/
SDL_esdaudio.c
327 lines (276 loc) · 7.39 KB
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
11
12
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13
Lesser General Public License for more details.
14
15
16
17
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18
19
Sam Lantinga
20
slouken@libsdl.org
21
22
23
24
25
26
27
28
29
30
*/
/* Allow access to an ESD network stream mixing buffer */
#ifdef ESD_SUPPORT
#include <errno.h>
#include <esd.h>
31
32
#include "SDL_stdlib.h"
#include "SDL_string.h"
33
34
35
36
37
38
39
40
#include "SDL_audio.h"
#include "SDL_error.h"
#include "SDL_audiomem.h"
#include "SDL_audio_c.h"
#include "SDL_timer.h"
#include "SDL_audiodev_c.h"
#include "SDL_esdaudio.h"
41
42
43
44
45
46
47
#ifdef ESD_DYNAMIC
#include "SDL_name.h"
#include "SDL_loadso.h"
#else
#define SDL_NAME(X) X
#endif
48
49
50
51
52
53
54
55
56
57
/* The tag name used by ESD audio */
#define ESD_DRIVER_NAME "esd"
/* Audio driver functions */
static int ESD_OpenAudio(_THIS, SDL_AudioSpec *spec);
static void ESD_WaitAudio(_THIS);
static void ESD_PlayAudio(_THIS);
static Uint8 *ESD_GetAudioBuf(_THIS);
static void ESD_CloseAudio(_THIS);
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
#ifdef ESD_DYNAMIC
static const char *esd_library = ESD_DYNAMIC;
static void *esd_handle = NULL;
static int esd_loaded = 0;
static int (*SDL_NAME(esd_open_sound))( const char *host );
static int (*SDL_NAME(esd_close))( int esd );
static int (*SDL_NAME(esd_play_stream))( esd_format_t format, int rate,
const char *host, const char *name );
static struct {
const char *name;
void **func;
} esd_functions[] = {
{ "esd_open_sound", (void **)&SDL_NAME(esd_open_sound) },
{ "esd_close", (void **)&SDL_NAME(esd_close) },
{ "esd_play_stream", (void **)&SDL_NAME(esd_play_stream) },
};
static void UnloadESDLibrary()
{
if ( esd_loaded ) {
SDL_UnloadObject(esd_handle);
esd_handle = NULL;
esd_loaded = 0;
}
}
static int LoadESDLibrary(void)
{
int i, retval = -1;
esd_handle = SDL_LoadObject(esd_library);
if ( esd_handle ) {
esd_loaded = 1;
retval = 0;
for ( i=0; i<SDL_TABLESIZE(esd_functions); ++i ) {
*esd_functions[i].func = SDL_LoadFunction(esd_handle, esd_functions[i].name);
96
if ( !*esd_functions[i].func ) {
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
retval = -1;
UnloadESDLibrary();
break;
}
}
}
return retval;
}
#else
static void UnloadESDLibrary()
{
return;
}
static int LoadESDLibrary(void)
{
return 0;
}
#endif /* ESD_DYNAMIC */
120
121
122
123
124
125
126
127
/* Audio driver bootstrap functions */
static int Audio_Available(void)
{
int connection;
int available;
available = 0;
128
129
130
131
if ( LoadESDLibrary() < 0 ) {
return available;
}
connection = SDL_NAME(esd_open_sound)(NULL);
132
133
if ( connection >= 0 ) {
available = 1;
134
SDL_NAME(esd_close)(connection);
135
}
136
UnloadESDLibrary();
137
138
139
140
141
return(available);
}
static void Audio_DeleteDevice(SDL_AudioDevice *device)
{
142
143
SDL_free(device->hidden);
SDL_free(device);
144
UnloadESDLibrary();
145
146
147
148
149
150
151
}
static SDL_AudioDevice *Audio_CreateDevice(int devindex)
{
SDL_AudioDevice *this;
/* Initialize all variables that we clean on shutdown */
152
LoadESDLibrary();
153
this = (SDL_AudioDevice *)SDL_malloc(sizeof(SDL_AudioDevice));
154
if ( this ) {
155
SDL_memset(this, 0, (sizeof *this));
156
this->hidden = (struct SDL_PrivateAudioData *)
157
SDL_malloc((sizeof *this->hidden));
158
159
160
161
}
if ( (this == NULL) || (this->hidden == NULL) ) {
SDL_OutOfMemory();
if ( this ) {
162
SDL_free(this);
163
164
165
}
return(0);
}
166
SDL_memset(this->hidden, 0, (sizeof *this->hidden));
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
audio_fd = -1;
/* Set the function pointers */
this->OpenAudio = ESD_OpenAudio;
this->WaitAudio = ESD_WaitAudio;
this->PlayAudio = ESD_PlayAudio;
this->GetAudioBuf = ESD_GetAudioBuf;
this->CloseAudio = ESD_CloseAudio;
this->free = Audio_DeleteDevice;
return this;
}
AudioBootStrap ESD_bootstrap = {
ESD_DRIVER_NAME, "Enlightened Sound Daemon",
Audio_Available, Audio_CreateDevice
};
/* This function waits until it is possible to write a full sound buffer */
static void ESD_WaitAudio(_THIS)
{
Sint32 ticks;
/* Check to see if the thread-parent process is still alive */
{ static int cnt = 0;
/* Note that this only works with thread implementations
that use a different process id for each thread.
*/
if (parent && (((++cnt)%10) == 0)) { /* Check every 10 loops */
if ( kill(parent, 0) < 0 ) {
this->enabled = 0;
}
}
}
/* Use timer for general audio synchronization */
ticks = ((Sint32)(next_frame - SDL_GetTicks()))-FUDGE_TICKS;
if ( ticks > 0 ) {
SDL_Delay(ticks);
}
}
static void ESD_PlayAudio(_THIS)
{
int written;
/* Write the audio data, checking for EAGAIN on broken audio drivers */
do {
written = write(audio_fd, mixbuf, mixlen);
if ( (written < 0) && ((errno == 0) || (errno == EAGAIN)) ) {
SDL_Delay(1); /* Let a little CPU time go by */
}
} while ( (written < 0) &&
((errno == 0) || (errno == EAGAIN) || (errno == EINTR)) );
/* Set the next write frame */
next_frame += frame_ticks;
/* If we couldn't write, assume fatal error for now */
if ( written < 0 ) {
this->enabled = 0;
}
}
static Uint8 *ESD_GetAudioBuf(_THIS)
{
return(mixbuf);
}
static void ESD_CloseAudio(_THIS)
{
if ( mixbuf != NULL ) {
SDL_FreeAudioMem(mixbuf);
mixbuf = NULL;
}
if ( audio_fd >= 0 ) {
244
SDL_NAME(esd_close)(audio_fd);
245
246
247
248
249
250
251
252
253
254
255
256
audio_fd = -1;
}
}
/* Try to get the name of the program */
static char *get_progname(void)
{
char *progname = NULL;
#ifdef linux
FILE *fp;
static char temp[BUFSIZ];
257
SDL_snprintf(temp, SDL_arraysize(temp), "/proc/%d/cmdline", getpid());
258
259
260
fp = fopen(temp, "r");
if ( fp != NULL ) {
if ( fgets(temp, sizeof(temp)-1, fp) ) {
261
progname = SDL_strrchr(temp, '/');
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
if ( progname == NULL ) {
progname = temp;
} else {
progname = progname+1;
}
}
fclose(fp);
}
#endif
return(progname);
}
static int ESD_OpenAudio(_THIS, SDL_AudioSpec *spec)
{
esd_format_t format;
/* Convert audio spec to the ESD audio format */
format = (ESD_STREAM | ESD_PLAY);
switch ( spec->format & 0xFF ) {
case 8:
format |= ESD_BITS8;
break;
case 16:
format |= ESD_BITS16;
break;
default:
SDL_SetError("Unsupported ESD audio format");
return(-1);
}
if ( spec->channels == 1 ) {
format |= ESD_MONO;
} else {
format |= ESD_STEREO;
}
#if 0
spec->samples = ESD_BUF_SIZE; /* Darn, no way to change this yet */
#endif
/* Open a connection to the ESD audio server */
301
audio_fd = SDL_NAME(esd_play_stream)(format, spec->freq, NULL, get_progname());
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
if ( audio_fd < 0 ) {
SDL_SetError("Couldn't open ESD connection");
return(-1);
}
/* Calculate the final parameters for this audio specification */
SDL_CalculateAudioSpec(spec);
frame_ticks = (float)(spec->samples*1000)/spec->freq;
next_frame = SDL_GetTicks()+frame_ticks;
/* Allocate mixing buffer */
mixlen = spec->size;
mixbuf = (Uint8 *)SDL_AllocAudioMem(mixlen);
if ( mixbuf == NULL ) {
return(-1);
}
318
SDL_memset(mixbuf, spec->silence, spec->size);
319
320
321
322
323
324
325
326
327
/* Get the parent process id (we're the parent of the audio thread) */
parent = getpid();
/* We're ready to rock and roll. :-) */
return(0);
}
#endif /* ESD_SUPPORT */