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1 /* |
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2 SDL - Simple DirectMedia Layer |
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3 Copyright (C) 1997-2006 Sam Lantinga |
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4 |
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5 This library is free software; you can redistribute it and/or |
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6 modify it under the terms of the GNU Lesser General Public |
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7 License as published by the Free Software Foundation; either |
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8 version 2.1 of the License, or (at your option) any later version. |
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9 |
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10 This library is distributed in the hope that it will be useful, |
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11 but WITHOUT ANY WARRANTY; without even the implied warranty of |
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12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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13 Lesser General Public License for more details. |
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14 |
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15 You should have received a copy of the GNU Lesser General Public |
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16 License along with this library; if not, write to the Free Software |
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17 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
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18 |
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19 Sam Lantinga |
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20 slouken@libsdl.org |
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21 */ |
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22 #include "SDL_config.h" |
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23 |
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24 /* This provides the default mixing callback for the SDL audio routines */ |
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25 |
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26 #include "SDL_cpuinfo.h" |
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27 #include "SDL_timer.h" |
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28 #include "SDL_audio.h" |
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29 #include "SDL_sysaudio.h" |
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30 #include "SDL_mixer_MMX.h" |
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31 #include "SDL_mixer_MMX_VC.h" |
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32 #include "SDL_mixer_m68k.h" |
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33 |
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34 /* This table is used to add two sound values together and pin |
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35 * the value to avoid overflow. (used with permission from ARDI) |
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36 * Changed to use 0xFE instead of 0xFF for better sound quality. |
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37 */ |
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38 static const Uint8 mix8[] = |
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39 { |
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40 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, |
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41 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, |
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42 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, |
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43 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, |
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44 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, |
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45 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, |
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46 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, |
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47 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, |
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48 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, |
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49 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, |
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50 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, |
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51 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x02, 0x03, |
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52 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, |
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53 0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, |
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54 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, |
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55 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, |
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56 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, |
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57 0x3B, 0x3C, 0x3D, 0x3E, 0x3F, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, |
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58 0x46, 0x47, 0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, |
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59 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x5B, |
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60 0x5C, 0x5D, 0x5E, 0x5F, 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, |
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61 0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70, 0x71, |
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62 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x7B, 0x7C, |
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63 0x7D, 0x7E, 0x7F, 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, |
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64 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F, 0x90, 0x91, 0x92, |
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65 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, |
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66 0x9E, 0x9F, 0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7, 0xA8, |
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67 0xA9, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF, 0xB0, 0xB1, 0xB2, 0xB3, |
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68 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD, 0xBE, |
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69 0xBF, 0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, |
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70 0xCA, 0xCB, 0xCC, 0xCD, 0xCE, 0xCF, 0xD0, 0xD1, 0xD2, 0xD3, 0xD4, |
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71 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF, |
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72 0xE0, 0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9, 0xEA, |
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73 0xEB, 0xEC, 0xED, 0xEE, 0xEF, 0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, |
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74 0xF6, 0xF7, 0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFE, 0xFE, |
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75 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, |
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76 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, |
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77 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, |
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78 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, |
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79 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, |
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80 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, |
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81 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, |
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82 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, |
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83 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, |
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84 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, |
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85 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, |
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86 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE |
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87 }; |
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88 |
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89 /* The volume ranges from 0 - 128 */ |
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90 #define ADJUST_VOLUME(s, v) (s = (s*v)/SDL_MIX_MAXVOLUME) |
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91 #define ADJUST_VOLUME_U8(s, v) (s = (((s-128)*v)/SDL_MIX_MAXVOLUME)+128) |
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92 |
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93 void SDL_MixAudio (Uint8 *dst, const Uint8 *src, Uint32 len, int volume) |
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94 { |
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95 Uint16 format; |
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96 |
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97 if ( volume == 0 ) { |
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98 return; |
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99 } |
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100 /* Mix the user-level audio format */ |
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101 if ( current_audio ) { |
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102 if ( current_audio->convert.needed ) { |
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103 format = current_audio->convert.src_format; |
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104 } else { |
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105 format = current_audio->spec.format; |
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106 } |
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107 } else { |
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108 /* HACK HACK HACK */ |
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109 format = AUDIO_S16; |
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110 } |
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111 switch (format) { |
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112 |
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113 case AUDIO_U8: { |
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114 #if defined(__GNUC__) && defined(__M68000__) && defined(SDL_ASSEMBLY_ROUTINES) |
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115 SDL_MixAudio_m68k_U8((char*)dst,(char*)src,(unsigned long)len,(long)volume,(char *)mix8); |
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116 #else |
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117 Uint8 src_sample; |
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118 |
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119 while ( len-- ) { |
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120 src_sample = *src; |
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121 ADJUST_VOLUME_U8(src_sample, volume); |
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122 *dst = mix8[*dst+src_sample]; |
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123 ++dst; |
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124 ++src; |
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125 } |
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126 #endif |
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127 } |
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128 break; |
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129 |
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130 case AUDIO_S8: { |
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131 #if defined(__GNUC__) && defined(__i386__) && defined(SDL_ASSEMBLY_ROUTINES) |
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132 if (SDL_HasMMX()) |
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133 { |
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134 SDL_MixAudio_MMX_S8((char*)dst,(char*)src,(unsigned int)len,(int)volume); |
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135 } |
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136 else |
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137 #elif ((defined(_MSC_VER) && defined(_M_IX86)) || defined(__WATCOMC__)) && defined(SDL_ASSEMBLY_ROUTINES) |
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138 if (SDL_HasMMX()) |
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139 { |
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140 SDL_MixAudio_MMX_S8_VC((char*)dst,(char*)src,(unsigned int)len,(int)volume); |
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141 } |
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142 else |
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143 #endif |
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144 #if defined(__GNUC__) && defined(__M68000__) && defined(SDL_ASSEMBLY_ROUTINES) |
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145 SDL_MixAudio_m68k_S8((char*)dst,(char*)src,(unsigned long)len,(long)volume); |
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146 #else |
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147 { |
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148 Sint8 *dst8, *src8; |
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149 Sint8 src_sample; |
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150 int dst_sample; |
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151 const int max_audioval = ((1<<(8-1))-1); |
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152 const int min_audioval = -(1<<(8-1)); |
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153 |
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154 src8 = (Sint8 *)src; |
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155 dst8 = (Sint8 *)dst; |
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156 while ( len-- ) { |
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157 src_sample = *src8; |
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158 ADJUST_VOLUME(src_sample, volume); |
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159 dst_sample = *dst8 + src_sample; |
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160 if ( dst_sample > max_audioval ) { |
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161 *dst8 = max_audioval; |
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162 } else |
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163 if ( dst_sample < min_audioval ) { |
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164 *dst8 = min_audioval; |
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165 } else { |
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166 *dst8 = dst_sample; |
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167 } |
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168 ++dst8; |
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169 ++src8; |
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170 } |
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171 } |
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172 #endif |
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173 } |
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174 break; |
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175 |
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176 case AUDIO_S16LSB: { |
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177 #if defined(__GNUC__) && defined(__i386__) && defined(SDL_ASSEMBLY_ROUTINES) |
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178 if (SDL_HasMMX()) |
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179 { |
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180 SDL_MixAudio_MMX_S16((char*)dst,(char*)src,(unsigned int)len,(int)volume); |
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181 } |
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182 else |
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183 #elif ((defined(_MSC_VER) && defined(_M_IX86)) || defined(__WATCOMC__)) && defined(SDL_ASSEMBLY_ROUTINES) |
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184 if (SDL_HasMMX()) |
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185 { |
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186 SDL_MixAudio_MMX_S16_VC((char*)dst,(char*)src,(unsigned int)len,(int)volume); |
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187 } |
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188 else |
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189 #endif |
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190 #if defined(__GNUC__) && defined(__M68000__) && defined(SDL_ASSEMBLY_ROUTINES) |
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191 SDL_MixAudio_m68k_S16LSB((short*)dst,(short*)src,(unsigned long)len,(long)volume); |
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192 #else |
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193 { |
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194 Sint16 src1, src2; |
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195 int dst_sample; |
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196 const int max_audioval = ((1<<(16-1))-1); |
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197 const int min_audioval = -(1<<(16-1)); |
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198 |
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199 len /= 2; |
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200 while ( len-- ) { |
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201 src1 = ((src[1])<<8|src[0]); |
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202 ADJUST_VOLUME(src1, volume); |
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203 src2 = ((dst[1])<<8|dst[0]); |
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204 src += 2; |
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205 dst_sample = src1+src2; |
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206 if ( dst_sample > max_audioval ) { |
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207 dst_sample = max_audioval; |
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208 } else |
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209 if ( dst_sample < min_audioval ) { |
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210 dst_sample = min_audioval; |
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211 } |
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212 dst[0] = dst_sample&0xFF; |
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213 dst_sample >>= 8; |
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214 dst[1] = dst_sample&0xFF; |
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215 dst += 2; |
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216 } |
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217 } |
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218 #endif |
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219 } |
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220 break; |
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221 |
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222 case AUDIO_S16MSB: { |
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223 #if defined(__GNUC__) && defined(__M68000__) && defined(SDL_ASSEMBLY_ROUTINES) |
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224 SDL_MixAudio_m68k_S16MSB((short*)dst,(short*)src,(unsigned long)len,(long)volume); |
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225 #else |
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226 Sint16 src1, src2; |
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227 int dst_sample; |
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228 const int max_audioval = ((1<<(16-1))-1); |
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229 const int min_audioval = -(1<<(16-1)); |
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230 |
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231 len /= 2; |
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232 while ( len-- ) { |
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233 src1 = ((src[0])<<8|src[1]); |
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234 ADJUST_VOLUME(src1, volume); |
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235 src2 = ((dst[0])<<8|dst[1]); |
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236 src += 2; |
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237 dst_sample = src1+src2; |
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238 if ( dst_sample > max_audioval ) { |
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239 dst_sample = max_audioval; |
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240 } else |
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241 if ( dst_sample < min_audioval ) { |
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242 dst_sample = min_audioval; |
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243 } |
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244 dst[1] = dst_sample&0xFF; |
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245 dst_sample >>= 8; |
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246 dst[0] = dst_sample&0xFF; |
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247 dst += 2; |
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248 } |
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249 #endif |
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250 } |
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251 break; |
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252 |
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253 default: /* If this happens... FIXME! */ |
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254 SDL_SetError("SDL_MixAudio(): unknown audio format"); |
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255 return; |
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256 } |
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257 } |
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258 |