SDL  2.0
SDL_esdaudio.c
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1 /*
2  Simple DirectMedia Layer
3  Copyright (C) 1997-2016 Sam Lantinga <slouken@libsdl.org>
4 
5  This software is provided 'as-is', without any express or implied
6  warranty. In no event will the authors be held liable for any damages
7  arising from the use of this software.
8 
9  Permission is granted to anyone to use this software for any purpose,
10  including commercial applications, and to alter it and redistribute it
11  freely, subject to the following restrictions:
12 
13  1. The origin of this software must not be misrepresented; you must not
14  claim that you wrote the original software. If you use this software
15  in a product, an acknowledgment in the product documentation would be
16  appreciated but is not required.
17  2. Altered source versions must be plainly marked as such, and must not be
18  misrepresented as being the original software.
19  3. This notice may not be removed or altered from any source distribution.
20 */
21 #include "../../SDL_internal.h"
22 
23 #if SDL_AUDIO_DRIVER_ESD
24 
25 /* Allow access to an ESD network stream mixing buffer */
26 
27 #include <sys/types.h>
28 #include <unistd.h>
29 #include <signal.h>
30 #include <errno.h>
31 #include <esd.h>
32 
33 #include "SDL_timer.h"
34 #include "SDL_audio.h"
35 #include "../SDL_audiomem.h"
36 #include "../SDL_audio_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 #ifdef SDL_AUDIO_DRIVER_ESD_DYNAMIC
47 
48 static const char *esd_library = SDL_AUDIO_DRIVER_ESD_DYNAMIC;
49 static void *esd_handle = NULL;
50 
51 static int (*SDL_NAME(esd_open_sound)) (const char *host);
52 static int (*SDL_NAME(esd_close)) (int esd);
53 static int (*SDL_NAME(esd_play_stream)) (esd_format_t format, int rate,
54  const char *host, const char *name);
55 
56 #define SDL_ESD_SYM(x) { #x, (void **) (char *) &SDL_NAME(x) }
57 static struct
58 {
59  const char *name;
60  void **func;
61 } const esd_functions[] = {
62  SDL_ESD_SYM(esd_open_sound),
63  SDL_ESD_SYM(esd_close), SDL_ESD_SYM(esd_play_stream),
64 };
65 
66 #undef SDL_ESD_SYM
67 
68 static void
69 UnloadESDLibrary()
70 {
71  if (esd_handle != NULL) {
72  SDL_UnloadObject(esd_handle);
73  esd_handle = NULL;
74  }
75 }
76 
77 static int
78 LoadESDLibrary(void)
79 {
80  int i, retval = -1;
81 
82  if (esd_handle == NULL) {
83  esd_handle = SDL_LoadObject(esd_library);
84  if (esd_handle) {
85  retval = 0;
86  for (i = 0; i < SDL_arraysize(esd_functions); ++i) {
87  *esd_functions[i].func =
88  SDL_LoadFunction(esd_handle, esd_functions[i].name);
89  if (!*esd_functions[i].func) {
90  retval = -1;
91  UnloadESDLibrary();
92  break;
93  }
94  }
95  }
96  }
97  return retval;
98 }
99 
100 #else
101 
102 static void
103 UnloadESDLibrary()
104 {
105  return;
106 }
107 
108 static int
109 LoadESDLibrary(void)
110 {
111  return 0;
112 }
113 
114 #endif /* SDL_AUDIO_DRIVER_ESD_DYNAMIC */
115 
116 
117 /* This function waits until it is possible to write a full sound buffer */
118 static void
119 ESD_WaitDevice(_THIS)
120 {
121  Sint32 ticks;
122 
123  /* Check to see if the thread-parent process is still alive */
124  {
125  static int cnt = 0;
126  /* Note that this only works with thread implementations
127  that use a different process id for each thread.
128  */
129  /* Check every 10 loops */
130  if (this->hidden->parent && (((++cnt) % 10) == 0)) {
131  if (kill(this->hidden->parent, 0) < 0 && errno == ESRCH) {
133  }
134  }
135  }
136 
137  /* Use timer for general audio synchronization */
138  ticks = ((Sint32) (this->hidden->next_frame - SDL_GetTicks())) - FUDGE_TICKS;
139  if (ticks > 0) {
140  SDL_Delay(ticks);
141  }
142 }
143 
144 static void
145 ESD_PlayDevice(_THIS)
146 {
147  int written = 0;
148 
149  /* Write the audio data, checking for EAGAIN on broken audio drivers */
150  do {
151  written = write(this->hidden->audio_fd,
152  this->hidden->mixbuf, this->hidden->mixlen);
153  if ((written < 0) && ((errno == 0) || (errno == EAGAIN))) {
154  SDL_Delay(1); /* Let a little CPU time go by */
155  }
156  } while ((written < 0) &&
157  ((errno == 0) || (errno == EAGAIN) || (errno == EINTR)));
158 
159  /* Set the next write frame */
160  this->hidden->next_frame += this->hidden->frame_ticks;
161 
162  /* If we couldn't write, assume fatal error for now */
163  if (written < 0) {
165  }
166 }
167 
168 static Uint8 *
169 ESD_GetDeviceBuf(_THIS)
170 {
171  return (this->hidden->mixbuf);
172 }
173 
174 static void
175 ESD_CloseDevice(_THIS)
176 {
177  if (this->hidden != NULL) {
178  SDL_FreeAudioMem(this->hidden->mixbuf);
179  this->hidden->mixbuf = NULL;
180  if (this->hidden->audio_fd >= 0) {
181  SDL_NAME(esd_close) (this->hidden->audio_fd);
182  this->hidden->audio_fd = -1;
183  }
184 
185  SDL_free(this->hidden);
186  this->hidden = NULL;
187  }
188 }
189 
190 /* Try to get the name of the program */
191 static char *
192 get_progname(void)
193 {
194  char *progname = NULL;
195 #ifdef __LINUX__
196  FILE *fp;
197  static char temp[BUFSIZ];
198 
199  SDL_snprintf(temp, SDL_arraysize(temp), "/proc/%d/cmdline", getpid());
200  fp = fopen(temp, "r");
201  if (fp != NULL) {
202  if (fgets(temp, sizeof(temp) - 1, fp)) {
203  progname = SDL_strrchr(temp, '/');
204  if (progname == NULL) {
205  progname = temp;
206  } else {
207  progname = progname + 1;
208  }
209  }
210  fclose(fp);
211  }
212 #endif
213  return (progname);
214 }
215 
216 
217 static int
218 ESD_OpenDevice(_THIS, void *handle, const char *devname, int iscapture)
219 {
220  esd_format_t format = (ESD_STREAM | ESD_PLAY);
221  SDL_AudioFormat test_format = 0;
222  int found = 0;
223 
224  /* Initialize all variables that we clean on shutdown */
225  this->hidden = (struct SDL_PrivateAudioData *)
226  SDL_malloc((sizeof *this->hidden));
227  if (this->hidden == NULL) {
228  return SDL_OutOfMemory();
229  }
230  SDL_memset(this->hidden, 0, (sizeof *this->hidden));
231  this->hidden->audio_fd = -1;
232 
233  /* Convert audio spec to the ESD audio format */
234  /* Try for a closest match on audio format */
235  for (test_format = SDL_FirstAudioFormat(this->spec.format);
236  !found && test_format; test_format = SDL_NextAudioFormat()) {
237 #ifdef DEBUG_AUDIO
238  fprintf(stderr, "Trying format 0x%4.4x\n", test_format);
239 #endif
240  found = 1;
241  switch (test_format) {
242  case AUDIO_U8:
243  format |= ESD_BITS8;
244  break;
245  case AUDIO_S16SYS:
246  format |= ESD_BITS16;
247  break;
248  default:
249  found = 0;
250  break;
251  }
252  }
253 
254  if (!found) {
255  ESD_CloseDevice(this);
256  return SDL_SetError("Couldn't find any hardware audio formats");
257  }
258 
259  if (this->spec.channels == 1) {
260  format |= ESD_MONO;
261  } else {
262  format |= ESD_STEREO;
263  }
264 #if 0
265  this->spec.samples = ESD_BUF_SIZE; /* Darn, no way to change this yet */
266 #endif
267 
268  /* Open a connection to the ESD audio server */
269  this->hidden->audio_fd =
270  SDL_NAME(esd_play_stream) (format, this->spec.freq, NULL,
271  get_progname());
272 
273  if (this->hidden->audio_fd < 0) {
274  ESD_CloseDevice(this);
275  return SDL_SetError("Couldn't open ESD connection");
276  }
277 
278  /* Calculate the final parameters for this audio specification */
280  this->hidden->frame_ticks =
281  (float) (this->spec.samples * 1000) / this->spec.freq;
282  this->hidden->next_frame = SDL_GetTicks() + this->hidden->frame_ticks;
283 
284  /* Allocate mixing buffer */
285  this->hidden->mixlen = this->spec.size;
286  this->hidden->mixbuf = (Uint8 *) SDL_AllocAudioMem(this->hidden->mixlen);
287  if (this->hidden->mixbuf == NULL) {
288  ESD_CloseDevice(this);
289  return SDL_OutOfMemory();
290  }
291  SDL_memset(this->hidden->mixbuf, this->spec.silence, this->spec.size);
292 
293  /* Get the parent process id (we're the parent of the audio thread) */
294  this->hidden->parent = getpid();
295 
296  /* We're ready to rock and roll. :-) */
297  return 0;
298 }
299 
300 static void
301 ESD_Deinitialize(void)
302 {
303  UnloadESDLibrary();
304 }
305 
306 static int
307 ESD_Init(SDL_AudioDriverImpl * impl)
308 {
309  if (LoadESDLibrary() < 0) {
310  return 0;
311  } else {
312  int connection = 0;
313 
314  /* Don't start ESD if it's not running */
315  SDL_setenv("ESD_NO_SPAWN", "1", 0);
316 
317  connection = SDL_NAME(esd_open_sound) (NULL);
318  if (connection < 0) {
319  UnloadESDLibrary();
320  SDL_SetError("ESD: esd_open_sound failed (no audio server?)");
321  return 0;
322  }
323  SDL_NAME(esd_close) (connection);
324  }
325 
326  /* Set the function pointers */
327  impl->OpenDevice = ESD_OpenDevice;
328  impl->PlayDevice = ESD_PlayDevice;
329  impl->WaitDevice = ESD_WaitDevice;
330  impl->GetDeviceBuf = ESD_GetDeviceBuf;
331  impl->CloseDevice = ESD_CloseDevice;
332  impl->Deinitialize = ESD_Deinitialize;
333  impl->OnlyHasDefaultOutputDevice = 1;
334 
335  return 1; /* this audio target is available. */
336 }
337 
338 
340  "esd", "Enlightened Sound Daemon", ESD_Init, 0
341 };
342 
343 #endif /* SDL_AUDIO_DRIVER_ESD */
344 
345 /* vi: set ts=4 sw=4 expandtab: */
SDL_AudioFormat SDL_FirstAudioFormat(SDL_AudioFormat format)
Definition: SDL_audio.c:1398
static int ticks
Definition: testtimer.c:24
#define SDL_FreeAudioMem
Definition: SDL_audiomem.h:24
void(* PlayDevice)(_THIS)
Definition: SDL_sysaudio.h:75
Uint16 samples
Definition: SDL_audio.h:174
void(* WaitDevice)(_THIS)
Definition: SDL_sysaudio.h:74
void SDL_OpenedAudioDeviceDisconnected(SDL_AudioDevice *device)
Definition: SDL_audio.c:364
Uint16 SDL_AudioFormat
Audio format flags.
Definition: SDL_audio.h:64
GLuint const GLchar * name
#define SDL_LoadObject
#define AUDIO_S16SYS
Definition: SDL_audio.h:123
#define SDL_UnloadObject
SDL_AudioFormat SDL_NextAudioFormat(void)
Definition: SDL_audio.c:1410
#define SDL_setenv
SDL_AudioSpec spec
Definition: loopwave.c:35
SDL_bool retval
#define AUDIO_U8
Definition: SDL_audio.h:89
Uint32 SDL_GetTicks(void)
Get the number of milliseconds since the SDL library initialization.
Uint8 channels
Definition: SDL_audio.h:172
#define _THIS
uint8_t Uint8
An unsigned 8-bit integer type.
Definition: SDL_stdinc.h:139
void SDL_free(void *mem)
void(* Deinitialize)(void)
Definition: SDL_sysaudio.h:83
void SDL_CalculateAudioSpec(SDL_AudioSpec *spec)
Definition: SDL_audio.c:1419
#define SDL_AllocAudioMem
Definition: SDL_audiomem.h:23
int32_t Sint32
A signed 32-bit integer type.
Definition: SDL_stdinc.h:151
#define FUDGE_TICKS
Definition: SDL_artsaudio.h:49
#define SDL_Delay
Uint32 size
Definition: SDL_audio.h:176
return Display return Display Bool Bool int int int return Display XEvent Bool(*) XPointer return Display return Display Drawable _Xconst char unsigned int unsigned int return Display Pixmap Pixmap XColor XColor unsigned int unsigned int return Display _Xconst char char int char return Display Visual unsigned int int int char unsigned int unsigned int in i)
Definition: SDL_x11sym.h:42
int(* OpenDevice)(_THIS, void *handle, const char *devname, int iscapture)
Definition: SDL_sysaudio.h:72
#define NULL
Definition: begin_code.h:143
#define SDL_OutOfMemory()
Definition: SDL_error.h:52
#define SDL_NAME(X)
Definition: SDL_name.h:29
#define SDL_SetError
void(* CloseDevice)(_THIS)
Definition: SDL_sysaudio.h:79
GLenum func
GLint GLint GLsizei GLsizei GLsizei GLint GLenum format
Definition: SDL_opengl.h:1565
SDL_AudioFormat format
Definition: SDL_audio.h:171
Uint8 *(* GetDeviceBuf)(_THIS)
Definition: SDL_sysaudio.h:77
#define SDL_snprintf
#define SDL_arraysize(array)
Definition: SDL_stdinc.h:93
#define SDL_malloc
AudioBootStrap ESD_bootstrap
void * SDL_LoadFunction(void *handle, const char *name)
#define SDL_strrchr
#define SDL_memset