View Full Version : codec for keying


Michael Galvan
February 22nd, 2006, 04:07 PM
I may be doing some green screen work in the future with the XL-H1. My question is what would be the best codec to capture to using the HD-SDI for the purposes of keying? The option for shooting on the HVX200 is there too, but is there a better compressed codec than DVCProHD for keying, that I could use the Canon for? I can't keep it in the uncompressed realm for storage reasons ... so what would be a suggested codec to convert to and work in Final Cut Pro?

Robert M Wright
February 22nd, 2006, 05:54 PM
I've never done keying, but I would think the Cineform 10bit 4:2:2 codec could work great.

Barlow Elton
February 22nd, 2006, 10:10 PM
Try Apple Intermediate Codec at a high bit rate or PhotoJPEG at 75% (4.2.2)

David Taylor
February 23rd, 2006, 12:37 AM
...what would be the best codec to capture to using the HD-SDI for the purposes of keying? ... so what would be a suggested codec to convert to and work in Final Cut Pro?
Michael (disclosure - I'm from CineForm), Robert is right. 10-bit CineForm Intermediate keys very well, although currently it is available only on a PC - in case that is an option for you.

If you'd like a little more detail, we participated in an XL H1 test shoot and 35mm film print exercise a few weeks ago managed by Scott Billups. We recorded from the XL H1 HD-SDI output into a Wafian HR-1 directly into 10-bit CineForm Intermediate files from which the filmout was performed. I wrote about this exercise in the following blog: http://cineform.blogspot.com/. In the post from January 17, 2006, I also included a quote from Scott related to keying work he did on the CineForm Intermediate green screen material that was shot as part of the filmout exercise.

Christopher Glaeser
February 24th, 2006, 12:25 AM
Which codec should I use for keying when grabbing the video via DV Rack and firewire?

Best,
Christopher

Robert M Wright
February 24th, 2006, 01:10 AM
Via DV Rack and firewire, you will get HDV (unless you have the camera shooting DV). HDV is what the camera will send.

Christopher Glaeser
February 24th, 2006, 11:15 AM
Via DV Rack and firewire, you will get HDV (unless you have the camera shooting DV). HDV is what the camera will send.

OK, thanks. So, to get Cineform codec when capturing from the camera without additional conversion steps, I would use Aspect HDLink?

Best,
Christopher

Robert M Wright
February 24th, 2006, 12:59 PM
I don't have Aspect, but yes, HD Link is CineForm's capture utility, that can be configured to convert to the CineForm codec while capturing.

Michael Galvan
February 24th, 2006, 04:03 PM
Thanks guys ...

What are your thoughts on using something like the animation codec?

Robert M Wright
February 24th, 2006, 06:34 PM
I don't know what the animation codec is. Is it something I should know about, but somehow managed to miss? (With a name like that, I would guess it to be something optimized for animated video, not video shot with a camera, so it wouldn't surprise me if I simply overlooked it.)

Robert Sanders
February 24th, 2006, 07:45 PM
It's a Mac/Quicktime codec. Very similar to RAW or uncompressed. The bandwidth is too high for anything other than a RAID.

Robert Sanders
February 24th, 2006, 07:51 PM
Mr. Wright,

How's that Intel Mac support coming? ;-)

Nick Jushchyshyn
February 24th, 2006, 07:54 PM
What tools will you be keying with?

Often, especially for an HD pipeline, it's easiest to work with individual image files per frame. So, shoot and capture with the best possible quality you have available (capture from the SDI to a 10 bit 4:2:2 codec), then render to TIFF or TGA files per frame for your visual effects pipeline.

This may sound cumbersome at first, but most visual effects applications tend to work best with image sequences rather than codec-wrapped video. And the 6 Megs per frame of a 1920x1080 TGA frame is half the size of what film guys are used to working with when handed Cineon plates. :)