Best File Format for keying?

Discussion in 'Digital Video' started by Rein37, Dec 2, 2010.

  1. Rein37 macrumors newbie

    Dec 2, 2010
    Hi all,

    A client I have wants to set up a green screen shoot in a month or so and she is shooting on some high-def slr camera that also does video apparently. In the future she is going to want to know what file format she should be giving me the footage in. What should I tell her? I use After Effects for my keying work.
    Thank you in advance!
  2. Sdougherty macrumors member

    Nov 8, 2009
    You need more specifics about the camera, and what file types you like to work with.
  3. drewyboy macrumors 65816

    Jan 27, 2005
    My guess is it's going to come in some type of h264 form. I've gotten some footage from a client before and he was using a T2i and gave it to me in .mov (h264), which was fine for the project, but h264 is 4:2:0 (canon dslr) which isn't the greatest for green screen. Also, if you can afford it, I'd use a 3rd party keyer. I'm particularly a fan for Primatte. So point being, for keying, a DSLR is not your friend by any means. I'm not saying you can't get decent results, but your client needs to know that. If you had a camera that had like SDI so you could grab the source at 422 or even 444, run it to a Ki-Pro capturing it in ProRes, then you'd be right in the money. I've done a few shoots that way, and all I can say is the keying, even using keylight, was absolutely night and day. Even though keying isn't a one click process, it seemed like it when I was using ProRes 422 captured from the SDI output. I know I went on a rabbit trail but I hope this helps some what. Please feel free to ask more questions.
  4. Rein37 thread starter macrumors newbie

    Dec 2, 2010
    Yeah, I just emailed her again to ask her about the camera and what not. I know it saves the footage to a SD card, but other than that I don't know. I was pretty much thinking mp4. That seems to work the best, but I don't know what she can do. I was just curious if there were file types that work best for keying and others that aren't so good. I know DV is horrendous, but luckily I'm not dealing with that here.
  5. handsome pete macrumors 68000

    Aug 15, 2008
    I'm with Drew on this one. 422 footage is leaps and bounds better for keying, so if that is an option then go that route.

    Based on the fact that they're currently shooting on DSLR, my guess is that the budget might be limited. So 422 might not be an option. None of them allow you to capture uncompressed out, except for the GH2 I believe.

    There are chroma interpolation plugins out there that might help a bit with the footage. But when it comes down to it, you can't magically insert information that wasn't captured in the first place so those will be limited.

    If it's not too much trouble, I would just ask for the h264 files from them and convert them to something like prores on your own. I wouldn't depend on them to do any of the compression/file conversion unless it's a time/money issue.
  6. Rein37 thread starter macrumors newbie

    Dec 2, 2010
    I use Key Correct Pro as a third party plug-in for After Effects. It does a pretty good job, even making DV footage look decent for keying. I've never used's good though, eh? And no SDI or Ki-Pro! It's not that high-end!
  7. Rein37 thread starter macrumors newbie

    Dec 2, 2010
    Ok, and if I do that than how do I go about converting the h264 to prores? Can something like Hand Break do that?
  8. handsome pete macrumors 68000

    Aug 15, 2008
    You're going to encounter a lot of the issues with keying h264 footage as you would with DV. Whereas DV uses 4:1:1 chroma sub sampling, H264 uses 4:2:0. Both the 4:1:1 and 4:2:0 schemes halve the bandwidth compared to no chroma sub sampling. So that is the biggest obstacle with keying. The added resolution since it is in HD will help you a little, but it's still going to be a pain in the ass. It also depends on what type of footage you will be keying. And by that I mean the actual content of the shot.

    Regardless, I'm still going to assume that whatever camera they're shooting on will only provide H264 footage since that's what all of the common SLRs used for video do. H264 is a delivery codec, so you will need to convert to and editor friendly format. Something lossless or virtually lossless like prores as I posted before will do.
  9. simsaladimbamba

    Nov 28, 2010
    MPEG Streamclip
  10. handsome pete macrumors 68000

    Aug 15, 2008
    Handbrake won't, but a common free utility that a lot of DSLR filmmakers are using to convert their footage is called MPEG Streamclip. I'm not sure exactly what codec it uses. It might be Apple Intermediate Codec if I remember correctly.

    ProRes is Apple only and you can only get it through having Final Cut Studio. So if you have access to that, then there you go.
  11. Rein37 thread starter macrumors newbie

    Dec 2, 2010
    OK, yeah I actually have MPEG Streamclip, and it doesn't have prores, but I have Final Cut. Is there a difference between what is apparently the normal Prores and Prores HQ? I'm assuming that HQ stands for high-quality, but how is it different from the normal one?
  12. Rein37 thread starter macrumors newbie

    Dec 2, 2010
    Ok, so the woman just got back to me with this email:

    "I am using a canon 5d mkii – its an hdslr. I think the raw camera files are .mov and I can transcode them to be uncompressed if needed"
  13. handsome pete macrumors 68000

    Aug 15, 2008
    Yeah, you should be fine with the regular Prores setting.

    The 5d compresses to h264. Since you have prores, then I would just ask her for the h264 files and convert them on your own. No need to bother with uncompressed.
  14. Rein37 thread starter macrumors newbie

    Dec 2, 2010
    Great, thank you!!! You guys have been most hopeful and I really appreciate it!

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