(Added note about IOSurface caching) |
m (Improved grammar.) |
||
| Line 1: | Line 1: | ||
'''AppleJPEGDriver''' is a kernel-extension providing accelerating encoding and decoding JPEG images via {{fwlink|IOSurface}}s, | '''AppleJPEGDriver''' is a kernel-extension providing accelerating encoding and decoding JPEG images via {{fwlink|IOSurface}}s, especially for those with [http://en.wikipedia.org/wiki/YUV422 YUV color space]. It powers the {{fwlink|AppleJPEG}} for decoding, {{fwlink|Camera}} for encoding, and {{fwlink|Celestial}} for both. | ||
== Methods == | == Methods == | ||
| Line 30: | Line 30: | ||
</source> | </source> | ||
For best results, use an | For best results, use an IOSurface that has the kIOSurfaceCacheMode property set to kIOMapInhibitCache. | ||
{{occlass|library=IOKit.framework|navbox=1}} | {{occlass|library=IOKit.framework|navbox=1}} | ||
Revision as of 02:34, 29 September 2013
AppleJPEGDriver is a kernel-extension providing accelerating encoding and decoding JPEG images via IOSurfaces, especially for those with YUV color space. It powers the AppleJPEG for decoding, Camera for encoding, and Celestial for both.
Methods
| Selector | Action | Input | Output |
|---|---|---|---|
| 0 | initializeDecoder | - | - |
| 1 | startDecoder | struct JPEGDriverArgs (40 bytes) | 40 bytes of stuff |
| 2 | initializeEncoder | - | - |
| 3 | startEncoder | struct JPEGDriverArgs (40 bytes) | 40 bytes of stuff. |
where
struct JPEGDriverArgs {
int must_be_zero_1;
IOSurfaceID src_surface /*in*/;
size_t src_size /*in*/;
int must_be_zero_2;
IOSurfaceID dest_surface /*in*/;
size_t dest_size /*in*/;
size_t result_size /*out*/;
size_t dest_width /*in*/;
size_t dest_height /*in*/;
int quality /*in: 4 gives decent quality */;
};
For best results, use an IOSurface that has the kIOSurfaceCacheMode property set to kIOMapInhibitCache.
| ||||||||