Welcome to the club of FCS color change sufferers.
Exactly what kind of video went to Compressor and what kind came out?
Exactly how you are judging the color change -- what application is used for playing the before and after videos?
Often the color change is a gamma change. This can happen in three ways.
- The new video can be made with gamma-shifted values throughout.
- The new video can be made with information in its header causing the player to shift the gamma.
- The player might shift the gamma just because of the kind of file.
Pro Media Tools from
Digital Rebellion includes the program "Gamma Shift Detector" to show if you have 1 or 2.
The color change might be a color space change. Again this can be in the video values or in header information. Pro Media Tools contains another program "QT Edit" for examining and editing QuickTime headers.
Exporting from FCP through Compressor sometimes makes a mess. It is safer to export a self-contained QuickTime file from FCP and drop that into Compressor.
Finally, whenever making a ProRes the advanced compression settings pane gives you a choice between "automatic" gamma correction and "no" gamma correction. Don't try reading Apple's mind. Try both ways and see if it makes a difference.
Dennis Couzin
Berlin, Germany
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