QuickTime 4 Reference

Creating an Image Transcoder Component

It is only necessary to understand image transcoder components if you are writing an image transcoder. To perform image transcoding, you should use the services provided by the Image Compression Manager.

Image transcoder components are standard Component Manager components. For details on creating components, see Mac OS For QuickTime Programmers.

Image transcoder components have a type of `imtc ' as defined below.



 
enum {

    ImageTranscodererComponentType = 'imtc'

};

The subtype field of the component defines the compressed image data format that the transcoder accepts as an input. The manufacturer field of the component defines the compressed image data format that the transcoder generates as output. For example, a trancoder from Motion JPEG Format A to Motion JPEG Format B would have a subtype of 'mjpg' and a manufacturer code of 'mjpb' . No component-specific flags are currently defined for transcoders; they should be set to 0. Each transcoder component function is described in "Image Transcoder Components Reference" in this chapter.

Example Image Transcoder Component