Road Map to QuickTime 3

Graphics Importer Components

Graphic importer components are used to display and save still images in various compressed formats. Apple-provided components read and write many common compressed image types. Support for cross-platform and web-derived images is provided, including the ability to query for capability by MIME type and by examination (a component can be asked to examine a file of unknown type to see if it can decompress the file). Graphics importer components were added to QuickTime as part of the QuickTime 2.5 release.

Applications make direct calls to graphic importer components, so this chapter is of interest to most QuickTime developers who work with still images or the web. Use the Image Compression Manager's GetGraphicsImporterForFile or GetGraphicsImporterForDataRef function to obtain a graphics importer component for a particular file or data reference (see "Working With Graphic Importers"). Applications programmers should also be familiar with the component manager, prior to working with graphics importer components (see the chapter "Component Manager").

Developers wishing to create new graphics importer components should refer to this chapter to implement a component that supports the required interface functions.

About Graphics Importer Components

QuickTime 3 Reference describes what graphic importer components do and shows how to use them from within an application. A code sample is included.

QuickTime Image File Format

QuickTime 3 Reference introduces the QuickTime image file format, and gives an overview of its features and benefits. This file format provides a universal container type for images stored by any method of compression. Image compressor components can open and save compressed images using the QuickTime image file format (see the section "Functions," below). The QuickTime image file format was added to QuickTime as part of release 2.5.

Functions

QuickTime 3 Reference defines the functions that are used to control graphics importer components. Functions are provided for: specifying the data source, which may be a file, a handle, or a data reference; validating and retrieving image data; getting image characteristics, such as compression method and pixel depth; setting drawing parameters, such as clipping and scaling; drawing images; saving image files as PICT or QuickTime image files; and getting MIME types.

• Specifying the Data Source
• GraphicsImportSetDataFile
• GraphicsImportGetDataFile
• GraphicsImportSetDataHandle
• GraphicsImportGetDataHandle
• GraphicsImportSetDataReference
• GraphicsImportGetDataReference
• GraphicsImportSetDataReferenceOffsetAndLimit
• GraphicsImportGetDataReferenceOffsetAndLimit
• Validating and Retrieving Image Data
• GraphicsImportValidate
• GraphicsImportReadData
• Getting Image Characteristics
• GraphicsImportGetNaturalBounds
• GraphicsImportGetImageDescription
• GraphicsImportGetDataOffsetAndSize
• Setting Drawing Parameters
• GraphicsImportSetBoundsRect
• GraphicsImportGetBoundsRect
• GraphicsImportSetMatrix
• GraphicsImportGetMatrix
• GraphicsImportSetClip
• GraphicsImportGetClip
• GraphicsImportSetGraphicsMode
• GraphicsImportGetGraphicsMode
• GraphicsImportSetQuality
• GraphicsImportGetQuality
• GraphicsImportSetSourceRect
• GraphicsImportGetSourceRect
• Drawing Images
• GraphicsImportSetGWorld
• GraphicsImportGetGWorld
• GraphicsImportDraw
• Saving Image Files
• GraphicsImportSaveAsPicture
• GraphicsImportSaveAsQuickTimeImageFile
• Getting MIME Types
• GraphicsImportGetMIMETypeList

Data Types

QuickTime 3 Reference gives definitions of the component type used for graphics importer components and the MIME type list.

• Graphics Importer Component Type
• MIME Type List