FCP 7 – Canvas window showing occasional dark green screen – Display resolution problem? Slow drive?

[John Rofrano]

[Michael Arnes] “I guess I may have to consider upgrading to X at some point.”

You do realize that FCP 7 was release in 2009 and was discontinued 4 years ago and is no longer supported right? So “may have to consider” is putting it mildly. 😉

[Michael Arnes] “Anyway, I used X Bench instead, which I guess is similar. I posted a screen shot of the result (not quite sure how to read it). Here below are the results for my G Drive, 7200 rpm, Firewire 800.”

From Xbench it looks like your FW800 drive is getting 75MB/s Read and 67MB/s Write. My G-Drive FW800 gets 79MB/s read and 78MB/s write so that’s consistent with what I’m seeing on my system too.

ProRes 4444 with Alpha Channel is 500Mbps (that’s megabits per second). To convert that into mega Bytes we divide the bits by 8 bits in a byte and get 62.5 MB/s. So your FW800 drive can read approximately 75 MB/s and ProRes 4444 requires 62 MB/s so you are right on the edge. You can see why you might occasionally get green video because the drive can’t keep up with the demands of playing back the stream.

[Michael Arnes] “Also, being that I’m a bit of a novice at all of this, I didn’t know there was such a thing as ProRes 444 (is that totally different from 4444?) In previous projects, I had always used ProRes 422. However, I just switched to 4444 because this is the first time I am shooting footage in front of a green screen. “

I’m sorry, I was using the term 444 to mean without the alpha channel. I see that “officially” Apple calls is “ProRes 4444” and “ProRes 4444 with Alpha Channel” which is technically inaccurate and confusing because the first 3 numbers represent the bit depth of RGB channels and the 4th is A (Alpha). I was referring to using the non-Alpha channel version but I see now that you can’t because you are keying in After Effects and not compositing in After Effects so you need the Alpha Chanel to carry the key into FCP 7.

[Michael Arnes] “* I’m shooting footage in front of a green screen (my camera shoots AVCHD)”

So you’re shooting 422 8-bit source.

[Michael Arnes] “* I convert footage to ProRes 422 (I had already done that before I learned about ProRes 4444).”

As you should be. There is no reason to encode 422 source as anything more than 422. You are not going to increase the quality by using more bits. The quality is forever 422.

[Michael Arnes] “* I import ProRes 422 footage into After Effects. Key out the green. Do some color treatment. I then render out as ProRes 4444. I render out foreground (subject) footage in a separate file from the background footage. In other words, I don’t commit and do the “compositing” part of this in After Effects, because I want the freedom to make editing decisions in FCP 7 later (being able to blend various foreground clips with various opacity settings, minus any background). Hope that makes sense.”

Yes, it makes sense and because you are not compositing in After Effects you need to use ProRes 4444 so that you can composite in FCP 7. If, however, FCP 7 can’t handle it… you may need to consider compositing in After Effects and export ProRes 422. Just sayin’… that’s an option you have to solve this.

[Michael Arnes] “* I import all ProRes 4444 files into FCP 7 and start editing. That’s when the trouble begins (the error green showing up here and there).”

Yea, so once again. Your FW800 drive is right on the edge of supporting ProRes 4444 500Mbps. Most people would probably say that you shouldn’t edit ProRes 4444 without a RAID array. I suggest you try faster storage as the first possible solution. If that doesn’t work, you might need to composite in After Effects and export ProRes 422 which FW800 and FCP 7 can handle more easily.

[Michael Arnes] “I’m still learning…”

Well… here is something to consider. If you learn FCP X and do all of you keying in FCP X, you would eliminate the need for After Effects and that whole workflow. You can edit AVCHD natively in FCP X and key it there, and you would avoid all of this trouble. Just something to consider.

~jr

http://www.johnrofrano.com
http://www.vasst.com

[Michael Arnes]

I really appreciate you taking the time to explain all of this John. Things are starting to make more sense now and I guess I have a couple of options to consider.

Thanks again!

[John Rofrano]

You’re welcome. Please let us know what worked for you when you final decide on a solution.

~jr

http://www.johnrofrano.com
http://www.vasst.com