Why does QuickTimes Movie Settings dialog for SheerVideo say “Medium Quality”?
The QuickTime compression user interface ordinarily displays a Quality slider. All SheerVideo encoders have exactly one quality setting: perfect, so the Quality slider has no effect on SheerVideo. Displaying the Quality slider would mislead users into thinking they can choose different encoding qualities, and thus perhaps waste their time trying out different quality settings. Eventually, QuickTime introduced a mechanism for encoders to remove the slider. Unfortunately, when the slider is removed, QuickTime assumes that the quality is Medium, even if the encoder specifies that it is lossless by setting the ‘codecInfoDoesLossless’ flag for the format. Presumably, the programmers at the time were only thinking of the DV-25 format, which is always medium quality, and have just never bothered to fix it, although BitJazz filed a bug report about the issue years ago.
