• Apple Final Cut Pro Legacy

  RoundTrip to/from Win AE -> gamma(?) shift

  Posted by Bob Cole on November 14, 2006 at 6:33 am

  Captured in FCP AJA Kona uncompressed 525 29.97 8 bit.
  Edited, then exported to same codec Quicktime.
  Imported to Windows After Effects, rendered two ways:

  1: Kona’s Windows codec “2vuy,” for “uncompressed 8-bit 4:2:2”
  result: no shift in picture’s brightness.

  2: Quicktime Animation codec, High quality
  result: much smaller file than #1, and a brighter picture.

  I actually like the brighter picture from #2, which means the video was a bit too dark to begin with…. and I really like the smaller file size from #2 because I have 300+ variations of these spots to deal with. But I’d like to know what’s going on with the QT Animation codec, for those times when I may need to use it.

  (Thanks to DRW and Dave Friend for helping me get this far — I went down the primrose path using DVCPro50 codec, and was not successful in Windows AE with it.)

  Thanks for any insights into the world of round-tripping to/from Windows. I know, I need to plunk down for Mac After Effects. Later.

  — Bob C

  Bob Cole replied 19 years, 8 months ago 2 Members · 2 Replies
• 2 Replies

• 

  Andy Gallagher

  November 14, 2006 at 5:02 pm

  Hi Bob,

  I think what you’re seeing is a colourspace conversion. Given the codec your original footage was using, AE is working in an 8-bit YUV colourspace. So you don’t see any shift when you render that out.
  On the other hand, Animation (as far as I know) is a lossless RGB codec. So you should get the same quality of image as using an uncompressed codec but a (slightly) smaller file. The key though is that it’s storing the image data as RGB, not YUV – so the program is converting between the two spaces. As they don’t line up properly you see colour and/or brightness shifts in the final picture.

  FYI, I think that Animation uses ‘Run-length’ compression – i.e. imagine you’ve got someone on a black background. An uncompressed codec would write seperate data for each black pixel of the background wheras Animation would just write ‘Black, repeated (x) times’. So it’s really dependant on the shot composition how much smaller the file would be.

  Hope that’s of some help!
• 

  Bob Cole

  November 15, 2006 at 1:12 am

  That was a great reply. Thanks so much for explaining that so clearly.

  — Bob C

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