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Diffstat (limited to 'distrib/sdl-1.2.12/src/audio/SDL_mixer.c')
-rw-r--r--distrib/sdl-1.2.12/src/audio/SDL_mixer.c258
1 files changed, 258 insertions, 0 deletions
diff --git a/distrib/sdl-1.2.12/src/audio/SDL_mixer.c b/distrib/sdl-1.2.12/src/audio/SDL_mixer.c
new file mode 100644
index 0000000..5e07a07
--- /dev/null
+++ b/distrib/sdl-1.2.12/src/audio/SDL_mixer.c
@@ -0,0 +1,258 @@
+/*
+ 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"
+
+/* This provides the default mixing callback for the SDL audio routines */
+
+#include "SDL_cpuinfo.h"
+#include "SDL_timer.h"
+#include "SDL_audio.h"
+#include "SDL_sysaudio.h"
+#include "SDL_mixer_MMX.h"
+#include "SDL_mixer_MMX_VC.h"
+#include "SDL_mixer_m68k.h"
+
+/* This table is used to add two sound values together and pin
+ * the value to avoid overflow. (used with permission from ARDI)
+ * Changed to use 0xFE instead of 0xFF for better sound quality.
+ */
+static const Uint8 mix8[] =
+{
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x02, 0x03,
+ 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
+ 0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19,
+ 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24,
+ 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F,
+ 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A,
+ 0x3B, 0x3C, 0x3D, 0x3E, 0x3F, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45,
+ 0x46, 0x47, 0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50,
+ 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x5B,
+ 0x5C, 0x5D, 0x5E, 0x5F, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66,
+ 0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70, 0x71,
+ 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x7B, 0x7C,
+ 0x7D, 0x7E, 0x7F, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
+ 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F, 0x90, 0x91, 0x92,
+ 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D,
+ 0x9E, 0x9F, 0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7, 0xA8,
+ 0xA9, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF, 0xB0, 0xB1, 0xB2, 0xB3,
+ 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD, 0xBE,
+ 0xBF, 0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9,
+ 0xCA, 0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD0, 0xD1, 0xD2, 0xD3, 0xD4,
+ 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF,
+ 0xE0, 0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9, 0xEA,
+ 0xEB, 0xEC, 0xED, 0xEE, 0xEF, 0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5,
+ 0xF6, 0xF7, 0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFE, 0xFE,
+ 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
+ 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
+ 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
+ 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
+ 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
+ 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
+ 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
+ 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
+ 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
+ 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
+ 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
+ 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE
+};
+
+/* The volume ranges from 0 - 128 */
+#define ADJUST_VOLUME(s, v) (s = (s*v)/SDL_MIX_MAXVOLUME)
+#define ADJUST_VOLUME_U8(s, v) (s = (((s-128)*v)/SDL_MIX_MAXVOLUME)+128)
+
+void SDL_MixAudio (Uint8 *dst, const Uint8 *src, Uint32 len, int volume)
+{
+ Uint16 format;
+
+ if ( volume == 0 ) {
+ return;
+ }
+ /* Mix the user-level audio format */
+ if ( current_audio ) {
+ if ( current_audio->convert.needed ) {
+ format = current_audio->convert.src_format;
+ } else {
+ format = current_audio->spec.format;
+ }
+ } else {
+ /* HACK HACK HACK */
+ format = AUDIO_S16;
+ }
+ switch (format) {
+
+ case AUDIO_U8: {
+#if defined(__GNUC__) && defined(__M68000__) && defined(SDL_ASSEMBLY_ROUTINES)
+ SDL_MixAudio_m68k_U8((char*)dst,(char*)src,(unsigned long)len,(long)volume,(char *)mix8);
+#else
+ Uint8 src_sample;
+
+ while ( len-- ) {
+ src_sample = *src;
+ ADJUST_VOLUME_U8(src_sample, volume);
+ *dst = mix8[*dst+src_sample];
+ ++dst;
+ ++src;
+ }
+#endif
+ }
+ break;
+
+ case AUDIO_S8: {
+#if defined(__GNUC__) && defined(__i386__) && defined(SDL_ASSEMBLY_ROUTINES)
+ if (SDL_HasMMX())
+ {
+ SDL_MixAudio_MMX_S8((char*)dst,(char*)src,(unsigned int)len,(int)volume);
+ }
+ else
+#elif ((defined(_MSC_VER) && defined(_M_IX86)) || defined(__WATCOMC__)) && defined(SDL_ASSEMBLY_ROUTINES)
+ if (SDL_HasMMX())
+ {
+ SDL_MixAudio_MMX_S8_VC((char*)dst,(char*)src,(unsigned int)len,(int)volume);
+ }
+ else
+#endif
+#if defined(__GNUC__) && defined(__M68000__) && defined(SDL_ASSEMBLY_ROUTINES)
+ SDL_MixAudio_m68k_S8((char*)dst,(char*)src,(unsigned long)len,(long)volume);
+#else
+ {
+ Sint8 *dst8, *src8;
+ Sint8 src_sample;
+ int dst_sample;
+ const int max_audioval = ((1<<(8-1))-1);
+ const int min_audioval = -(1<<(8-1));
+
+ src8 = (Sint8 *)src;
+ dst8 = (Sint8 *)dst;
+ while ( len-- ) {
+ src_sample = *src8;
+ ADJUST_VOLUME(src_sample, volume);
+ dst_sample = *dst8 + src_sample;
+ if ( dst_sample > max_audioval ) {
+ *dst8 = max_audioval;
+ } else
+ if ( dst_sample < min_audioval ) {
+ *dst8 = min_audioval;
+ } else {
+ *dst8 = dst_sample;
+ }
+ ++dst8;
+ ++src8;
+ }
+ }
+#endif
+ }
+ break;
+
+ case AUDIO_S16LSB: {
+#if defined(__GNUC__) && defined(__i386__) && defined(SDL_ASSEMBLY_ROUTINES)
+ if (SDL_HasMMX())
+ {
+ SDL_MixAudio_MMX_S16((char*)dst,(char*)src,(unsigned int)len,(int)volume);
+ }
+ else
+#elif ((defined(_MSC_VER) && defined(_M_IX86)) || defined(__WATCOMC__)) && defined(SDL_ASSEMBLY_ROUTINES)
+ if (SDL_HasMMX())
+ {
+ SDL_MixAudio_MMX_S16_VC((char*)dst,(char*)src,(unsigned int)len,(int)volume);
+ }
+ else
+#endif
+#if defined(__GNUC__) && defined(__M68000__) && defined(SDL_ASSEMBLY_ROUTINES)
+ SDL_MixAudio_m68k_S16LSB((short*)dst,(short*)src,(unsigned long)len,(long)volume);
+#else
+ {
+ Sint16 src1, src2;
+ int dst_sample;
+ const int max_audioval = ((1<<(16-1))-1);
+ const int min_audioval = -(1<<(16-1));
+
+ len /= 2;
+ while ( len-- ) {
+ src1 = ((src[1])<<8|src[0]);
+ ADJUST_VOLUME(src1, volume);
+ src2 = ((dst[1])<<8|dst[0]);
+ src += 2;
+ dst_sample = src1+src2;
+ if ( dst_sample > max_audioval ) {
+ dst_sample = max_audioval;
+ } else
+ if ( dst_sample < min_audioval ) {
+ dst_sample = min_audioval;
+ }
+ dst[0] = dst_sample&0xFF;
+ dst_sample >>= 8;
+ dst[1] = dst_sample&0xFF;
+ dst += 2;
+ }
+ }
+#endif
+ }
+ break;
+
+ case AUDIO_S16MSB: {
+#if defined(__GNUC__) && defined(__M68000__) && defined(SDL_ASSEMBLY_ROUTINES)
+ SDL_MixAudio_m68k_S16MSB((short*)dst,(short*)src,(unsigned long)len,(long)volume);
+#else
+ Sint16 src1, src2;
+ int dst_sample;
+ const int max_audioval = ((1<<(16-1))-1);
+ const int min_audioval = -(1<<(16-1));
+
+ len /= 2;
+ while ( len-- ) {
+ src1 = ((src[0])<<8|src[1]);
+ ADJUST_VOLUME(src1, volume);
+ src2 = ((dst[0])<<8|dst[1]);
+ src += 2;
+ dst_sample = src1+src2;
+ if ( dst_sample > max_audioval ) {
+ dst_sample = max_audioval;
+ } else
+ if ( dst_sample < min_audioval ) {
+ dst_sample = min_audioval;
+ }
+ dst[1] = dst_sample&0xFF;
+ dst_sample >>= 8;
+ dst[0] = dst_sample&0xFF;
+ dst += 2;
+ }
+#endif
+ }
+ break;
+
+ default: /* If this happens... FIXME! */
+ SDL_SetError("SDL_MixAudio(): unknown audio format");
+ return;
+ }
+}
+
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