Mercurial > sdl-ios-xcode
annotate docs/html/sdlaudiospec.html @ 641:df178851293b
Date: 28 Jun 2003 22:42:52 +0100
From: Alan Swanson
Subject: Re: [SDL] New XFree 4.3 Video Mode Patch
I have a wee amendment that moves the qsort in set_best_resolution
to only occur after failing to find an exact match only. This would
make absolutely sure we get a user set mode.
While I've never had any problems for my normal resolutions (1280x1024,
1024x768, 800x600 & 640,480) while closely examining the output from
qsort I've noticed it doesn't seem to sort the modes fully. These is
one definite wrong at 1152x768 and a few that just look wrong to me.
From a program (attached) I made to examine this more easily. X has
sorted its mode list using the same method as ours (plus frequency),
and our user modes get inserted without any other movement.
On the patch I've made I've also changed cmpmodes to sort on vertical
resolution and then horizontal. Ie vertical is now most significant
bit.
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Sat, 28 Jun 2003 21:52:26 +0000 |
| parents | e5bc29de3f0a |
| children | 355632dca928 |
| rev | line source |
|---|---|
| 0 | 1 <HTML |
| 2 ><HEAD | |
| 3 ><TITLE | |
| 4 >SDL_AudioSpec</TITLE | |
| 5 ><META | |
| 6 NAME="GENERATOR" | |
|
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7 CONTENT="Modular DocBook HTML Stylesheet Version 1.64 |
| 0 | 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 | |
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76 NAME="AEN6119" |
| 0 | 77 ></A |
| 78 ><H2 | |
| 79 >Name</H2 | |
| 80 >SDL_AudioSpec -- Audio Specification Structure</DIV | |
| 81 ><DIV | |
| 82 CLASS="REFSECT1" | |
| 83 ><A | |
|
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84 NAME="AEN6122" |
| 0 | 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 | |
|
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104 NAME="AEN6125" |
| 0 | 105 ></A |
| 106 ><H2 | |
| 107 >Structure Data</H2 | |
| 108 ><DIV | |
| 109 CLASS="INFORMALTABLE" | |
| 110 ><A | |
|
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111 NAME="AEN6127" |
| 0 | 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 | |
|
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248 NAME="AEN6162" |
| 0 | 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 | |
|
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298 NAME="AEN6176" |
| 0 | 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 | |
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502 NAME="AEN6251" |
| 0 | 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 > |