Mercurial > sdl-ios-xcode

comparison src/audio/sun/SDL_sunaudio.c @ 1662:782fd950bd46 SDL-1.3

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Revamp of the video system in progress - adding support for multiple displays, multiple windows, and a full video mode selection API. WARNING: None of the video drivers have been updated for the new API yet! The API is still under design and very fluid. The code is now run through a consistent indent format: indent -i4 -nut -nsc -br -ce The headers are being converted to automatically generate doxygen documentation.
author Sam Lantinga <slouken@libsdl.org>
date Sun, 28 May 2006 13:04:16 +0000
parents af30090c0330
children 4da1ee79c9af
comparison
equal deleted inserted replaced
1661:281d3f4870e5 1662:782fd950bd46
46 46
47 /* Open the audio device for playback, and don't block if busy */ 47 /* Open the audio device for playback, and don't block if busy */
48 #define OPEN_FLAGS (O_WRONLY|O_NONBLOCK) 48 #define OPEN_FLAGS (O_WRONLY|O_NONBLOCK)
49 49
50 /* Audio driver functions */ 50 /* Audio driver functions */
51 static int DSP_OpenAudio(_THIS, SDL_AudioSpec *spec); 51 static int DSP_OpenAudio (_THIS, SDL_AudioSpec * spec);
52 static void DSP_WaitAudio(_THIS); 52 static void DSP_WaitAudio (_THIS);
53 static void DSP_PlayAudio(_THIS); 53 static void DSP_PlayAudio (_THIS);
54 static Uint8 *DSP_GetAudioBuf(_THIS); 54 static Uint8 *DSP_GetAudioBuf (_THIS);
55 static void DSP_CloseAudio(_THIS); 55 static void DSP_CloseAudio (_THIS);
56 56
57 static Uint8 snd2au(int sample); 57 static Uint8 snd2au (int sample);
58 58
59 /* Audio driver bootstrap functions */ 59 /* Audio driver bootstrap functions */
60 60
61 static int Audio_Available(void) 61 static int
62 { 62 Audio_Available (void)
63 int fd; 63 {
64 int available; 64 int fd;
65 65 int available;
66 available = 0; 66
67 fd = SDL_OpenAudioPath(NULL, 0, OPEN_FLAGS, 1); 67 available = 0;
68 if ( fd >= 0 ) { 68 fd = SDL_OpenAudioPath (NULL, 0, OPEN_FLAGS, 1);
69 available = 1; 69 if (fd >= 0) {
70 close(fd); 70 available = 1;
71 } 71 close (fd);
72 return(available); 72 }
73 } 73 return (available);
74 74 }
75 static void Audio_DeleteDevice(SDL_AudioDevice *device) 75
76 { 76 static void
77 SDL_free(device->hidden); 77 Audio_DeleteDevice (SDL_AudioDevice * device)
78 SDL_free(device); 78 {
79 } 79 SDL_free (device->hidden);
80 80 SDL_free (device);
81 static SDL_AudioDevice *Audio_CreateDevice(int devindex) 81 }
82 { 82
83 SDL_AudioDevice *this; 83 static SDL_AudioDevice *
84 84 Audio_CreateDevice (int devindex)
85 /* Initialize all variables that we clean on shutdown */ 85 {
86 this = (SDL_AudioDevice *)SDL_malloc(sizeof(SDL_AudioDevice)); 86 SDL_AudioDevice *this;
87 if ( this ) { 87
88 SDL_memset(this, 0, (sizeof *this)); 88 /* Initialize all variables that we clean on shutdown */
89 this->hidden = (struct SDL_PrivateAudioData *) 89 this = (SDL_AudioDevice *) SDL_malloc (sizeof (SDL_AudioDevice));
90 SDL_malloc((sizeof *this->hidden)); 90 if (this) {
91 } 91 SDL_memset (this, 0, (sizeof *this));
92 if ( (this == NULL) || (this->hidden == NULL) ) { 92 this->hidden = (struct SDL_PrivateAudioData *)
93 SDL_OutOfMemory(); 93 SDL_malloc ((sizeof *this->hidden));
94 if ( this ) { 94 }
95 SDL_free(this); 95 if ((this == NULL) || (this->hidden == NULL)) {
96 } 96 SDL_OutOfMemory ();
97 return(0); 97 if (this) {
98 } 98 SDL_free (this);
99 SDL_memset(this->hidden, 0, (sizeof *this->hidden)); 99 }
100 audio_fd = -1; 100 return (0);
101 101 }
102 /* Set the function pointers */ 102 SDL_memset (this->hidden, 0, (sizeof *this->hidden));
103 this->OpenAudio = DSP_OpenAudio; 103 audio_fd = -1;
104 this->WaitAudio = DSP_WaitAudio; 104
105 this->PlayAudio = DSP_PlayAudio; 105 /* Set the function pointers */
106 this->GetAudioBuf = DSP_GetAudioBuf; 106 this->OpenAudio = DSP_OpenAudio;
107 this->CloseAudio = DSP_CloseAudio; 107 this->WaitAudio = DSP_WaitAudio;
108 108 this->PlayAudio = DSP_PlayAudio;
109 this->free = Audio_DeleteDevice; 109 this->GetAudioBuf = DSP_GetAudioBuf;
110 110 this->CloseAudio = DSP_CloseAudio;
111 return this; 111
112 this->free = Audio_DeleteDevice;
113
114 return this;
112 } 115 }
113 116
114 AudioBootStrap SUNAUDIO_bootstrap = { 117 AudioBootStrap SUNAUDIO_bootstrap = {
115 "audio", "UNIX /dev/audio interface", 118 "audio", "UNIX /dev/audio interface",
116 Audio_Available, Audio_CreateDevice 119 Audio_Available, Audio_CreateDevice
117 }; 120 };
118 121
119 #ifdef DEBUG_AUDIO 122 #ifdef DEBUG_AUDIO
120 void CheckUnderflow(_THIS) 123 void
124 CheckUnderflow (_THIS)
121 { 125 {
122 #ifdef AUDIO_GETINFO 126 #ifdef AUDIO_GETINFO
123 audio_info_t info; 127 audio_info_t info;
124 int left; 128 int left;
125 129
126 ioctl(audio_fd, AUDIO_GETINFO, &info); 130 ioctl (audio_fd, AUDIO_GETINFO, &info);
127 left = (written - info.play.samples); 131 left = (written - info.play.samples);
128 if ( written && (left == 0) ) { 132 if (written && (left == 0)) {
129 fprintf(stderr, "audio underflow!\n"); 133 fprintf (stderr, "audio underflow!\n");
130 } 134 }
131 #endif 135 #endif
132 } 136 }
133 #endif 137 #endif
134 138
135 void DSP_WaitAudio(_THIS) 139 void
140 DSP_WaitAudio (_THIS)
136 { 141 {
137 #ifdef AUDIO_GETINFO 142 #ifdef AUDIO_GETINFO
138 #define SLEEP_FUDGE 10 /* 10 ms scheduling fudge factor */ 143 #define SLEEP_FUDGE 10 /* 10 ms scheduling fudge factor */
139 audio_info_t info; 144 audio_info_t info;
140 Sint32 left; 145 Sint32 left;
141 146
142 ioctl(audio_fd, AUDIO_GETINFO, &info); 147 ioctl (audio_fd, AUDIO_GETINFO, &info);
143 left = (written - info.play.samples); 148 left = (written - info.play.samples);
144 if ( left > fragsize ) { 149 if (left > fragsize) {
145 Sint32 sleepy; 150 Sint32 sleepy;
146 151
147 sleepy = ((left - fragsize)/frequency); 152 sleepy = ((left - fragsize) / frequency);
148 sleepy -= SLEEP_FUDGE; 153 sleepy -= SLEEP_FUDGE;
149 if ( sleepy > 0 ) { 154 if (sleepy > 0) {
150 SDL_Delay(sleepy); 155 SDL_Delay (sleepy);
151 } 156 }
152 } 157 }
153 #else 158 #else
154 fd_set fdset; 159 fd_set fdset;
155 160
156 FD_ZERO(&fdset); 161 FD_ZERO (&fdset);
157 FD_SET(audio_fd, &fdset); 162 FD_SET (audio_fd, &fdset);
158 select(audio_fd+1, NULL, &fdset, NULL, NULL); 163 select (audio_fd + 1, NULL, &fdset, NULL, NULL);
159 #endif 164 #endif
160 } 165 }
161 166
162 void DSP_PlayAudio(_THIS) 167 void
163 { 168 DSP_PlayAudio (_THIS)
164 /* Write the audio data */ 169 {
165 if ( ulaw_only ) { 170 /* Write the audio data */
166 /* Assuming that this->spec.freq >= 8000 Hz */ 171 if (ulaw_only) {
167 int accum, incr, pos; 172 /* Assuming that this->spec.freq >= 8000 Hz */
168 Uint8 *aubuf; 173 int accum, incr, pos;
169 174 Uint8 *aubuf;
170 accum = 0; 175
171 incr = this->spec.freq/8; 176 accum = 0;
172 aubuf = ulaw_buf; 177 incr = this->spec.freq / 8;
173 switch (audio_fmt & 0xFF) { 178 aubuf = ulaw_buf;
174 case 8: { 179 switch (audio_fmt & 0xFF) {
175 Uint8 *sndbuf; 180 case 8:
176 181 {
177 sndbuf = mixbuf; 182 Uint8 *sndbuf;
178 for ( pos=0; pos < fragsize; ++pos ) { 183
179 *aubuf = snd2au((0x80-*sndbuf)*64); 184 sndbuf = mixbuf;
180 accum += incr; 185 for (pos = 0; pos < fragsize; ++pos) {
181 while ( accum > 0 ) { 186 *aubuf = snd2au ((0x80 - *sndbuf) * 64);
182 accum -= 1000; 187 accum += incr;
183 sndbuf += 1; 188 while (accum > 0) {
184 } 189 accum -= 1000;
185 aubuf += 1; 190 sndbuf += 1;
186 } 191 }
187 } 192 aubuf += 1;
188 break; 193 }
189 case 16: { 194 }
190 Sint16 *sndbuf; 195 break;
191 196 case 16:
192 sndbuf = (Sint16 *)mixbuf; 197 {
193 for ( pos=0; pos < fragsize; ++pos ) { 198 Sint16 *sndbuf;
194 *aubuf = snd2au(*sndbuf/4); 199
195 accum += incr; 200 sndbuf = (Sint16 *) mixbuf;
196 while ( accum > 0 ) { 201 for (pos = 0; pos < fragsize; ++pos) {
197 accum -= 1000; 202 *aubuf = snd2au (*sndbuf / 4);
198 sndbuf += 1; 203 accum += incr;
199 } 204 while (accum > 0) {
200 aubuf += 1; 205 accum -= 1000;
201 } 206 sndbuf += 1;
202 } 207 }
203 break; 208 aubuf += 1;
204 } 209 }
210 }
211 break;
212 }
205 #ifdef DEBUG_AUDIO 213 #ifdef DEBUG_AUDIO
206 CheckUnderflow(this); 214 CheckUnderflow (this);
207 #endif 215 #endif
208 if ( write(audio_fd, ulaw_buf, fragsize) < 0 ) { 216 if (write (audio_fd, ulaw_buf, fragsize) < 0) {
209 /* Assume fatal error, for now */ 217 /* Assume fatal error, for now */
210 this->enabled = 0; 218 this->enabled = 0;
211 } 219 }
212 written += fragsize; 220 written += fragsize;
213 } else { 221 } else {
214 #ifdef DEBUG_AUDIO 222 #ifdef DEBUG_AUDIO
215 CheckUnderflow(this); 223 CheckUnderflow (this);
216 #endif 224 #endif
217 if ( write(audio_fd, mixbuf, this->spec.size) < 0 ) { 225 if (write (audio_fd, mixbuf, this->spec.size) < 0) {
218 /* Assume fatal error, for now */ 226 /* Assume fatal error, for now */
219 this->enabled = 0; 227 this->enabled = 0;
220 } 228 }
221 written += fragsize; 229 written += fragsize;
222 } 230 }
223 } 231 }
224 232
225 Uint8 *DSP_GetAudioBuf(_THIS) 233 Uint8 *
226 { 234 DSP_GetAudioBuf (_THIS)
227 return(mixbuf); 235 {
228 } 236 return (mixbuf);
229 237 }
230 void DSP_CloseAudio(_THIS) 238
231 { 239 void
232 if ( mixbuf != NULL ) { 240 DSP_CloseAudio (_THIS)
233 SDL_FreeAudioMem(mixbuf); 241 {
234 mixbuf = NULL; 242 if (mixbuf != NULL) {
235 } 243 SDL_FreeAudioMem (mixbuf);
236 if ( ulaw_buf != NULL ) { 244 mixbuf = NULL;
237 SDL_free(ulaw_buf); 245 }
238 ulaw_buf = NULL; 246 if (ulaw_buf != NULL) {
239 } 247 SDL_free (ulaw_buf);
240 close(audio_fd); 248 ulaw_buf = NULL;
241 } 249 }
242 250 close (audio_fd);
243 int DSP_OpenAudio(_THIS, SDL_AudioSpec *spec) 251 }
244 { 252
245 char audiodev[1024]; 253 int
254 DSP_OpenAudio (_THIS, SDL_AudioSpec * spec)
255 {
256 char audiodev[1024];
246 #ifdef AUDIO_SETINFO 257 #ifdef AUDIO_SETINFO
247 int enc; 258 int enc;
248 #endif 259 #endif
249 int desired_freq = spec->freq; 260 int desired_freq = spec->freq;
250 261
251 /* Initialize our freeable variables, in case we fail*/ 262 /* Initialize our freeable variables, in case we fail */
252 audio_fd = -1; 263 audio_fd = -1;
253 mixbuf = NULL; 264 mixbuf = NULL;
254 ulaw_buf = NULL; 265 ulaw_buf = NULL;
255 266
256 /* Determine the audio parameters from the AudioSpec */ 267 /* Determine the audio parameters from the AudioSpec */
257 switch ( spec->format & 0xFF ) { 268 switch (spec->format & 0xFF) {
258 269
259 case 8: { /* Unsigned 8 bit audio data */ 270 case 8:
260 spec->format = AUDIO_U8; 271 { /* Unsigned 8 bit audio data */
272 spec->format = AUDIO_U8;
261 #ifdef AUDIO_SETINFO 273 #ifdef AUDIO_SETINFO
262 enc = AUDIO_ENCODING_LINEAR8; 274 enc = AUDIO_ENCODING_LINEAR8;
263 #endif 275 #endif
264 } 276 }
265 break; 277 break;
266 278
267 case 16: { /* Signed 16 bit audio data */ 279 case 16:
268 spec->format = AUDIO_S16SYS; 280 { /* Signed 16 bit audio data */
281 spec->format = AUDIO_S16SYS;
269 #ifdef AUDIO_SETINFO 282 #ifdef AUDIO_SETINFO
270 enc = AUDIO_ENCODING_LINEAR; 283 enc = AUDIO_ENCODING_LINEAR;
271 #endif 284 #endif
272 } 285 }
273 break; 286 break;
274 287
275 default: { 288 default:
276 SDL_SetError("Unsupported audio format"); 289 {
277 return(-1); 290 SDL_SetError ("Unsupported audio format");
278 } 291 return (-1);
279 } 292 }
280 audio_fmt = spec->format; 293 }
281 294 audio_fmt = spec->format;
282 /* Open the audio device */ 295
283 audio_fd = SDL_OpenAudioPath(audiodev, sizeof(audiodev), OPEN_FLAGS, 1); 296 /* Open the audio device */
284 if ( audio_fd < 0 ) { 297 audio_fd = SDL_OpenAudioPath (audiodev, sizeof (audiodev), OPEN_FLAGS, 1);
285 SDL_SetError("Couldn't open %s: %s", audiodev, 298 if (audio_fd < 0) {
286 strerror(errno)); 299 SDL_SetError ("Couldn't open %s: %s", audiodev, strerror (errno));
287 return(-1); 300 return (-1);
288 } 301 }
289 302
290 ulaw_only = 0; /* modern Suns do support linear audio */ 303 ulaw_only = 0; /* modern Suns do support linear audio */
291 #ifdef AUDIO_SETINFO 304 #ifdef AUDIO_SETINFO
292 for(;;) { 305 for (;;) {
293 audio_info_t info; 306 audio_info_t info;
294 AUDIO_INITINFO(&info); /* init all fields to "no change" */ 307 AUDIO_INITINFO (&info); /* init all fields to "no change" */
295 308
296 /* Try to set the requested settings */ 309 /* Try to set the requested settings */
297 info.play.sample_rate = spec->freq; 310 info.play.sample_rate = spec->freq;
298 info.play.channels = spec->channels; 311 info.play.channels = spec->channels;
299 info.play.precision = (enc == AUDIO_ENCODING_ULAW) 312 info.play.precision = (enc == AUDIO_ENCODING_ULAW)
300 ? 8 : spec->format & 0xff; 313 ? 8 : spec->format & 0xff;
301 info.play.encoding = enc; 314 info.play.encoding = enc;
302 if( ioctl(audio_fd, AUDIO_SETINFO, &info) == 0 ) { 315 if (ioctl (audio_fd, AUDIO_SETINFO, &info) == 0) {
303 316
304 /* Check to be sure we got what we wanted */ 317 /* Check to be sure we got what we wanted */
305 if(ioctl(audio_fd, AUDIO_GETINFO, &info) < 0) { 318 if (ioctl (audio_fd, AUDIO_GETINFO, &info) < 0) {
306 SDL_SetError("Error getting audio parameters: %s", 319 SDL_SetError ("Error getting audio parameters: %s",
307 strerror(errno)); 320 strerror (errno));
308 return -1; 321 return -1;
309 } 322 }
310 if(info.play.encoding == enc 323 if (info.play.encoding == enc
311 && info.play.precision == (spec->format & 0xff) 324 && info.play.precision == (spec->format & 0xff)
312 && info.play.channels == spec->channels) { 325 && info.play.channels == spec->channels) {
313 /* Yow! All seems to be well! */ 326 /* Yow! All seems to be well! */
314 spec->freq = info.play.sample_rate; 327 spec->freq = info.play.sample_rate;
315 break; 328 break;
316 } 329 }
317 } 330 }
318 331
319 switch(enc) { 332 switch (enc) {
320 case AUDIO_ENCODING_LINEAR8: 333 case AUDIO_ENCODING_LINEAR8:
321 /* unsigned 8bit apparently not supported here */ 334 /* unsigned 8bit apparently not supported here */
322 enc = AUDIO_ENCODING_LINEAR; 335 enc = AUDIO_ENCODING_LINEAR;
323 spec->format = AUDIO_S16SYS; 336 spec->format = AUDIO_S16SYS;
324 break; /* try again */ 337 break; /* try again */
325 338
326 case AUDIO_ENCODING_LINEAR: 339 case AUDIO_ENCODING_LINEAR:
327 /* linear 16bit didn't work either, resort to µ-law */ 340 /* linear 16bit didn't work either, resort to µ-law */
328 enc = AUDIO_ENCODING_ULAW; 341 enc = AUDIO_ENCODING_ULAW;
329 spec->channels = 1; 342 spec->channels = 1;
330 spec->freq = 8000; 343 spec->freq = 8000;
331 spec->format = AUDIO_U8; 344 spec->format = AUDIO_U8;
332 ulaw_only = 1; 345 ulaw_only = 1;
333 break; 346 break;
334 347
335 default: 348 default:
336 /* oh well... */ 349 /* oh well... */
337 SDL_SetError("Error setting audio parameters: %s", 350 SDL_SetError ("Error setting audio parameters: %s",
338 strerror(errno)); 351 strerror (errno));
339 return -1; 352 return -1;
340 } 353 }
341 } 354 }
342 #endif /* AUDIO_SETINFO */ 355 #endif /* AUDIO_SETINFO */
343 written = 0; 356 written = 0;
344 357
345 /* We can actually convert on-the-fly to U-Law */ 358 /* We can actually convert on-the-fly to U-Law */
346 if ( ulaw_only ) { 359 if (ulaw_only) {
347 spec->freq = desired_freq; 360 spec->freq = desired_freq;
348 fragsize = (spec->samples*1000)/(spec->freq/8); 361 fragsize = (spec->samples * 1000) / (spec->freq / 8);
349 frequency = 8; 362 frequency = 8;
350 ulaw_buf = (Uint8 *)SDL_malloc(fragsize); 363 ulaw_buf = (Uint8 *) SDL_malloc (fragsize);
351 if ( ulaw_buf == NULL ) { 364 if (ulaw_buf == NULL) {
352 SDL_OutOfMemory(); 365 SDL_OutOfMemory ();
353 return(-1); 366 return (-1);
354 } 367 }
355 spec->channels = 1; 368 spec->channels = 1;
356 } else { 369 } else {
357 fragsize = spec->samples; 370 fragsize = spec->samples;
358 frequency = spec->freq/1000; 371 frequency = spec->freq / 1000;
359 } 372 }
360 #ifdef DEBUG_AUDIO 373 #ifdef DEBUG_AUDIO
361 fprintf(stderr, "Audio device %s U-Law only\n", 374 fprintf (stderr, "Audio device %s U-Law only\n",
362 ulaw_only ? "is" : "is not"); 375 ulaw_only ? "is" : "is not");
363 fprintf(stderr, "format=0x%x chan=%d freq=%d\n", 376 fprintf (stderr, "format=0x%x chan=%d freq=%d\n",
364 spec->format, spec->channels, spec->freq); 377 spec->format, spec->channels, spec->freq);
365 #endif 378 #endif
366 379
367 /* Update the fragment size as size in bytes */ 380 /* Update the fragment size as size in bytes */
368 SDL_CalculateAudioSpec(spec); 381 SDL_CalculateAudioSpec (spec);
369 382
370 /* Allocate mixing buffer */ 383 /* Allocate mixing buffer */
371 mixbuf = (Uint8 *)SDL_AllocAudioMem(spec->size); 384 mixbuf = (Uint8 *) SDL_AllocAudioMem (spec->size);
372 if ( mixbuf == NULL ) { 385 if (mixbuf == NULL) {
373 SDL_OutOfMemory(); 386 SDL_OutOfMemory ();
374 return(-1); 387 return (-1);
375 } 388 }
376 SDL_memset(mixbuf, spec->silence, spec->size); 389 SDL_memset (mixbuf, spec->silence, spec->size);
377 390
378 /* We're ready to rock and roll. :-) */ 391 /* We're ready to rock and roll. :-) */
379 return(0); 392 return (0);
380 } 393 }
381 394
382 /************************************************************************/ 395 /************************************************************************/
383 /* This function (snd2au()) copyrighted: */ 396 /* This function (snd2au()) copyrighted: */
384 /************************************************************************/ 397 /************************************************************************/
395 /* Rich Gopstein and Harris Corporation make no representations */ 408 /* Rich Gopstein and Harris Corporation make no representations */
396 /* about the suitability of this software for any purpose. It */ 409 /* about the suitability of this software for any purpose. It */
397 /* provided "as is" without express or implied warranty. */ 410 /* provided "as is" without express or implied warranty. */
398 /************************************************************************/ 411 /************************************************************************/
399 412
400 static Uint8 snd2au(int sample) 413 static Uint8
401 { 414 snd2au (int sample)
402 415 {
403 int mask; 416
404 417 int mask;
405 if (sample < 0) { 418
406 sample = -sample; 419 if (sample < 0) {
407 mask = 0x7f; 420 sample = -sample;
408 } else { 421 mask = 0x7f;
409 mask = 0xff; 422 } else {
410 } 423 mask = 0xff;
411 424 }
412 if (sample < 32) { 425
413 sample = 0xF0 | (15 - sample / 2); 426 if (sample < 32) {
414 } else if (sample < 96) { 427 sample = 0xF0 | (15 - sample / 2);
415 sample = 0xE0 | (15 - (sample - 32) / 4); 428 } else if (sample < 96) {
416 } else if (sample < 224) { 429 sample = 0xE0 | (15 - (sample - 32) / 4);
417 sample = 0xD0 | (15 - (sample - 96) / 8); 430 } else if (sample < 224) {
418 } else if (sample < 480) { 431 sample = 0xD0 | (15 - (sample - 96) / 8);
419 sample = 0xC0 | (15 - (sample - 224) / 16); 432 } else if (sample < 480) {
420 } else if (sample < 992) { 433 sample = 0xC0 | (15 - (sample - 224) / 16);
421 sample = 0xB0 | (15 - (sample - 480) / 32); 434 } else if (sample < 992) {
422 } else if (sample < 2016) { 435 sample = 0xB0 | (15 - (sample - 480) / 32);
423 sample = 0xA0 | (15 - (sample - 992) / 64); 436 } else if (sample < 2016) {
424 } else if (sample < 4064) { 437 sample = 0xA0 | (15 - (sample - 992) / 64);
425 sample = 0x90 | (15 - (sample - 2016) / 128); 438 } else if (sample < 4064) {
426 } else if (sample < 8160) { 439 sample = 0x90 | (15 - (sample - 2016) / 128);
427 sample = 0x80 | (15 - (sample - 4064) / 256); 440 } else if (sample < 8160) {
428 } else { 441 sample = 0x80 | (15 - (sample - 4064) / 256);
429 sample = 0x80; 442 } else {
430 } 443 sample = 0x80;
431 return (mask & sample); 444 }
432 } 445 return (mask & sample);
446 }
447
448 /* vi: set ts=4 sw=4 expandtab: */