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ioHD - Audio out of sync only if Bars/tone also captured???

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  • ioHD - Audio out of sync only if Bars/tone also captured???

    Using AJA VTR Exchange software and ioHD, capturing 720p/24 HD footage from HDX Panasonic 900 Cam to SDI input, audio to xlr ins.

    All works well, timecode is there, audio and video in sync. Quicktime files dragged into FCP 6 work perfectly.

    However, IF there are any bars and tone as part of the capture, either at the beginning of the clip, in the middle, whatever.... the audio and video shifts apart significantly.

    For example, what on the tape might have been 30 seconds of bars and tone, the audio comes through correctly, but the bars video will go on another 45 seconds longer than the 30 seconds recorded on tape.... throwing the rest of the audio and video off by that much for the rest of the capture. There is no drift, it is just a chunk moved down the timeline (or in the Quicktime movie) as the video of the bars has somehow been expanded pushing all the video past that downstream on the timeline. The captured clip will end with the audio, but any real video that was on the tape at the end, and which was played back and appeared to be captured during the ingest, is not even there.

    What am I missing here. IS there some setting in AJA control panel I'm missing? Are the bars somehow fed in at a different frame rate through the aja???

    Some data: all latest firmware
    New MacPro 3.0 quad core, 8GB ram
    Caldig 4tb raid 5
    FCP 6

    On the AJA:
    Input SDI 1
    Video Format 720p59.94, Conversion Up Anamorphic, Down letterbox.
    Digital out: 720p59.94

    On VTR Xchange:
    Compression type ProRes 422 HQ
    Frames per second 23.98
    Source: 720p59.94 8bit (1280x720) varicam

    Any clues how to resolve this???


  • #2
    Found answer elsewhere but will leave this posted in case others have similar issue and are wondering.

    The Panasonic cameras like HDX900 generate bars only only at base frame rate, in this case 60fps and do not have flagged frames for 24p.

    So long and short of it, DON'T capture bars from the Panny tape based HD cams, or it may throw everything off depending on your capture set up and desired frame rate.


    • #3
      Thanks for that tip!!!



      • #4
        Over 30 years in Broadcast Film and