| 1 | <HTML |
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| 4 | >SDL_AudioSpec</TITLE |
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| 19 | TITLE="SDL_OpenAudio" |
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| 29 | CLASS="NAVHEADER" |
| 30 | ><TABLE |
| 31 | SUMMARY="Header navigation table" |
| 32 | WIDTH="100%" |
| 33 | BORDER="0" |
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| 35 | CELLSPACING="0" |
| 36 | ><TR |
| 37 | ><TH |
| 38 | COLSPAN="3" |
| 39 | ALIGN="center" |
| 40 | >SDL Library Documentation</TH |
| 41 | ></TR |
| 42 | ><TR |
| 43 | ><TD |
| 44 | WIDTH="10%" |
| 45 | ALIGN="left" |
| 46 | VALIGN="bottom" |
| 47 | ><A |
| 48 | HREF="audio.html" |
| 49 | ACCESSKEY="P" |
| 50 | >Prev</A |
| 51 | ></TD |
| 52 | ><TD |
| 53 | WIDTH="80%" |
| 54 | ALIGN="center" |
| 55 | VALIGN="bottom" |
| 56 | ></TD |
| 57 | ><TD |
| 58 | WIDTH="10%" |
| 59 | ALIGN="right" |
| 60 | VALIGN="bottom" |
| 61 | ><A |
| 62 | HREF="sdlopenaudio.html" |
| 63 | ACCESSKEY="N" |
| 64 | >Next</A |
| 65 | ></TD |
| 66 | ></TR |
| 67 | ></TABLE |
| 68 | ><HR |
| 69 | ALIGN="LEFT" |
| 70 | WIDTH="100%"></DIV |
| 71 | ><H1 |
| 72 | ><A |
| 73 | NAME="SDLAUDIOSPEC" |
| 74 | ></A |
| 75 | >SDL_AudioSpec</H1 |
| 76 | ><DIV |
| 77 | CLASS="REFNAMEDIV" |
| 78 | ><A |
| 79 | NAME="AEN6507" |
| 80 | ></A |
| 81 | ><H2 |
| 82 | >Name</H2 |
| 83 | >SDL_AudioSpec -- Audio Specification Structure</DIV |
| 84 | ><DIV |
| 85 | CLASS="REFSECT1" |
| 86 | ><A |
| 87 | NAME="AEN6510" |
| 88 | ></A |
| 89 | ><H2 |
| 90 | >Structure Definition</H2 |
| 91 | ><PRE |
| 92 | CLASS="PROGRAMLISTING" |
| 93 | >typedef struct{ |
| 94 | int freq; |
| 95 | Uint16 format; |
| 96 | Uint8 channels; |
| 97 | Uint8 silence; |
| 98 | Uint16 samples; |
| 99 | Uint32 size; |
| 100 | void (*callback)(void *userdata, Uint8 *stream, int len); |
| 101 | void *userdata; |
| 102 | } SDL_AudioSpec;</PRE |
| 103 | ></DIV |
| 104 | ><DIV |
| 105 | CLASS="REFSECT1" |
| 106 | ><A |
| 107 | NAME="AEN6513" |
| 108 | ></A |
| 109 | ><H2 |
| 110 | >Structure Data</H2 |
| 111 | ><DIV |
| 112 | CLASS="INFORMALTABLE" |
| 113 | ><A |
| 114 | NAME="AEN6515" |
| 115 | ></A |
| 116 | ><P |
| 117 | ></P |
| 118 | ><TABLE |
| 119 | BORDER="0" |
| 120 | CLASS="CALSTABLE" |
| 121 | ><TBODY |
| 122 | ><TR |
| 123 | ><TD |
| 124 | ALIGN="LEFT" |
| 125 | VALIGN="TOP" |
| 126 | ><TT |
| 127 | CLASS="STRUCTFIELD" |
| 128 | ><I |
| 129 | >freq</I |
| 130 | ></TT |
| 131 | ></TD |
| 132 | ><TD |
| 133 | ALIGN="LEFT" |
| 134 | VALIGN="TOP" |
| 135 | >Audio frequency in samples per second</TD |
| 136 | ></TR |
| 137 | ><TR |
| 138 | ><TD |
| 139 | ALIGN="LEFT" |
| 140 | VALIGN="TOP" |
| 141 | ><TT |
| 142 | CLASS="STRUCTFIELD" |
| 143 | ><I |
| 144 | >format</I |
| 145 | ></TT |
| 146 | ></TD |
| 147 | ><TD |
| 148 | ALIGN="LEFT" |
| 149 | VALIGN="TOP" |
| 150 | >Audio data format</TD |
| 151 | ></TR |
| 152 | ><TR |
| 153 | ><TD |
| 154 | ALIGN="LEFT" |
| 155 | VALIGN="TOP" |
| 156 | ><TT |
| 157 | CLASS="STRUCTFIELD" |
| 158 | ><I |
| 159 | >channels</I |
| 160 | ></TT |
| 161 | ></TD |
| 162 | ><TD |
| 163 | ALIGN="LEFT" |
| 164 | VALIGN="TOP" |
| 165 | >Number of channels: 1 mono, 2 stereo</TD |
| 166 | ></TR |
| 167 | ><TR |
| 168 | ><TD |
| 169 | ALIGN="LEFT" |
| 170 | VALIGN="TOP" |
| 171 | ><TT |
| 172 | CLASS="STRUCTFIELD" |
| 173 | ><I |
| 174 | >silence</I |
| 175 | ></TT |
| 176 | ></TD |
| 177 | ><TD |
| 178 | ALIGN="LEFT" |
| 179 | VALIGN="TOP" |
| 180 | >Audio buffer silence value (calculated)</TD |
| 181 | ></TR |
| 182 | ><TR |
| 183 | ><TD |
| 184 | ALIGN="LEFT" |
| 185 | VALIGN="TOP" |
| 186 | ><TT |
| 187 | CLASS="STRUCTFIELD" |
| 188 | ><I |
| 189 | >samples</I |
| 190 | ></TT |
| 191 | ></TD |
| 192 | ><TD |
| 193 | ALIGN="LEFT" |
| 194 | VALIGN="TOP" |
| 195 | >Audio buffer size in samples</TD |
| 196 | ></TR |
| 197 | ><TR |
| 198 | ><TD |
| 199 | ALIGN="LEFT" |
| 200 | VALIGN="TOP" |
| 201 | ><TT |
| 202 | CLASS="STRUCTFIELD" |
| 203 | ><I |
| 204 | >size</I |
| 205 | ></TT |
| 206 | ></TD |
| 207 | ><TD |
| 208 | ALIGN="LEFT" |
| 209 | VALIGN="TOP" |
| 210 | >Audio buffer size in bytes (calculated)</TD |
| 211 | ></TR |
| 212 | ><TR |
| 213 | ><TD |
| 214 | ALIGN="LEFT" |
| 215 | VALIGN="TOP" |
| 216 | ><TT |
| 217 | CLASS="STRUCTFIELD" |
| 218 | ><I |
| 219 | >callback(..)</I |
| 220 | ></TT |
| 221 | ></TD |
| 222 | ><TD |
| 223 | ALIGN="LEFT" |
| 224 | VALIGN="TOP" |
| 225 | >Callback function for filling the audio buffer</TD |
| 226 | ></TR |
| 227 | ><TR |
| 228 | ><TD |
| 229 | ALIGN="LEFT" |
| 230 | VALIGN="TOP" |
| 231 | ><TT |
| 232 | CLASS="STRUCTFIELD" |
| 233 | ><I |
| 234 | >userdata</I |
| 235 | ></TT |
| 236 | ></TD |
| 237 | ><TD |
| 238 | ALIGN="LEFT" |
| 239 | VALIGN="TOP" |
| 240 | >Pointer the user data which is passed to the callback function</TD |
| 241 | ></TR |
| 242 | ></TBODY |
| 243 | ></TABLE |
| 244 | ><P |
| 245 | ></P |
| 246 | ></DIV |
| 247 | ></DIV |
| 248 | ><DIV |
| 249 | CLASS="REFSECT1" |
| 250 | ><A |
| 251 | NAME="AEN6550" |
| 252 | ></A |
| 253 | ><H2 |
| 254 | >Description</H2 |
| 255 | ><P |
| 256 | >The <SPAN |
| 257 | CLASS="STRUCTNAME" |
| 258 | >SDL_AudioSpec</SPAN |
| 259 | > structure is used to describe the format of some audio data. This structure is used by <A |
| 260 | HREF="sdlopenaudio.html" |
| 261 | ><TT |
| 262 | CLASS="FUNCTION" |
| 263 | >SDL_OpenAudio</TT |
| 264 | ></A |
| 265 | > and <A |
| 266 | HREF="sdlloadwav.html" |
| 267 | ><TT |
| 268 | CLASS="FUNCTION" |
| 269 | >SDL_LoadWAV</TT |
| 270 | ></A |
| 271 | >. While all fields are used by <TT |
| 272 | CLASS="FUNCTION" |
| 273 | >SDL_OpenAudio</TT |
| 274 | > only <TT |
| 275 | CLASS="STRUCTFIELD" |
| 276 | ><I |
| 277 | >freq</I |
| 278 | ></TT |
| 279 | >, <TT |
| 280 | CLASS="STRUCTFIELD" |
| 281 | ><I |
| 282 | >format</I |
| 283 | ></TT |
| 284 | >, <TT |
| 285 | CLASS="STRUCTFIELD" |
| 286 | ><I |
| 287 | >samples</I |
| 288 | ></TT |
| 289 | > and <TT |
| 290 | CLASS="STRUCTFIELD" |
| 291 | ><I |
| 292 | >channels</I |
| 293 | ></TT |
| 294 | > are used by <TT |
| 295 | CLASS="FUNCTION" |
| 296 | >SDL_LoadWAV</TT |
| 297 | >. We will detail these common members here.</P |
| 298 | ><DIV |
| 299 | CLASS="INFORMALTABLE" |
| 300 | ><A |
| 301 | NAME="AEN6564" |
| 302 | ></A |
| 303 | ><P |
| 304 | ></P |
| 305 | ><TABLE |
| 306 | BORDER="0" |
| 307 | CLASS="CALSTABLE" |
| 308 | ><TBODY |
| 309 | ><TR |
| 310 | ><TD |
| 311 | ALIGN="LEFT" |
| 312 | VALIGN="TOP" |
| 313 | ><TT |
| 314 | CLASS="STRUCTFIELD" |
| 315 | ><I |
| 316 | >freq</I |
| 317 | ></TT |
| 318 | ></TD |
| 319 | ><TD |
| 320 | ALIGN="LEFT" |
| 321 | VALIGN="TOP" |
| 322 | ><P |
| 323 | >The number of samples sent to the sound device every second. Common values are 11025, 22050 and 44100. The higher the better.</P |
| 324 | ></TD |
| 325 | ></TR |
| 326 | ><TR |
| 327 | ><TD |
| 328 | ALIGN="LEFT" |
| 329 | VALIGN="TOP" |
| 330 | ><TT |
| 331 | CLASS="STRUCTFIELD" |
| 332 | ><I |
| 333 | >format</I |
| 334 | ></TT |
| 335 | ></TD |
| 336 | ><TD |
| 337 | ALIGN="LEFT" |
| 338 | VALIGN="TOP" |
| 339 | ><P |
| 340 | >Specifies the size and type of each sample element |
| 341 | <P |
| 342 | ></P |
| 343 | ><DIV |
| 344 | CLASS="VARIABLELIST" |
| 345 | ><DL |
| 346 | ><DT |
| 347 | ><TT |
| 348 | CLASS="LITERAL" |
| 349 | >AUDIO_U8</TT |
| 350 | ></DT |
| 351 | ><DD |
| 352 | ><P |
| 353 | >Unsigned 8-bit samples</P |
| 354 | ></DD |
| 355 | ><DT |
| 356 | ><TT |
| 357 | CLASS="LITERAL" |
| 358 | >AUDIO_S8</TT |
| 359 | ></DT |
| 360 | ><DD |
| 361 | ><P |
| 362 | >Signed 8-bit samples</P |
| 363 | ></DD |
| 364 | ><DT |
| 365 | ><TT |
| 366 | CLASS="LITERAL" |
| 367 | >AUDIO_U16</TT |
| 368 | > or <TT |
| 369 | CLASS="LITERAL" |
| 370 | >AUDIO_U16LSB</TT |
| 371 | ></DT |
| 372 | ><DD |
| 373 | ><P |
| 374 | >Unsigned 16-bit little-endian samples</P |
| 375 | ></DD |
| 376 | ><DT |
| 377 | ><TT |
| 378 | CLASS="LITERAL" |
| 379 | >AUDIO_S16</TT |
| 380 | > or <TT |
| 381 | CLASS="LITERAL" |
| 382 | >AUDIO_S16LSB</TT |
| 383 | ></DT |
| 384 | ><DD |
| 385 | ><P |
| 386 | >Signed 16-bit little-endian samples</P |
| 387 | ></DD |
| 388 | ><DT |
| 389 | ><TT |
| 390 | CLASS="LITERAL" |
| 391 | >AUDIO_U16MSB</TT |
| 392 | ></DT |
| 393 | ><DD |
| 394 | ><P |
| 395 | >Unsigned 16-bit big-endian samples</P |
| 396 | ></DD |
| 397 | ><DT |
| 398 | ><TT |
| 399 | CLASS="LITERAL" |
| 400 | >AUDIO_S16MSB</TT |
| 401 | ></DT |
| 402 | ><DD |
| 403 | ><P |
| 404 | >Signed 16-bit big-endian samples</P |
| 405 | ></DD |
| 406 | ><DT |
| 407 | ><TT |
| 408 | CLASS="LITERAL" |
| 409 | >AUDIO_U16SYS</TT |
| 410 | ></DT |
| 411 | ><DD |
| 412 | ><P |
| 413 | >Either <TT |
| 414 | CLASS="LITERAL" |
| 415 | >AUDIO_U16LSB</TT |
| 416 | > or <TT |
| 417 | CLASS="LITERAL" |
| 418 | >AUDIO_U16MSB</TT |
| 419 | > depending on you systems endianness</P |
| 420 | ></DD |
| 421 | ><DT |
| 422 | ><TT |
| 423 | CLASS="LITERAL" |
| 424 | >AUDIO_S16SYS</TT |
| 425 | ></DT |
| 426 | ><DD |
| 427 | ><P |
| 428 | >Either <TT |
| 429 | CLASS="LITERAL" |
| 430 | >AUDIO_S16LSB</TT |
| 431 | > or <TT |
| 432 | CLASS="LITERAL" |
| 433 | >AUDIO_S16MSB</TT |
| 434 | > depending on you systems endianness</P |
| 435 | ></DD |
| 436 | ></DL |
| 437 | ></DIV |
| 438 | ></P |
| 439 | ></TD |
| 440 | ></TR |
| 441 | ><TR |
| 442 | ><TD |
| 443 | ALIGN="LEFT" |
| 444 | VALIGN="TOP" |
| 445 | ><TT |
| 446 | CLASS="STRUCTFIELD" |
| 447 | ><I |
| 448 | >channels</I |
| 449 | ></TT |
| 450 | ></TD |
| 451 | ><TD |
| 452 | ALIGN="LEFT" |
| 453 | VALIGN="TOP" |
| 454 | >The number of seperate sound channels. 1 is mono (single channel), 2 is stereo (dual channel).</TD |
| 455 | ></TR |
| 456 | ><TR |
| 457 | ><TD |
| 458 | ALIGN="LEFT" |
| 459 | VALIGN="TOP" |
| 460 | ><TT |
| 461 | CLASS="STRUCTFIELD" |
| 462 | ><I |
| 463 | >samples</I |
| 464 | ></TT |
| 465 | ></TD |
| 466 | ><TD |
| 467 | ALIGN="LEFT" |
| 468 | VALIGN="TOP" |
| 469 | >When used with <A |
| 470 | HREF="sdlopenaudio.html" |
| 471 | ><TT |
| 472 | CLASS="FUNCTION" |
| 473 | >SDL_OpenAudio</TT |
| 474 | ></A |
| 475 | > this refers to the size of the audio buffer in samples. A sample a chunk of audio data of the size specified in <TT |
| 476 | CLASS="PARAMETER" |
| 477 | ><I |
| 478 | >format</I |
| 479 | ></TT |
| 480 | > mulitplied by the number of channels. When the <SPAN |
| 481 | CLASS="STRUCTNAME" |
| 482 | >SDL_AudioSpec</SPAN |
| 483 | > is used with <A |
| 484 | HREF="sdlloadwav.html" |
| 485 | ><TT |
| 486 | CLASS="FUNCTION" |
| 487 | >SDL_LoadWAV</TT |
| 488 | ></A |
| 489 | > <TT |
| 490 | CLASS="STRUCTFIELD" |
| 491 | ><I |
| 492 | >samples</I |
| 493 | ></TT |
| 494 | > is set to 4096.</TD |
| 495 | ></TR |
| 496 | ></TBODY |
| 497 | ></TABLE |
| 498 | ><P |
| 499 | ></P |
| 500 | ></DIV |
| 501 | ></DIV |
| 502 | ><DIV |
| 503 | CLASS="REFSECT1" |
| 504 | ><A |
| 505 | NAME="AEN6639" |
| 506 | ></A |
| 507 | ><H2 |
| 508 | >See Also</H2 |
| 509 | ><P |
| 510 | ><A |
| 511 | HREF="sdlopenaudio.html" |
| 512 | ><TT |
| 513 | CLASS="FUNCTION" |
| 514 | >SDL_OpenAudio</TT |
| 515 | ></A |
| 516 | >, |
| 517 | <A |
| 518 | HREF="sdlloadwav.html" |
| 519 | ><TT |
| 520 | CLASS="FUNCTION" |
| 521 | >SDL_LoadWAV</TT |
| 522 | ></A |
| 523 | ></P |
| 524 | ></DIV |
| 525 | ><DIV |
| 526 | CLASS="NAVFOOTER" |
| 527 | ><HR |
| 528 | ALIGN="LEFT" |
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| 535 | ><TR |
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| 538 | ALIGN="left" |
| 539 | VALIGN="top" |
| 540 | ><A |
| 541 | HREF="audio.html" |
| 542 | ACCESSKEY="P" |
| 543 | >Prev</A |
| 544 | ></TD |
| 545 | ><TD |
| 546 | WIDTH="34%" |
| 547 | ALIGN="center" |
| 548 | VALIGN="top" |
| 549 | ><A |
| 550 | HREF="index.html" |
| 551 | ACCESSKEY="H" |
| 552 | >Home</A |
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| 558 | ><A |
| 559 | HREF="sdlopenaudio.html" |
| 560 | ACCESSKEY="N" |
| 561 | >Next</A |
| 562 | ></TD |
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| 568 | VALIGN="top" |
| 569 | >Audio</TD |
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| 571 | WIDTH="34%" |
| 572 | ALIGN="center" |
| 573 | VALIGN="top" |
| 574 | ><A |
| 575 | HREF="audio.html" |
| 576 | ACCESSKEY="U" |
| 577 | >Up</A |
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| 583 | >SDL_OpenAudio</TD |
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| 589 | > |