Inside Macintosh: QuickTime Components /

Chapter 5 - Sequence Grabber Components / Sequence Grabber Components Reference

Sequence Grabber Component Functions / Working With Video Channels

SGSetVideoCompressorType

The SGSetVideoCompressorType function allows you to specify the type of image compression to be applied to the captured video images.

pascal ComponentResult SGSetVideoCompressorType (SGChannel c,
                                           OSType compressorType);

c

Specifies the reference that identifies the channel for this operation. You obtain this reference from the SGNewChannel function, described on page 5-29.

compressorType

Specifies the type of image compression to use. The value of this parameter must correspond to one of the image compressor types supported by the Image Compression Manager. Currently, six CodecType values are provided by Apple. You should use the GetCodecNameList function to retrieve these names, so that your application can take advantage of new compressor types that may be added in the future. For each CodecType value in the following list, the corresponding compression method is also identified by its text
string name.

	Compressor type	Compressor name
	'rpza'	video compressor
	'jpeg'	photo compressor
	'rle '	animation compressor
	'raw '	raw compressor
	'smc '	graphics compressor
	'cvid'	compact video compressor

See the chapter "Image Compression Manager" in Inside Macintosh: QuickTime for information about valid compressor types. If this value is set to 0, the default compression type is selected.

DESCRIPTION

In addition, the SGSetVideoCompressorType function resets all image-compression parameters to their default values. You can then use the SGSetVideoCompressor function, described on page 5-78, to change the compression parameters.

SPECIAL CONSIDERATIONS

You cannot call the SGSetVideoCompressorType function during a record operation or after you have prepared the sequence grabber component for a record operation (by calling the SGPrepare function, described on page 5-40).

RESULT CODES

cantDoThatInCurrentMode	-9402	Request invalid in current mode
notEnoughMemoryToGrab	-9403	Insufficient memory for record operation
deviceCantMeetRequest	-9408	Device cannot support grabber

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