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 (at) libsdl.org 21 */ 22 #include "SDL_config.h" 23 24 /* Allow access to a raw mixing buffer */ 25 26 #ifdef HAVE_SIGNAL_H 27 #include <signal.h> 28 #endif 29 #include <unistd.h> 30 31 #include "SDL_timer.h" 32 #include "SDL_audio.h" 33 #include "../SDL_audiomem.h" 34 #include "../SDL_audio_c.h" 35 #include "../SDL_audiodev_c.h" 36 #include "SDL_artsaudio.h" 37 38 #ifdef SDL_AUDIO_DRIVER_ARTS_DYNAMIC 39 #include "SDL_name.h" 40 #include "SDL_loadso.h" 41 #else 42 #define SDL_NAME(X) X 43 #endif 44 45 /* The tag name used by artsc audio */ 46 #define ARTS_DRIVER_NAME "arts" 47 48 /* Audio driver functions */ 49 static int ARTS_OpenAudio(_THIS, SDL_AudioSpec *spec); 50 static void ARTS_WaitAudio(_THIS); 51 static void ARTS_PlayAudio(_THIS); 52 static Uint8 *ARTS_GetAudioBuf(_THIS); 53 static void ARTS_CloseAudio(_THIS); 54 55 #ifdef SDL_AUDIO_DRIVER_ARTS_DYNAMIC 56 57 static const char *arts_library = SDL_AUDIO_DRIVER_ARTS_DYNAMIC; 58 static void *arts_handle = NULL; 59 static int arts_loaded = 0; 60 61 static int (*SDL_NAME(arts_init))(void); 62 static void (*SDL_NAME(arts_free))(void); 63 static arts_stream_t (*SDL_NAME(arts_play_stream))(int rate, int bits, int channels, const char *name); 64 static int (*SDL_NAME(arts_stream_set))(arts_stream_t s, arts_parameter_t param, int value); 65 static int (*SDL_NAME(arts_stream_get))(arts_stream_t s, arts_parameter_t param); 66 static int (*SDL_NAME(arts_write))(arts_stream_t s, const void *buffer, int count); 67 static void (*SDL_NAME(arts_close_stream))(arts_stream_t s); 68 static int (*SDL_NAME(arts_suspended))(void); 69 static const char *(*SDL_NAME(arts_error_text))(int errorcode); 70 71 static struct { 72 const char *name; 73 void **func; 74 } arts_functions[] = { 75 { "arts_init", (void **)&SDL_NAME(arts_init) }, 76 { "arts_free", (void **)&SDL_NAME(arts_free) }, 77 { "arts_play_stream", (void **)&SDL_NAME(arts_play_stream) }, 78 { "arts_stream_set", (void **)&SDL_NAME(arts_stream_set) }, 79 { "arts_stream_get", (void **)&SDL_NAME(arts_stream_get) }, 80 { "arts_write", (void **)&SDL_NAME(arts_write) }, 81 { "arts_close_stream", (void **)&SDL_NAME(arts_close_stream) }, 82 { "arts_suspended", (void **)&SDL_NAME(arts_suspended) }, 83 { "arts_error_text", (void **)&SDL_NAME(arts_error_text) }, 84 }; 85 86 static void UnloadARTSLibrary() 87 { 88 if ( arts_loaded ) { 89 SDL_UnloadObject(arts_handle); 90 arts_handle = NULL; 91 arts_loaded = 0; 92 } 93 } 94 95 static int LoadARTSLibrary(void) 96 { 97 int i, retval = -1; 98 99 arts_handle = SDL_LoadObject(arts_library); 100 if ( arts_handle ) { 101 arts_loaded = 1; 102 retval = 0; 103 for ( i=0; i<SDL_arraysize(arts_functions); ++i ) { 104 *arts_functions[i].func = SDL_LoadFunction(arts_handle, arts_functions[i].name); 105 if ( !*arts_functions[i].func ) { 106 retval = -1; 107 UnloadARTSLibrary(); 108 break; 109 } 110 } 111 } 112 return retval; 113 } 114 115 #else 116 117 static void UnloadARTSLibrary() 118 { 119 return; 120 } 121 122 static int LoadARTSLibrary(void) 123 { 124 return 0; 125 } 126 127 #endif /* SDL_AUDIO_DRIVER_ARTS_DYNAMIC */ 128 129 /* Audio driver bootstrap functions */ 130 131 static int Audio_Available(void) 132 { 133 int available = 0; 134 135 if ( LoadARTSLibrary() < 0 ) { 136 return available; 137 } 138 if ( SDL_NAME(arts_init)() == 0 ) { 139 if ( SDL_NAME(arts_suspended)() ) { 140 /* Play a stream so aRts doesn't crash */ 141 arts_stream_t stream2; 142 stream2=SDL_NAME(arts_play_stream)(44100, 16, 2, "SDL"); 143 SDL_NAME(arts_write)(stream2, "", 0); 144 SDL_NAME(arts_close_stream)(stream2); 145 available = 1; 146 } 147 SDL_NAME(arts_free)(); 148 } 149 UnloadARTSLibrary(); 150 151 return available; 152 } 153 154 static void Audio_DeleteDevice(SDL_AudioDevice *device) 155 { 156 SDL_free(device->hidden); 157 SDL_free(device); 158 UnloadARTSLibrary(); 159 } 160 161 static SDL_AudioDevice *Audio_CreateDevice(int devindex) 162 { 163 SDL_AudioDevice *this; 164 165 /* Initialize all variables that we clean on shutdown */ 166 LoadARTSLibrary(); 167 this = (SDL_AudioDevice *)SDL_malloc(sizeof(SDL_AudioDevice)); 168 if ( this ) { 169 SDL_memset(this, 0, (sizeof *this)); 170 this->hidden = (struct SDL_PrivateAudioData *) 171 SDL_malloc((sizeof *this->hidden)); 172 } 173 if ( (this == NULL) || (this->hidden == NULL) ) { 174 SDL_OutOfMemory(); 175 if ( this ) { 176 SDL_free(this); 177 } 178 return(0); 179 } 180 SDL_memset(this->hidden, 0, (sizeof *this->hidden)); 181 stream = 0; 182 183 /* Set the function pointers */ 184 this->OpenAudio = ARTS_OpenAudio; 185 this->WaitAudio = ARTS_WaitAudio; 186 this->PlayAudio = ARTS_PlayAudio; 187 this->GetAudioBuf = ARTS_GetAudioBuf; 188 this->CloseAudio = ARTS_CloseAudio; 189 190 this->free = Audio_DeleteDevice; 191 192 return this; 193 } 194 195 AudioBootStrap ARTS_bootstrap = { 196 ARTS_DRIVER_NAME, "Analog Realtime Synthesizer", 197 Audio_Available, Audio_CreateDevice 198 }; 199 200 /* This function waits until it is possible to write a full sound buffer */ 201 static void ARTS_WaitAudio(_THIS) 202 { 203 Sint32 ticks; 204 205 /* Check to see if the thread-parent process is still alive */ 206 { static int cnt = 0; 207 /* Note that this only works with thread implementations 208 that use a different process id for each thread. 209 */ 210 if (parent && (((++cnt)%10) == 0)) { /* Check every 10 loops */ 211 if ( kill(parent, 0) < 0 ) { 212 this->enabled = 0; 213 } 214 } 215 } 216 217 /* Use timer for general audio synchronization */ 218 ticks = ((Sint32)(next_frame - SDL_GetTicks()))-FUDGE_TICKS; 219 if ( ticks > 0 ) { 220 SDL_Delay(ticks); 221 } 222 } 223 224 static void ARTS_PlayAudio(_THIS) 225 { 226 int written; 227 228 /* Write the audio data */ 229 written = SDL_NAME(arts_write)(stream, mixbuf, mixlen); 230 231 /* If timer synchronization is enabled, set the next write frame */ 232 if ( frame_ticks ) { 233 next_frame += frame_ticks; 234 } 235 236 /* If we couldn't write, assume fatal error for now */ 237 if ( written < 0 ) { 238 this->enabled = 0; 239 } 240 #ifdef DEBUG_AUDIO 241 fprintf(stderr, "Wrote %d bytes of audio data\n", written); 242 #endif 243 } 244 245 static Uint8 *ARTS_GetAudioBuf(_THIS) 246 { 247 return(mixbuf); 248 } 249 250 static void ARTS_CloseAudio(_THIS) 251 { 252 if ( mixbuf != NULL ) { 253 SDL_FreeAudioMem(mixbuf); 254 mixbuf = NULL; 255 } 256 if ( stream ) { 257 SDL_NAME(arts_close_stream)(stream); 258 stream = 0; 259 } 260 SDL_NAME(arts_free)(); 261 } 262 263 static int ARTS_OpenAudio(_THIS, SDL_AudioSpec *spec) 264 { 265 int bits, frag_spec; 266 Uint16 test_format, format; 267 int error_code; 268 269 /* Reset the timer synchronization flag */ 270 frame_ticks = 0.0; 271 272 mixbuf = NULL; 273 274 /* Try for a closest match on audio format */ 275 format = 0; 276 bits = 0; 277 for ( test_format = SDL_FirstAudioFormat(spec->format); 278 ! format && test_format; ) { 279 #ifdef DEBUG_AUDIO 280 fprintf(stderr, "Trying format 0x%4.4x\n", test_format); 281 #endif 282 switch ( test_format ) { 283 case AUDIO_U8: 284 bits = 8; 285 format = 1; 286 break; 287 case AUDIO_S16LSB: 288 bits = 16; 289 format = 1; 290 break; 291 default: 292 format = 0; 293 break; 294 } 295 if ( ! format ) { 296 test_format = SDL_NextAudioFormat(); 297 } 298 } 299 if ( format == 0 ) { 300 SDL_SetError("Couldn't find any hardware audio formats"); 301 return(-1); 302 } 303 spec->format = test_format; 304 305 error_code = SDL_NAME(arts_init)(); 306 if ( error_code != 0 ) { 307 SDL_SetError("Unable to initialize ARTS: %s", SDL_NAME(arts_error_text)(error_code)); 308 return(-1); 309 } 310 if ( ! SDL_NAME(arts_suspended)() ) { 311 SDL_SetError("ARTS can not open audio device"); 312 return(-1); 313 } 314 stream = SDL_NAME(arts_play_stream)(spec->freq, bits, spec->channels, "SDL"); 315 316 /* Calculate the final parameters for this audio specification */ 317 SDL_CalculateAudioSpec(spec); 318 319 /* Determine the power of two of the fragment size */ 320 for ( frag_spec = 0; (0x01<<frag_spec) < spec->size; ++frag_spec ); 321 if ( (0x01<<frag_spec) != spec->size ) { 322 SDL_SetError("Fragment size must be a power of two"); 323 return(-1); 324 } 325 frag_spec |= 0x00020000; /* two fragments, for low latency */ 326 327 #ifdef ARTS_P_PACKET_SETTINGS 328 SDL_NAME(arts_stream_set)(stream, ARTS_P_PACKET_SETTINGS, frag_spec); 329 #else 330 SDL_NAME(arts_stream_set)(stream, ARTS_P_PACKET_SIZE, frag_spec&0xffff); 331 SDL_NAME(arts_stream_set)(stream, ARTS_P_PACKET_COUNT, frag_spec>>16); 332 #endif 333 spec->size = SDL_NAME(arts_stream_get)(stream, ARTS_P_PACKET_SIZE); 334 335 /* Allocate mixing buffer */ 336 mixlen = spec->size; 337 mixbuf = (Uint8 *)SDL_AllocAudioMem(mixlen); 338 if ( mixbuf == NULL ) { 339 return(-1); 340 } 341 SDL_memset(mixbuf, spec->silence, spec->size); 342 343 /* Get the parent process id (we're the parent of the audio thread) */ 344 parent = getpid(); 345 346 /* We're ready to rock and roll. :-) */ 347 return(0); 348 } 349
