| 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 Library General Public |
| 7 | License as published by the Free Software Foundation; either |
| 8 | version 2 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 | Library General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU Library General Public |
| 16 | License along with this library; if not, write to the Free |
| 17 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 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 | #include <sys/types.h> |
| 27 | #include <signal.h> /* For kill() */ |
| 28 | |
| 29 | #include "SDL_timer.h" |
| 30 | #include "SDL_audio.h" |
| 31 | #include "../SDL_audiomem.h" |
| 32 | #include "../SDL_audio_c.h" |
| 33 | #include "SDL_alsa_audio.h" |
| 34 | |
| 35 | #ifdef SDL_AUDIO_DRIVER_ALSA_DYNAMIC |
| 36 | #include "SDL_name.h" |
| 37 | #include "SDL_loadso.h" |
| 38 | #else |
| 39 | #define SDL_NAME(X) X |
| 40 | #endif |
| 41 | |
| 42 | |
| 43 | /* The tag name used by ALSA audio */ |
| 44 | #define DRIVER_NAME "alsa" |
| 45 | |
| 46 | /* Audio driver functions */ |
| 47 | static int ALSA_OpenAudio(_THIS, SDL_AudioSpec *spec); |
| 48 | static void ALSA_WaitAudio(_THIS); |
| 49 | static void ALSA_PlayAudio(_THIS); |
| 50 | static Uint8 *ALSA_GetAudioBuf(_THIS); |
| 51 | static void ALSA_CloseAudio(_THIS); |
| 52 | |
| 53 | #ifdef SDL_AUDIO_DRIVER_ALSA_DYNAMIC |
| 54 | |
| 55 | static const char *alsa_library = SDL_AUDIO_DRIVER_ALSA_DYNAMIC; |
| 56 | static void *alsa_handle = NULL; |
| 57 | static int alsa_loaded = 0; |
| 58 | |
| 59 | static int (*SDL_NAME(snd_pcm_open))(snd_pcm_t **pcm, const char *name, snd_pcm_stream_t stream, int mode); |
| 60 | static int (*SDL_NAME(snd_pcm_close))(snd_pcm_t *pcm); |
| 61 | static snd_pcm_sframes_t (*SDL_NAME(snd_pcm_writei))(snd_pcm_t *pcm, const void *buffer, snd_pcm_uframes_t size); |
| 62 | static int (*SDL_NAME(snd_pcm_recover))(snd_pcm_t *pcm, int err, int silent); |
| 63 | static int (*SDL_NAME(snd_pcm_prepare))(snd_pcm_t *pcm); |
| 64 | static int (*SDL_NAME(snd_pcm_drain))(snd_pcm_t *pcm); |
| 65 | static const char *(*SDL_NAME(snd_strerror))(int errnum); |
| 66 | static size_t (*SDL_NAME(snd_pcm_hw_params_sizeof))(void); |
| 67 | static size_t (*SDL_NAME(snd_pcm_sw_params_sizeof))(void); |
| 68 | static void (*SDL_NAME(snd_pcm_hw_params_copy))(snd_pcm_hw_params_t *dst, const snd_pcm_hw_params_t *src); |
| 69 | static int (*SDL_NAME(snd_pcm_hw_params_any))(snd_pcm_t *pcm, snd_pcm_hw_params_t *params); |
| 70 | static int (*SDL_NAME(snd_pcm_hw_params_set_access))(snd_pcm_t *pcm, snd_pcm_hw_params_t *params, snd_pcm_access_t access); |
| 71 | static int (*SDL_NAME(snd_pcm_hw_params_set_format))(snd_pcm_t *pcm, snd_pcm_hw_params_t *params, snd_pcm_format_t val); |
| 72 | static int (*SDL_NAME(snd_pcm_hw_params_set_channels))(snd_pcm_t *pcm, snd_pcm_hw_params_t *params, unsigned int val); |
| 73 | static int (*SDL_NAME(snd_pcm_hw_params_get_channels))(const snd_pcm_hw_params_t *params, unsigned int *val); |
| 74 | static int (*SDL_NAME(snd_pcm_hw_params_set_rate_near))(snd_pcm_t *pcm, snd_pcm_hw_params_t *params, unsigned int *val, int *dir); |
| 75 | static int (*SDL_NAME(snd_pcm_hw_params_set_period_size_near))(snd_pcm_t *pcm, snd_pcm_hw_params_t *params, snd_pcm_uframes_t *val, int *dir); |
| 76 | static int (*SDL_NAME(snd_pcm_hw_params_get_period_size))(const snd_pcm_hw_params_t *params, snd_pcm_uframes_t *frames, int *dir); |
| 77 | static int (*SDL_NAME(snd_pcm_hw_params_set_periods_near))(snd_pcm_t *pcm, snd_pcm_hw_params_t *params, unsigned int *val, int *dir); |
| 78 | static int (*SDL_NAME(snd_pcm_hw_params_get_periods))(const snd_pcm_hw_params_t *params, unsigned int *val, int *dir); |
| 79 | static int (*SDL_NAME(snd_pcm_hw_params_set_buffer_size_near))(snd_pcm_t *pcm, snd_pcm_hw_params_t *params, snd_pcm_uframes_t *val); |
| 80 | static int (*SDL_NAME(snd_pcm_hw_params_get_buffer_size))(const snd_pcm_hw_params_t *params, snd_pcm_uframes_t *val); |
| 81 | static int (*SDL_NAME(snd_pcm_hw_params))(snd_pcm_t *pcm, snd_pcm_hw_params_t *params); |
| 82 | /* |
| 83 | */ |
| 84 | static int (*SDL_NAME(snd_pcm_sw_params_current))(snd_pcm_t *pcm, snd_pcm_sw_params_t *swparams); |
| 85 | static int (*SDL_NAME(snd_pcm_sw_params_set_start_threshold))(snd_pcm_t *pcm, snd_pcm_sw_params_t *params, snd_pcm_uframes_t val); |
| 86 | static int (*SDL_NAME(snd_pcm_sw_params))(snd_pcm_t *pcm, snd_pcm_sw_params_t *params); |
| 87 | static int (*SDL_NAME(snd_pcm_nonblock))(snd_pcm_t *pcm, int nonblock); |
| 88 | static int (*SDL_NAME(snd_pcm_wait))(snd_pcm_t *pcm, int timeout); |
| 89 | #define snd_pcm_hw_params_sizeof SDL_NAME(snd_pcm_hw_params_sizeof) |
| 90 | #define snd_pcm_sw_params_sizeof SDL_NAME(snd_pcm_sw_params_sizeof) |
| 91 | |
| 92 | /* cast funcs to char* first, to please GCC's strict aliasing rules. */ |
| 93 | static struct { |
| 94 | const char *name; |
| 95 | void **func; |
| 96 | } alsa_functions[] = { |
| 97 | { "snd_pcm_open", (void**)(char*)&SDL_NAME(snd_pcm_open) }, |
| 98 | { "snd_pcm_close", (void**)(char*)&SDL_NAME(snd_pcm_close) }, |
| 99 | { "snd_pcm_writei", (void**)(char*)&SDL_NAME(snd_pcm_writei) }, |
| 100 | { "snd_pcm_recover", (void**)(char*)&SDL_NAME(snd_pcm_recover) }, |
| 101 | { "snd_pcm_prepare", (void**)(char*)&SDL_NAME(snd_pcm_prepare) }, |
| 102 | { "snd_pcm_drain", (void**)(char*)&SDL_NAME(snd_pcm_drain) }, |
| 103 | { "snd_strerror", (void**)(char*)&SDL_NAME(snd_strerror) }, |
| 104 | { "snd_pcm_hw_params_sizeof", (void**)(char*)&SDL_NAME(snd_pcm_hw_params_sizeof) }, |
| 105 | { "snd_pcm_sw_params_sizeof", (void**)(char*)&SDL_NAME(snd_pcm_sw_params_sizeof) }, |
| 106 | { "snd_pcm_hw_params_copy", (void**)(char*)&SDL_NAME(snd_pcm_hw_params_copy) }, |
| 107 | { "snd_pcm_hw_params_any", (void**)(char*)&SDL_NAME(snd_pcm_hw_params_any) }, |
| 108 | { "snd_pcm_hw_params_set_access", (void**)(char*)&SDL_NAME(snd_pcm_hw_params_set_access) }, |
| 109 | { "snd_pcm_hw_params_set_format", (void**)(char*)&SDL_NAME(snd_pcm_hw_params_set_format) }, |
| 110 | { "snd_pcm_hw_params_set_channels", (void**)(char*)&SDL_NAME(snd_pcm_hw_params_set_channels) }, |
| 111 | { "snd_pcm_hw_params_get_channels", (void**)(char*)&SDL_NAME(snd_pcm_hw_params_get_channels) }, |
| 112 | { "snd_pcm_hw_params_set_rate_near", (void**)(char*)&SDL_NAME(snd_pcm_hw_params_set_rate_near) }, |
| 113 | { "snd_pcm_hw_params_set_period_size_near", (void**)(char*)&SDL_NAME(snd_pcm_hw_params_set_period_size_near) }, |
| 114 | { "snd_pcm_hw_params_get_period_size", (void**)(char*)&SDL_NAME(snd_pcm_hw_params_get_period_size) }, |
| 115 | { "snd_pcm_hw_params_set_periods_near", (void**)(char*)&SDL_NAME(snd_pcm_hw_params_set_periods_near) }, |
| 116 | { "snd_pcm_hw_params_get_periods", (void**)(char*)&SDL_NAME(snd_pcm_hw_params_get_periods) }, |
| 117 | { "snd_pcm_hw_params_set_buffer_size_near", (void**)(char*)&SDL_NAME(snd_pcm_hw_params_set_buffer_size_near) }, |
| 118 | { "snd_pcm_hw_params_get_buffer_size", (void**)(char*)&SDL_NAME(snd_pcm_hw_params_get_buffer_size) }, |
| 119 | { "snd_pcm_hw_params", (void**)(char*)&SDL_NAME(snd_pcm_hw_params) }, |
| 120 | { "snd_pcm_sw_params_current", (void**)(char*)&SDL_NAME(snd_pcm_sw_params_current) }, |
| 121 | { "snd_pcm_sw_params_set_start_threshold", (void**)(char*)&SDL_NAME(snd_pcm_sw_params_set_start_threshold) }, |
| 122 | { "snd_pcm_sw_params", (void**)(char*)&SDL_NAME(snd_pcm_sw_params) }, |
| 123 | { "snd_pcm_nonblock", (void**)(char*)&SDL_NAME(snd_pcm_nonblock) }, |
| 124 | { "snd_pcm_wait", (void**)(char*)&SDL_NAME(snd_pcm_wait) }, |
| 125 | }; |
| 126 | |
| 127 | static void UnloadALSALibrary(void) { |
| 128 | if (alsa_loaded) { |
| 129 | SDL_UnloadObject(alsa_handle); |
| 130 | alsa_handle = NULL; |
| 131 | alsa_loaded = 0; |
| 132 | } |
| 133 | } |
| 134 | |
| 135 | static int LoadALSALibrary(void) { |
| 136 | int i, retval = -1; |
| 137 | |
| 138 | alsa_handle = SDL_LoadObject(alsa_library); |
| 139 | if (alsa_handle) { |
| 140 | alsa_loaded = 1; |
| 141 | retval = 0; |
| 142 | for (i = 0; i < SDL_arraysize(alsa_functions); i++) { |
| 143 | *alsa_functions[i].func = SDL_LoadFunction(alsa_handle,alsa_functions[i].name); |
| 144 | if (!*alsa_functions[i].func) { |
| 145 | retval = -1; |
| 146 | UnloadALSALibrary(); |
| 147 | break; |
| 148 | } |
| 149 | } |
| 150 | } |
| 151 | return retval; |
| 152 | } |
| 153 | |
| 154 | #else |
| 155 | |
| 156 | static void UnloadALSALibrary(void) { |
| 157 | return; |
| 158 | } |
| 159 | |
| 160 | static int LoadALSALibrary(void) { |
| 161 | return 0; |
| 162 | } |
| 163 | |
| 164 | #endif /* SDL_AUDIO_DRIVER_ALSA_DYNAMIC */ |
| 165 | |
| 166 | static const char *get_audio_device(int channels) |
| 167 | { |
| 168 | const char *device; |
| 169 | |
| 170 | device = SDL_getenv("AUDIODEV"); /* Is there a standard variable name? */ |
| 171 | if ( device == NULL ) { |
| 172 | switch (channels) { |
| 173 | case 6: |
| 174 | device = "plug:surround51"; |
| 175 | break; |
| 176 | case 4: |
| 177 | device = "plug:surround40"; |
| 178 | break; |
| 179 | default: |
| 180 | device = "default"; |
| 181 | break; |
| 182 | } |
| 183 | } |
| 184 | return device; |
| 185 | } |
| 186 | |
| 187 | /* Audio driver bootstrap functions */ |
| 188 | |
| 189 | static int Audio_Available(void) |
| 190 | { |
| 191 | int available; |
| 192 | int status; |
| 193 | snd_pcm_t *handle; |
| 194 | |
| 195 | available = 0; |
| 196 | if (LoadALSALibrary() < 0) { |
| 197 | return available; |
| 198 | } |
| 199 | status = SDL_NAME(snd_pcm_open)(&handle, get_audio_device(2), SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK); |
| 200 | if ( status >= 0 ) { |
| 201 | available = 1; |
| 202 | SDL_NAME(snd_pcm_close)(handle); |
| 203 | } |
| 204 | UnloadALSALibrary(); |
| 205 | return(available); |
| 206 | } |
| 207 | |
| 208 | static void Audio_DeleteDevice(SDL_AudioDevice *device) |
| 209 | { |
| 210 | SDL_free(device->hidden); |
| 211 | SDL_free(device); |
| 212 | UnloadALSALibrary(); |
| 213 | } |
| 214 | |
| 215 | static SDL_AudioDevice *Audio_CreateDevice(int devindex) |
| 216 | { |
| 217 | SDL_AudioDevice *this; |
| 218 | |
| 219 | /* Initialize all variables that we clean on shutdown */ |
| 220 | LoadALSALibrary(); |
| 221 | this = (SDL_AudioDevice *)SDL_malloc(sizeof(SDL_AudioDevice)); |
| 222 | if ( this ) { |
| 223 | SDL_memset(this, 0, (sizeof *this)); |
| 224 | this->hidden = (struct SDL_PrivateAudioData *) |
| 225 | SDL_malloc((sizeof *this->hidden)); |
| 226 | } |
| 227 | if ( (this == NULL) || (this->hidden == NULL) ) { |
| 228 | SDL_OutOfMemory(); |
| 229 | if ( this ) { |
| 230 | SDL_free(this); |
| 231 | } |
| 232 | return(0); |
| 233 | } |
| 234 | SDL_memset(this->hidden, 0, (sizeof *this->hidden)); |
| 235 | |
| 236 | /* Set the function pointers */ |
| 237 | this->OpenAudio = ALSA_OpenAudio; |
| 238 | this->WaitAudio = ALSA_WaitAudio; |
| 239 | this->PlayAudio = ALSA_PlayAudio; |
| 240 | this->GetAudioBuf = ALSA_GetAudioBuf; |
| 241 | this->CloseAudio = ALSA_CloseAudio; |
| 242 | |
| 243 | this->free = Audio_DeleteDevice; |
| 244 | |
| 245 | return this; |
| 246 | } |
| 247 | |
| 248 | AudioBootStrap ALSA_bootstrap = { |
| 249 | DRIVER_NAME, "ALSA PCM audio", |
| 250 | Audio_Available, Audio_CreateDevice |
| 251 | }; |
| 252 | |
| 253 | /* This function waits until it is possible to write a full sound buffer */ |
| 254 | static void ALSA_WaitAudio(_THIS) |
| 255 | { |
| 256 | /* We're in blocking mode, so there's nothing to do here */ |
| 257 | } |
| 258 | |
| 259 | |
| 260 | /* |
| 261 | * http://bugzilla.libsdl.org/show_bug.cgi?id=110 |
| 262 | * "For Linux ALSA, this is FL-FR-RL-RR-C-LFE |
| 263 | * and for Windows DirectX [and CoreAudio], this is FL-FR-C-LFE-RL-RR" |
| 264 | */ |
| 265 | #define SWIZ6(T) \ |
| 266 | T *ptr = (T *) mixbuf; \ |
| 267 | const Uint32 count = (this->spec.samples / 6); \ |
| 268 | Uint32 i; \ |
| 269 | for (i = 0; i < count; i++, ptr += 6) { \ |
| 270 | T tmp; \ |
| 271 | tmp = ptr[2]; ptr[2] = ptr[4]; ptr[4] = tmp; \ |
| 272 | tmp = ptr[3]; ptr[3] = ptr[5]; ptr[5] = tmp; \ |
| 273 | } |
| 274 | |
| 275 | static __inline__ void swizzle_alsa_channels_6_64bit(_THIS) { SWIZ6(Uint64); } |
| 276 | static __inline__ void swizzle_alsa_channels_6_32bit(_THIS) { SWIZ6(Uint32); } |
| 277 | static __inline__ void swizzle_alsa_channels_6_16bit(_THIS) { SWIZ6(Uint16); } |
| 278 | static __inline__ void swizzle_alsa_channels_6_8bit(_THIS) { SWIZ6(Uint8); } |
| 279 | |
| 280 | #undef SWIZ6 |
| 281 | |
| 282 | |
| 283 | /* |
| 284 | * Called right before feeding this->mixbuf to the hardware. Swizzle channels |
| 285 | * from Windows/Mac order to the format alsalib will want. |
| 286 | */ |
| 287 | static __inline__ void swizzle_alsa_channels(_THIS) |
| 288 | { |
| 289 | if (this->spec.channels == 6) { |
| 290 | const Uint16 fmtsize = (this->spec.format & 0xFF); /* bits/channel. */ |
| 291 | if (fmtsize == 16) |
| 292 | swizzle_alsa_channels_6_16bit(this); |
| 293 | else if (fmtsize == 8) |
| 294 | swizzle_alsa_channels_6_8bit(this); |
| 295 | else if (fmtsize == 32) |
| 296 | swizzle_alsa_channels_6_32bit(this); |
| 297 | else if (fmtsize == 64) |
| 298 | swizzle_alsa_channels_6_64bit(this); |
| 299 | } |
| 300 | |
| 301 | /* !!! FIXME: update this for 7.1 if needed, later. */ |
| 302 | } |
| 303 | |
| 304 | |
| 305 | static void ALSA_PlayAudio(_THIS) |
| 306 | { |
| 307 | int status; |
| 308 | snd_pcm_uframes_t frames_left; |
| 309 | const Uint8 *sample_buf = (const Uint8 *) mixbuf; |
| 310 | const int frame_size = (((int) (this->spec.format & 0xFF)) / 8) * this->spec.channels; |
| 311 | |
| 312 | swizzle_alsa_channels(this); |
| 313 | |
| 314 | frames_left = ((snd_pcm_uframes_t) this->spec.samples); |
| 315 | |
| 316 | while ( frames_left > 0 && this->enabled ) { |
| 317 | /* This works, but needs more testing before going live */ |
| 318 | /*SDL_NAME(snd_pcm_wait)(pcm_handle, -1);*/ |
| 319 | |
| 320 | status = SDL_NAME(snd_pcm_writei)(pcm_handle, sample_buf, frames_left); |
| 321 | if ( status < 0 ) { |
| 322 | if ( status == -EAGAIN ) { |
| 323 | /* Apparently snd_pcm_recover() doesn't handle this case - does it assume snd_pcm_wait() above? */ |
| 324 | SDL_Delay(1); |
| 325 | continue; |
| 326 | } |
| 327 | status = SDL_NAME(snd_pcm_recover)(pcm_handle, status, 0); |
| 328 | if ( status < 0 ) { |
| 329 | /* Hmm, not much we can do - abort */ |
| 330 | fprintf(stderr, "ALSA write failed (unrecoverable): %s\n", SDL_NAME(snd_strerror)(status)); |
| 331 | this->enabled = 0; |
| 332 | return; |
| 333 | } |
| 334 | continue; |
| 335 | } |
| 336 | sample_buf += status * frame_size; |
| 337 | frames_left -= status; |
| 338 | } |
| 339 | } |
| 340 | |
| 341 | static Uint8 *ALSA_GetAudioBuf(_THIS) |
| 342 | { |
| 343 | return(mixbuf); |
| 344 | } |
| 345 | |
| 346 | static void ALSA_CloseAudio(_THIS) |
| 347 | { |
| 348 | if ( mixbuf != NULL ) { |
| 349 | SDL_FreeAudioMem(mixbuf); |
| 350 | mixbuf = NULL; |
| 351 | } |
| 352 | if ( pcm_handle ) { |
| 353 | SDL_NAME(snd_pcm_drain)(pcm_handle); |
| 354 | SDL_NAME(snd_pcm_close)(pcm_handle); |
| 355 | pcm_handle = NULL; |
| 356 | } |
| 357 | } |
| 358 | |
| 359 | static int ALSA_finalize_hardware(_THIS, SDL_AudioSpec *spec, snd_pcm_hw_params_t *hwparams, int override) |
| 360 | { |
| 361 | int status; |
| 362 | snd_pcm_uframes_t bufsize; |
| 363 | |
| 364 | /* "set" the hardware with the desired parameters */ |
| 365 | status = SDL_NAME(snd_pcm_hw_params)(pcm_handle, hwparams); |
| 366 | if ( status < 0 ) { |
| 367 | return(-1); |
| 368 | } |
| 369 | |
| 370 | /* Get samples for the actual buffer size */ |
| 371 | status = SDL_NAME(snd_pcm_hw_params_get_buffer_size)(hwparams, &bufsize); |
| 372 | if ( status < 0 ) { |
| 373 | return(-1); |
| 374 | } |
| 375 | if ( !override && bufsize != spec->samples * 2 ) { |
| 376 | return(-1); |
| 377 | } |
| 378 | |
| 379 | /* FIXME: Is this safe to do? */ |
| 380 | spec->samples = bufsize / 2; |
| 381 | |
| 382 | /* This is useful for debugging */ |
| 383 | if ( getenv("SDL_AUDIO_ALSA_DEBUG") ) { |
| 384 | snd_pcm_uframes_t persize = 0; |
| 385 | unsigned int periods = 0; |
| 386 | |
| 387 | SDL_NAME(snd_pcm_hw_params_get_period_size)(hwparams, &persize, NULL); |
| 388 | SDL_NAME(snd_pcm_hw_params_get_periods)(hwparams, &periods, NULL); |
| 389 | |
| 390 | fprintf(stderr, "ALSA: period size = %ld, periods = %u, buffer size = %lu\n", persize, periods, bufsize); |
| 391 | } |
| 392 | return(0); |
| 393 | } |
| 394 | |
| 395 | static int ALSA_set_period_size(_THIS, SDL_AudioSpec *spec, snd_pcm_hw_params_t *params, int override) |
| 396 | { |
| 397 | const char *env; |
| 398 | int status; |
| 399 | snd_pcm_hw_params_t *hwparams; |
| 400 | snd_pcm_uframes_t frames; |
| 401 | unsigned int periods; |
| 402 | |
| 403 | /* Copy the hardware parameters for this setup */ |
| 404 | snd_pcm_hw_params_alloca(&hwparams); |
| 405 | SDL_NAME(snd_pcm_hw_params_copy)(hwparams, params); |
| 406 | |
| 407 | if ( !override ) { |
| 408 | env = getenv("SDL_AUDIO_ALSA_SET_PERIOD_SIZE"); |
| 409 | if ( env ) { |
| 410 | override = SDL_atoi(env); |
| 411 | if ( override == 0 ) { |
| 412 | return(-1); |
| 413 | } |
| 414 | } |
| 415 | } |
| 416 | |
| 417 | frames = spec->samples; |
| 418 | status = SDL_NAME(snd_pcm_hw_params_set_period_size_near)(pcm_handle, hwparams, &frames, NULL); |
| 419 | if ( status < 0 ) { |
| 420 | return(-1); |
| 421 | } |
| 422 | |
| 423 | periods = 2; |
| 424 | status = SDL_NAME(snd_pcm_hw_params_set_periods_near)(pcm_handle, hwparams, &periods, NULL); |
| 425 | if ( status < 0 ) { |
| 426 | return(-1); |
| 427 | } |
| 428 | |
| 429 | return ALSA_finalize_hardware(this, spec, hwparams, override); |
| 430 | } |
| 431 | |
| 432 | static int ALSA_set_buffer_size(_THIS, SDL_AudioSpec *spec, snd_pcm_hw_params_t *params, int override) |
| 433 | { |
| 434 | const char *env; |
| 435 | int status; |
| 436 | snd_pcm_hw_params_t *hwparams; |
| 437 | snd_pcm_uframes_t frames; |
| 438 | |
| 439 | /* Copy the hardware parameters for this setup */ |
| 440 | snd_pcm_hw_params_alloca(&hwparams); |
| 441 | SDL_NAME(snd_pcm_hw_params_copy)(hwparams, params); |
| 442 | |
| 443 | if ( !override ) { |
| 444 | env = getenv("SDL_AUDIO_ALSA_SET_BUFFER_SIZE"); |
| 445 | if ( env ) { |
| 446 | override = SDL_atoi(env); |
| 447 | if ( override == 0 ) { |
| 448 | return(-1); |
| 449 | } |
| 450 | } |
| 451 | } |
| 452 | |
| 453 | frames = spec->samples * 2; |
| 454 | status = SDL_NAME(snd_pcm_hw_params_set_buffer_size_near)(pcm_handle, hwparams, &frames); |
| 455 | if ( status < 0 ) { |
| 456 | return(-1); |
| 457 | } |
| 458 | |
| 459 | return ALSA_finalize_hardware(this, spec, hwparams, override); |
| 460 | } |
| 461 | |
| 462 | static int ALSA_OpenAudio(_THIS, SDL_AudioSpec *spec) |
| 463 | { |
| 464 | int status; |
| 465 | snd_pcm_hw_params_t *hwparams; |
| 466 | snd_pcm_sw_params_t *swparams; |
| 467 | snd_pcm_format_t format; |
| 468 | unsigned int rate; |
| 469 | unsigned int channels; |
| 470 | Uint16 test_format; |
| 471 | |
| 472 | /* Open the audio device */ |
| 473 | /* Name of device should depend on # channels in spec */ |
| 474 | status = SDL_NAME(snd_pcm_open)(&pcm_handle, get_audio_device(spec->channels), SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK); |
| 475 | |
| 476 | if ( status < 0 ) { |
| 477 | SDL_SetError("Couldn't open audio device: %s", SDL_NAME(snd_strerror)(status)); |
| 478 | return(-1); |
| 479 | } |
| 480 | |
| 481 | /* Figure out what the hardware is capable of */ |
| 482 | snd_pcm_hw_params_alloca(&hwparams); |
| 483 | status = SDL_NAME(snd_pcm_hw_params_any)(pcm_handle, hwparams); |
| 484 | if ( status < 0 ) { |
| 485 | SDL_SetError("Couldn't get hardware config: %s", SDL_NAME(snd_strerror)(status)); |
| 486 | ALSA_CloseAudio(this); |
| 487 | return(-1); |
| 488 | } |
| 489 | |
| 490 | /* SDL only uses interleaved sample output */ |
| 491 | status = SDL_NAME(snd_pcm_hw_params_set_access)(pcm_handle, hwparams, SND_PCM_ACCESS_RW_INTERLEAVED); |
| 492 | if ( status < 0 ) { |
| 493 | SDL_SetError("Couldn't set interleaved access: %s", SDL_NAME(snd_strerror)(status)); |
| 494 | ALSA_CloseAudio(this); |
| 495 | return(-1); |
| 496 | } |
| 497 | |
| 498 | /* Try for a closest match on audio format */ |
| 499 | status = -1; |
| 500 | for ( test_format = SDL_FirstAudioFormat(spec->format); |
| 501 | test_format && (status < 0); ) { |
| 502 | switch ( test_format ) { |
| 503 | case AUDIO_U8: |
| 504 | format = SND_PCM_FORMAT_U8; |
| 505 | break; |
| 506 | case AUDIO_S8: |
| 507 | format = SND_PCM_FORMAT_S8; |
| 508 | break; |
| 509 | case AUDIO_S16LSB: |
| 510 | format = SND_PCM_FORMAT_S16_LE; |
| 511 | break; |
| 512 | case AUDIO_S16MSB: |
| 513 | format = SND_PCM_FORMAT_S16_BE; |
| 514 | break; |
| 515 | case AUDIO_U16LSB: |
| 516 | format = SND_PCM_FORMAT_U16_LE; |
| 517 | break; |
| 518 | case AUDIO_U16MSB: |
| 519 | format = SND_PCM_FORMAT_U16_BE; |
| 520 | break; |
| 521 | default: |
| 522 | format = 0; |
| 523 | break; |
| 524 | } |
| 525 | if ( format != 0 ) { |
| 526 | status = SDL_NAME(snd_pcm_hw_params_set_format)(pcm_handle, hwparams, format); |
| 527 | } |
| 528 | if ( status < 0 ) { |
| 529 | test_format = SDL_NextAudioFormat(); |
| 530 | } |
| 531 | } |
| 532 | if ( status < 0 ) { |
| 533 | SDL_SetError("Couldn't find any hardware audio formats"); |
| 534 | ALSA_CloseAudio(this); |
| 535 | return(-1); |
| 536 | } |
| 537 | spec->format = test_format; |
| 538 | |
| 539 | /* Set the number of channels */ |
| 540 | status = SDL_NAME(snd_pcm_hw_params_set_channels)(pcm_handle, hwparams, spec->channels); |
| 541 | channels = spec->channels; |
| 542 | if ( status < 0 ) { |
| 543 | status = SDL_NAME(snd_pcm_hw_params_get_channels)(hwparams, &channels); |
| 544 | if ( status < 0 ) { |
| 545 | SDL_SetError("Couldn't set audio channels"); |
| 546 | ALSA_CloseAudio(this); |
| 547 | return(-1); |
| 548 | } |
| 549 | spec->channels = channels; |
| 550 | } |
| 551 | |
| 552 | /* Set the audio rate */ |
| 553 | rate = spec->freq; |
| 554 | |
| 555 | status = SDL_NAME(snd_pcm_hw_params_set_rate_near)(pcm_handle, hwparams, &rate, NULL); |
| 556 | if ( status < 0 ) { |
| 557 | SDL_SetError("Couldn't set audio frequency: %s", SDL_NAME(snd_strerror)(status)); |
| 558 | ALSA_CloseAudio(this); |
| 559 | return(-1); |
| 560 | } |
| 561 | spec->freq = rate; |
| 562 | |
| 563 | /* Set the buffer size, in samples */ |
| 564 | if ( ALSA_set_period_size(this, spec, hwparams, 0) < 0 && |
| 565 | ALSA_set_buffer_size(this, spec, hwparams, 0) < 0 ) { |
| 566 | /* Failed to set desired buffer size, do the best you can... */ |
| 567 | if ( ALSA_set_period_size(this, spec, hwparams, 1) < 0 ) { |
| 568 | SDL_SetError("Couldn't set hardware audio parameters: %s", SDL_NAME(snd_strerror)(status)); |
| 569 | ALSA_CloseAudio(this); |
| 570 | return(-1); |
| 571 | } |
| 572 | } |
| 573 | |
| 574 | /* Set the software parameters */ |
| 575 | snd_pcm_sw_params_alloca(&swparams); |
| 576 | status = SDL_NAME(snd_pcm_sw_params_current)(pcm_handle, swparams); |
| 577 | if ( status < 0 ) { |
| 578 | SDL_SetError("Couldn't get software config: %s", SDL_NAME(snd_strerror)(status)); |
| 579 | ALSA_CloseAudio(this); |
| 580 | return(-1); |
| 581 | } |
| 582 | status = SDL_NAME(snd_pcm_sw_params_set_start_threshold)(pcm_handle, swparams, 1); |
| 583 | if ( status < 0 ) { |
| 584 | SDL_SetError("Couldn't set start threshold: %s", SDL_NAME(snd_strerror)(status)); |
| 585 | ALSA_CloseAudio(this); |
| 586 | return(-1); |
| 587 | } |
| 588 | status = SDL_NAME(snd_pcm_sw_params)(pcm_handle, swparams); |
| 589 | if ( status < 0 ) { |
| 590 | SDL_SetError("Couldn't set software audio parameters: %s", SDL_NAME(snd_strerror)(status)); |
| 591 | ALSA_CloseAudio(this); |
| 592 | return(-1); |
| 593 | } |
| 594 | |
| 595 | /* Calculate the final parameters for this audio specification */ |
| 596 | SDL_CalculateAudioSpec(spec); |
| 597 | |
| 598 | /* Allocate mixing buffer */ |
| 599 | mixlen = spec->size; |
| 600 | mixbuf = (Uint8 *)SDL_AllocAudioMem(mixlen); |
| 601 | if ( mixbuf == NULL ) { |
| 602 | ALSA_CloseAudio(this); |
| 603 | return(-1); |
| 604 | } |
| 605 | SDL_memset(mixbuf, spec->silence, spec->size); |
| 606 | |
| 607 | /* Switch to blocking mode for playback */ |
| 608 | SDL_NAME(snd_pcm_nonblock)(pcm_handle, 0); |
| 609 | |
| 610 | /* We're ready to rock and roll. :-) */ |
| 611 | return(0); |
| 612 | } |