SetImageDescriptionExtension
Your component may use the SetImageDescriptionExtension function to create or update the extended data for an image.
pascal OSErr SetImageDescriptionExtension
(ImageDescriptionHandle desc,
Handle extension,
long idType);
desc
- Contains a handle to the appropriate image description structure. The
SetImageDescriptionExtension function updates the size of the image description to accommodate the new extended data.
extension
- Contains a handle to the new extended data. The
SetImageDescriptionExtension function uses this data to update the extended data for the image described by the image description referred to by the desc parameter.
idType
- Specifies the extension's type value. Use this parameter to assign a data type to the extension. Use a four-character code, similar to an
OSType field value.
DESCRIPTION
The Image Compression Manager appends the extended data for an image to the appropriate image description structure (see the chapter "Image Compression Manager" in Inside Macintosh: QuickTime for information about image description structures). Note that each compressor type may have its own format for the extended data that is stored with an image. The extended data is similar in concept to the user data that applications can associate with QuickTime movies--see the chapter "Movie Toolbox" in Inside Macintosh: QuickTime for more information about user data in QuickTime movies. Once you have added extended data to an image, you cannot delete it.
RESULT CODES
| noErr | 0 | No error |
| paramErr | -50 | Invalid parameter specified |
| memFullErr | -108 | Not enough memory available |
| noCodecErr | -8961 | Image Compression Manager could not find the specified compressor |
| codecExtensionNotFoundErr | -8971 | Requested extension is not in the image description |
