Latest post Thu, Sep 4 2008 9:47 AM by Sycophant. 2 replies.
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  • Wed, Sep 3 2008 5:27 AM

    • Sycophant
    • Top 75 Contributor
    • Joined on Thu, Oct 13 2005
    • Auckland, New Zealand
    • Posts 773
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    Varicam via Firewire for 25fps

    I actually understand that this request is very difficult for a number of reasons, but now that Avid supports 720p25 I thought maybe there was some hope in asking.

    Shooting Varicam in PAL regions at 25fps results in quite a problematic thing - a tape recorded 720p at 60Hz with 25 active frames per second. Avid can't communicate with the deck (AJ-HD1400, and I presume 1200 and 1800 too) because in the native modes the Firewire signal is DVCPRO HD 720 at 59.94Hz or 60Hz.

    The HD1400 offers a built in solution to this, and that is it's '25(HD)' mode, which generates frame-accurate 25fps timecode from the active frames and outputs (via HD-SDI only) a 1080i50 signal. In this mode the Firewire is still in 60Hz.

    Neither Avid nor FCP has any way of capturing this material correctly. The closest you can get is in a 24p project where it will see the 60Hz Firewire signal, and discard the non-active frames, you can then export the frames and reimport into a 25fps project, but that loses audio and timecode.

    The only application on the market I've found that can deal with Varicam 25fps over Firewire is EDIUS Broadcast - which will see the deck, control the deck and capture correct 25fps material. The biggest drawback is the timecode - as the deck is using a 30fps timebase in this mode the timecode is 30fps, although only 25 frames are recorded, resulting in footage that runs at 25fps but has timecode that goes up to :29 and misses a few frames in the middle of each second. I was never able to successfully recapture with this setting.

    If Avid can come up with some magical solution to the insanity that is Varicam in non-NTSC framerates then I will arrange bottles of good New Zealand wine for the development team.

    All manner of fancy edity stuff [view my complete system specs]

    Dylan Reeve - Editor and Stuff
    Auckland, New Zealand

    My opinions are my own.

  • Thu, Sep 4 2008 5:23 AM In reply to

    Re: Varicam via Firewire for 25fps

    Yea 25/60 is such a weird format. I am not sure the solution for this. It would be basically be similar to 24/30 workflow where frames are removed and heavy metadata tracking is happening in the back.

    25/50 is your friend :)

    I know it does not help much. We had the same issue with one or 2 tapes shot here  in the US for a US/UK project. Had it converted to HDCAM and called it a day :(

    Intel E6600, Windows XP SP2, EVGA 8800 GT, 4GB RAM, Creative X-Fi. [view my complete system specs]
  • Thu, Sep 4 2008 9:47 AM In reply to

    • Sycophant
    • Top 75 Contributor
    • Joined on Thu, Oct 13 2005
    • Auckland, New Zealand
    • Posts 773
    • Points 9,525

    Re: Varicam via Firewire for 25fps

    Yeah, we just finished a series shot on DVCPRO HD with Varicam, about 120 tapes all up. Our deck (the AJ-HD1400) has options to work with the format, but it's a little frustrating as it's HD-SDI only. As we had no HD I/O beyond Firewire at the time we had to make a decision about how to do the finishing and went with FCP/Blackmagic solution (this was before DX).

    The 25HD mode is a little tricky too as it forces a hardware cross-convert to 1080i as there isn't a 25fps 720p HD-SDI mode. I suppose they could have made it possible to do 720p50 (with frame-doubling), but that's a *** to edit.

    We ended up doing DV offline in Avid (in '25 SD' mode via Composite into Analogue Mojo) then finished in FCP in ProRes 422 HQ. Was frequently frustrating, but worked overall.

    For the second series I think there will be a Mojo DX instead.

    All manner of fancy edity stuff [view my complete system specs]

    Dylan Reeve - Editor and Stuff
    Auckland, New Zealand

    My opinions are my own.

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