Inside Macintosh: QuickTime /

Chapter 3 - Image Compression Manager / Image Compression Manager Reference

Image Compression Manager Functions / Changing Sequence-Decompression Parameters

SetDSequenceMatte

The SetDSequenceMatte function assigns a blend matte to the sequence.

pascal OSErr SetDSequenceMatte (ImageSequence seqID,
                                 PixMapHandle matte,
                                 const Rect *matteRect);

seqID

Contains the unique sequence identifier that was returned by the DecompressSequenceBegin function (described on page 3-107).

matte

Contains a handle to a pixel map that contains a blend matte. You can use the blend matte to cause the decompressed image to be blended into the destination pixel map. The matte can be defined at any supported
pixel depth--the matte depth need not correspond to the source or destination depths. However, the matte must be in the coordinate system of the source image. If you want to turn off the blend matte, set this parameter to nil.

matteRect

Contains a pointer to the boundary rectangle for the matte. The decompressor uses only that portion of the matte that lies within the specified rectangle. This rectangle must be the same size as the source rectangle you specify with the SetDSequenceSrcRect function (described on page 3-125) or with the srcRect parameter to the DecompressSequenceBegin function. To specify the matte pixel map bounds, pass nil in this parameter.

DESCRIPTION

The decompressor uses the matte to blend the decompressed image into the destination pixel map. The new matte and matte boundary rectangle take effect with the next frame in the sequence. You should not dispose of the matte until the Image Compression Manager is finished with the sequence.

RESULT CODES

noErr	0	No error
paramErr	-50	Invalid parameter specified

Memory Manager errors