Technical Q&A's

QTMTB 03 - Matrix Functions, QuickTime Rotation and Skew aren't Implemented (1-May-95)

Q We can't apply the rotation and skew effects to a QuickTime 1.5 movie. We've created an identity matrix, applied RotateMatrix to the matrix, set the matrix to the movie using SetMovieMatrix, and played the movie. The movie didn't rotate but the movieRect rotated and the movie scaled to the movieRect. Is there anything wrong with what we're doing?

A Rotation and skew will give you correct results for matrix operations but they haven't been implemented into QuickTime movie playback yet. Scaling and offset transformations now work with movies and images; rotation and skew are important future directions. Meanwhile, you can accomplish rotation and skewing by playing a movie to an off-screen GWorld and then use QuickDraw GX or your own graphics routines to display the rotated or skewed off-screen Gworld.

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