SheerVideoWhy is my video displayed slightly lighter|darker with Sheer?
The brightness is related to a parameter called “gamma”, which measures how quickly the spacing between brightness levels grows. DV and other standard-definition video formats have a fixed gamma level of 2.2, corresponding to the brightness of television. The Mac display has a gamma of 1.8; and on a PC, display gamma is usually 2.5. When DV and other fixed-gamma formats are displayed, the DV or other codec adjusts the gamma to that of the display. In contrast, when DV and other video formats are exported to a variable-gamma format such as SheerVideo, the gamma remains at 2.2, so that any processing of the Sheer-encoded video will happen at the correct gamma of 2.2, just as it would for the original DV or other video format. The Sheer codecs themselves never alter the gamma level of the pixels, since doing so would destroy image information. When Sheer-encoded video is displayed, the Sheer decoders let QuickTime know that the source gamma level is 2.2.
