| 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 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 | } |