Mercurial > sdl-ios-xcode

comparison docs/html/sdlaudiospec.html @ 0:74212992fb08

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Initial revision
author Sam Lantinga <slouken@lokigames.com>
date Thu, 26 Apr 2001 16:45:43 +0000
parents
children 55f1f1b3e27d
comparison
equal deleted inserted replaced
-1:000000000000 0:74212992fb08
1 <HTML
2 ><HEAD
3 ><TITLE
4 >SDL_AudioSpec</TITLE
5 ><META
6 NAME="GENERATOR"
7 CONTENT="Modular DocBook HTML Stylesheet Version 1.61
8 "><LINK
9 REL="HOME"
10 TITLE="SDL Library Documentation"
11 HREF="index.html"><LINK
12 REL="UP"
13 TITLE="Audio"
14 HREF="audio.html"><LINK
15 REL="PREVIOUS"
16 TITLE="Audio"
17 HREF="audio.html"><LINK
18 REL="NEXT"
19 TITLE="SDL_OpenAudio"
20 HREF="sdlopenaudio.html"></HEAD
21 ><BODY
22 CLASS="REFENTRY"
23 BGCOLOR="#FFF8DC"
24 TEXT="#000000"
25 LINK="#0000ee"
26 VLINK="#551a8b"
27 ALINK="#ff0000"
28 ><DIV
29 CLASS="NAVHEADER"
30 ><TABLE
31 WIDTH="100%"
32 BORDER="0"
33 CELLPADDING="0"
34 CELLSPACING="0"
35 ><TR
36 ><TH
37 COLSPAN="3"
38 ALIGN="center"
39 >SDL Library Documentation</TH
40 ></TR
41 ><TR
42 ><TD
43 WIDTH="10%"
44 ALIGN="left"
45 VALIGN="bottom"
46 ><A
47 HREF="audio.html"
48 >Prev</A
49 ></TD
50 ><TD
51 WIDTH="80%"
52 ALIGN="center"
53 VALIGN="bottom"
54 ></TD
55 ><TD
56 WIDTH="10%"
57 ALIGN="right"
58 VALIGN="bottom"
59 ><A
60 HREF="sdlopenaudio.html"
61 >Next</A
62 ></TD
63 ></TR
64 ></TABLE
65 ><HR
66 ALIGN="LEFT"
67 WIDTH="100%"></DIV
68 ><H1
69 ><A
70 NAME="SDLAUDIOSPEC"
71 >SDL_AudioSpec</A
72 ></H1
73 ><DIV
74 CLASS="REFNAMEDIV"
75 ><A
76 NAME="AEN5885"
77 ></A
78 ><H2
79 >Name</H2
80 >SDL_AudioSpec&nbsp;--&nbsp;Audio Specification Structure</DIV
81 ><DIV
82 CLASS="REFSECT1"
83 ><A
84 NAME="AEN5888"
85 ></A
86 ><H2
87 >Structure Definition</H2
88 ><PRE
89 CLASS="PROGRAMLISTING"
90 >typedef struct{
91 int freq;
92 Uint16 format;
93 Uint8 channels;
94 Uint8 silence;
95 Uint16 samples;
96 Uint32 size;
97 void (*callback)(void *userdata, Uint8 *stream, int len);
98 void *userdata;
99 } SDL_AudioSpec;</PRE
100 ></DIV
101 ><DIV
102 CLASS="REFSECT1"
103 ><A
104 NAME="AEN5891"
105 ></A
106 ><H2
107 >Structure Data</H2
108 ><DIV
109 CLASS="INFORMALTABLE"
110 ><A
111 NAME="AEN5893"
112 ></A
113 ><P
114 ></P
115 ><TABLE
116 BORDER="0"
117 CLASS="CALSTABLE"
118 ><TBODY
119 ><TR
120 ><TD
121 ALIGN="LEFT"
122 VALIGN="TOP"
123 ><TT
124 CLASS="STRUCTFIELD"
125 ><I
126 >freq</I
127 ></TT
128 ></TD
129 ><TD
130 ALIGN="LEFT"
131 VALIGN="TOP"
132 >Audio frequency in samples per second</TD
133 ></TR
134 ><TR
135 ><TD
136 ALIGN="LEFT"
137 VALIGN="TOP"
138 ><TT
139 CLASS="STRUCTFIELD"
140 ><I
141 >format</I
142 ></TT
143 ></TD
144 ><TD
145 ALIGN="LEFT"
146 VALIGN="TOP"
147 >Audio data format</TD
148 ></TR
149 ><TR
150 ><TD
151 ALIGN="LEFT"
152 VALIGN="TOP"
153 ><TT
154 CLASS="STRUCTFIELD"
155 ><I
156 >channels</I
157 ></TT
158 ></TD
159 ><TD
160 ALIGN="LEFT"
161 VALIGN="TOP"
162 >Number of channels: 1 mono, 2 stereo</TD
163 ></TR
164 ><TR
165 ><TD
166 ALIGN="LEFT"
167 VALIGN="TOP"
168 ><TT
169 CLASS="STRUCTFIELD"
170 ><I
171 >silence</I
172 ></TT
173 ></TD
174 ><TD
175 ALIGN="LEFT"
176 VALIGN="TOP"
177 >Audio buffer silence value (calculated)</TD
178 ></TR
179 ><TR
180 ><TD
181 ALIGN="LEFT"
182 VALIGN="TOP"
183 ><TT
184 CLASS="STRUCTFIELD"
185 ><I
186 >samples</I
187 ></TT
188 ></TD
189 ><TD
190 ALIGN="LEFT"
191 VALIGN="TOP"
192 >Audio buffer size in samples</TD
193 ></TR
194 ><TR
195 ><TD
196 ALIGN="LEFT"
197 VALIGN="TOP"
198 ><TT
199 CLASS="STRUCTFIELD"
200 ><I
201 >size</I
202 ></TT
203 ></TD
204 ><TD
205 ALIGN="LEFT"
206 VALIGN="TOP"
207 >Audio buffer size in bytes (calculated)</TD
208 ></TR
209 ><TR
210 ><TD
211 ALIGN="LEFT"
212 VALIGN="TOP"
213 ><TT
214 CLASS="STRUCTFIELD"
215 ><I
216 >callback(..)</I
217 ></TT
218 ></TD
219 ><TD
220 ALIGN="LEFT"
221 VALIGN="TOP"
222 >Callback function for filling the audio buffer</TD
223 ></TR
224 ><TR
225 ><TD
226 ALIGN="LEFT"
227 VALIGN="TOP"
228 ><TT
229 CLASS="STRUCTFIELD"
230 ><I
231 >userdata</I
232 ></TT
233 ></TD
234 ><TD
235 ALIGN="LEFT"
236 VALIGN="TOP"
237 >Pointer the user data which is passed to the callback function</TD
238 ></TR
239 ></TBODY
240 ></TABLE
241 ><P
242 ></P
243 ></DIV
244 ></DIV
245 ><DIV
246 CLASS="REFSECT1"
247 ><A
248 NAME="AEN5928"
249 ></A
250 ><H2
251 >Description</H2
252 ><P
253 >The <SPAN
254 CLASS="STRUCTNAME"
255 >SDL_AudioSpec</SPAN
256 > structure is used to describe the format of some audio data. This structure is used by <A
257 HREF="sdlopenaudio.html"
258 ><TT
259 CLASS="FUNCTION"
260 >SDL_OpenAudio</TT
261 ></A
262 > and <A
263 HREF="sdlloadwav.html"
264 ><TT
265 CLASS="FUNCTION"
266 >SDL_LoadWAV</TT
267 ></A
268 >. While all fields are used by <TT
269 CLASS="FUNCTION"
270 >SDL_OpenAudio</TT
271 > only <TT
272 CLASS="STRUCTFIELD"
273 ><I
274 >freq</I
275 ></TT
276 >, <TT
277 CLASS="STRUCTFIELD"
278 ><I
279 >format</I
280 ></TT
281 >, <TT
282 CLASS="STRUCTFIELD"
283 ><I
284 >samples</I
285 ></TT
286 > and <TT
287 CLASS="STRUCTFIELD"
288 ><I
289 >channels</I
290 ></TT
291 > are used by <TT
292 CLASS="FUNCTION"
293 >SDL_LoadWAV</TT
294 >. We will detail these common members here.</P
295 ><DIV
296 CLASS="INFORMALTABLE"
297 ><A
298 NAME="AEN5942"
299 ></A
300 ><P
301 ></P
302 ><TABLE
303 BORDER="0"
304 CLASS="CALSTABLE"
305 ><TBODY
306 ><TR
307 ><TD
308 ALIGN="LEFT"
309 VALIGN="TOP"
310 ><TT
311 CLASS="STRUCTFIELD"
312 ><I
313 >freq</I
314 ></TT
315 ></TD
316 ><TD
317 ALIGN="LEFT"
318 VALIGN="TOP"
319 ><P
320 >The number of samples sent to the sound device every second. Common values are 11025, 22050 and 44100. The higher the better.</P
321 ></TD
322 ></TR
323 ><TR
324 ><TD
325 ALIGN="LEFT"
326 VALIGN="TOP"
327 ><TT
328 CLASS="STRUCTFIELD"
329 ><I
330 >format</I
331 ></TT
332 ></TD
333 ><TD
334 ALIGN="LEFT"
335 VALIGN="TOP"
336 ><P
337 >Specifies the size and type of each sample element
338 <P
339 ></P
340 ><DIV
341 CLASS="VARIABLELIST"
342 ><DL
343 ><DT
344 ><TT
345 CLASS="LITERAL"
346 >AUDIO_U8</TT
347 ></DT
348 ><DD
349 ><P
350 >Unsigned 8-bit samples</P
351 ></DD
352 ><DT
353 ><TT
354 CLASS="LITERAL"
355 >AUDIO_S8</TT
356 ></DT
357 ><DD
358 ><P
359 >Signed 8-bit samples</P
360 ></DD
361 ><DT
362 ><TT
363 CLASS="LITERAL"
364 >AUDIO_U16</TT
365 > or <TT
366 CLASS="LITERAL"
367 >AUDIO_U16LSB</TT
368 ></DT
369 ><DD
370 ><P
371 >Unsigned 16-bit little-endian samples</P
372 ></DD
373 ><DT
374 ><TT
375 CLASS="LITERAL"
376 >AUDIO_S16</TT
377 > or <TT
378 CLASS="LITERAL"
379 >AUDIO_S16LSB</TT
380 ></DT
381 ><DD
382 ><P
383 >Signed 16-bit little-endian samples</P
384 ></DD
385 ><DT
386 ><TT
387 CLASS="LITERAL"
388 >AUDIO_U16MSB</TT
389 ></DT
390 ><DD
391 ><P
392 >Unsigned 16-bit big-endian samples</P
393 ></DD
394 ><DT
395 ><TT
396 CLASS="LITERAL"
397 >AUDIO_S16MSB</TT
398 ></DT
399 ><DD
400 ><P
401 >Signed 16-bit big-endian samples</P
402 ></DD
403 ><DT
404 ><TT
405 CLASS="LITERAL"
406 >AUDIO_U16SYS</TT
407 ></DT
408 ><DD
409 ><P
410 >Either <TT
411 CLASS="LITERAL"
412 >AUDIO_U16LSB</TT
413 > or <TT
414 CLASS="LITERAL"
415 >AUDIO_U16MSB</TT
416 > depending on you systems endianness</P
417 ></DD
418 ><DT
419 ><TT
420 CLASS="LITERAL"
421 >AUDIO_S16SYS</TT
422 ></DT
423 ><DD
424 ><P
425 >Either <TT
426 CLASS="LITERAL"
427 >AUDIO_S16LSB</TT
428 > or <TT
429 CLASS="LITERAL"
430 >AUDIO_S16MSB</TT
431 > depending on you systems endianness</P
432 ></DD
433 ></DL
434 ></DIV
435 ></P
436 ></TD
437 ></TR
438 ><TR
439 ><TD
440 ALIGN="LEFT"
441 VALIGN="TOP"
442 ><TT
443 CLASS="STRUCTFIELD"
444 ><I
445 >channels</I
446 ></TT
447 ></TD
448 ><TD
449 ALIGN="LEFT"
450 VALIGN="TOP"
451 >The number of seperate sound channels. 1 is mono (single channel), 2 is stereo (dual channel).</TD
452 ></TR
453 ><TR
454 ><TD
455 ALIGN="LEFT"
456 VALIGN="TOP"
457 ><TT
458 CLASS="STRUCTFIELD"
459 ><I
460 >samples</I
461 ></TT
462 ></TD
463 ><TD
464 ALIGN="LEFT"
465 VALIGN="TOP"
466 >When used with <A
467 HREF="sdlopenaudio.html"
468 ><TT
469 CLASS="FUNCTION"
470 >SDL_OpenAudio</TT
471 ></A
472 > this refers to the size of the audio buffer in samples. A sample a chunk of audio data of the size specified in <TT
473 CLASS="PARAMETER"
474 ><I
475 >format</I
476 ></TT
477 > mulitplied by the number of channels. When the <SPAN
478 CLASS="STRUCTNAME"
479 >SDL_AudioSpec</SPAN
480 > is used with <A
481 HREF="sdlloadwav.html"
482 ><TT
483 CLASS="FUNCTION"
484 >SDL_LoadWAV</TT
485 ></A
486 > <TT
487 CLASS="STRUCTFIELD"
488 ><I
489 >samples</I
490 ></TT
491 > is set to 4096.</TD
492 ></TR
493 ></TBODY
494 ></TABLE
495 ><P
496 ></P
497 ></DIV
498 ></DIV
499 ><DIV
500 CLASS="REFSECT1"
501 ><A
502 NAME="AEN6017"
503 ></A
504 ><H2
505 >See Also</H2
506 ><P
507 ><A
508 HREF="sdlopenaudio.html"
509 ><TT
510 CLASS="FUNCTION"
511 >SDL_OpenAudio</TT
512 ></A
513 >,
514 <A
515 HREF="sdlloadwav.html"
516 ><TT
517 CLASS="FUNCTION"
518 >SDL_LoadWAV</TT
519 ></A
520 ></P
521 ></DIV
522 ><DIV
523 CLASS="NAVFOOTER"
524 ><HR
525 ALIGN="LEFT"
526 WIDTH="100%"><TABLE
527 WIDTH="100%"
528 BORDER="0"
529 CELLPADDING="0"
530 CELLSPACING="0"
531 ><TR
532 ><TD
533 WIDTH="33%"
534 ALIGN="left"
535 VALIGN="top"
536 ><A
537 HREF="audio.html"
538 >Prev</A
539 ></TD
540 ><TD
541 WIDTH="34%"
542 ALIGN="center"
543 VALIGN="top"
544 ><A
545 HREF="index.html"
546 >Home</A
547 ></TD
548 ><TD
549 WIDTH="33%"
550 ALIGN="right"
551 VALIGN="top"
552 ><A
553 HREF="sdlopenaudio.html"
554 >Next</A
555 ></TD
556 ></TR
557 ><TR
558 ><TD
559 WIDTH="33%"
560 ALIGN="left"
561 VALIGN="top"
562 >Audio</TD
563 ><TD
564 WIDTH="34%"
565 ALIGN="center"
566 VALIGN="top"
567 ><A
568 HREF="audio.html"
569 >Up</A
570 ></TD
571 ><TD
572 WIDTH="33%"
573 ALIGN="right"
574 VALIGN="top"
575 >SDL_OpenAudio</TD
576 ></TR
577 ></TABLE
578 ></DIV
579 ></BODY
580 ></HTML
581 >