src/audio/SDL_mixer.c
author Sam Lantinga
Fri, 11 Feb 2011 22:37:15 -0800
changeset 5262 b530ef003506
parent 3697 f7b03b6838cb
child 5535 96594ac5fd1a
permissions -rw-r--r--
Happy 2011! :)
     1 /*
     2     SDL - Simple DirectMedia Layer
     3     Copyright (C) 1997-2011 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(__mcoldfire__) && 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(SDL_BUGGY_MMX_MIXERS) /* buggy, so we're disabling them. --ryan. */
   126 #if defined(__GNUC__) && defined(__i386__) && defined(SDL_ASSEMBLY_ROUTINES)
   127             if (SDL_HasMMX()) {
   128                 SDL_MixAudio_MMX_S8((char *) dst, (char *) src,
   129                                     (unsigned int) len, (int) volume);
   130             } else
   131 #elif ((defined(_MSC_VER) && defined(_M_IX86)) || defined(__WATCOMC__)) && defined(SDL_ASSEMBLY_ROUTINES)
   132             if (SDL_HasMMX()) {
   133                 SDL_MixAudio_MMX_S8_VC((char *) dst, (char *) src,
   134                                        (unsigned int) len, (int) volume);
   135             } else
   136 #endif
   137 #endif
   138 #if defined(__GNUC__) && defined(__M68000__) && !defined(__mcoldfire__) && defined(SDL_ASSEMBLY_ROUTINES)
   139                 SDL_MixAudio_m68k_S8((char *) dst, (char *) src,
   140                                      (unsigned long) len, (long) volume);
   141 #else
   142             {
   143                 Sint8 *dst8, *src8;
   144                 Sint8 src_sample;
   145                 int dst_sample;
   146                 const int max_audioval = ((1 << (8 - 1)) - 1);
   147                 const int min_audioval = -(1 << (8 - 1));
   148 
   149                 src8 = (Sint8 *) src;
   150                 dst8 = (Sint8 *) dst;
   151                 while (len--) {
   152                     src_sample = *src8;
   153                     ADJUST_VOLUME(src_sample, volume);
   154                     dst_sample = *dst8 + src_sample;
   155                     if (dst_sample > max_audioval) {
   156                         *dst8 = max_audioval;
   157                     } else if (dst_sample < min_audioval) {
   158                         *dst8 = min_audioval;
   159                     } else {
   160                         *dst8 = dst_sample;
   161                     }
   162                     ++dst8;
   163                     ++src8;
   164                 }
   165             }
   166 #endif
   167         }
   168         break;
   169 
   170     case AUDIO_S16LSB:
   171         {
   172 #if defined(SDL_BUGGY_MMX_MIXERS) /* buggy, so we're disabling them. --ryan. */
   173 #if defined(__GNUC__) && defined(__i386__) && defined(SDL_ASSEMBLY_ROUTINES)
   174             if (SDL_HasMMX()) {
   175                 SDL_MixAudio_MMX_S16((char *) dst, (char *) src,
   176                                      (unsigned int) len, (int) volume);
   177             } else
   178 #elif ((defined(_MSC_VER) && defined(_M_IX86)) || defined(__WATCOMC__)) && defined(SDL_ASSEMBLY_ROUTINES)
   179             if (SDL_HasMMX()) {
   180                 SDL_MixAudio_MMX_S16_VC((char *) dst, (char *) src,
   181                                         (unsigned int) len, (int) volume);
   182             } else
   183 #endif
   184 #endif
   185 #if defined(__GNUC__) && defined(__M68000__) && !defined(__mcoldfire__) && defined(SDL_ASSEMBLY_ROUTINES)
   186                 SDL_MixAudio_m68k_S16LSB((short *) dst, (short *) src,
   187                                          (unsigned long) len, (long) volume);
   188 #else
   189             {
   190                 Sint16 src1, src2;
   191                 int dst_sample;
   192                 const int max_audioval = ((1 << (16 - 1)) - 1);
   193                 const int min_audioval = -(1 << (16 - 1));
   194 
   195                 len /= 2;
   196                 while (len--) {
   197                     src1 = ((src[1]) << 8 | src[0]);
   198                     ADJUST_VOLUME(src1, volume);
   199                     src2 = ((dst[1]) << 8 | dst[0]);
   200                     src += 2;
   201                     dst_sample = src1 + src2;
   202                     if (dst_sample > max_audioval) {
   203                         dst_sample = max_audioval;
   204                     } else if (dst_sample < min_audioval) {
   205                         dst_sample = min_audioval;
   206                     }
   207                     dst[0] = dst_sample & 0xFF;
   208                     dst_sample >>= 8;
   209                     dst[1] = dst_sample & 0xFF;
   210                     dst += 2;
   211                 }
   212             }
   213 #endif
   214         }
   215         break;
   216 
   217     case AUDIO_S16MSB:
   218         {
   219 #if defined(__GNUC__) && defined(__M68000__) && !defined(__mcoldfire__) && defined(SDL_ASSEMBLY_ROUTINES)
   220             SDL_MixAudio_m68k_S16MSB((short *) dst, (short *) src,
   221                                      (unsigned long) len, (long) volume);
   222 #else
   223             Sint16 src1, src2;
   224             int dst_sample;
   225             const int max_audioval = ((1 << (16 - 1)) - 1);
   226             const int min_audioval = -(1 << (16 - 1));
   227 
   228             len /= 2;
   229             while (len--) {
   230                 src1 = ((src[0]) << 8 | src[1]);
   231                 ADJUST_VOLUME(src1, volume);
   232                 src2 = ((dst[0]) << 8 | dst[1]);
   233                 src += 2;
   234                 dst_sample = src1 + src2;
   235                 if (dst_sample > max_audioval) {
   236                     dst_sample = max_audioval;
   237                 } else if (dst_sample < min_audioval) {
   238                     dst_sample = min_audioval;
   239                 }
   240                 dst[1] = dst_sample & 0xFF;
   241                 dst_sample >>= 8;
   242                 dst[0] = dst_sample & 0xFF;
   243                 dst += 2;
   244             }
   245 #endif
   246         }
   247         break;
   248 
   249     case AUDIO_S32LSB:
   250         {
   251             const Uint32 *src32 = (Uint32 *) src;
   252             Uint32 *dst32 = (Uint32 *) dst;
   253             Sint64 src1, src2;
   254             Sint64 dst_sample;
   255             const Sint64 max_audioval = ((((Sint64) 1) << (32 - 1)) - 1);
   256             const Sint64 min_audioval = -(((Sint64) 1) << (32 - 1));
   257 
   258             len /= 4;
   259             while (len--) {
   260                 src1 = (Sint64) ((Sint32) SDL_SwapLE32(*src32));
   261                 src32++;
   262                 ADJUST_VOLUME(src1, volume);
   263                 src2 = (Sint64) ((Sint32) SDL_SwapLE32(*dst32));
   264                 dst_sample = src1 + src2;
   265                 if (dst_sample > max_audioval) {
   266                     dst_sample = max_audioval;
   267                 } else if (dst_sample < min_audioval) {
   268                     dst_sample = min_audioval;
   269                 }
   270                 *(dst32++) = SDL_SwapLE32((Uint32) ((Sint32) dst_sample));
   271             }
   272         }
   273         break;
   274 
   275     case AUDIO_S32MSB:
   276         {
   277             const Uint32 *src32 = (Uint32 *) src;
   278             Uint32 *dst32 = (Uint32 *) dst;
   279             Sint64 src1, src2;
   280             Sint64 dst_sample;
   281             const Sint64 max_audioval = ((((Sint64) 1) << (32 - 1)) - 1);
   282             const Sint64 min_audioval = -(((Sint64) 1) << (32 - 1));
   283 
   284             len /= 4;
   285             while (len--) {
   286                 src1 = (Sint64) ((Sint32) SDL_SwapBE32(*src32));
   287                 src32++;
   288                 ADJUST_VOLUME(src1, volume);
   289                 src2 = (Sint64) ((Sint32) SDL_SwapBE32(*dst32));
   290                 dst_sample = src1 + src2;
   291                 if (dst_sample > max_audioval) {
   292                     dst_sample = max_audioval;
   293                 } else if (dst_sample < min_audioval) {
   294                     dst_sample = min_audioval;
   295                 }
   296                 *(dst32++) = SDL_SwapBE32((Uint32) ((Sint32) dst_sample));
   297             }
   298         }
   299         break;
   300 
   301     case AUDIO_F32LSB:
   302         {
   303             const float fmaxvolume = 1.0f / ((float) SDL_MIX_MAXVOLUME);
   304             const float fvolume = (float) volume;
   305             const float *src32 = (float *) src;
   306             float *dst32 = (float *) dst;
   307             float src1, src2;
   308             double dst_sample;
   309             /* !!! FIXME: are these right? */
   310             const double max_audioval = 3.402823466e+38F;
   311             const double min_audioval = -3.402823466e+38F;
   312 
   313             len /= 4;
   314             while (len--) {
   315                 src1 = ((SDL_SwapFloatLE(*src32) * fvolume) * fmaxvolume);
   316                 src2 = SDL_SwapFloatLE(*dst32);
   317                 src32++;
   318 
   319                 dst_sample = ((double) src1) + ((double) src2);
   320                 if (dst_sample > max_audioval) {
   321                     dst_sample = max_audioval;
   322                 } else if (dst_sample < min_audioval) {
   323                     dst_sample = min_audioval;
   324                 }
   325                 *(dst32++) = SDL_SwapFloatLE((float) dst_sample);
   326             }
   327         }
   328         break;
   329 
   330     case AUDIO_F32MSB:
   331         {
   332             const float fmaxvolume = 1.0f / ((float) SDL_MIX_MAXVOLUME);
   333             const float fvolume = (float) volume;
   334             const float *src32 = (float *) src;
   335             float *dst32 = (float *) dst;
   336             float src1, src2;
   337             double dst_sample;
   338             /* !!! FIXME: are these right? */
   339             const double max_audioval = 3.402823466e+38F;
   340             const double min_audioval = -3.402823466e+38F;
   341 
   342             len /= 4;
   343             while (len--) {
   344                 src1 = ((SDL_SwapFloatBE(*src32) * fvolume) * fmaxvolume);
   345                 src2 = SDL_SwapFloatBE(*dst32);
   346                 src32++;
   347 
   348                 dst_sample = ((double) src1) + ((double) src2);
   349                 if (dst_sample > max_audioval) {
   350                     dst_sample = max_audioval;
   351                 } else if (dst_sample < min_audioval) {
   352                     dst_sample = min_audioval;
   353                 }
   354                 *(dst32++) = SDL_SwapFloatBE((float) dst_sample);
   355             }
   356         }
   357         break;
   358 
   359     default:                   /* If this happens... FIXME! */
   360         SDL_SetError("SDL_MixAudio(): unknown audio format");
   361         return;
   362     }
   363 }
   364 
   365 /* vi: set ts=4 sw=4 expandtab: */