• AJA Video Systems

  KONA2 – audio output offset over SDI

  Posted by Matt Lyon on April 16, 2006 at 8:35 pm

  I’ve searched the archive and it doesn’t appear anyone has reported this problem. We are outputting using a KONA2 card and are finding the embedded audio on the SDI signal precedes the picture by 1-1.5 frames. This offset does not drift, remaining consistent over the duration of a 20 minute reel output. I first noticed this on beta/digi-beta outputs, but I’ve sinced tried feeding our KONA2 output directly into a KONA LH and have confirmed the same issue. Here’s our settings:

  1080psf 23.976 DVCproHD footage. Video output set to “AJA 1080 29.97 8 bit” with FCP pulldown set to 2:3:2:3 and the KONA control panel set to do a downconvert to 29.97 525.

  Dual 2gig G5 w/ 4gig of RAM. All footage is on external firewire 800 drives. FCP 5.0.4 and OS X 10.4.5, quicktime 7.0.4.

  In my current testing configuration, I’m running an SDI cable directly between the KONA cards, so I’ve ruled out that any external hardware or switchers are creating this problem.

  One workaround is to pre-offset the audio tracks, but since the offset the KONA introduces does not seem to remain consistent, this isn’t a totally reliable workaround.

  Any help would be greatly appreciated,

  Matt Lyon
  1st Assistant Editor
  Toronto

  Matt Lyon replied 20 years, 4 months ago 2 Members · 3 Replies
• 3 Replies

• 

  Jeremy Garchow

  April 17, 2006 at 2:10 am

  Where does your 1080 psf footage originate from? Does the SDI output normally without downconvert?

  Jeremy
• 

  Matt Lyon

  April 17, 2006 at 4:12 am

  The original footage is captured directly from camera original tapes, Sony F900, shooting HDCam format. Since our HD deck is a player only, we haven’t done any HD outputs yet to test whether the audio is offset with those settings. Tomorrow I will try capturing full HD directly from one KONA to the other and see if the audio is offset.

  Matt Lyon
  1st Assistant Editor
  Toronto
• 

  Matt Lyon

  April 21, 2006 at 3:38 pm

  Sorry for the long replay, got busy doing conforms and couldn’t test this …

  I appears that when doing a straight output, with no downconvert or 2:3 pulldown business, Audio is bang on. Maybe this is some issue w/ the interaction between the software pulldown and the KONA downconvert?

  Is there a way to do the 3:2 pulldown on the hardware card itself and take FCP out of the picture?

  thanks,

  Matt Lyon
  1st Assistant Editor
  Toronto

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