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URGENT – random green lines and dots when rendering
Hello,
I’m editing a 35mm film transferred to DigiBeta 29.97. I am using the Decklink 4:4:4 card, Final Cut Pro 5.0.4 and Quicktime 7.1.3
Very often, when I render, I get these very weird green lines, or dots in a straight line in various colors. Sometimes they are very visible, sometimes they are not (the green lines are many times hidden by movement in the frame, similarly with the dots). This proves to be very annoying, since every time after I render I need to check the shot frame by frame. After I re-render, they disappera most of the time – if not, I just re-render until they go away.
Now I finished the film and I want to change the subtitles, make a 24p version and so on. I find myself AGAIN checking every shot I changed frame by frame as I’ve been fooled many times and missed some lines. Even now I’m not 100% sure I have spotted them all.
This is getting too tedious and I’m sure it’s the card or the Blackmagic codec to blame. I’ve been searching Creative Cow and saw that other people had similar issues, yet a conclusion is never reached. I find myself with the prospect of losing one-two days with this project only checking if there are no damn lines or small dots in the frame.
I’d love to post some frame grabs if I knew how, but I want this problem solved if possible.
Anyone has any ideas? Thanks so much,
Mike
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10 Replies
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I’ve had similar very annoying issues and have raised the issue serveral times. I really hope FCP 6 fixes this. I’m assuming you are rendering PSD files when you get this? Re-rendering doesnt always do the trick for me. Several solutions that I have come up with….save still as tif’s. Of course, this doesnt work when you want a layered PSD file. Another option is to switch rendering on the timeline from 10 bit to 8 bit. That should cure your problems.
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No, I am rendering normal video files.
To go to a 8-bit timeline would defeat the purpose of editing in Digibeta uncompressed 10 bit.I am still verifying and re-verifying every version and I am still finding those annoying green lines or dots here and there, small, in a corner of a frame or something (as if on purpose to escape my eye!). I am going nuts.
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Hi,
Could you send us a frame or two in the original as well as the rendered clip which demonstrates this issue? Are you using the File > Export > Quicktime Movie option Final Cut Pro?
Have you also tried:
a) Rendering to a different drive
b) Checking the status of the memory in your system. There’s a freeware RAM checker called Rember which you can find on Macupdate.com. I’ve come across artefacts in rendered video caused by corrupted memory.regards
Kristian Lam
Blackmagic Design -
Never seen that issue with actual video files….only stills. Yes…the 8 bit option isn’t optimal…it was a suggestion for a quick fix.
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I have had this problem, not just with Blackmagic but also with Cinewave. It seems to be tied to the Apple uncompressed 10 bit codec, especially when combined with anything with an alpha channel. I usually use 8 bit because of this. It probably won’t be resolved until Apple fixes the 10 bit codec. You could try the Blackmagic 10 bit RGB codec if you can deal with the color conversion and lack of real-time effects.
Chris Paul
POV -
OK I will send the stills – I have them already saved. To what e-mail address? I will send them ASAP.
It doesn’t happen when exporting. Only on the timeline, when I render something, occasionally this problem shows up. Sometimes the artifacts are very easy to spot, sometimes they are tiny and I find them much later. Sometimes they only appear for a singe frame, and are virtually impossible to detect if you don’t play frame by frame specifically for this problem.
I tried rendering to a different drive, no difference.
I haven’t checked my RAM but I doubt this is the problem, since it only happens when I am in my DigiBeta project.
Thanks.
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Sorry, left out my contact details. Please send to support[at]blackmagic-design.com
[medavoym] “It doesn’t happen when exporting. Only on the timeline, when I render something, “
Does it show up in the Canvas window of Final Cut Pro after rendering? Please check through the video output and when you come across a problematic frame on the output of the card, check if it’s also in Final Cut Pro’s canvas window. Thanks.
regards
Kristian Lam
Blackmagic Design -
Thanks I will send the pics right now.
Yes, it shows in canvas as well, not only on my CRT monitor. If I render out a quicktime self-contained file, it’s there as well.
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Hi,
If you’re seeing this in the Canvas window in Final Cut Pro, then there’s a high chance it’s not the card’s output. IT could be codec related or something else.
Try this. Quit out of Final Cut Pro, go into “/Library/Quicktime” and move any “Blackmagic” related files to the desktop. Restart Final Cut Pro and then see if this issue is still happening. We actually use Apple’s Uncompressed codec in Final Cut Pro.
regards
Kristian Lam
Blackmagic Design -
Sounds like a common problem, some files will NEVER work in 10-bit. What I do is make an 8-bit sequence for the offending areas, and export it as a Quicktime. Then I import the quicktime into a 10-bit sequence. You may not want to use 8 bit, but face it, sometimes 10 bit does not work!
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