Random but persistent flicker - IoHD
by Tim Kirby
on
Apr 21, 2008 at 9:41:33 pm
Just wrapped up a nice job on some TVC's, uncompressed SD and all was going well. Switched to to a not quite as glamourous but no less important training video DV job and began having trouble with preview /output.
It's a random but persistent occasional frame flicker on my monitor/output from IoHD...have checked component, Svideo and composite outputs and it's the same - checked all cables, rebooted, powercylced, checked project/sequence/aja settings, changed monitors... Reverted to the uncompressed job - same problem there now.
I'm a bit flummoxed now - anyone got any ideas? I know I can revert to firewire for this job (going to have to when the client is here tomorrow) but I'd like to crack this before I'm up against it again.
2 x 3Ghz Quad Core Xeon
8 Gig Ram
FCS 2
AJA IoHD
Tim
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Man cannot discover new oceans until he has the courage to lose sight of the shore.
Re: Random but persistent flicker - IoHD by Ken Botelho on Apr 22, 2008 at 12:16:52 am
Dont worry your not alone, I have had this issue since day 1, I thought i was going crazy until I saw your post. I have only seen this issue on passthrough or holding still frames in FC, fortunately this doesn't happen during continuous playback through FinalCut, or i would return this thing in a heartbeat.
Re: Random but persistent flicker - IoHD by Tim Kirby on Apr 22, 2008 at 7:41:02 am
Thanks for the replies...this is definitely not interlace twitter - it's flashing and flickering sometimes at the top of the picture, then the bottom, then accross the whole frame.I'm getting it not only on passthrough of holding frames, but during playback. It's also a brand new problem, I've been using this IoHD since last November and not had this issue. It looks like you would expect output with a dodgy cable to look - if it's not cable related I'm guessing there is something up inside my IoHD?
At the moment there is nothing else at all connected to my MacPro other than the Aja IoHD. Recently there has been a hired in Digibeta deck, normally there is a Sony HVR M25 with an Addenda Lanc-RS422 adapter.
UPDATE! After writing the above I realised one additional connection change I hadn't tried yet -so I plugged the new IoHD firewire cable into my second FWbus on the MacPro....guess what...the problem has gone. Praise be.
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Man cannot discover new oceans until he has the courage to lose sight of the shore.
Re: Random but persistent flicker - IoHD by Jeremy Garchow on Apr 22, 2008 at 3:32:16 pm
[Tim Kirby]"UPDATE! After writing the above I realised one additional connection change I hadn't tried yet -so I plugged the new IoHD firewire cable into my second FWbus on the MacPro....guess what...the problem has gone."
I was going to suggest putting your ioHD on the Mac bus and your drives on the Sonnet card.
Re: Random but persistent flicker - IoHD by Ken Botelho on Apr 22, 2008 at 11:56:07 am
Not "twitter" the entire screen flashes a frame of black from time to time..... Strange, I have the IoHd on a separate bus too (sonnet card). I since its intermittent and random its difficult to reproduce at my will.
Re: Random but persistent flicker - IoHD by Jim Randall on Jul 28, 2008 at 8:57:44 pm
I too am having a flicker with playback with the ioHD. However, I can replicate the problem when it happens. It ALWAYS happens with a lower third super (made with LiveType.) In this last project the segment had six lower thirds in one five-minute segment.
The host names appears at the first and the last of the segment (the same file) and is steady. The other two, also shown twice in the segment using the same file causes the picture behind the super to flicker vertically. It will ALWAYS flicker on these two files.
The lower thirds are made using the same "master template" as the other dozen or so lower thirds in the program. They are all steady.
Playing the program on the computer does not give any hint there is a problem. I see it when it passes through the ioHD into the HDTV studio switcher. I see it on ioHO control monitor. The program is produced in 1920 X 1080i.
This problem occurs somewhere in every program I have produced using the ioHD. We have switched the ioHD's with a brand new unit. It is the same result.
It does not matter if the clip the lower third is over was up converted from 1440 X 1080i or a native 1920 1080i.
I'm using Apple ProRes 422 1920 X 10801 (HQ).
I have exported the program out to a QuickTime movie and played it back. Same result in the same place! I have played it back from the original sequence time line (rendered) same result.
I tried switching the FW from the back of the MAC Pro to the front as suggested. Problem still there, and occurs with same two files, in the same place. I have even run the program on a different computer use a different ioHD!
The program and running on our Apple SANS network.
Re: Random but persistent flicker - IoHD by gary adcock on Jul 29, 2008 at 11:57:28 am
[Jim Randall]"The host names appears at the first and the last of the segment (the same file) and is steady. The other two, also shown twice in the segment using the same file causes the picture behind the super to flicker vertically. It will ALWAYS flicker on these two files. "
OK
that right there leads me to think that it is your file and not the IoHD, since this is not happening on all of the L3's just a couple- I has to be something with the way that those files are created.
have you tried them in a new seq with no footage / different footage behind them?
have you looked at other tools.
have you FULLY RENDERED the file out before playback?
[Jim Randall]"Playing the program on the computer does not give any hint there is a problem. I see it when it passes through the ioHD into the HDTV studio switcher"
you are sure it is not your graphics?
gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows
Inside look at the IoHD
Re: Random but persistent flicker - IoHD by Bobby Jones on Feb 19, 2009 at 3:08:49 pm
I had this exact same problem when working in 1080i. I tried 3 different Io HD boxes, chaneged driver software, changed firewire cables and ports with no success. Later had the same problem on a brand new Mac Pro. I set my field dominace to NONE and the flicker stoped. It does make some of the livetype graphics a touch blury becuase they are inteneded to be interlaced but thats a better option than the video shifting.
