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Forums AJA Video Systems What’s happened?

  • What’s happened?

  • Mike Zimbard

    October 24, 2008 at 10:48 pm

    Is that acknowledged in the manual? Seems like a big deal and I can’t remember ever hearing that before regarding the hardware down-converts.

  • Jeremy Garchow

    October 24, 2008 at 11:31 pm

    I haven’t looked for it in the manual:

    https://forums.creativecow.net/thread/98/871096

  • gary adcock

    October 26, 2008 at 3:20 pm

    [Mike Zimbard] ” Jeremy can you explain why? I’m trying to understand why a frame would be lost. Aren’t you just going from 1920×1080 @25 fps to 768×576 @25fps”

    Mike the frame is not lost, but delayed since it takes specific amount of time to pass the signal thru the chips doing the conversions (be they up or down – NTSC or PAL)

    Kona Conversions are delayed by 1 frame for continuity (all decks and encoders that handle this type of conversions maintain at least this amount of delay– some like Terenex are more, with as much as 3-10 frames depending on the image processing required).

    This delay is because that signal has to pass thru the additional circuitry needed for the conversions- One frame is necessary since some formats have fields and some frames it had to be tied to the shortest period of time that covers all formats.

    make since?

    gary adcock
    Studio37
    HD & Film Consultation
    Post and Production Workflows

    Inside look at the IoHD

  • Mike Zimbard

    October 27, 2008 at 2:11 am

    Yes Gary – makes perfect sense. Thanks very much. Is it easiest to account for this delay by just marking in 1 frame earlier on your SD VTR so that your record in-point is where you want it?

  • gary adcock

    October 27, 2008 at 1:26 pm

    [Mike Zimbard] “Thanks very much. Is it easiest to account for this delay by just marking in 1 frame earlier on your SD VTR so that your record in-point is where you want it?”

    For FCP yes.

    gary adcock
    Studio37
    HD & Film Consultation
    Post and Production Workflows

    Inside look at the IoHD

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