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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 This driver was written by: |
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23 Erik Inge Bolsų |
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24 knan@mo.himolde.no |
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25 */ |
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26 #include "SDL_config.h" |
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27 |
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28 /* Allow access to a raw mixing buffer */ |
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29 |
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30 #include <signal.h> |
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31 #include <unistd.h> |
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32 |
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33 #include "SDL_timer.h" |
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34 #include "SDL_audio.h" |
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35 #include "../SDL_audiomem.h" |
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36 #include "../SDL_audio_c.h" |
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37 #include "../SDL_audiodev_c.h" |
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38 #include "SDL_nasaudio.h" |
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39 |
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40 /* The tag name used by artsc audio */ |
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41 #define NAS_DRIVER_NAME "nas" |
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42 |
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43 static struct SDL_PrivateAudioData *this2 = NULL; |
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44 |
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45 /* Audio driver functions */ |
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46 static int NAS_OpenAudio(_THIS, SDL_AudioSpec *spec); |
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47 static void NAS_WaitAudio(_THIS); |
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48 static void NAS_PlayAudio(_THIS); |
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49 static Uint8 *NAS_GetAudioBuf(_THIS); |
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50 static void NAS_CloseAudio(_THIS); |
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51 |
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52 /* Audio driver bootstrap functions */ |
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53 |
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54 static int Audio_Available(void) |
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55 { |
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56 AuServer *aud = AuOpenServer("", 0, NULL, 0, NULL, NULL); |
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57 if (!aud) return 0; |
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58 |
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59 AuCloseServer(aud); |
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60 return 1; |
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61 } |
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62 |
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63 static void Audio_DeleteDevice(SDL_AudioDevice *device) |
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64 { |
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65 SDL_free(device->hidden); |
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66 SDL_free(device); |
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67 } |
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68 |
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69 static SDL_AudioDevice *Audio_CreateDevice(int devindex) |
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70 { |
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71 SDL_AudioDevice *this; |
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72 |
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73 /* Initialize all variables that we clean on shutdown */ |
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74 this = (SDL_AudioDevice *)SDL_malloc(sizeof(SDL_AudioDevice)); |
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75 if ( this ) { |
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76 SDL_memset(this, 0, (sizeof *this)); |
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77 this->hidden = (struct SDL_PrivateAudioData *) |
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78 SDL_malloc((sizeof *this->hidden)); |
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79 } |
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80 if ( (this == NULL) || (this->hidden == NULL) ) { |
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81 SDL_OutOfMemory(); |
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82 if ( this ) { |
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83 SDL_free(this); |
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84 } |
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85 return(0); |
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86 } |
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87 SDL_memset(this->hidden, 0, (sizeof *this->hidden)); |
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88 |
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89 /* Set the function pointers */ |
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90 this->OpenAudio = NAS_OpenAudio; |
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91 this->WaitAudio = NAS_WaitAudio; |
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92 this->PlayAudio = NAS_PlayAudio; |
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93 this->GetAudioBuf = NAS_GetAudioBuf; |
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94 this->CloseAudio = NAS_CloseAudio; |
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95 |
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96 this->free = Audio_DeleteDevice; |
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97 |
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98 return this; |
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99 } |
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100 |
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101 AudioBootStrap NAS_bootstrap = { |
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102 NAS_DRIVER_NAME, "Network Audio System", |
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103 Audio_Available, Audio_CreateDevice |
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104 }; |
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105 |
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106 /* This function waits until it is possible to write a full sound buffer */ |
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107 static void NAS_WaitAudio(_THIS) |
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108 { |
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109 while ( this->hidden->buf_free < this->hidden->mixlen ) { |
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110 AuEvent ev; |
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111 AuNextEvent(this->hidden->aud, AuTrue, &ev); |
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112 AuDispatchEvent(this->hidden->aud, &ev); |
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113 } |
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114 } |
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115 |
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116 static void NAS_PlayAudio(_THIS) |
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117 { |
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118 while (this->hidden->mixlen > this->hidden->buf_free) { /* We think the buffer is full? Yikes! Ask the server for events, |
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119 in the hope that some of them is LowWater events telling us more |
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120 of the buffer is free now than what we think. */ |
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121 AuEvent ev; |
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122 AuNextEvent(this->hidden->aud, AuTrue, &ev); |
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123 AuDispatchEvent(this->hidden->aud, &ev); |
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124 } |
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125 this->hidden->buf_free -= this->hidden->mixlen; |
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126 |
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127 /* Write the audio data */ |
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128 AuWriteElement(this->hidden->aud, this->hidden->flow, 0, this->hidden->mixlen, this->hidden->mixbuf, AuFalse, NULL); |
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129 |
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130 this->hidden->written += this->hidden->mixlen; |
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131 |
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132 #ifdef DEBUG_AUDIO |
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133 fprintf(stderr, "Wrote %d bytes of audio data\n", this->hidden->mixlen); |
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134 #endif |
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135 } |
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136 |
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137 static Uint8 *NAS_GetAudioBuf(_THIS) |
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138 { |
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139 return(this->hidden->mixbuf); |
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140 } |
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141 |
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142 static void NAS_CloseAudio(_THIS) |
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143 { |
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144 if ( this->hidden->mixbuf != NULL ) { |
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145 SDL_FreeAudioMem(this->hidden->mixbuf); |
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146 this->hidden->mixbuf = NULL; |
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147 } |
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148 if ( this->hidden->aud ) { |
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149 AuCloseServer(this->hidden->aud); |
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150 this->hidden->aud = 0; |
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151 } |
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152 } |
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153 |
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154 static unsigned char sdlformat_to_auformat(unsigned int fmt) |
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155 { |
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156 switch (fmt) |
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157 { |
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158 case AUDIO_U8: |
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159 return AuFormatLinearUnsigned8; |
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160 case AUDIO_S8: |
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161 return AuFormatLinearSigned8; |
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162 case AUDIO_U16LSB: |
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163 return AuFormatLinearUnsigned16LSB; |
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164 case AUDIO_U16MSB: |
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165 return AuFormatLinearUnsigned16MSB; |
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166 case AUDIO_S16LSB: |
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167 return AuFormatLinearSigned16LSB; |
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168 case AUDIO_S16MSB: |
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169 return AuFormatLinearSigned16MSB; |
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170 } |
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171 return AuNone; |
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172 } |
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173 |
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174 static AuBool |
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175 event_handler(AuServer* aud, AuEvent* ev, AuEventHandlerRec* hnd) |
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176 { |
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177 switch (ev->type) { |
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178 case AuEventTypeElementNotify: { |
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179 AuElementNotifyEvent* event = (AuElementNotifyEvent *)ev; |
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180 |
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181 switch (event->kind) { |
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182 case AuElementNotifyKindLowWater: |
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183 if (this2->buf_free >= 0) { |
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184 this2->really += event->num_bytes; |
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185 gettimeofday(&this2->last_tv, 0); |
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186 this2->buf_free += event->num_bytes; |
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187 } else { |
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188 this2->buf_free = event->num_bytes; |
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189 } |
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190 break; |
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191 case AuElementNotifyKindState: |
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192 switch (event->cur_state) { |
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193 case AuStatePause: |
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194 if (event->reason != AuReasonUser) { |
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195 if (this2->buf_free >= 0) { |
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196 this2->really += event->num_bytes; |
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197 gettimeofday(&this2->last_tv, 0); |
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198 this2->buf_free += event->num_bytes; |
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199 } else { |
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200 this2->buf_free = event->num_bytes; |
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201 } |
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202 } |
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203 break; |
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204 } |
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205 } |
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206 } |
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207 } |
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208 return AuTrue; |
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209 } |
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210 |
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211 static AuDeviceID |
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212 find_device(_THIS, int nch) |
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213 { |
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214 int i; |
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215 for (i = 0; i < AuServerNumDevices(this->hidden->aud); i++) { |
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216 if ((AuDeviceKind(AuServerDevice(this->hidden->aud, i)) == |
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217 AuComponentKindPhysicalOutput) && |
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218 AuDeviceNumTracks(AuServerDevice(this->hidden->aud, i)) == nch) { |
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219 return AuDeviceIdentifier(AuServerDevice(this->hidden->aud, i)); |
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220 } |
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221 } |
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222 return AuNone; |
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223 } |
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224 |
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225 static int NAS_OpenAudio(_THIS, SDL_AudioSpec *spec) |
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226 { |
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227 AuElement elms[3]; |
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228 int buffer_size; |
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229 Uint16 test_format, format; |
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230 |
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231 this->hidden->mixbuf = NULL; |
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232 |
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233 /* Try for a closest match on audio format */ |
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234 format = 0; |
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235 for ( test_format = SDL_FirstAudioFormat(spec->format); |
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236 ! format && test_format; ) { |
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237 format = sdlformat_to_auformat(test_format); |
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238 |
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239 if (format == AuNone) { |
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240 test_format = SDL_NextAudioFormat(); |
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241 } |
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242 } |
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243 if ( format == 0 ) { |
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244 SDL_SetError("Couldn't find any hardware audio formats"); |
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245 return(-1); |
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246 } |
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247 spec->format = test_format; |
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248 |
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249 this->hidden->aud = AuOpenServer("", 0, NULL, 0, NULL, NULL); |
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250 if (this->hidden->aud == 0) |
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251 { |
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252 SDL_SetError("Couldn't open connection to NAS server"); |
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253 return (-1); |
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254 } |
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255 |
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256 this->hidden->dev = find_device(this, spec->channels); |
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257 if ((this->hidden->dev == AuNone) || (!(this->hidden->flow = AuCreateFlow(this->hidden->aud, NULL)))) { |
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258 AuCloseServer(this->hidden->aud); |
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259 this->hidden->aud = 0; |
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260 SDL_SetError("Couldn't find a fitting playback device on NAS server"); |
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261 return (-1); |
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262 } |
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263 |
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264 buffer_size = spec->freq; |
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265 if (buffer_size < 4096) |
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266 buffer_size = 4096; |
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267 |
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268 if (buffer_size > 32768) |
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269 buffer_size = 32768; /* So that the buffer won't get unmanageably big. */ |
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270 |
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271 /* Calculate the final parameters for this audio specification */ |
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272 SDL_CalculateAudioSpec(spec); |
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273 |
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274 this2 = this->hidden; |
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275 |
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276 AuMakeElementImportClient(elms, spec->freq, format, spec->channels, AuTrue, |
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277 buffer_size, buffer_size / 4, 0, NULL); |
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278 AuMakeElementExportDevice(elms+1, 0, this->hidden->dev, spec->freq, |
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279 AuUnlimitedSamples, 0, NULL); |
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280 AuSetElements(this->hidden->aud, this->hidden->flow, AuTrue, 2, elms, NULL); |
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281 AuRegisterEventHandler(this->hidden->aud, AuEventHandlerIDMask, 0, this->hidden->flow, |
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282 event_handler, (AuPointer) NULL); |
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283 |
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284 AuStartFlow(this->hidden->aud, this->hidden->flow, NULL); |
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285 |
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286 /* Allocate mixing buffer */ |
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287 this->hidden->mixlen = spec->size; |
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288 this->hidden->mixbuf = (Uint8 *)SDL_AllocAudioMem(this->hidden->mixlen); |
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289 if ( this->hidden->mixbuf == NULL ) { |
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290 return(-1); |
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291 } |
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292 SDL_memset(this->hidden->mixbuf, spec->silence, spec->size); |
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293 |
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294 /* Get the parent process id (we're the parent of the audio thread) */ |
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295 this->hidden->parent = getpid(); |
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296 |
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297 /* We're ready to rock and roll. :-) */ |
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298 return(0); |
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299 } |