FORUMS: list search recent posts

Random but persistent flicker - IoHD

COW Forums : AJA Video Systems

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
Tim Kirby
Random but persistent flicker - IoHD
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



-----------------------------
Man cannot discover new oceans until he has the courage to lose sight of the shore.


Return to posts index

Jeremy Garchow
Re: Random but persistent flicker - IoHD
on Apr 21, 2008 at 10:16:23 pm

What do you mean by frame flicker? Are you referenced/genlocked? What other gear is hooked up to your machine and what kind of machine do you have?


Return to posts index

Ken Botelho
Re: Random but persistent flicker - IoHD
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.



Return to posts index


Jeremy Garchow
Re: Random but persistent flicker - IoHD
on Apr 22, 2008 at 3:11:45 am

[Ken Botelho] " I have only seen this issue on passthrough or holding still frames in FC"

Are you sure that's not interlace twitter?


Return to posts index

Tim Kirby
Re: Random but persistent flicker - IoHD
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.



-----------------------------
Man cannot discover new oceans until he has the courage to lose sight of the shore.


Return to posts index

Jeremy Garchow
Re: Random but persistent flicker - IoHD
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.

Nice one.

Jeremy


Return to posts index


Ken Botelho
Re: Random but persistent flicker - IoHD
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.



Return to posts index

Jeremy Garchow
Re: Random but persistent flicker - IoHD
on Apr 22, 2008 at 3:32:45 pm

Ken, take Tim's advice.


Return to posts index

Ken Botelho
Re: Random but persistent flicker - IoHD
on Apr 24, 2008 at 1:37:11 am

[Jeremy Garchow] "Q"

Thanks Jeremy, I will leave it connected to the logic board bus for some time and let everyone know if i still have problems. Fingers crossed....





Return to posts index


Jim Randall
Re: Random but persistent flicker - IoHD
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.

JR



Return to posts index

Jeremy Garchow
Re: Random but persistent flicker - IoHD
on Jul 29, 2008 at 2:01:52 am

I don't use LiveType so it's hard for me to judge, but have you tired rendering out of LiveType first then bringing in that movie?


Return to posts index

gary adcock
Re: Random but persistent flicker - IoHD
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




Return to posts index


Jim Randall
Re: Random but persistent flicker - IoHD
on Aug 8, 2008 at 8:21:49 pm

Thanksa for the tips. I render the final FC timeline before I export it to QuickTime movie. This seems to have fixed the problem.



Return to posts index

Bobby Jones
Re: Random but persistent flicker - IoHD
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.



Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2017 CreativeCOW.net All Rights Reserved
[TOP]