QM_SetVideoMediaCompression

QM_SetVideoMediaCompression(movieRef; trackID; codecType; codecQuality; codecDepth):error
	movieRef	Longint	Movie reference
	trackID	Longint	Track ID
	codecType	String4	Codec type
	codecQuality	Longint	Compression quality
	codecDepth	Longint	Color depth
	error	Longint	Error result

Changes the compression options that are used when adding samples to a video track.

Parameter movieRef is the reference to the movie instance. The movie reference must have been previously obtained with a call to QM_NewMovieFromFile.

Parameter trackID is the ID of the track.

Parameter codecType is the four character identifier of the compressor (codec) component. For a list of available compressor components, use the QM_GetCodecList command.

Parameter codecQuality is the compression quality. QMedia defines the following constants for specifying the compression quality:

qm_MinQuality	0	Minimum compression quality.
qm_LowQuality	256	Low compression quality.
qm_NormalQuality	512	Normal compression quality.
qm_HighQuality	768	High compression quality.
qm_MaxQuality	1023	Maximum compression quality.
qm_LosslessQuality	1024	Lossless compression quality.

Parameter codecDepth specifies the color depth at which video samples are compressed. A value of 0 means that the compressor component must choose the best depth for the video samples.

QMedia sets the default compression options to the following values:

Codec:	"jpeg"
Quality:	qm_NormalQuality (512)
Depth:	0 (use best depth)

Example

`Set the compression settings for video track $trackID

C_STRING(4;$codec)
C_LONGINT($quality;$depth)

$codec:="jpeg" `JPEG codec
$quality:=qm_HighQuality `High quality
$depth:=0 `Best depth

$err:=QM_SetVideoMediaCompression ($movie;$trackID;$codec;$quality;0)

Related commands

QM_GetVideoMediaCompression	Returns the compression options of new video samples.
QM_DoCodecSettingsDialog	Displays the compression settings dialog.
QM_GetCodecs	Returns the list of all QuickTime codecs