H.264 COLOR SYNC & GAMMA

When I export to either QuickTime or MP4 using the H.264 codec there is a very noticeable gamma and saturation shift when compared to the original Animation codec master. I've scoured the web. There are some suggestions out there. I need a real answer.

There are two real answers. The first is don't use Animation. That's an ancient 8-bit RGB format with well-known issues.

The second is don't judge your footage on a computer monitor.

Thank you kindly for your suggestions. Your advice is appreciated. This video is for the web so of course I'm going to view it on a computer monitor just like every other viewer will see it. Animation is an excellent, battle-tested codec. Anyone else?

Good News:
Media Encoder was able to take the Animation Codec master and compress it to MP4 with H.264 codec sans unacceptable color and gamma shift.

Exporting from FCP as Uncompressed 10 Bit or ProRes422HQ allowed for color and gamma accurate transcoding to MP4 with H.264. I guess that is because of the difference between RGB and YPbPr / YUV. I use Animation when round tripping because it is lossless and I Avoid ProRes422HQ when round tripping because it is lossy. I could use ProRes4x4 but I've not yet upgraded to 7. Thanks again.

Animation is not lossless. It's uncompressed, but it's not even close to being lossless. You lose far more by taking a 10-bit source down to 8-bit RGB than you do by rendering to ProRes 422.

Compressor has an issue converting between RGB and YUV. This is because in most RGB codecs, gamma values and color spaces are not flagged, so the software has to make an assumption. Adobe and Apple have, for quite a while, been working with two different default gamma values when it comes to dealing with RGB sources- in Macs, for RGB, gamma usually defaults to 1.8 (until SL), and for PCs, it varies between 2 and 2.2.

Now, here is a myth. Animation is a lossless intermediate only if your source file is 8 bit RGB and uses the same color profile as your input source. Otherwise, rounding errors will occur.

I have to add that between Macs and PCs, you may not have that much of a choice and animation is sometimes used. But when you're exporting between FCP and Compressor, Animation is really one of the worst things you can use. Okay, there are worse... But heck, there are better choices.



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