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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.
  • Loading branch information
icculus committed Aug 24, 2006
1 parent edf6cb3 commit 7505c043f0588ed69f30ddf8b63e1aa50ead9907
@@ -286,10 +286,10 @@ SDL_UnlockAudio_Default(SDL_AudioDevice * audio)
SDL_mutexV(audio->mixer_lock);
}

static Uint16
static SDL_AudioFormat
SDL_ParseAudioFormat(const char *string)
{
Uint16 format = 0;
SDL_AudioFormat format = 0;

switch (*string) {
case 'U':
@@ -740,26 +740,34 @@ SDL_AudioQuit(void)
}
}

#define NUM_FORMATS 6
#define NUM_FORMATS 10
static int format_idx;
static int format_idx_sub;
static Uint16 format_list[NUM_FORMATS][NUM_FORMATS] = {
static SDL_AudioFormat format_list[NUM_FORMATS][NUM_FORMATS] = {
{AUDIO_U8, AUDIO_S8, AUDIO_S16LSB, AUDIO_S16MSB, AUDIO_U16LSB,
AUDIO_U16MSB},
AUDIO_U16MSB, AUDIO_S32LSB, AUDIO_S32MSB, AUDIO_F32LSB, AUDIO_F32MSB},
{AUDIO_S8, AUDIO_U8, AUDIO_S16LSB, AUDIO_S16MSB, AUDIO_U16LSB,
AUDIO_U16MSB},
{AUDIO_S16LSB, AUDIO_S16MSB, AUDIO_U16LSB, AUDIO_U16MSB, AUDIO_U8,
AUDIO_S8},
{AUDIO_S16MSB, AUDIO_S16LSB, AUDIO_U16MSB, AUDIO_U16LSB, AUDIO_U8,
AUDIO_S8},
{AUDIO_U16LSB, AUDIO_U16MSB, AUDIO_S16LSB, AUDIO_S16MSB, AUDIO_U8,
AUDIO_S8},
{AUDIO_U16MSB, AUDIO_U16LSB, AUDIO_S16MSB, AUDIO_S16LSB, AUDIO_U8,
AUDIO_S8},
AUDIO_U16MSB, AUDIO_S32LSB, AUDIO_S32MSB, AUDIO_F32LSB, AUDIO_F32MSB},
{AUDIO_S16LSB, AUDIO_S16MSB, AUDIO_U16LSB, AUDIO_U16MSB, AUDIO_S32LSB,
AUDIO_S32MSB, AUDIO_F32LSB, AUDIO_F32MSB, AUDIO_U8, AUDIO_S8},
{AUDIO_S16MSB, AUDIO_S16LSB, AUDIO_U16MSB, AUDIO_U16LSB, AUDIO_S32MSB,
AUDIO_S32LSB, AUDIO_F32MSB, AUDIO_F32LSB, AUDIO_U8, AUDIO_S8},
{AUDIO_U16LSB, AUDIO_U16MSB, AUDIO_S16LSB, AUDIO_S16MSB, AUDIO_S32LSB,
AUDIO_S32MSB, AUDIO_F32LSB, AUDIO_F32MSB, AUDIO_U8, AUDIO_S8},
{AUDIO_U16MSB, AUDIO_U16LSB, AUDIO_S16MSB, AUDIO_S16LSB, AUDIO_S32MSB,
AUDIO_S32LSB, AUDIO_F32MSB, AUDIO_F32LSB, AUDIO_U8, AUDIO_S8},
{AUDIO_S32LSB, AUDIO_S32MSB, AUDIO_U16LSB, AUDIO_U16MSB, AUDIO_S16LSB,
AUDIO_S16MSB, AUDIO_F32LSB, AUDIO_F32MSB, AUDIO_U8, AUDIO_S8},
{AUDIO_S32MSB, AUDIO_S32LSB, AUDIO_U16MSB, AUDIO_U16LSB, AUDIO_S16MSB,
AUDIO_S16LSB, AUDIO_F32LSB, AUDIO_F32MSB, AUDIO_U8, AUDIO_S8},
{AUDIO_F32LSB, AUDIO_F32MSB, AUDIO_S32LSB, AUDIO_S32MSB, AUDIO_U16LSB,
AUDIO_U16MSB, AUDIO_S16LSB, AUDIO_S16MSB, AUDIO_U8, AUDIO_S8},
{AUDIO_F32MSB, AUDIO_F32LSB, AUDIO_S32MSB, AUDIO_S32LSB, AUDIO_U16MSB,
AUDIO_U16LSB, AUDIO_S16MSB, AUDIO_S16LSB, AUDIO_U8, AUDIO_S8},
};

Uint16
SDL_FirstAudioFormat(Uint16 format)
SDL_AudioFormat
SDL_FirstAudioFormat(SDL_AudioFormat format)
{
for (format_idx = 0; format_idx < NUM_FORMATS; ++format_idx) {
if (format_list[format_idx][0] == format) {
@@ -770,7 +778,7 @@ SDL_FirstAudioFormat(Uint16 format)
return (SDL_NextAudioFormat());
}

Uint16
SDL_AudioFormat
SDL_NextAudioFormat(void)
{
if ((format_idx == NUM_FORMATS) || (format_idx_sub == NUM_FORMATS)) {
@@ -24,12 +24,22 @@
/* Functions and variables exported from SDL_audio.c for SDL_sysaudio.c */

/* Functions to get a list of "close" audio formats */
extern Uint16 SDL_FirstAudioFormat(Uint16 format);
extern Uint16 SDL_NextAudioFormat(void);
extern SDL_AudioFormat SDL_FirstAudioFormat(SDL_AudioFormat format);
extern SDL_AudioFormat SDL_NextAudioFormat(void);

/* Function to calculate the size and silence for a SDL_AudioSpec */
extern void SDL_CalculateAudioSpec(SDL_AudioSpec * spec);

/* The actual mixing thread function */
extern int SDLCALL SDL_RunAudio(void *audiop);

/* this is used internally to access some autogenerated code. */
typedef struct
{
SDL_AudioFormat src_fmt;
SDL_AudioFormat dst_fmt;
SDL_AudioFilter filter;
} SDL_AudioTypeFilters;
extern const SDL_AudioTypeFilters sdl_audio_type_filters[];

/* vi: set ts=4 sw=4 expandtab: */

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