| 1 | /* |
| 2 | SDL - Simple DirectMedia Layer |
| 3 | Copyright (C) 1997-2009 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 | /* 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 | } |