1 /*
2 SDL - Simple DirectMedia Layer
3 Copyright (C) 1997-2006 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
UnloadESDLibrary()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
LoadESDLibrary(void)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
UnloadESDLibrary()106 static void UnloadESDLibrary()
107 {
108 return;
109 }
110
LoadESDLibrary(void)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
Audio_Available(void)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
Audio_DeleteDevice(SDL_AudioDevice * device)138 static void Audio_DeleteDevice(SDL_AudioDevice *device)
139 {
140 SDL_free(device->hidden);
141 SDL_free(device);
142 UnloadESDLibrary();
143 }
144
Audio_CreateDevice(int devindex)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 */
ESD_WaitAudio(_THIS)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
ESD_PlayAudio(_THIS)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
ESD_GetAudioBuf(_THIS)230 static Uint8 *ESD_GetAudioBuf(_THIS)
231 {
232 return(mixbuf);
233 }
234
ESD_CloseAudio(_THIS)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 */
get_progname(void)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
ESD_OpenAudio(_THIS,SDL_AudioSpec * spec)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