow.net/thread/8/1090666#1090917

    Thanks everybody.

    It’s like what Lenin said… you look for the person who will benefit, and, uh, uh…

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