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AJA - HD->SD Downconvert + 3:2 problems

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steve coulter
AJA - HD->SD Downconvert + 3:2 problems
on Apr 2, 2009 at 3:53:39 pm

Hey oh. I've posted here before regarding my AJA woes and you guys were pretty awesome about helping out. Here's another brain buster:

Using FCP 6 on a Mac Pro (dual 2.66 dualcore, 5gb ram) and Kona LHe (latest drivers 6.03)

Editing HD in 23.976 and trying to put out to DigiBeta through the Letterbox Downconvert and 3:2 pulldown to make it 29.97.

Apparently, but maybe just in our case, this can't happen on a Kona LHe. Perhaps I'm asking it to do too much? The problem is that it misses the in point by a seemingly random number of frames every time I edit to tape. It will be a frame late the first time, then without changing anything I will try again and it will be 2 frames late. I deliberately set the in point a frame earlier, and it ends up being 3 frames late, and so on and so forth. Also - the audio rarely syncs. If I had a whole day to lay off some 1 minute tv spots, that would be fine. But recently deadlines were pushed due to this issue.

I've worked around it by rendering out the HD sequences, importing them to after effects, Letterboxing them, and then rendering them out with 3:2 pulldown, reimporting to FCP and laying off straight SD. This takes time.

Any one have any suggestions? We haven't dealt with that much HD stuff but there will only be more as time goes on.. and we've always had this problem regardless of driver version w/Kona. I was hoping this last update would fix it. Should I break down and call tech support?

Lemme knows.
Steve




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Jeremy Garchow
Re: AJA - HD->SD Downconvert + 3:2 problems
on Apr 2, 2009 at 4:10:07 pm

How exactly are you performing the down convert?

Jeremy


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steve coulter
Re: AJA - HD->SD Downconvert + 3:2 problems
on Apr 2, 2009 at 4:11:39 pm

I set the video playback in Final CUt to play the HD footage natively (1920x1080, 23.976) and then set the Kona outputs to downconvert to 525i by letterbox from the Kona Control Panel.

If there's an alternative way to do it.. I haven't yet discovered it.

Steve


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Jeremy Garchow
Re: AJA - HD->SD Downconvert + 3:2 problems
on Apr 2, 2009 at 4:19:01 pm

Yeah, that's it. Just had to be sure.

OK, next.

What deck protocol do you have set in your output?

How fast are your scratch drives?


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steve coulter
Re: AJA - HD->SD Downconvert + 3:2 problems
on Apr 2, 2009 at 5:03:22 pm

Hey. Using a Sony DVW500 digibeta deck controlled via serial rs422 (from the kona).. and using the Aja Kona 1080i 29.97 playback mode in FCP and associated deck control preset. The scratch drives are a RAID system which are quite fast. They pass the disk test thing in the Kona Utils with around 330 MB/s read and write.





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Jeremy Garchow
Re: AJA - HD->SD Downconvert + 3:2 problems
on Apr 2, 2009 at 7:42:51 pm

Yeah, that sounds about right, but there's no reason your audio and video should drift out of sync.

Maybe call AJA.




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Tyler Parent
Re: AJA - HD->SD Downconvert + 3:2 problems
on Apr 17, 2009 at 4:30:46 pm

We've had the exact same problem for months. If a solution is found please post it. Thanks.

Tyler Parent
Film Sound One


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steve coulter
Re: AJA - HD->SD Downconvert + 3:2 problems
on Apr 17, 2009 at 5:37:41 pm

Hey Tyler.. doesn't seem to be much info on this. I may contact AJA at some point today or next week. I wonder if we should have splurged for a Kona 3 instead of the LHe, if the problem is LHe specific. Or, perhaps a different box altogether would be a solve. I hear the new Matrox box is pretty solid.

Someone a while back mentioned the problem might be the PCI-Express configuration - in that the Mac doesn't recognize the AJA card as a video card, simply as a "Intel PCI-to-PCI bridge". The people who configured our systems said that this wasn't an issue.



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steve coulter
Re: AJA - HD->SD Downconvert + 3:2 problems
on Apr 24, 2009 at 2:16:41 pm

Hey Tyler.. I think I've found something to make it work. I tried this for a few outputs yesterday and it went off with no problems. Here's what I did:

- set 10 second preroll in Device Control Presets
- under AV Devices in Audio/Video settings, I de-selected "Mirror on desktop"
- in the timeline RT tab I set the pulldown to 2:3:3:2 (from 2:3:2:3)

Seems to work. I output a sequence of 8 x :30 second spots with no problem. Let me know if this works for you.

Steve


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Jeremy Garchow
Re: AJA - HD->SD Downconvert + 3:2 problems
on Apr 24, 2009 at 9:17:44 pm

[steve coulter] "- in the timeline RT tab I set the pulldown to 2:3:3:2 (from 2:3:2:3) "

I wouldn' recommend that as that is advanced pulldown and might get flagged as incorrect by broadcasters.

Jeremy


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