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 an ESD network stream mixing buffer */ 25 26 #include <sys/types.h> 27 #include <unistd.h> 28 #include <signal.h> 29 #include <errno.h> 30 #include <esd.h> 31 32 #include "SDL_timer.h" 33 #include "SDL_audio.h" 34 #include "../SDL_audiomem.h" 35 #include "../SDL_audio_c.h" 36 #include "../SDL_audiodev_c.h" 37 #include "SDL_esdaudio.h" 38 39 #ifdef SDL_AUDIO_DRIVER_ESD_DYNAMIC 40 #include "SDL_name.h" 41 #include "SDL_loadso.h" 42 #else 43 #define SDL_NAME(X) X 44 #endif 45 46 /* The tag name used by ESD audio */ 47 #define ESD_DRIVER_NAME "esd" 48 49 /* Audio driver functions */ 50 static int ESD_OpenAudio(_THIS, SDL_AudioSpec *spec); 51 static void ESD_WaitAudio(_THIS); 52 static void ESD_PlayAudio(_THIS); 53 static Uint8 *ESD_GetAudioBuf(_THIS); 54 static void ESD_CloseAudio(_THIS); 55 56 #ifdef SDL_AUDIO_DRIVER_ESD_DYNAMIC 57 58 static const char *esd_library = SDL_AUDIO_DRIVER_ESD_DYNAMIC; 59 static void *esd_handle = NULL; 60 static int esd_loaded = 0; 61 62 static int (*SDL_NAME(esd_open_sound))( const char *host ); 63 static int (*SDL_NAME(esd_close))( int esd ); 64 static int (*SDL_NAME(esd_play_stream))( esd_format_t format, int rate, 65 const char *host, const char *name ); 66 static struct { 67 const char *name; 68 void **func; 69 } esd_functions[] = { 70 { "esd_open_sound", (void **)&SDL_NAME(esd_open_sound) }, 71 { "esd_close", (void **)&SDL_NAME(esd_close) }, 72 { "esd_play_stream", (void **)&SDL_NAME(esd_play_stream) }, 73 }; 74 75 static void UnloadESDLibrary() 76 { 77 if ( esd_loaded ) { 78 SDL_UnloadObject(esd_handle); 79 esd_handle = NULL; 80 esd_loaded = 0; 81 } 82 } 83 84 static int LoadESDLibrary(void) 85 { 86 int i, retval = -1; 87 88 esd_handle = SDL_LoadObject(esd_library); 89 if ( esd_handle ) { 90 esd_loaded = 1; 91 retval = 0; 92 for ( i=0; i<SDL_arraysize(esd_functions); ++i ) { 93 *esd_functions[i].func = SDL_LoadFunction(esd_handle, esd_functions[i].name); 94 if ( !*esd_functions[i].func ) { 95 retval = -1; 96 UnloadESDLibrary(); 97 break; 98 } 99 } 100 } 101 return retval; 102 } 103 104 #else 105 106 static void UnloadESDLibrary() 107 { 108 return; 109 } 110 111 static int LoadESDLibrary(void) 112 { 113 return 0; 114 } 115 116 #endif /* SDL_AUDIO_DRIVER_ESD_DYNAMIC */ 117 118 /* Audio driver bootstrap functions */ 119 120 static int Audio_Available(void) 121 { 122 int connection; 123 int available; 124 125 available = 0; 126 if ( LoadESDLibrary() < 0 ) { 127 return available; 128 } 129 connection = SDL_NAME(esd_open_sound)(NULL); 130 if ( connection >= 0 ) { 131 available = 1; 132 SDL_NAME(esd_close)(connection); 133 } 134 UnloadESDLibrary(); 135 return(available); 136 } 137 138 static void Audio_DeleteDevice(SDL_AudioDevice *device) 139 { 140 SDL_free(device->hidden); 141 SDL_free(device); 142 UnloadESDLibrary(); 143 } 144 145 static SDL_AudioDevice *Audio_CreateDevice(int devindex) 146 { 147 SDL_AudioDevice *this; 148 149 /* Initialize all variables that we clean on shutdown */ 150 LoadESDLibrary(); 151 this = (SDL_AudioDevice *)SDL_malloc(sizeof(SDL_AudioDevice)); 152 if ( this ) { 153 SDL_memset(this, 0, (sizeof *this)); 154 this->hidden = (struct SDL_PrivateAudioData *) 155 SDL_malloc((sizeof *this->hidden)); 156 } 157 if ( (this == NULL) || (this->hidden == NULL) ) { 158 SDL_OutOfMemory(); 159 if ( this ) { 160 SDL_free(this); 161 } 162 return(0); 163 } 164 SDL_memset(this->hidden, 0, (sizeof *this->hidden)); 165 audio_fd = -1; 166 167 /* Set the function pointers */ 168 this->OpenAudio = ESD_OpenAudio; 169 this->WaitAudio = ESD_WaitAudio; 170 this->PlayAudio = ESD_PlayAudio; 171 this->GetAudioBuf = ESD_GetAudioBuf; 172 this->CloseAudio = ESD_CloseAudio; 173 174 this->free = Audio_DeleteDevice; 175 176 return this; 177 } 178 179 AudioBootStrap ESD_bootstrap = { 180 ESD_DRIVER_NAME, "Enlightened Sound Daemon", 181 Audio_Available, Audio_CreateDevice 182 }; 183 184 /* This function waits until it is possible to write a full sound buffer */ 185 static void ESD_WaitAudio(_THIS) 186 { 187 Sint32 ticks; 188 189 /* Check to see if the thread-parent process is still alive */ 190 { static int cnt = 0; 191 /* Note that this only works with thread implementations 192 that use a different process id for each thread. 193 */ 194 if (parent && (((++cnt)%10) == 0)) { /* Check every 10 loops */ 195 if ( kill(parent, 0) < 0 ) { 196 this->enabled = 0; 197 } 198 } 199 } 200 201 /* Use timer for general audio synchronization */ 202 ticks = ((Sint32)(next_frame - SDL_GetTicks()))-FUDGE_TICKS; 203 if ( ticks > 0 ) { 204 SDL_Delay(ticks); 205 } 206 } 207 208 static void ESD_PlayAudio(_THIS) 209 { 210 int written; 211 212 /* Write the audio data, checking for EAGAIN on broken audio drivers */ 213 do { 214 written = write(audio_fd, mixbuf, mixlen); 215 if ( (written < 0) && ((errno == 0) || (errno == EAGAIN)) ) { 216 SDL_Delay(1); /* Let a little CPU time go by */ 217 } 218 } while ( (written < 0) && 219 ((errno == 0) || (errno == EAGAIN) || (errno == EINTR)) ); 220 221 /* Set the next write frame */ 222 next_frame += frame_ticks; 223 224 /* If we couldn't write, assume fatal error for now */ 225 if ( written < 0 ) { 226 this->enabled = 0; 227 } 228 } 229 230 static Uint8 *ESD_GetAudioBuf(_THIS) 231 { 232 return(mixbuf); 233 } 234 235 static void ESD_CloseAudio(_THIS) 236 { 237 if ( mixbuf != NULL ) { 238 SDL_FreeAudioMem(mixbuf); 239 mixbuf = NULL; 240 } 241 if ( audio_fd >= 0 ) { 242 SDL_NAME(esd_close)(audio_fd); 243 audio_fd = -1; 244 } 245 } 246 247 /* Try to get the name of the program */ 248 static char *get_progname(void) 249 { 250 char *progname = NULL; 251 #ifdef __LINUX__ 252 FILE *fp; 253 static char temp[BUFSIZ]; 254 255 SDL_snprintf(temp, SDL_arraysize(temp), "/proc/%d/cmdline", getpid()); 256 fp = fopen(temp, "r"); 257 if ( fp != NULL ) { 258 if ( fgets(temp, sizeof(temp)-1, fp) ) { 259 progname = SDL_strrchr(temp, '/'); 260 if ( progname == NULL ) { 261 progname = temp; 262 } else { 263 progname = progname+1; 264 } 265 } 266 fclose(fp); 267 } 268 #endif 269 return(progname); 270 } 271 272 static int ESD_OpenAudio(_THIS, SDL_AudioSpec *spec) 273 { 274 esd_format_t format; 275 276 /* Convert audio spec to the ESD audio format */ 277 format = (ESD_STREAM | ESD_PLAY); 278 switch ( spec->format & 0xFF ) { 279 case 8: 280 format |= ESD_BITS8; 281 break; 282 case 16: 283 format |= ESD_BITS16; 284 break; 285 default: 286 SDL_SetError("Unsupported ESD audio format"); 287 return(-1); 288 } 289 if ( spec->channels == 1 ) { 290 format |= ESD_MONO; 291 } else { 292 format |= ESD_STEREO; 293 } 294 #if 0 295 spec->samples = ESD_BUF_SIZE; /* Darn, no way to change this yet */ 296 #endif 297 298 /* Open a connection to the ESD audio server */ 299 audio_fd = SDL_NAME(esd_play_stream)(format, spec->freq, NULL, get_progname()); 300 if ( audio_fd < 0 ) { 301 SDL_SetError("Couldn't open ESD connection"); 302 return(-1); 303 } 304 305 /* Calculate the final parameters for this audio specification */ 306 SDL_CalculateAudioSpec(spec); 307 frame_ticks = (float)(spec->samples*1000)/spec->freq; 308 next_frame = SDL_GetTicks()+frame_ticks; 309 310 /* Allocate mixing buffer */ 311 mixlen = spec->size; 312 mixbuf = (Uint8 *)SDL_AllocAudioMem(mixlen); 313 if ( mixbuf == NULL ) { 314 return(-1); 315 } 316 SDL_memset(mixbuf, spec->silence, spec->size); 317 318 /* Get the parent process id (we're the parent of the audio thread) */ 319 parent = getpid(); 320 321 /* We're ready to rock and roll. :-) */ 322 return(0); 323 } 324
