Mercurial > sdl-ios-xcode
view src/audio/dsp/SDL_dspaudio.h @ 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 | c121d94672cb |
children | 5f6550e5184f 589bc3d060cd |
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/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2006 Sam Lantinga This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA Sam Lantinga slouken@libsdl.org */ #include "SDL_config.h" #ifndef _SDL_dspaudio_h #define _SDL_dspaudio_h #include "../SDL_sysaudio.h" /* Hidden "this" pointer for the video functions */ #define _THIS SDL_AudioDevice *this struct SDL_PrivateAudioData { /* The file descriptor for the audio device */ int audio_fd; /* The parent process id, to detect when application quits */ pid_t parent; /* Raw mixing buffer */ Uint8 *mixbuf; int mixlen; }; #define FUDGE_TICKS 10 /* The scheduler overhead ticks per frame */ /* Old variable names */ #define audio_fd (this->hidden->audio_fd) #define parent (this->hidden->parent) #define mixbuf (this->hidden->mixbuf) #define mixlen (this->hidden->mixlen) #define frame_ticks (this->hidden->frame_ticks) #define next_frame (this->hidden->next_frame) #endif /* _SDL_dspaudio_h */ /* vi: set ts=4 sw=4 expandtab: */