H264 gives better results than ProRes 422(HQ) or Uncompressed?!

[David Roth weiss]

I’d be willing to bet that those pink aberrations would not be there if you used ProRes 422 instead of HQ.

And, I’d be will to bet that in AE the render was either premultiplied or not premultiplied, and whichever it is, that’s the issue.

David Roth Weiss
Director/Editor/Colorist
David Weiss Productions, Inc.
Los Angeles
https://www.drwfilms.com

Don’t miss my new tutorial: Prepare for a seamless transition to FCP X and OS X Lion
https://library.creativecow.net/weiss_roth_david/FCP-10-MAC-Lion/1

POST-PRODUCTION WITHOUT THE USUAL INSANITY ™

Creative COW contributing editor and a forum host of the Business & Marketing and Apple Final Cut Pro forums.

[Matt Lyon]

If the original clip truly has no problems, then you should find the clip in the earliest cut of the movie you mention, select it, then right click>”reveal in finder.” Open that clip in quicktime player 7 and trim out just the section you need for VFX. Use “save as…” to give the movie a new name, and send that short clip to the VFX artist. Now he/she is working with the closest to original generation footage possible and hopefully with none of the problems you are seeing.

Just out of curiousity, are there any filters or motion effects being applied to the clip before you did the problematic exports?

Hope this helps,

Matt Lyon
Editor
Toronto

[Adrian Makai]

Thanks for the input but the problem has nothing to do with the VFX step. As mentioned a couple of posts up, I tried going back to the earliest cut of the movie (before anything had been done other than dropping the clips into FCP) and exporting that sequence to QT. Same proble – looks fine playing in the timeline or when exported to H.264. Looks smeared when exporting to uncompressed or PR422HQ.

Still a mystery…

[Adrian Makai]

Interesting. Why would 422 be better than 422HQ? I always thought the latter is supposed to be better.

And what might account for the fact that if I just open the original 422HQ clip in QT, it plays fine? I posted a clean still from that clip a few posts above – no pink smear.

[David Roth weiss]

[Adrian Makai] “Interesting. Why would 422 be better than 422HQ? I always thought the latter is supposed to be better.
“

From time to time HQ simply kicks off some problems that ProRes 422 just doesn’t. I’m not 100% certain why, it’s just the way it is.

[Adrian Makai] “And what might account for the fact that if I just open the original 422HQ clip in QT, it plays fine? I posted a clean still from that clip a few posts above – no pink smear.”

It’s most likely some type of generational thing with ProRes HQ. I’ve never seen anything like that with ProRes 422

David Roth Weiss
Director/Editor/Colorist
David Weiss Productions, Inc.
Los Angeles
https://www.drwfilms.com

Don’t miss my new tutorial: Prepare for a seamless transition to FCP X and OS X Lion
https://library.creativecow.net/weiss_roth_david/FCP-10-MAC-Lion/1

POST-PRODUCTION WITHOUT THE USUAL INSANITY ™

Creative COW contributing editor and a forum host of the Business & Marketing and Apple Final Cut Pro forums.

[Matt Lyon]

Hi Adrian, I meant to say “colorist” instead of VFX artist. I was trying to show you a way to send “clean” footage, without introducing the artifacts. If your footage looks fine in the FCP timeline, then you need to examine how you do your exporting, because a “self contained quicktime” should theoretically be a 1:1 copy of your clip, with no re-compression (assuming you haven’t applied any filters/motion tab effects, etc). Based on your original post, the problem might be that your changed your timeline setting to “ucompressed” before you did your export … there is no reason to do that. Leave your timeline settings so they match your clip setting and simply export a self contained quicktime.

Prores HQ is generally considered overkill unless you are editing 4K footage, to answer your other question.

Your workflow involves tons of codec and color space conversion so it is not surprising that problems are being introduced. In general, you should strive for as few transcodes as possible. Changing your prores footage to 10 bit uncompressed does not make it look better. I would only do it your colorist specifically can only work with that format. Also, when you exported your whole movie as TIFFs, the image files would have been limited to 8 bit color depth.

Matt Lyon
Editor
Toronto

[Adrian Makai]

Thanks for the feedback, Matt.

Even if I don’t change my timeline to 10-bit, but keep it at ProRes422 HQ (identical to the base clips) – same problem! I was originally doing that before I tried 10-bit.

Thanks for the reminder on TIFFs 8-bit limitation. The original footage was 8-bit, so hopefully we didn’t lose any quality when sending to VFX. It didn’t look like any quality was lost.

It’s only after VFX have been applied with higher bit-rate layers, that we are now trying to stick to 10-bit.

[Adrian Makai]

Actually, one reason we used TIFFs is because it was supposed to be lossless, or so we thought?

Does FCP limit TIFF output to 8-bit regardless of the bit-rate of the footage? If yes, that would be nuts…

[Michael Gissing]

Interesting that the artifacting is on the 10 bit exports and not the H264 which is 8 bit.

Try an 8 bit uncompressed and see if that helps. It is clearly something to do with peak whites. Another left field idea is to drop the 3 way cc and bring the peak whites to 100 or just under and see if that helps with the 10 bit exports

[Matt Lyon]

TIFF images themselves are lossless, but when you export from a video codec to tiffs, you are converting from YUV color space to RGB color space. That introduces issues, like the the fact they have different color gamuts.

There is no such thing as 10 bit TIFF files, just 8 bit per channel or 16 bit per channel (and maybe floating point? I can’t remember…). In any case, FCP doesn’t do 16 bit per channel anything, so I don’t think it is “nuts” that it is limited to 8 bit per channel TIFFs. Last I checked, quicktime player won’t open 16 bit TIFFs either.

Matt Lyon
Editor
Toronto