Inside Macintosh: QuickTime Components
This section describes functions that are invoked by the Image Compression Manager but do not correspond to functions called by applications. The Image Compression Manager may call these functions at any time.
Your component receives the CDPreCompress request before compressing an image or a band of an image. The Image Compression Manager also calls this function when processing a sequence. In that case, the Image Compression Manager calls this function whenever the parameters governing the sequence operation have changed substantially. Your component indicates whether it can perform the requested compression operation.
pascal ComponentResult CDPreCompress
(CodecCompressParams *params);
Your component should return a 0 result code to indicate that it can handle the request. In addition, your component indicates any limitations on its capabilities in a compressor capability structure (see "The Compressor Capability Structure," for details). Your component should return a result code of codecConditionError if it cannot field the compression request.
Your component receives the CDBandCompress request to compress an image or a band of an image. The image may be part of a sequence.
pascal ComponentResult CDBandCompress
(CodecCompressParams *params);
Your component receives the CDPreDecompress request before decompressing an image or a band of an image. The Image Compression Manager also calls this function when processing a sequence. In that case, the Image Compression Manager calls this function whenever the parameters governing the sequence operation have changed substantially. Your component indicates whether it can perform the requested decompression operation.
pascal ComponentResult CDPreDecompress
(CodecDecompressParams *params);
Your component should return a 0 result code to indicate that it can handle the request. In addition, your component indicates any limitations on its capabilities in a compressor capability structure (see The Compressor Capability Structure for a description of that structure). Return a result code of codecConditionError if your component cannot field the decompression request.
Your component receives the CDBandDecompress request to decompress an image or a band of an image. The image may be part of a sequence.
pascal ComponentResult CDBandDecompress
(CodecDecompressParams *params);