Inside Macintosh: QuickTime Components
Use the control flags request to retrieve or modify the control flags used by the standard dialog component. The standard dialog component passes these flags through to the image compressor it uses to compress your image or sequence. These flags are Image Compression Manager control flags, as described in the chapter "Image Compression Manager" in Inside Macintosh: QuickTime.
You supply a pointer to a flags field of data type CodecFlags (this is an Image Compression Manager data type). If you are retrieving the flags, the standard dialog component places the current flags into this field. If you are setting new flag values, place your desired settings into the field--the component uses these new flag settings.
By default, the standard dialog component sets all flags to 0 when it compresses still images. When it is compressing sequences, the component sets the codecFlagsPreviousUpdate and codecFlagsUpdatePreviousComp flags to 1. Typically, you should not need to change these flag settings.