Mercurial > sdl-ios-xcode
view docs/man3/SDL_Overlay.3 @ 1982:3b4ce57c6215
First shot at new audio data types (int32 and float32).
Notable changes:
- Converters between types are autogenerated. Instead of making multiple
passes over the data with seperate filters for endianess, size, signedness,
etc, converting between data types is always one specialized filter. This
simplifies SDL_BuildAudioCVT(), which otherwise had a million edge cases
with the new types, and makes the actually conversions more CPU cache
friendly. Left a stub for adding specific optimized versions of these
routines (SSE/MMX/Altivec, assembler, etc)
- Autogenerated converters are built by SDL/src/audio/sdlgenaudiocvt.pl. This
does not need to be run unless tweaking the code, and thus doesn't need
integration into the build system.
- Went through all the drivers and tried to weed out all the "Uint16"
references that are better specified with the new SDL_AudioFormat typedef.
- Cleaned out a bunch of hardcoded bitwise magic numbers and replaced them
with new SDL_AUDIO_* macros.
- Added initial float32 and int32 support code. Theoretically, existing
drivers will push these through converters to get the data they want to
feed to the hardware.
Still TODO:
- Optimize and debug new converters.
- Update the CoreAudio backend to accept float32 data directly.
- Other backends, too?
- SDL_LoadWAV() needs to be updated to support int32 and float32 .wav files
(both of which exist and can be generated by 'sox' for testing purposes).
- Update the mixer to handle new datatypes.
- Optionally update SDL_sound and SDL_mixer, etc.
| author | Ryan C. Gordon <icculus@icculus.org> |
|---|---|
| date | Thu, 24 Aug 2006 12:10:46 +0000 |
| parents | e5bc29de3f0a |
| children | 546f7c1eb755 |
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.TH "SDL_Overlay" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" .SH "NAME" SDL_Overlay\- YUV video overlay .SH "STRUCTURE DEFINITION" .PP .nf \f(CWtypedef struct{ Uint32 format; int w, h; int planes; Uint16 *pitches; Uint8 **pixels; Uint32 hw_overlay:1; } SDL_Overlay;\fR .fi .PP .SH "STRUCTURE DATA" .TP 20 \fBformat\fR Overlay format (see below) .TP 20 \fBw, h\fR Width and height of overlay .TP 20 \fBplanes\fR Number of planes in the overlay\&. Usually either 1 or 3 .TP 20 \fBpitches\fR An array of pitches, one for each plane\&. Pitch is the length of a row in bytes\&. .TP 20 \fBpixels\fR An array of pointers to teh data of each plane\&. The overlay should be locked before these pointers are used\&. .TP 20 \fBhw_overlay\fR This will be set to 1 if the overlay is hardware accelerated\&. .SH "DESCRIPTION" .PP A \fBSDL_Overlay\fR is similar to a \fI\fBSDL_Surface\fR\fR except it stores a YUV overlay\&. All the fields are read only, except for \fBpixels\fR which should be \fIlocked\fR before use\&. The \fBformat\fR field stores the format of the overlay which is one of the following: .PP .nf \f(CW#define SDL_YV12_OVERLAY 0x32315659 /* Planar mode: Y + V + U */ #define SDL_IYUV_OVERLAY 0x56555949 /* Planar mode: Y + U + V */ #define SDL_YUY2_OVERLAY 0x32595559 /* Packed mode: Y0+U0+Y1+V0 */ #define SDL_UYVY_OVERLAY 0x59565955 /* Packed mode: U0+Y0+V0+Y1 */ #define SDL_YVYU_OVERLAY 0x55595659 /* Packed mode: Y0+V0+Y1+U0 */\fR .fi .PP More information on YUV formats can be found at \fIhttp://www\&.webartz\&.com/fourcc/indexyuv\&.htm (link to URL http://www.webartz.com/fourcc/indexyuv.htm) \fR\&. .SH "SEE ALSO" .PP \fI\fBSDL_CreateYUVOverlay\fP\fR, \fI\fBSDL_LockYUVOverlay\fP\fR, \fI\fBSDL_UnlockYUVOverlay\fP\fR, \fI\fBSDL_FreeYUVOverlay\fP\fR ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01