1 /* 2 SDL - Simple DirectMedia Layer 3 Copyright (C) 1997-2012 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_suspend))(void); 69 static int (*SDL_NAME(arts_suspended))(void); 70 static const char *(*SDL_NAME(arts_error_text))(int errorcode); 71 72 static struct { 73 const char *name; 74 void **func; 75 } arts_functions[] = { 76 { "arts_init", (void **)&SDL_NAME(arts_init) }, 77 { "arts_free", (void **)&SDL_NAME(arts_free) }, 78 { "arts_play_stream", (void **)&SDL_NAME(arts_play_stream) }, 79 { "arts_stream_set", (void **)&SDL_NAME(arts_stream_set) }, 80 { "arts_stream_get", (void **)&SDL_NAME(arts_stream_get) }, 81 { "arts_write", (void **)&SDL_NAME(arts_write) }, 82 { "arts_close_stream", (void **)&SDL_NAME(arts_close_stream) }, 83 { "arts_suspend", (void **)&SDL_NAME(arts_suspend) }, 84 { "arts_suspended", (void **)&SDL_NAME(arts_suspended) }, 85 { "arts_error_text", (void **)&SDL_NAME(arts_error_text) }, 86 }; 87 88 static void UnloadARTSLibrary() 89 { 90 if ( arts_loaded ) { 91 SDL_UnloadObject(arts_handle); 92 arts_handle = NULL; 93 arts_loaded = 0; 94 } 95 } 96 97 static int LoadARTSLibrary(void) 98 { 99 int i, retval = -1; 100 101 arts_handle = SDL_LoadObject(arts_library); 102 if ( arts_handle ) { 103 arts_loaded = 1; 104 retval = 0; 105 for ( i=0; i<SDL_arraysize(arts_functions); ++i ) { 106 *arts_functions[i].func = SDL_LoadFunction(arts_handle, arts_functions[i].name); 107 if ( !*arts_functions[i].func ) { 108 retval = -1; 109 UnloadARTSLibrary(); 110 break; 111 } 112 } 113 } 114 return retval; 115 } 116 117 #else 118 119 static void UnloadARTSLibrary() 120 { 121 return; 122 } 123 124 static int LoadARTSLibrary(void) 125 { 126 return 0; 127 } 128 129 #endif /* SDL_AUDIO_DRIVER_ARTS_DYNAMIC */ 130 131 /* Audio driver bootstrap functions */ 132 133 static int ARTS_Suspend(void) 134 { 135 const Uint32 abortms = SDL_GetTicks() + 3000; /* give up after 3 secs */ 136 while ( (!SDL_NAME(arts_suspended)()) && (SDL_GetTicks() < abortms) ) { 137 if ( SDL_NAME(arts_suspend)() ) { 138 break; 139 } 140 } 141 142 return SDL_NAME(arts_suspended)(); 143 } 144 145 static int Audio_Available(void) 146 { 147 int available = 0; 148 149 if ( LoadARTSLibrary() < 0 ) { 150 return available; 151 } 152 if ( SDL_NAME(arts_init)() == 0 ) { 153 if ( ARTS_Suspend() ) { 154 /* Play a stream so aRts doesn't crash */ 155 arts_stream_t stream2; 156 stream2=SDL_NAME(arts_play_stream)(44100, 16, 2, "SDL"); 157 SDL_NAME(arts_write)(stream2, "", 0); 158 SDL_NAME(arts_close_stream)(stream2); 159 available = 1; 160 } 161 SDL_NAME(arts_free)(); 162 } 163 UnloadARTSLibrary(); 164 165 return available; 166 } 167 168 static void Audio_DeleteDevice(SDL_AudioDevice *device) 169 { 170 SDL_free(device->hidden); 171 SDL_free(device); 172 UnloadARTSLibrary(); 173 } 174 175 static SDL_AudioDevice *Audio_CreateDevice(int devindex) 176 { 177 SDL_AudioDevice *this; 178 179 /* Initialize all variables that we clean on shutdown */ 180 LoadARTSLibrary(); 181 this = (SDL_AudioDevice *)SDL_malloc(sizeof(SDL_AudioDevice)); 182 if ( this ) { 183 SDL_memset(this, 0, (sizeof *this)); 184 this->hidden = (struct SDL_PrivateAudioData *) 185 SDL_malloc((sizeof *this->hidden)); 186 } 187 if ( (this == NULL) || (this->hidden == NULL) ) { 188 SDL_OutOfMemory(); 189 if ( this ) { 190 SDL_free(this); 191 } 192 return(0); 193 } 194 SDL_memset(this->hidden, 0, (sizeof *this->hidden)); 195 stream = 0; 196 197 /* Set the function pointers */ 198 this->OpenAudio = ARTS_OpenAudio; 199 this->WaitAudio = ARTS_WaitAudio; 200 this->PlayAudio = ARTS_PlayAudio; 201 this->GetAudioBuf = ARTS_GetAudioBuf; 202 this->CloseAudio = ARTS_CloseAudio; 203 204 this->free = Audio_DeleteDevice; 205 206 return this; 207 } 208 209 AudioBootStrap ARTS_bootstrap = { 210 ARTS_DRIVER_NAME, "Analog Realtime Synthesizer", 211 Audio_Available, Audio_CreateDevice 212 }; 213 214 /* This function waits until it is possible to write a full sound buffer */ 215 static void ARTS_WaitAudio(_THIS) 216 { 217 Sint32 ticks; 218 219 /* Check to see if the thread-parent process is still alive */ 220 { static int cnt = 0; 221 /* Note that this only works with thread implementations 222 that use a different process id for each thread. 223 */ 224 if (parent && (((++cnt)%10) == 0)) { /* Check every 10 loops */ 225 if ( kill(parent, 0) < 0 ) { 226 this->enabled = 0; 227 } 228 } 229 } 230 231 /* Use timer for general audio synchronization */ 232 ticks = ((Sint32)(next_frame - SDL_GetTicks()))-FUDGE_TICKS; 233 if ( ticks > 0 ) { 234 SDL_Delay(ticks); 235 } 236 } 237 238 static void ARTS_PlayAudio(_THIS) 239 { 240 int written; 241 242 /* Write the audio data */ 243 written = SDL_NAME(arts_write)(stream, mixbuf, mixlen); 244 245 /* If timer synchronization is enabled, set the next write frame */ 246 if ( frame_ticks ) { 247 next_frame += frame_ticks; 248 } 249 250 /* If we couldn't write, assume fatal error for now */ 251 if ( written < 0 ) { 252 this->enabled = 0; 253 } 254 #ifdef DEBUG_AUDIO 255 fprintf(stderr, "Wrote %d bytes of audio data\n", written); 256 #endif 257 } 258 259 static Uint8 *ARTS_GetAudioBuf(_THIS) 260 { 261 return(mixbuf); 262 } 263 264 static void ARTS_CloseAudio(_THIS) 265 { 266 if ( mixbuf != NULL ) { 267 SDL_FreeAudioMem(mixbuf); 268 mixbuf = NULL; 269 } 270 if ( stream ) { 271 SDL_NAME(arts_close_stream)(stream); 272 stream = 0; 273 } 274 SDL_NAME(arts_free)(); 275 } 276 277 static int ARTS_OpenAudio(_THIS, SDL_AudioSpec *spec) 278 { 279 int bits, frag_spec; 280 Uint16 test_format, format; 281 int error_code; 282 283 /* Reset the timer synchronization flag */ 284 frame_ticks = 0.0; 285 286 mixbuf = NULL; 287 288 /* Try for a closest match on audio format */ 289 format = 0; 290 bits = 0; 291 for ( test_format = SDL_FirstAudioFormat(spec->format); 292 ! format && test_format; ) { 293 #ifdef DEBUG_AUDIO 294 fprintf(stderr, "Trying format 0x%4.4x\n", test_format); 295 #endif 296 switch ( test_format ) { 297 case AUDIO_U8: 298 bits = 8; 299 format = 1; 300 break; 301 case AUDIO_S16LSB: 302 bits = 16; 303 format = 1; 304 break; 305 default: 306 format = 0; 307 break; 308 } 309 if ( ! format ) { 310 test_format = SDL_NextAudioFormat(); 311 } 312 } 313 if ( format == 0 ) { 314 SDL_SetError("Couldn't find any hardware audio formats"); 315 return(-1); 316 } 317 spec->format = test_format; 318 319 error_code = SDL_NAME(arts_init)(); 320 if ( error_code != 0 ) { 321 SDL_SetError("Unable to initialize ARTS: %s", SDL_NAME(arts_error_text)(error_code)); 322 return(-1); 323 } 324 if ( ! ARTS_Suspend() ) { 325 SDL_SetError("ARTS can not open audio device"); 326 return(-1); 327 } 328 stream = SDL_NAME(arts_play_stream)(spec->freq, bits, spec->channels, "SDL"); 329 330 /* Calculate the final parameters for this audio specification */ 331 SDL_CalculateAudioSpec(spec); 332 333 /* Determine the power of two of the fragment size */ 334 for ( frag_spec = 0; (0x01<<frag_spec) < spec->size; ++frag_spec ); 335 if ( (0x01<<frag_spec) != spec->size ) { 336 SDL_SetError("Fragment size must be a power of two"); 337 return(-1); 338 } 339 frag_spec |= 0x00020000; /* two fragments, for low latency */ 340 341 #ifdef ARTS_P_PACKET_SETTINGS 342 SDL_NAME(arts_stream_set)(stream, ARTS_P_PACKET_SETTINGS, frag_spec); 343 #else 344 SDL_NAME(arts_stream_set)(stream, ARTS_P_PACKET_SIZE, frag_spec&0xffff); 345 SDL_NAME(arts_stream_set)(stream, ARTS_P_PACKET_COUNT, frag_spec>>16); 346 #endif 347 spec->size = SDL_NAME(arts_stream_get)(stream, ARTS_P_PACKET_SIZE); 348 349 /* Allocate mixing buffer */ 350 mixlen = spec->size; 351 mixbuf = (Uint8 *)SDL_AllocAudioMem(mixlen); 352 if ( mixbuf == NULL ) { 353 return(-1); 354 } 355 SDL_memset(mixbuf, spec->silence, spec->size); 356 357 /* Get the parent process id (we're the parent of the audio thread) */ 358 parent = getpid(); 359 360 /* We're ready to rock and roll. :-) */ 361 return(0); 362 } 363
