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.
libsdl-org · Aug 24, 2006 · 7505c04 · 7505c04
1 parent edf6cb3
commit 7505c04
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Showing 16 changed files with 3,465 additions and 693 deletions.
diff --git a/src/audio/SDL_audio.c b/src/audio/SDL_audio.c
@@ -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)) {

diff --git a/src/audio/SDL_audio_c.h b/src/audio/SDL_audio_c.h
@@ -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: */