Latest post Tue, Jan 21 2020 12:46 PM by Pat Horridge. 3 replies.
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  • Mon, Jan 13 2020 3:47 PM

    • iliagin
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    • Joined on Tue, Oct 17 2017
    • Posts 8
    • Points 100

    Progressive out of sync

    Hello,

     

    I was trying to synchronize material of documentary I'm editing and came to quite a strange problem (or at least one I've never experienced in Avid). I've a single file of two and half hours recording, and about a dozen of video files. First, I tried to make Autosync based on waveform, but got an autosync of about a second, so I've tried to sync with inpoints, which should have solved the problem, but surprisingly the result was frustrating.

    While the close seconds to the inpoints I've used are fine, everything that comes before and after them are still out of sync by a second (more or less). I suppose it should be a symptom of Progressive out of sync, which can be caused by difference in FPS, but both seems to be on 25 (if I believe the information in file itself and in Avid).

     

    Do you have any idea what could cause it and are there any solutions that come to your mind so I can synchronize the files correctly?

     

    Thanks in advance!

  • Tue, Jan 21 2020 9:12 AM In reply to

    Re: Progressive out of sync

    Don't forget Audio files only have an FPS as an indicator for timecode. The actual audio rate is controlled by the samplerate.

    Are the audio files lagging behind the video or getting ahead of the video?

    If the original audio rocording was made at an incorrect samplerate that isn't relected in the metadata of the file Avid will play it at that indicated sample rate and you will get a speed difference.

    44.1K to 48K is nearly 20% difference.

    What sample rate does Avid indicate for the audio files?

    ACI Moderator. I'm not employed by Avid or work for them. I just do this in my spare time. Normally using the current Media Composer version on My... [view my complete system specs]

     

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  • Tue, Jan 21 2020 10:25 AM In reply to

    • iliagin
    • Not Ranked
    • Joined on Tue, Oct 17 2017
    • Posts 8
    • Points 100

    Re: Progressive out of sync

    Yeah, you're right. The audio was recorded in 44.1k (and so getting ahead of the video). Is there anything to do inside Avid? 

  • Tue, Jan 21 2020 12:46 PM In reply to

    Re: Progressive out of sync

    There is a setting for sample rate conversion while playing.

    But I'd try Transcoding the audio and then selecting the option to force the sample rate and bit depth

    Then test with a trancoded Audio file.

    ACI Moderator. I'm not employed by Avid or work for them. I just do this in my spare time. Normally using the current Media Composer version on My... [view my complete system specs]

     

    Broadcast & Post Production Consultant / Trainer  Avid Certified Instructor VET

     

    QC/QAR Training - Understanding Digital Media - Advanced Files * Compression - Avid Ingest - PSE fixing courses and more

    All bespoke and delivered onsite at yours.

     

    T 07581 201248 | E pat@vet.co.uk | W www.vet.co.uk |

    -

    Follow me on Twitter Pat_H_VET

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