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  1. Hello everybody

    Last week I recorded a concert with two cameras and a mixer (multi track). The concert lasted about 2 x 1 hour 15 minutes
    I have a problem with synchronizing 3 files.
    I have three different files from different sources:
    2 video files from 2 different Sony cameras
    1 file from the mixer (audio)

    I can synchronize the two video files without any problems. However, there are problems when I synchronize the audio file. At the end of the first part (after 1 hour), the files are no longer in sync. The audio file is a little ahead or the video file is a little behind.

    Here are the details of the files
    Video1:
    Type: MPEG movie
    File size: 1.98 GB
    Image size: 1440 x 1080
    Frame rate: 25.00
    Source audio format: 48000 Hz - Compressed - Stereo
    Project audio format: 48000 Hz - 32-bit floating point - stereo
    Total duration: 01: 16: 14: 24
    Pixel aspect ratio: 1.3333
    Alpha: None
    Video codec type: AVCHD H.264 4: 2: 0

    Video 2:
    Type: MPEG movie
    File size: 1.98 GB
    Image size: 1920 x 1080
    Frame rate: 25.00
    Source audio format: 48000 Hz - Compressed - 5.1 (L, R, C, LFE, Ls, Rs)
    Project audio format: 48000 Hz - 32-bit floating point - 5.1 (L, R, C, LFE, Ls, Rs)
    Total duration: 01: 33: 27: 17
    Pixel aspect ratio: 1.0
    Alpha: None
    Video codec type: AVCHD H.264 4: 2: 0

    Audio:
    Type: waveform audio
    File size: 1.29 GB
    Source audio format: 48000 Hz - 24 bit stereo
    Project audio format: 48000 Hz - 32-bit floating point - stereo
    Total duration: 01: 20: 00: 32716

    The sequence settings in Premiere Pro CC are as follows:
    Sequence 01
    1920 x 1080
    01; 20; 34; 19, 25.00 fps
    48000 Hz - stereo

    What could be the problem? How do I get the files in sync?

    Thank you in advance.
    Chris
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  2. Video Part 1 Lenght 01: 16: 14: 24
    Video Part 2 Lenght 01: 33: 27: 17
    Audio WAV Lenght 01: 20: 00: 32
    What do you want to synchronize with?
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  3. The two video files are from different angles. So a project with multi cam. Audio was recorded by the mixer and must then be synchronized with the two videos (multi cam).
    Image
    [Attachment 54797 - Click to enlarge]
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  4. So you want to use only the video track of both videos and only the WAV file as audio, right?
    Then compare the audio track of Video1 with the audio WAV in an audio editor and you will find the difference or the gap visually and adjust the WAV.
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  5. Thank you for your message
    that's exactly how I did it. The beginning works perfectly. But after more than an hour, the two tracks are no longer in sync
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  6. Your images indicate you're using Premiere. Use the rate-stretch tool to lengthen the audio until the waveform matches the video.

    Only rate-stretch your external recorder track. Leave the others alone.
    It helps to add an edit (razor tool) at your known sync point near the head so you are only adjusting the tail. You can go back and remove the add edit once you are in sync.
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  7. There must be a point on the timeline at which the two audio tracks are out of sync. It looks like a piece is missing on the WAV. If so. you can copy the missing piece from one of the two video sound tracks and paste and adjust it in WAV. I don't know if this works in Premiere Pro CC. If not, use another audio editor, e.g. Audacity.
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  8. Member Cornucopia's Avatar
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    See how much the difference is.

    If it is the difference between sample rates (44.1kHz vs 48kHz) that should be a difference between 79.5 minutes and 86.5 minutes, and fixing this would require interpreting as wrong SR (to fix shift) and then doing samplerate conversion (to get to match SR of the other clips & timeline).
    If difference is smaller it could be pulldown issues, which would require a similar process, but different rates.
    If nothing fits those easy differences, there is a likely an unfortunate BREAK somewhere in one (or more) of your clips to account for the disontinuity.

    Btw, have you LISTENED to the combined timeline? Do a test and put a cam sound on L channel and board sound on R and listen, and you should very clearly hear when it gets out of sync, and hear whether it gets progressively off or whether it is an abrupt shift.


    Scott
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