src/audio/SDL_mixer.c
author Sam Lantinga <slouken@libsdl.org>
Sun, 29 Oct 2006 14:45:46 +0000
changeset 2063 dea73e1d07b0
parent 2049 5f6550e5184f
child 2130 3ee59c43d784
permissions -rw-r--r--
Merged Ryan's fix, in case we need it later.
     1 /*
     2     SDL - Simple DirectMedia Layer
     3     Copyright (C) 1997-2006 Sam Lantinga
     4 
     5     This library is free software; you can redistribute it and/or
     6     modify it under the terms of the GNU Lesser General Public
     7     License as published by the Free Software Foundation; either
     8     version 2.1 of the License, or (at your option) any later version.
     9 
    10     This library is distributed in the hope that it will be useful,
    11     but WITHOUT ANY WARRANTY; without even the implied warranty of
    12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    13     Lesser General Public License for more details.
    14 
    15     You should have received a copy of the GNU Lesser General Public
    16     License along with this library; if not, write to the Free Software
    17     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
    18 
    19     Sam Lantinga
    20     slouken@libsdl.org
    21 */
    22 #include "SDL_config.h"
    23 
    24 /* This provides the default mixing callback for the SDL audio routines */
    25 
    26 #include "SDL_cpuinfo.h"
    27 #include "SDL_timer.h"
    28 #include "SDL_audio.h"
    29 #include "SDL_sysaudio.h"
    30 #include "SDL_mixer_MMX.h"
    31 #include "SDL_mixer_MMX_VC.h"
    32 #include "SDL_mixer_m68k.h"
    33 
    34 /* This table is used to add two sound values together and pin
    35  * the value to avoid overflow.  (used with permission from ARDI)
    36  * Changed to use 0xFE instead of 0xFF for better sound quality.
    37  */
    38 static const Uint8 mix8[] = {
    39     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    40     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    41     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    42     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    43     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    44     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    45     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    46     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    47     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    48     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    49     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    50     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x02, 0x03,
    51     0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
    52     0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19,
    53     0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24,
    54     0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F,
    55     0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A,
    56     0x3B, 0x3C, 0x3D, 0x3E, 0x3F, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45,
    57     0x46, 0x47, 0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50,
    58     0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x5B,
    59     0x5C, 0x5D, 0x5E, 0x5F, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66,
    60     0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70, 0x71,
    61     0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x7B, 0x7C,
    62     0x7D, 0x7E, 0x7F, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
    63     0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F, 0x90, 0x91, 0x92,
    64     0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D,
    65     0x9E, 0x9F, 0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7, 0xA8,
    66     0xA9, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF, 0xB0, 0xB1, 0xB2, 0xB3,
    67     0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD, 0xBE,
    68     0xBF, 0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9,
    69     0xCA, 0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD0, 0xD1, 0xD2, 0xD3, 0xD4,
    70     0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF,
    71     0xE0, 0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9, 0xEA,
    72     0xEB, 0xEC, 0xED, 0xEE, 0xEF, 0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5,
    73     0xF6, 0xF7, 0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFE, 0xFE,
    74     0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
    75     0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
    76     0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
    77     0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
    78     0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
    79     0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
    80     0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
    81     0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
    82     0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
    83     0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
    84     0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE,
    85     0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE
    86 };
    87 
    88 /* The volume ranges from 0 - 128 */
    89 #define ADJUST_VOLUME(s, v)	(s = (s*v)/SDL_MIX_MAXVOLUME)
    90 #define ADJUST_VOLUME_U8(s, v)	(s = (((s-128)*v)/SDL_MIX_MAXVOLUME)+128)
    91 
    92 
    93 void
    94 SDL_MixAudioFormat(Uint8 * dst, const Uint8 * src, SDL_AudioFormat format,
    95                    Uint32 len, int volume)
    96 {
    97     if (volume == 0) {
    98         return;
    99     }
   100 
   101     switch (format) {
   102 
   103     case AUDIO_U8:
   104         {
   105 #if defined(__GNUC__) && defined(__M68000__) && defined(SDL_ASSEMBLY_ROUTINES)
   106             SDL_MixAudio_m68k_U8((char *) dst, (char *) src,
   107                                  (unsigned long) len, (long) volume,
   108                                  (char *) mix8);
   109 #else
   110             Uint8 src_sample;
   111 
   112             while (len--) {
   113                 src_sample = *src;
   114                 ADJUST_VOLUME_U8(src_sample, volume);
   115                 *dst = mix8[*dst + src_sample];
   116                 ++dst;
   117                 ++src;
   118             }
   119 #endif
   120         }
   121         break;
   122 
   123     case AUDIO_S8:
   124         {
   125 #if defined(__GNUC__) && defined(__i386__) && defined(SDL_ASSEMBLY_ROUTINES)
   126             if (SDL_HasMMX()) {
   127                 SDL_MixAudio_MMX_S8((char *) dst, (char *) src,
   128                                     (unsigned int) len, (int) volume);
   129             } else
   130 #elif ((defined(_MSC_VER) && defined(_M_IX86)) || defined(__WATCOMC__)) && defined(SDL_ASSEMBLY_ROUTINES)
   131             if (SDL_HasMMX()) {
   132                 SDL_MixAudio_MMX_S8_VC((char *) dst, (char *) src,
   133                                        (unsigned int) len, (int) volume);
   134             } else
   135 #endif
   136 #if defined(__GNUC__) && defined(__M68000__) && defined(SDL_ASSEMBLY_ROUTINES)
   137                 SDL_MixAudio_m68k_S8((char *) dst, (char *) src,
   138                                      (unsigned long) len, (long) volume);
   139 #else
   140             {
   141                 Sint8 *dst8, *src8;
   142                 Sint8 src_sample;
   143                 int dst_sample;
   144                 const int max_audioval = ((1 << (8 - 1)) - 1);
   145                 const int min_audioval = -(1 << (8 - 1));
   146 
   147                 src8 = (Sint8 *) src;
   148                 dst8 = (Sint8 *) dst;
   149                 while (len--) {
   150                     src_sample = *src8;
   151                     ADJUST_VOLUME(src_sample, volume);
   152                     dst_sample = *dst8 + src_sample;
   153                     if (dst_sample > max_audioval) {
   154                         *dst8 = max_audioval;
   155                     } else if (dst_sample < min_audioval) {
   156                         *dst8 = min_audioval;
   157                     } else {
   158                         *dst8 = dst_sample;
   159                     }
   160                     ++dst8;
   161                     ++src8;
   162                 }
   163             }
   164 #endif
   165         }
   166         break;
   167 
   168     case AUDIO_S16LSB:
   169         {
   170 #if defined(__GNUC__) && defined(__i386__) && defined(SDL_ASSEMBLY_ROUTINES)
   171             if (SDL_HasMMX()) {
   172                 SDL_MixAudio_MMX_S16((char *) dst, (char *) src,
   173                                      (unsigned int) len, (int) volume);
   174             } else
   175 #elif ((defined(_MSC_VER) && defined(_M_IX86)) || defined(__WATCOMC__)) && defined(SDL_ASSEMBLY_ROUTINES)
   176             if (SDL_HasMMX()) {
   177                 SDL_MixAudio_MMX_S16_VC((char *) dst, (char *) src,
   178                                         (unsigned int) len, (int) volume);
   179             } else
   180 #endif
   181 #if defined(__GNUC__) && defined(__M68000__) && defined(SDL_ASSEMBLY_ROUTINES)
   182                 SDL_MixAudio_m68k_S16LSB((short *) dst, (short *) src,
   183                                          (unsigned long) len, (long) volume);
   184 #else
   185             {
   186                 Sint16 src1, src2;
   187                 int dst_sample;
   188                 const int max_audioval = ((1 << (16 - 1)) - 1);
   189                 const int min_audioval = -(1 << (16 - 1));
   190 
   191                 len /= 2;
   192                 while (len--) {
   193                     src1 = ((src[1]) << 8 | src[0]);
   194                     ADJUST_VOLUME(src1, volume);
   195                     src2 = ((dst[1]) << 8 | dst[0]);
   196                     src += 2;
   197                     dst_sample = src1 + src2;
   198                     if (dst_sample > max_audioval) {
   199                         dst_sample = max_audioval;
   200                     } else if (dst_sample < min_audioval) {
   201                         dst_sample = min_audioval;
   202                     }
   203                     dst[0] = dst_sample & 0xFF;
   204                     dst_sample >>= 8;
   205                     dst[1] = dst_sample & 0xFF;
   206                     dst += 2;
   207                 }
   208             }
   209 #endif
   210         }
   211         break;
   212 
   213     case AUDIO_S16MSB:
   214         {
   215 #if defined(__GNUC__) && defined(__M68000__) && defined(SDL_ASSEMBLY_ROUTINES)
   216             SDL_MixAudio_m68k_S16MSB((short *) dst, (short *) src,
   217                                      (unsigned long) len, (long) volume);
   218 #else
   219             Sint16 src1, src2;
   220             int dst_sample;
   221             const int max_audioval = ((1 << (16 - 1)) - 1);
   222             const int min_audioval = -(1 << (16 - 1));
   223 
   224             len /= 2;
   225             while (len--) {
   226                 src1 = ((src[0]) << 8 | src[1]);
   227                 ADJUST_VOLUME(src1, volume);
   228                 src2 = ((dst[0]) << 8 | dst[1]);
   229                 src += 2;
   230                 dst_sample = src1 + src2;
   231                 if (dst_sample > max_audioval) {
   232                     dst_sample = max_audioval;
   233                 } else if (dst_sample < min_audioval) {
   234                     dst_sample = min_audioval;
   235                 }
   236                 dst[1] = dst_sample & 0xFF;
   237                 dst_sample >>= 8;
   238                 dst[0] = dst_sample & 0xFF;
   239                 dst += 2;
   240             }
   241 #endif
   242         }
   243         break;
   244 
   245     case AUDIO_S32LSB:
   246         {
   247             const Uint32 *src32 = (Uint32 *) src;
   248             Uint32 *dst32 = (Uint32 *) dst;
   249             Sint64 src1, src2;
   250             Sint64 dst_sample;
   251             const Sint64 max_audioval = ((((Sint64) 1) << (32 - 1)) - 1);
   252             const Sint64 min_audioval = -(((Sint64) 1) << (32 - 1));
   253 
   254             len /= 4;
   255             while (len--) {
   256                 src1 = (Sint64) ((Sint32) SDL_SwapLE32(*src32));
   257                 src32++;
   258                 ADJUST_VOLUME(src1, volume);
   259                 src2 = (Sint64) ((Sint32) SDL_SwapLE32(*dst32));
   260                 dst_sample = src1 + src2;
   261                 if (dst_sample > max_audioval) {
   262                     dst_sample = max_audioval;
   263                 } else if (dst_sample < min_audioval) {
   264                     dst_sample = min_audioval;
   265                 }
   266                 *(dst32++) = SDL_SwapLE32((Uint32) ((Sint32) dst_sample));
   267             }
   268         }
   269         break;
   270 
   271     case AUDIO_S32MSB:
   272         {
   273             const Uint32 *src32 = (Uint32 *) src;
   274             Uint32 *dst32 = (Uint32 *) dst;
   275             Sint64 src1, src2;
   276             Sint64 dst_sample;
   277             const Sint64 max_audioval = ((((Sint64) 1) << (32 - 1)) - 1);
   278             const Sint64 min_audioval = -(((Sint64) 1) << (32 - 1));
   279 
   280             len /= 4;
   281             while (len--) {
   282                 src1 = (Sint64) ((Sint32) SDL_SwapBE32(*src32));
   283                 src32++;
   284                 ADJUST_VOLUME(src1, volume);
   285                 src2 = (Sint64) ((Sint32) SDL_SwapBE32(*dst32));
   286                 dst_sample = src1 + src2;
   287                 if (dst_sample > max_audioval) {
   288                     dst_sample = max_audioval;
   289                 } else if (dst_sample < min_audioval) {
   290                     dst_sample = min_audioval;
   291                 }
   292                 *(dst32++) = SDL_SwapBE32((Uint32) ((Sint32) dst_sample));
   293             }
   294         }
   295         break;
   296 
   297     case AUDIO_F32LSB:
   298         {
   299             const float fmaxvolume = 1.0f / ((float) SDL_MIX_MAXVOLUME);
   300             const float fvolume = (float) volume;
   301             const float *src32 = (float *) src;
   302             float *dst32 = (float *) dst;
   303             float src1, src2;
   304             double dst_sample;
   305             /* !!! FIXME: are these right? */
   306             const double max_audioval = 3.40282347e+38F;
   307             const double min_audioval = -3.40282347e+38F;
   308 
   309             len /= 4;
   310             while (len--) {
   311                 src1 = ((SDL_SwapFloatLE(*src32) * fvolume) * fmaxvolume);
   312                 src2 = SDL_SwapFloatLE(*dst32);
   313                 src32++;
   314 
   315                 dst_sample = ((double) src1) + ((double) src2);
   316                 if (dst_sample > max_audioval) {
   317                     dst_sample = max_audioval;
   318                 } else if (dst_sample < min_audioval) {
   319                     dst_sample = min_audioval;
   320                 }
   321                 *(dst32++) = SDL_SwapFloatLE((float) dst_sample);
   322             }
   323         }
   324         break;
   325 
   326     case AUDIO_F32MSB:
   327         {
   328             const float fmaxvolume = 1.0f / ((float) SDL_MIX_MAXVOLUME);
   329             const float fvolume = (float) volume;
   330             const float *src32 = (float *) src;
   331             float *dst32 = (float *) dst;
   332             float src1, src2;
   333             double dst_sample;
   334             /* !!! FIXME: are these right? */
   335             const double max_audioval = 3.40282347e+38F;
   336             const double min_audioval = -3.40282347e+38F;
   337 
   338             len /= 4;
   339             while (len--) {
   340                 src1 = ((SDL_SwapFloatBE(*src32) * fvolume) * fmaxvolume);
   341                 src2 = SDL_SwapFloatBE(*dst32);
   342                 src32++;
   343 
   344                 dst_sample = ((double) src1) + ((double) src2);
   345                 if (dst_sample > max_audioval) {
   346                     dst_sample = max_audioval;
   347                 } else if (dst_sample < min_audioval) {
   348                     dst_sample = min_audioval;
   349                 }
   350                 *(dst32++) = SDL_SwapFloatBE((float) dst_sample);
   351             }
   352         }
   353         break;
   354 
   355     default:                   /* If this happens... FIXME! */
   356         SDL_SetError("SDL_MixAudio(): unknown audio format");
   357         return;
   358     }
   359 }
   360 
   361 /* vi: set ts=4 sw=4 expandtab: */