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Kona 2 – ProRes plays fine in 8 bit, but not 10 bit – WHY?
I have just installed Final Cut Studio 2 and the new Kona 4.0 drivers. When I load a Pro-Res (HQ) clip (1080i) into a Pro-Res (HQ) timeline (1080i) and play the video out via the Kona 2 using the 8bit 1080i setting it plays fine (smooth without issue), but when I change the setting to the 10 bit 1080i setting and try to play back – FCP stop and says that it’s dropped to many frames (In 10 bit mode it nearly comes to a halt). If I don’t use the kona output it plays fine on the computer monitor.
So it plays fine without the kona output, and with the output set at 8bits, but doesn’t play when set for 10bits. Is this a kona/FCP bug, or is something changing between settings that would cause this?
Thanks,
Chris -
6 Replies
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system specs?
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Dual 2.7 G5. Files running off a single SATA drive.
Initially I thought it might be the system, but like I said in the above post, the media play fine with the kona 8 bit output, or when there is no kona output. So it seems like it can handle playing the file, just not when the Kona output is set to 10 bit. Don’t understand what that would be the case.
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So it does seem to be a system spec issue. I dropped the frame rate in the RT button settings to “half” and it will play fine (well choppy as it’s supposed to).
What I don’t understand is that it will play fine with an 8bit Kona 2 output, and no Kona output at all, but when you switch to 10bit it drastically increases resources it needs. How/why does that happen. I would assume the file resource requirements would stay the same, and that the Kona handled the output (8 or 10 bit).
Anybody know what changes / why the requirements go up when outputting 10bit Pro-Res?
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Sometimes I have to have the Kona card video playback set to 8-bit to play 10-bit footage. I don’t know why, but you might try several different settings from FCP’s video playback menu to see if one works.
Good luck!
-Russ
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I have never had luck with only a single SATA drive for 8 and 10 bit uncompressed SDI SD material, or DVCProHD. I ALWAYS use a minimum of 2 SATA drives striped RAID 0 to do this – and all of this was way before Pro Res 422 or Pro Res 422 HQ. And today, with the port multipliers out, running a box with 5 drives is no big deal. You have a bandwidth issue.
Bob Zelin
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I have had this same issue while using a 5-drive RAID with 350 mBps playback speeds, so I don’t think it’s necessarily a bandwidth issue. Although Bob is right that you’re expecting too much from that drive. In my case the fix was to reinstall the Kona driver. On my system the picture from the Kona would get completely scrambled if set to 10 bit, and switching to 8 bit display looked fine.
Joe Murray
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