FCP 7 AND MOTION 4 FADE UP AND FADE OUT banding/artifacting/CRAP!

I'm suddenly noticing when exporting a movie from the timeline, the FADE UP and/or FADE OUT to BLACK has this weird banding to it. In MOTION 4, if I create the same effect, it seems to be better, sometimes perfect. But when I bring it BACK into my timeline in FCP 7, add it to the sequence and then render out
a completed movie, IT'S THERE AGAIN. I am typically rendering via QT Conversion, H.264, 1920x1080 then uploading finished product to TV Stations. Am shooting with either Canon T2i or 5D - - transcode to pro res 422 and everything edits and looks great. CROSS DISSOLVES between shots in timeline look fine.
It's the beginning OPEN TITLE situations when you want to FADE UP from black that it is the most noticeable. What does one have to do to have a simple, clean FADE UP FROM BLACK for crying out loud!?!?!?!?!?!?!?!?!?!? - Mike M.

Don't go to H.264. Banding is common in lower res formats, especially in gradients.

Quote
Jude Cotter
Don't go to H.264. Banding is common in lower res formats, especially in gradients.

H.264 isn't a low res codec. H.264, like the ProRes and the uncompressed codecs, can be used for a range of resolutions from sub-SD to supra-HD. Nor is H.264 an unsharp codec when it is used with a sufficient data rate for the resolution. H.264 is low bit-depth codec: 8-bits rather than 10-bits, making it more prone to banding. But whose monitor is 10-bits? Also H.264 is an interframe compressed codec, so one might suspect that it could mishandle fades. This needs to be checked before slamming H.264 as the source of Mike M.'s problem.

What exactly is Mike M.'s problem? banding/artifacting/CRAP! Banding is when a smooth spatial gradient shows steps. Distinct tones appear where there should be none. Banding is a phenomenon within a single frame. But in a fade the bands move, making them more noticeable.

8-bit coding alone can't produce serious banding, but image processing of 8-bit images can exaggerate the steps. For example the original 8-bit image might have a step from code 200 to code 201 that would be barely visible. Suppose an effect changes the two bands to codes ~200½ and ~201½. Suppose the first code rounds down and the second code rounds up. Now the step goes from code 200 to code 202 and is definitely visible. The "rounding errors" have reduced the 8-bit coding to 7-bit coding. And then the next effect is applied, etc. This is why it is good to work in a 10-bit codec even when release will be in 8-bits. Mike M. seems to have only outputted in H.264.

It should be studied whether H.264 bands more than an 8-bit codec should. H.264 might skimp at low data rates, but at high data rates does it look any worse than 8-bit uncompressed?

I verified that FCP7 fades are 10-bit by making a 956 frame long cross dissolve between superwhite code 1019 and black 64. The FCP7 dissolve is perfectly linear in code value. Each value between 64 and 1019 appears in the dissolve once. I've my own grief with FCP7 fades. They often appear temporally unsmooth. This experiment seems to absolve FCP7. Can my playback be that bad?

Dennis Couzin
Berlin, Germany