| 1 | /* |
| 2 | SDL - Simple DirectMedia Layer |
| 3 | Copyright (C) 1997-2009 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 | This library is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | Lesser General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU Lesser General Public |
| 16 | License along with this library; if not, write to the Free Software |
| 17 | Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| 18 | |
| 19 | Sam Lantinga |
| 20 | slouken@libsdl.org |
| 21 | */ |
| 22 | #include "SDL_config.h" |
| 23 | |
| 24 | /* Functions for audio drivers to perform runtime conversion of audio format */ |
| 25 | |
| 26 | #include "SDL_audio.h" |
| 27 | |
| 28 | |
| 29 | /* Effectively mix right and left channels into a single channel */ |
| 30 | void SDLCALL SDL_ConvertMono(SDL_AudioCVT *cvt, Uint16 format) |
| 31 | { |
| 32 | int i; |
| 33 | Sint32 sample; |
| 34 | |
| 35 | #ifdef DEBUG_CONVERT |
| 36 | fprintf(stderr, "Converting to mono\n"); |
| 37 | #endif |
| 38 | switch (format&0x8018) { |
| 39 | |
| 40 | case AUDIO_U8: { |
| 41 | Uint8 *src, *dst; |
| 42 | |
| 43 | src = cvt->buf; |
| 44 | dst = cvt->buf; |
| 45 | for ( i=cvt->len_cvt/2; i; --i ) { |
| 46 | sample = src[0] + src[1]; |
| 47 | *dst = (Uint8)(sample / 2); |
| 48 | src += 2; |
| 49 | dst += 1; |
| 50 | } |
| 51 | } |
| 52 | break; |
| 53 | |
| 54 | case AUDIO_S8: { |
| 55 | Sint8 *src, *dst; |
| 56 | |
| 57 | src = (Sint8 *)cvt->buf; |
| 58 | dst = (Sint8 *)cvt->buf; |
| 59 | for ( i=cvt->len_cvt/2; i; --i ) { |
| 60 | sample = src[0] + src[1]; |
| 61 | *dst = (Sint8)(sample / 2); |
| 62 | src += 2; |
| 63 | dst += 1; |
| 64 | } |
| 65 | } |
| 66 | break; |
| 67 | |
| 68 | case AUDIO_U16: { |
| 69 | Uint8 *src, *dst; |
| 70 | |
| 71 | src = cvt->buf; |
| 72 | dst = cvt->buf; |
| 73 | if ( (format & 0x1000) == 0x1000 ) { |
| 74 | for ( i=cvt->len_cvt/4; i; --i ) { |
| 75 | sample = (Uint16)((src[0]<<8)|src[1])+ |
| 76 | (Uint16)((src[2]<<8)|src[3]); |
| 77 | sample /= 2; |
| 78 | dst[1] = (sample&0xFF); |
| 79 | sample >>= 8; |
| 80 | dst[0] = (sample&0xFF); |
| 81 | src += 4; |
| 82 | dst += 2; |
| 83 | } |
| 84 | } else { |
| 85 | for ( i=cvt->len_cvt/4; i; --i ) { |
| 86 | sample = (Uint16)((src[1]<<8)|src[0])+ |
| 87 | (Uint16)((src[3]<<8)|src[2]); |
| 88 | sample /= 2; |
| 89 | dst[0] = (sample&0xFF); |
| 90 | sample >>= 8; |
| 91 | dst[1] = (sample&0xFF); |
| 92 | src += 4; |
| 93 | dst += 2; |
| 94 | } |
| 95 | } |
| 96 | } |
| 97 | break; |
| 98 | |
| 99 | case AUDIO_S16: { |
| 100 | Uint8 *src, *dst; |
| 101 | |
| 102 | src = cvt->buf; |
| 103 | dst = cvt->buf; |
| 104 | if ( (format & 0x1000) == 0x1000 ) { |
| 105 | for ( i=cvt->len_cvt/4; i; --i ) { |
| 106 | sample = (Sint16)((src[0]<<8)|src[1])+ |
| 107 | (Sint16)((src[2]<<8)|src[3]); |
| 108 | sample /= 2; |
| 109 | dst[1] = (sample&0xFF); |
| 110 | sample >>= 8; |
| 111 | dst[0] = (sample&0xFF); |
| 112 | src += 4; |
| 113 | dst += 2; |
| 114 | } |
| 115 | } else { |
| 116 | for ( i=cvt->len_cvt/4; i; --i ) { |
| 117 | sample = (Sint16)((src[1]<<8)|src[0])+ |
| 118 | (Sint16)((src[3]<<8)|src[2]); |
| 119 | sample /= 2; |
| 120 | dst[0] = (sample&0xFF); |
| 121 | sample >>= 8; |
| 122 | dst[1] = (sample&0xFF); |
| 123 | src += 4; |
| 124 | dst += 2; |
| 125 | } |
| 126 | } |
| 127 | } |
| 128 | break; |
| 129 | } |
| 130 | cvt->len_cvt /= 2; |
| 131 | if ( cvt->filters[++cvt->filter_index] ) { |
| 132 | cvt->filters[cvt->filter_index](cvt, format); |
| 133 | } |
| 134 | } |
| 135 | |
| 136 | /* Discard top 4 channels */ |
| 137 | void SDLCALL SDL_ConvertStrip(SDL_AudioCVT *cvt, Uint16 format) |
| 138 | { |
| 139 | int i; |
| 140 | Sint32 lsample, rsample; |
| 141 | |
| 142 | #ifdef DEBUG_CONVERT |
| 143 | fprintf(stderr, "Converting down to stereo\n"); |
| 144 | #endif |
| 145 | switch (format&0x8018) { |
| 146 | |
| 147 | case AUDIO_U8: { |
| 148 | Uint8 *src, *dst; |
| 149 | |
| 150 | src = cvt->buf; |
| 151 | dst = cvt->buf; |
| 152 | for ( i=cvt->len_cvt/6; i; --i ) { |
| 153 | dst[0] = src[0]; |
| 154 | dst[1] = src[1]; |
| 155 | src += 6; |
| 156 | dst += 2; |
| 157 | } |
| 158 | } |
| 159 | break; |
| 160 | |
| 161 | case AUDIO_S8: { |
| 162 | Sint8 *src, *dst; |
| 163 | |
| 164 | src = (Sint8 *)cvt->buf; |
| 165 | dst = (Sint8 *)cvt->buf; |
| 166 | for ( i=cvt->len_cvt/6; i; --i ) { |
| 167 | dst[0] = src[0]; |
| 168 | dst[1] = src[1]; |
| 169 | src += 6; |
| 170 | dst += 2; |
| 171 | } |
| 172 | } |
| 173 | break; |
| 174 | |
| 175 | case AUDIO_U16: { |
| 176 | Uint8 *src, *dst; |
| 177 | |
| 178 | src = cvt->buf; |
| 179 | dst = cvt->buf; |
| 180 | if ( (format & 0x1000) == 0x1000 ) { |
| 181 | for ( i=cvt->len_cvt/12; i; --i ) { |
| 182 | lsample = (Uint16)((src[0]<<8)|src[1]); |
| 183 | rsample = (Uint16)((src[2]<<8)|src[3]); |
| 184 | dst[1] = (lsample&0xFF); |
| 185 | lsample >>= 8; |
| 186 | dst[0] = (lsample&0xFF); |
| 187 | dst[3] = (rsample&0xFF); |
| 188 | rsample >>= 8; |
| 189 | dst[2] = (rsample&0xFF); |
| 190 | src += 12; |
| 191 | dst += 4; |
| 192 | } |
| 193 | } else { |
| 194 | for ( i=cvt->len_cvt/12; i; --i ) { |
| 195 | lsample = (Uint16)((src[1]<<8)|src[0]); |
| 196 | rsample = (Uint16)((src[3]<<8)|src[2]); |
| 197 | dst[0] = (lsample&0xFF); |
| 198 | lsample >>= 8; |
| 199 | dst[1] = (lsample&0xFF); |
| 200 | dst[2] = (rsample&0xFF); |
| 201 | rsample >>= 8; |
| 202 | dst[3] = (rsample&0xFF); |
| 203 | src += 12; |
| 204 | dst += 4; |
| 205 | } |
| 206 | } |
| 207 | } |
| 208 | break; |
| 209 | |
| 210 | case AUDIO_S16: { |
| 211 | Uint8 *src, *dst; |
| 212 | |
| 213 | src = cvt->buf; |
| 214 | dst = cvt->buf; |
| 215 | if ( (format & 0x1000) == 0x1000 ) { |
| 216 | for ( i=cvt->len_cvt/12; i; --i ) { |
| 217 | lsample = (Sint16)((src[0]<<8)|src[1]); |
| 218 | rsample = (Sint16)((src[2]<<8)|src[3]); |
| 219 | dst[1] = (lsample&0xFF); |
| 220 | lsample >>= 8; |
| 221 | dst[0] = (lsample&0xFF); |
| 222 | dst[3] = (rsample&0xFF); |
| 223 | rsample >>= 8; |
| 224 | dst[2] = (rsample&0xFF); |
| 225 | src += 12; |
| 226 | dst += 4; |
| 227 | } |
| 228 | } else { |
| 229 | for ( i=cvt->len_cvt/12; i; --i ) { |
| 230 | lsample = (Sint16)((src[1]<<8)|src[0]); |
| 231 | rsample = (Sint16)((src[3]<<8)|src[2]); |
| 232 | dst[0] = (lsample&0xFF); |
| 233 | lsample >>= 8; |
| 234 | dst[1] = (lsample&0xFF); |
| 235 | dst[2] = (rsample&0xFF); |
| 236 | rsample >>= 8; |
| 237 | dst[3] = (rsample&0xFF); |
| 238 | src += 12; |
| 239 | dst += 4; |
| 240 | } |
| 241 | } |
| 242 | } |
| 243 | break; |
| 244 | } |
| 245 | cvt->len_cvt /= 3; |
| 246 | if ( cvt->filters[++cvt->filter_index] ) { |
| 247 | cvt->filters[cvt->filter_index](cvt, format); |
| 248 | } |
| 249 | } |
| 250 | |
| 251 | |
| 252 | /* Discard top 2 channels of 6 */ |
| 253 | void SDLCALL SDL_ConvertStrip_2(SDL_AudioCVT *cvt, Uint16 format) |
| 254 | { |
| 255 | int i; |
| 256 | Sint32 lsample, rsample; |
| 257 | |
| 258 | #ifdef DEBUG_CONVERT |
| 259 | fprintf(stderr, "Converting 6 down to quad\n"); |
| 260 | #endif |
| 261 | switch (format&0x8018) { |
| 262 | |
| 263 | case AUDIO_U8: { |
| 264 | Uint8 *src, *dst; |
| 265 | |
| 266 | src = cvt->buf; |
| 267 | dst = cvt->buf; |
| 268 | for ( i=cvt->len_cvt/4; i; --i ) { |
| 269 | dst[0] = src[0]; |
| 270 | dst[1] = src[1]; |
| 271 | src += 4; |
| 272 | dst += 2; |
| 273 | } |
| 274 | } |
| 275 | break; |
| 276 | |
| 277 | case AUDIO_S8: { |
| 278 | Sint8 *src, *dst; |
| 279 | |
| 280 | src = (Sint8 *)cvt->buf; |
| 281 | dst = (Sint8 *)cvt->buf; |
| 282 | for ( i=cvt->len_cvt/4; i; --i ) { |
| 283 | dst[0] = src[0]; |
| 284 | dst[1] = src[1]; |
| 285 | src += 4; |
| 286 | dst += 2; |
| 287 | } |
| 288 | } |
| 289 | break; |
| 290 | |
| 291 | case AUDIO_U16: { |
| 292 | Uint8 *src, *dst; |
| 293 | |
| 294 | src = cvt->buf; |
| 295 | dst = cvt->buf; |
| 296 | if ( (format & 0x1000) == 0x1000 ) { |
| 297 | for ( i=cvt->len_cvt/8; i; --i ) { |
| 298 | lsample = (Uint16)((src[0]<<8)|src[1]); |
| 299 | rsample = (Uint16)((src[2]<<8)|src[3]); |
| 300 | dst[1] = (lsample&0xFF); |
| 301 | lsample >>= 8; |
| 302 | dst[0] = (lsample&0xFF); |
| 303 | dst[3] = (rsample&0xFF); |
| 304 | rsample >>= 8; |
| 305 | dst[2] = (rsample&0xFF); |
| 306 | src += 8; |
| 307 | dst += 4; |
| 308 | } |
| 309 | } else { |
| 310 | for ( i=cvt->len_cvt/8; i; --i ) { |
| 311 | lsample = (Uint16)((src[1]<<8)|src[0]); |
| 312 | rsample = (Uint16)((src[3]<<8)|src[2]); |
| 313 | dst[0] = (lsample&0xFF); |
| 314 | lsample >>= 8; |
| 315 | dst[1] = (lsample&0xFF); |
| 316 | dst[2] = (rsample&0xFF); |
| 317 | rsample >>= 8; |
| 318 | dst[3] = (rsample&0xFF); |
| 319 | src += 8; |
| 320 | dst += 4; |
| 321 | } |
| 322 | } |
| 323 | } |
| 324 | break; |
| 325 | |
| 326 | case AUDIO_S16: { |
| 327 | Uint8 *src, *dst; |
| 328 | |
| 329 | src = cvt->buf; |
| 330 | dst = cvt->buf; |
| 331 | if ( (format & 0x1000) == 0x1000 ) { |
| 332 | for ( i=cvt->len_cvt/8; i; --i ) { |
| 333 | lsample = (Sint16)((src[0]<<8)|src[1]); |
| 334 | rsample = (Sint16)((src[2]<<8)|src[3]); |
| 335 | dst[1] = (lsample&0xFF); |
| 336 | lsample >>= 8; |
| 337 | dst[0] = (lsample&0xFF); |
| 338 | dst[3] = (rsample&0xFF); |
| 339 | rsample >>= 8; |
| 340 | dst[2] = (rsample&0xFF); |
| 341 | src += 8; |
| 342 | dst += 4; |
| 343 | } |
| 344 | } else { |
| 345 | for ( i=cvt->len_cvt/8; i; --i ) { |
| 346 | lsample = (Sint16)((src[1]<<8)|src[0]); |
| 347 | rsample = (Sint16)((src[3]<<8)|src[2]); |
| 348 | dst[0] = (lsample&0xFF); |
| 349 | lsample >>= 8; |
| 350 | dst[1] = (lsample&0xFF); |
| 351 | dst[2] = (rsample&0xFF); |
| 352 | rsample >>= 8; |
| 353 | dst[3] = (rsample&0xFF); |
| 354 | src += 8; |
| 355 | dst += 4; |
| 356 | } |
| 357 | } |
| 358 | } |
| 359 | break; |
| 360 | } |
| 361 | cvt->len_cvt /= 2; |
| 362 | if ( cvt->filters[++cvt->filter_index] ) { |
| 363 | cvt->filters[cvt->filter_index](cvt, format); |
| 364 | } |
| 365 | } |
| 366 | |
| 367 | /* Duplicate a mono channel to both stereo channels */ |
| 368 | void SDLCALL SDL_ConvertStereo(SDL_AudioCVT *cvt, Uint16 format) |
| 369 | { |
| 370 | int i; |
| 371 | |
| 372 | #ifdef DEBUG_CONVERT |
| 373 | fprintf(stderr, "Converting to stereo\n"); |
| 374 | #endif |
| 375 | if ( (format & 0xFF) == 16 ) { |
| 376 | Uint16 *src, *dst; |
| 377 | |
| 378 | src = (Uint16 *)(cvt->buf+cvt->len_cvt); |
| 379 | dst = (Uint16 *)(cvt->buf+cvt->len_cvt*2); |
| 380 | for ( i=cvt->len_cvt/2; i; --i ) { |
| 381 | dst -= 2; |
| 382 | src -= 1; |
| 383 | dst[0] = src[0]; |
| 384 | dst[1] = src[0]; |
| 385 | } |
| 386 | } else { |
| 387 | Uint8 *src, *dst; |
| 388 | |
| 389 | src = cvt->buf+cvt->len_cvt; |
| 390 | dst = cvt->buf+cvt->len_cvt*2; |
| 391 | for ( i=cvt->len_cvt; i; --i ) { |
| 392 | dst -= 2; |
| 393 | src -= 1; |
| 394 | dst[0] = src[0]; |
| 395 | dst[1] = src[0]; |
| 396 | } |
| 397 | } |
| 398 | cvt->len_cvt *= 2; |
| 399 | if ( cvt->filters[++cvt->filter_index] ) { |
| 400 | cvt->filters[cvt->filter_index](cvt, format); |
| 401 | } |
| 402 | } |
| 403 | |
| 404 | |
| 405 | /* Duplicate a stereo channel to a pseudo-5.1 stream */ |
| 406 | void SDLCALL SDL_ConvertSurround(SDL_AudioCVT *cvt, Uint16 format) |
| 407 | { |
| 408 | int i; |
| 409 | |
| 410 | #ifdef DEBUG_CONVERT |
| 411 | fprintf(stderr, "Converting stereo to surround\n"); |
| 412 | #endif |
| 413 | switch (format&0x8018) { |
| 414 | |
| 415 | case AUDIO_U8: { |
| 416 | Uint8 *src, *dst, lf, rf, ce; |
| 417 | |
| 418 | src = (Uint8 *)(cvt->buf+cvt->len_cvt); |
| 419 | dst = (Uint8 *)(cvt->buf+cvt->len_cvt*3); |
| 420 | for ( i=cvt->len_cvt; i; --i ) { |
| 421 | dst -= 6; |
| 422 | src -= 2; |
| 423 | lf = src[0]; |
| 424 | rf = src[1]; |
| 425 | ce = (lf/2) + (rf/2); |
| 426 | dst[0] = lf; |
| 427 | dst[1] = rf; |
| 428 | dst[2] = lf - ce; |
| 429 | dst[3] = rf - ce; |
| 430 | dst[4] = ce; |
| 431 | dst[5] = ce; |
| 432 | } |
| 433 | } |
| 434 | break; |
| 435 | |
| 436 | case AUDIO_S8: { |
| 437 | Sint8 *src, *dst, lf, rf, ce; |
| 438 | |
| 439 | src = (Sint8 *)cvt->buf+cvt->len_cvt; |
| 440 | dst = (Sint8 *)cvt->buf+cvt->len_cvt*3; |
| 441 | for ( i=cvt->len_cvt; i; --i ) { |
| 442 | dst -= 6; |
| 443 | src -= 2; |
| 444 | lf = src[0]; |
| 445 | rf = src[1]; |
| 446 | ce = (lf/2) + (rf/2); |
| 447 | dst[0] = lf; |
| 448 | dst[1] = rf; |
| 449 | dst[2] = lf - ce; |
| 450 | dst[3] = rf - ce; |
| 451 | dst[4] = ce; |
| 452 | dst[5] = ce; |
| 453 | } |
| 454 | } |
| 455 | break; |
| 456 | |
| 457 | case AUDIO_U16: { |
| 458 | Uint8 *src, *dst; |
| 459 | Uint16 lf, rf, ce, lr, rr; |
| 460 | |
| 461 | src = cvt->buf+cvt->len_cvt; |
| 462 | dst = cvt->buf+cvt->len_cvt*3; |
| 463 | |
| 464 | if ( (format & 0x1000) == 0x1000 ) { |
| 465 | for ( i=cvt->len_cvt/4; i; --i ) { |
| 466 | dst -= 12; |
| 467 | src -= 4; |
| 468 | lf = (Uint16)((src[0]<<8)|src[1]); |
| 469 | rf = (Uint16)((src[2]<<8)|src[3]); |
| 470 | ce = (lf/2) + (rf/2); |
| 471 | rr = lf - ce; |
| 472 | lr = rf - ce; |
| 473 | dst[1] = (lf&0xFF); |
| 474 | dst[0] = ((lf>>8)&0xFF); |
| 475 | dst[3] = (rf&0xFF); |
| 476 | dst[2] = ((rf>>8)&0xFF); |
| 477 | |
| 478 | dst[1+4] = (lr&0xFF); |
| 479 | dst[0+4] = ((lr>>8)&0xFF); |
| 480 | dst[3+4] = (rr&0xFF); |
| 481 | dst[2+4] = ((rr>>8)&0xFF); |
| 482 | |
| 483 | dst[1+8] = (ce&0xFF); |
| 484 | dst[0+8] = ((ce>>8)&0xFF); |
| 485 | dst[3+8] = (ce&0xFF); |
| 486 | dst[2+8] = ((ce>>8)&0xFF); |
| 487 | } |
| 488 | } else { |
| 489 | for ( i=cvt->len_cvt/4; i; --i ) { |
| 490 | dst -= 12; |
| 491 | src -= 4; |
| 492 | lf = (Uint16)((src[1]<<8)|src[0]); |
| 493 | rf = (Uint16)((src[3]<<8)|src[2]); |
| 494 | ce = (lf/2) + (rf/2); |
| 495 | rr = lf - ce; |
| 496 | lr = rf - ce; |
| 497 | dst[0] = (lf&0xFF); |
| 498 | dst[1] = ((lf>>8)&0xFF); |
| 499 | dst[2] = (rf&0xFF); |
| 500 | dst[3] = ((rf>>8)&0xFF); |
| 501 | |
| 502 | dst[0+4] = (lr&0xFF); |
| 503 | dst[1+4] = ((lr>>8)&0xFF); |
| 504 | dst[2+4] = (rr&0xFF); |
| 505 | dst[3+4] = ((rr>>8)&0xFF); |
| 506 | |
| 507 | dst[0+8] = (ce&0xFF); |
| 508 | dst[1+8] = ((ce>>8)&0xFF); |
| 509 | dst[2+8] = (ce&0xFF); |
| 510 | dst[3+8] = ((ce>>8)&0xFF); |
| 511 | } |
| 512 | } |
| 513 | } |
| 514 | break; |
| 515 | |
| 516 | case AUDIO_S16: { |
| 517 | Uint8 *src, *dst; |
| 518 | Sint16 lf, rf, ce, lr, rr; |
| 519 | |
| 520 | src = cvt->buf+cvt->len_cvt; |
| 521 | dst = cvt->buf+cvt->len_cvt*3; |
| 522 | |
| 523 | if ( (format & 0x1000) == 0x1000 ) { |
| 524 | for ( i=cvt->len_cvt/4; i; --i ) { |
| 525 | dst -= 12; |
| 526 | src -= 4; |
| 527 | lf = (Sint16)((src[0]<<8)|src[1]); |
| 528 | rf = (Sint16)((src[2]<<8)|src[3]); |
| 529 | ce = (lf/2) + (rf/2); |
| 530 | rr = lf - ce; |
| 531 | lr = rf - ce; |
| 532 | dst[1] = (lf&0xFF); |
| 533 | dst[0] = ((lf>>8)&0xFF); |
| 534 | dst[3] = (rf&0xFF); |
| 535 | dst[2] = ((rf>>8)&0xFF); |
| 536 | |
| 537 | dst[1+4] = (lr&0xFF); |
| 538 | dst[0+4] = ((lr>>8)&0xFF); |
| 539 | dst[3+4] = (rr&0xFF); |
| 540 | dst[2+4] = ((rr>>8)&0xFF); |
| 541 | |
| 542 | dst[1+8] = (ce&0xFF); |
| 543 | dst[0+8] = ((ce>>8)&0xFF); |
| 544 | dst[3+8] = (ce&0xFF); |
| 545 | dst[2+8] = ((ce>>8)&0xFF); |
| 546 | } |
| 547 | } else { |
| 548 | for ( i=cvt->len_cvt/4; i; --i ) { |
| 549 | dst -= 12; |
| 550 | src -= 4; |
| 551 | lf = (Sint16)((src[1]<<8)|src[0]); |
| 552 | rf = (Sint16)((src[3]<<8)|src[2]); |
| 553 | ce = (lf/2) + (rf/2); |
| 554 | rr = lf - ce; |
| 555 | lr = rf - ce; |
| 556 | dst[0] = (lf&0xFF); |
| 557 | dst[1] = ((lf>>8)&0xFF); |
| 558 | dst[2] = (rf&0xFF); |
| 559 | dst[3] = ((rf>>8)&0xFF); |
| 560 | |
| 561 | dst[0+4] = (lr&0xFF); |
| 562 | dst[1+4] = ((lr>>8)&0xFF); |
| 563 | dst[2+4] = (rr&0xFF); |
| 564 | dst[3+4] = ((rr>>8)&0xFF); |
| 565 | |
| 566 | dst[0+8] = (ce&0xFF); |
| 567 | dst[1+8] = ((ce>>8)&0xFF); |
| 568 | dst[2+8] = (ce&0xFF); |
| 569 | dst[3+8] = ((ce>>8)&0xFF); |
| 570 | } |
| 571 | } |
| 572 | } |
| 573 | break; |
| 574 | } |
| 575 | cvt->len_cvt *= 3; |
| 576 | if ( cvt->filters[++cvt->filter_index] ) { |
| 577 | cvt->filters[cvt->filter_index](cvt, format); |
| 578 | } |
| 579 | } |
| 580 | |
| 581 | |
| 582 | /* Duplicate a stereo channel to a pseudo-4.0 stream */ |
| 583 | void SDLCALL SDL_ConvertSurround_4(SDL_AudioCVT *cvt, Uint16 format) |
| 584 | { |
| 585 | int i; |
| 586 | |
| 587 | #ifdef DEBUG_CONVERT |
| 588 | fprintf(stderr, "Converting stereo to quad\n"); |
| 589 | #endif |
| 590 | switch (format&0x8018) { |
| 591 | |
| 592 | case AUDIO_U8: { |
| 593 | Uint8 *src, *dst, lf, rf, ce; |
| 594 | |
| 595 | src = (Uint8 *)(cvt->buf+cvt->len_cvt); |
| 596 | dst = (Uint8 *)(cvt->buf+cvt->len_cvt*2); |
| 597 | for ( i=cvt->len_cvt; i; --i ) { |
| 598 | dst -= 4; |
| 599 | src -= 2; |
| 600 | lf = src[0]; |
| 601 | rf = src[1]; |
| 602 | ce = (lf/2) + (rf/2); |
| 603 | dst[0] = lf; |
| 604 | dst[1] = rf; |
| 605 | dst[2] = lf - ce; |
| 606 | dst[3] = rf - ce; |
| 607 | } |
| 608 | } |
| 609 | break; |
| 610 | |
| 611 | case AUDIO_S8: { |
| 612 | Sint8 *src, *dst, lf, rf, ce; |
| 613 | |
| 614 | src = (Sint8 *)cvt->buf+cvt->len_cvt; |
| 615 | dst = (Sint8 *)cvt->buf+cvt->len_cvt*2; |
| 616 | for ( i=cvt->len_cvt; i; --i ) { |
| 617 | dst -= 4; |
| 618 | src -= 2; |
| 619 | lf = src[0]; |
| 620 | rf = src[1]; |
| 621 | ce = (lf/2) + (rf/2); |
| 622 | dst[0] = lf; |
| 623 | dst[1] = rf; |
| 624 | dst[2] = lf - ce; |
| 625 | dst[3] = rf - ce; |
| 626 | } |
| 627 | } |
| 628 | break; |
| 629 | |
| 630 | case AUDIO_U16: { |
| 631 | Uint8 *src, *dst; |
| 632 | Uint16 lf, rf, ce, lr, rr; |
| 633 | |
| 634 | src = cvt->buf+cvt->len_cvt; |
| 635 | dst = cvt->buf+cvt->len_cvt*2; |
| 636 | |
| 637 | if ( (format & 0x1000) == 0x1000 ) { |
| 638 | for ( i=cvt->len_cvt/4; i; --i ) { |
| 639 | dst -= 8; |
| 640 | src -= 4; |
| 641 | lf = (Uint16)((src[0]<<8)|src[1]); |
| 642 | rf = (Uint16)((src[2]<<8)|src[3]); |
| 643 | ce = (lf/2) + (rf/2); |
| 644 | rr = lf - ce; |
| 645 | lr = rf - ce; |
| 646 | dst[1] = (lf&0xFF); |
| 647 | dst[0] = ((lf>>8)&0xFF); |
| 648 | dst[3] = (rf&0xFF); |
| 649 | dst[2] = ((rf>>8)&0xFF); |
| 650 | |
| 651 | dst[1+4] = (lr&0xFF); |
| 652 | dst[0+4] = ((lr>>8)&0xFF); |
| 653 | dst[3+4] = (rr&0xFF); |
| 654 | dst[2+4] = ((rr>>8)&0xFF); |
| 655 | } |
| 656 | } else { |
| 657 | for ( i=cvt->len_cvt/4; i; --i ) { |
| 658 | dst -= 8; |
| 659 | src -= 4; |
| 660 | lf = (Uint16)((src[1]<<8)|src[0]); |
| 661 | rf = (Uint16)((src[3]<<8)|src[2]); |
| 662 | ce = (lf/2) + (rf/2); |
| 663 | rr = lf - ce; |
| 664 | lr = rf - ce; |
| 665 | dst[0] = (lf&0xFF); |
| 666 | dst[1] = ((lf>>8)&0xFF); |
| 667 | dst[2] = (rf&0xFF); |
| 668 | dst[3] = ((rf>>8)&0xFF); |
| 669 | |
| 670 | dst[0+4] = (lr&0xFF); |
| 671 | dst[1+4] = ((lr>>8)&0xFF); |
| 672 | dst[2+4] = (rr&0xFF); |
| 673 | dst[3+4] = ((rr>>8)&0xFF); |
| 674 | } |
| 675 | } |
| 676 | } |
| 677 | break; |
| 678 | |
| 679 | case AUDIO_S16: { |
| 680 | Uint8 *src, *dst; |
| 681 | Sint16 lf, rf, ce, lr, rr; |
| 682 | |
| 683 | src = cvt->buf+cvt->len_cvt; |
| 684 | dst = cvt->buf+cvt->len_cvt*2; |
| 685 | |
| 686 | if ( (format & 0x1000) == 0x1000 ) { |
| 687 | for ( i=cvt->len_cvt/4; i; --i ) { |
| 688 | dst -= 8; |
| 689 | src -= 4; |
| 690 | lf = (Sint16)((src[0]<<8)|src[1]); |
| 691 | rf = (Sint16)((src[2]<<8)|src[3]); |
| 692 | ce = (lf/2) + (rf/2); |
| 693 | rr = lf - ce; |
| 694 | lr = rf - ce; |
| 695 | dst[1] = (lf&0xFF); |
| 696 | dst[0] = ((lf>>8)&0xFF); |
| 697 | dst[3] = (rf&0xFF); |
| 698 | dst[2] = ((rf>>8)&0xFF); |
| 699 | |
| 700 | dst[1+4] = (lr&0xFF); |
| 701 | dst[0+4] = ((lr>>8)&0xFF); |
| 702 | dst[3+4] = (rr&0xFF); |
| 703 | dst[2+4] = ((rr>>8)&0xFF); |
| 704 | } |
| 705 | } else { |
| 706 | for ( i=cvt->len_cvt/4; i; --i ) { |
| 707 | dst -= 8; |
| 708 | src -= 4; |
| 709 | lf = (Sint16)((src[1]<<8)|src[0]); |
| 710 | rf = (Sint16)((src[3]<<8)|src[2]); |
| 711 | ce = (lf/2) + (rf/2); |
| 712 | rr = lf - ce; |
| 713 | lr = rf - ce; |
| 714 | dst[0] = (lf&0xFF); |
| 715 | dst[1] = ((lf>>8)&0xFF); |
| 716 | dst[2] = (rf&0xFF); |
| 717 | dst[3] = ((rf>>8)&0xFF); |
| 718 | |
| 719 | dst[0+4] = (lr&0xFF); |
| 720 | dst[1+4] = ((lr>>8)&0xFF); |
| 721 | dst[2+4] = (rr&0xFF); |
| 722 | dst[3+4] = ((rr>>8)&0xFF); |
| 723 | } |
| 724 | } |
| 725 | } |
| 726 | break; |
| 727 | } |
| 728 | cvt->len_cvt *= 2; |
| 729 | if ( cvt->filters[++cvt->filter_index] ) { |
| 730 | cvt->filters[cvt->filter_index](cvt, format); |
| 731 | } |
| 732 | } |
| 733 | |
| 734 | |
| 735 | /* Convert 8-bit to 16-bit - LSB */ |
| 736 | void SDLCALL SDL_Convert16LSB(SDL_AudioCVT *cvt, Uint16 format) |
| 737 | { |
| 738 | int i; |
| 739 | Uint8 *src, *dst; |
| 740 | |
| 741 | #ifdef DEBUG_CONVERT |
| 742 | fprintf(stderr, "Converting to 16-bit LSB\n"); |
| 743 | #endif |
| 744 | src = cvt->buf+cvt->len_cvt; |
| 745 | dst = cvt->buf+cvt->len_cvt*2; |
| 746 | for ( i=cvt->len_cvt; i; --i ) { |
| 747 | src -= 1; |
| 748 | dst -= 2; |
| 749 | dst[1] = *src; |
| 750 | dst[0] = 0; |
| 751 | } |
| 752 | format = ((format & ~0x0008) | AUDIO_U16LSB); |
| 753 | cvt->len_cvt *= 2; |
| 754 | if ( cvt->filters[++cvt->filter_index] ) { |
| 755 | cvt->filters[cvt->filter_index](cvt, format); |
| 756 | } |
| 757 | } |
| 758 | /* Convert 8-bit to 16-bit - MSB */ |
| 759 | void SDLCALL SDL_Convert16MSB(SDL_AudioCVT *cvt, Uint16 format) |
| 760 | { |
| 761 | int i; |
| 762 | Uint8 *src, *dst; |
| 763 | |
| 764 | #ifdef DEBUG_CONVERT |
| 765 | fprintf(stderr, "Converting to 16-bit MSB\n"); |
| 766 | #endif |
| 767 | src = cvt->buf+cvt->len_cvt; |
| 768 | dst = cvt->buf+cvt->len_cvt*2; |
| 769 | for ( i=cvt->len_cvt; i; --i ) { |
| 770 | src -= 1; |
| 771 | dst -= 2; |
| 772 | dst[0] = *src; |
| 773 | dst[1] = 0; |
| 774 | } |
| 775 | format = ((format & ~0x0008) | AUDIO_U16MSB); |
| 776 | cvt->len_cvt *= 2; |
| 777 | if ( cvt->filters[++cvt->filter_index] ) { |
| 778 | cvt->filters[cvt->filter_index](cvt, format); |
| 779 | } |
| 780 | } |
| 781 | |
| 782 | /* Convert 16-bit to 8-bit */ |
| 783 | void SDLCALL SDL_Convert8(SDL_AudioCVT *cvt, Uint16 format) |
| 784 | { |
| 785 | int i; |
| 786 | Uint8 *src, *dst; |
| 787 | |
| 788 | #ifdef DEBUG_CONVERT |
| 789 | fprintf(stderr, "Converting to 8-bit\n"); |
| 790 | #endif |
| 791 | src = cvt->buf; |
| 792 | dst = cvt->buf; |
| 793 | if ( (format & 0x1000) != 0x1000 ) { /* Little endian */ |
| 794 | ++src; |
| 795 | } |
| 796 | for ( i=cvt->len_cvt/2; i; --i ) { |
| 797 | *dst = *src; |
| 798 | src += 2; |
| 799 | dst += 1; |
| 800 | } |
| 801 | format = ((format & ~0x9010) | AUDIO_U8); |
| 802 | cvt->len_cvt /= 2; |
| 803 | if ( cvt->filters[++cvt->filter_index] ) { |
| 804 | cvt->filters[cvt->filter_index](cvt, format); |
| 805 | } |
| 806 | } |
| 807 | |
| 808 | /* Toggle signed/unsigned */ |
| 809 | void SDLCALL SDL_ConvertSign(SDL_AudioCVT *cvt, Uint16 format) |
| 810 | { |
| 811 | int i; |
| 812 | Uint8 *data; |
| 813 | |
| 814 | #ifdef DEBUG_CONVERT |
| 815 | fprintf(stderr, "Converting audio signedness\n"); |
| 816 | #endif |
| 817 | data = cvt->buf; |
| 818 | if ( (format & 0xFF) == 16 ) { |
| 819 | if ( (format & 0x1000) != 0x1000 ) { /* Little endian */ |
| 820 | ++data; |
| 821 | } |
| 822 | for ( i=cvt->len_cvt/2; i; --i ) { |
| 823 | *data ^= 0x80; |
| 824 | data += 2; |
| 825 | } |
| 826 | } else { |
| 827 | for ( i=cvt->len_cvt; i; --i ) { |
| 828 | *data++ ^= 0x80; |
| 829 | } |
| 830 | } |
| 831 | format = (format ^ 0x8000); |
| 832 | if ( cvt->filters[++cvt->filter_index] ) { |
| 833 | cvt->filters[cvt->filter_index](cvt, format); |
| 834 | } |
| 835 | } |
| 836 | |
| 837 | /* Toggle endianness */ |
| 838 | void SDLCALL SDL_ConvertEndian(SDL_AudioCVT *cvt, Uint16 format) |
| 839 | { |
| 840 | int i; |
| 841 | Uint8 *data, tmp; |
| 842 | |
| 843 | #ifdef DEBUG_CONVERT |
| 844 | fprintf(stderr, "Converting audio endianness\n"); |
| 845 | #endif |
| 846 | data = cvt->buf; |
| 847 | for ( i=cvt->len_cvt/2; i; --i ) { |
| 848 | tmp = data[0]; |
| 849 | data[0] = data[1]; |
| 850 | data[1] = tmp; |
| 851 | data += 2; |
| 852 | } |
| 853 | format = (format ^ 0x1000); |
| 854 | if ( cvt->filters[++cvt->filter_index] ) { |
| 855 | cvt->filters[cvt->filter_index](cvt, format); |
| 856 | } |
| 857 | } |
| 858 | |
| 859 | /* Convert rate up by multiple of 2 */ |
| 860 | void SDLCALL SDL_RateMUL2(SDL_AudioCVT *cvt, Uint16 format) |
| 861 | { |
| 862 | int i; |
| 863 | Uint8 *src, *dst; |
| 864 | |
| 865 | #ifdef DEBUG_CONVERT |
| 866 | fprintf(stderr, "Converting audio rate * 2\n"); |
| 867 | #endif |
| 868 | src = cvt->buf+cvt->len_cvt; |
| 869 | dst = cvt->buf+cvt->len_cvt*2; |
| 870 | switch (format & 0xFF) { |
| 871 | case 8: |
| 872 | for ( i=cvt->len_cvt; i; --i ) { |
| 873 | src -= 1; |
| 874 | dst -= 2; |
| 875 | dst[0] = src[0]; |
| 876 | dst[1] = src[0]; |
| 877 | } |
| 878 | break; |
| 879 | case 16: |
| 880 | for ( i=cvt->len_cvt/2; i; --i ) { |
| 881 | src -= 2; |
| 882 | dst -= 4; |
| 883 | dst[0] = src[0]; |
| 884 | dst[1] = src[1]; |
| 885 | dst[2] = src[0]; |
| 886 | dst[3] = src[1]; |
| 887 | } |
| 888 | break; |
| 889 | } |
| 890 | cvt->len_cvt *= 2; |
| 891 | if ( cvt->filters[++cvt->filter_index] ) { |
| 892 | cvt->filters[cvt->filter_index](cvt, format); |
| 893 | } |
| 894 | } |
| 895 | |
| 896 | |
| 897 | /* Convert rate up by multiple of 2, for stereo */ |
| 898 | void SDLCALL SDL_RateMUL2_c2(SDL_AudioCVT *cvt, Uint16 format) |
| 899 | { |
| 900 | int i; |
| 901 | Uint8 *src, *dst; |
| 902 | |
| 903 | #ifdef DEBUG_CONVERT |
| 904 | fprintf(stderr, "Converting audio rate * 2\n"); |
| 905 | #endif |
| 906 | src = cvt->buf+cvt->len_cvt; |
| 907 | dst = cvt->buf+cvt->len_cvt*2; |
| 908 | switch (format & 0xFF) { |
| 909 | case 8: |
| 910 | for ( i=cvt->len_cvt/2; i; --i ) { |
| 911 | src -= 2; |
| 912 | dst -= 4; |
| 913 | dst[0] = src[0]; |
| 914 | dst[1] = src[1]; |
| 915 | dst[2] = src[0]; |
| 916 | dst[3] = src[1]; |
| 917 | } |
| 918 | break; |
| 919 | case 16: |
| 920 | for ( i=cvt->len_cvt/4; i; --i ) { |
| 921 | src -= 4; |
| 922 | dst -= 8; |
| 923 | dst[0] = src[0]; |
| 924 | dst[1] = src[1]; |
| 925 | dst[2] = src[2]; |
| 926 | dst[3] = src[3]; |
| 927 | dst[4] = src[0]; |
| 928 | dst[5] = src[1]; |
| 929 | dst[6] = src[2]; |
| 930 | dst[7] = src[3]; |
| 931 | } |
| 932 | break; |
| 933 | } |
| 934 | cvt->len_cvt *= 2; |
| 935 | if ( cvt->filters[++cvt->filter_index] ) { |
| 936 | cvt->filters[cvt->filter_index](cvt, format); |
| 937 | } |
| 938 | } |
| 939 | |
| 940 | /* Convert rate up by multiple of 2, for quad */ |
| 941 | void SDLCALL SDL_RateMUL2_c4(SDL_AudioCVT *cvt, Uint16 format) |
| 942 | { |
| 943 | int i; |
| 944 | Uint8 *src, *dst; |
| 945 | |
| 946 | #ifdef DEBUG_CONVERT |
| 947 | fprintf(stderr, "Converting audio rate * 2\n"); |
| 948 | #endif |
| 949 | src = cvt->buf+cvt->len_cvt; |
| 950 | dst = cvt->buf+cvt->len_cvt*2; |
| 951 | switch (format & 0xFF) { |
| 952 | case 8: |
| 953 | for ( i=cvt->len_cvt/4; i; --i ) { |
| 954 | src -= 4; |
| 955 | dst -= 8; |
| 956 | dst[0] = src[0]; |
| 957 | dst[1] = src[1]; |
| 958 | dst[2] = src[2]; |
| 959 | dst[3] = src[3]; |
| 960 | dst[4] = src[0]; |
| 961 | dst[5] = src[1]; |
| 962 | dst[6] = src[2]; |
| 963 | dst[7] = src[3]; |
| 964 | } |
| 965 | break; |
| 966 | case 16: |
| 967 | for ( i=cvt->len_cvt/8; i; --i ) { |
| 968 | src -= 8; |
| 969 | dst -= 16; |
| 970 | dst[0] = src[0]; |
| 971 | dst[1] = src[1]; |
| 972 | dst[2] = src[2]; |
| 973 | dst[3] = src[3]; |
| 974 | dst[4] = src[4]; |
| 975 | dst[5] = src[5]; |
| 976 | dst[6] = src[6]; |
| 977 | dst[7] = src[7]; |
| 978 | dst[8] = src[0]; |
| 979 | dst[9] = src[1]; |
| 980 | dst[10] = src[2]; |
| 981 | dst[11] = src[3]; |
| 982 | dst[12] = src[4]; |
| 983 | dst[13] = src[5]; |
| 984 | dst[14] = src[6]; |
| 985 | dst[15] = src[7]; |
| 986 | } |
| 987 | break; |
| 988 | } |
| 989 | cvt->len_cvt *= 2; |
| 990 | if ( cvt->filters[++cvt->filter_index] ) { |
| 991 | cvt->filters[cvt->filter_index](cvt, format); |
| 992 | } |
| 993 | } |
| 994 | |
| 995 | |
| 996 | /* Convert rate up by multiple of 2, for 5.1 */ |
| 997 | void SDLCALL SDL_RateMUL2_c6(SDL_AudioCVT *cvt, Uint16 format) |
| 998 | { |
| 999 | int i; |
| 1000 | Uint8 *src, *dst; |
| 1001 | |
| 1002 | #ifdef DEBUG_CONVERT |
| 1003 | fprintf(stderr, "Converting audio rate * 2\n"); |
| 1004 | #endif |
| 1005 | src = cvt->buf+cvt->len_cvt; |
| 1006 | dst = cvt->buf+cvt->len_cvt*2; |
| 1007 | switch (format & 0xFF) { |
| 1008 | case 8: |
| 1009 | for ( i=cvt->len_cvt/6; i; --i ) { |
| 1010 | src -= 6; |
| 1011 | dst -= 12; |
| 1012 | dst[0] = src[0]; |
| 1013 | dst[1] = src[1]; |
| 1014 | dst[2] = src[2]; |
| 1015 | dst[3] = src[3]; |
| 1016 | dst[4] = src[4]; |
| 1017 | dst[5] = src[5]; |
| 1018 | dst[6] = src[0]; |
| 1019 | dst[7] = src[1]; |
| 1020 | dst[8] = src[2]; |
| 1021 | dst[9] = src[3]; |
| 1022 | dst[10] = src[4]; |
| 1023 | dst[11] = src[5]; |
| 1024 | } |
| 1025 | break; |
| 1026 | case 16: |
| 1027 | for ( i=cvt->len_cvt/12; i; --i ) { |
| 1028 | src -= 12; |
| 1029 | dst -= 24; |
| 1030 | dst[0] = src[0]; |
| 1031 | dst[1] = src[1]; |
| 1032 | dst[2] = src[2]; |
| 1033 | dst[3] = src[3]; |
| 1034 | dst[4] = src[4]; |
| 1035 | dst[5] = src[5]; |
| 1036 | dst[6] = src[6]; |
| 1037 | dst[7] = src[7]; |
| 1038 | dst[8] = src[8]; |
| 1039 | dst[9] = src[9]; |
| 1040 | dst[10] = src[10]; |
| 1041 | dst[11] = src[11]; |
| 1042 | dst[12] = src[0]; |
| 1043 | dst[13] = src[1]; |
| 1044 | dst[14] = src[2]; |
| 1045 | dst[15] = src[3]; |
| 1046 | dst[16] = src[4]; |
| 1047 | dst[17] = src[5]; |
| 1048 | dst[18] = src[6]; |
| 1049 | dst[19] = src[7]; |
| 1050 | dst[20] = src[8]; |
| 1051 | dst[21] = src[9]; |
| 1052 | dst[22] = src[10]; |
| 1053 | dst[23] = src[11]; |
| 1054 | } |
| 1055 | break; |
| 1056 | } |
| 1057 | cvt->len_cvt *= 2; |
| 1058 | if ( cvt->filters[++cvt->filter_index] ) { |
| 1059 | cvt->filters[cvt->filter_index](cvt, format); |
| 1060 | } |
| 1061 | } |
| 1062 | |
| 1063 | /* Convert rate down by multiple of 2 */ |
| 1064 | void SDLCALL SDL_RateDIV2(SDL_AudioCVT *cvt, Uint16 format) |
| 1065 | { |
| 1066 | int i; |
| 1067 | Uint8 *src, *dst; |
| 1068 | |
| 1069 | #ifdef DEBUG_CONVERT |
| 1070 | fprintf(stderr, "Converting audio rate / 2\n"); |
| 1071 | #endif |
| 1072 | src = cvt->buf; |
| 1073 | dst = cvt->buf; |
| 1074 | switch (format & 0xFF) { |
| 1075 | case 8: |
| 1076 | for ( i=cvt->len_cvt/2; i; --i ) { |
| 1077 | dst[0] = src[0]; |
| 1078 | src += 2; |
| 1079 | dst += 1; |
| 1080 | } |
| 1081 | break; |
| 1082 | case 16: |
| 1083 | for ( i=cvt->len_cvt/4; i; --i ) { |
| 1084 | dst[0] = src[0]; |
| 1085 | dst[1] = src[1]; |
| 1086 | src += 4; |
| 1087 | dst += 2; |
| 1088 | } |
| 1089 | break; |
| 1090 | } |
| 1091 | cvt->len_cvt /= 2; |
| 1092 | if ( cvt->filters[++cvt->filter_index] ) { |
| 1093 | cvt->filters[cvt->filter_index](cvt, format); |
| 1094 | } |
| 1095 | } |
| 1096 | |
| 1097 | |
| 1098 | /* Convert rate down by multiple of 2, for stereo */ |
| 1099 | void SDLCALL SDL_RateDIV2_c2(SDL_AudioCVT *cvt, Uint16 format) |
| 1100 | { |
| 1101 | int i; |
| 1102 | Uint8 *src, *dst; |
| 1103 | |
| 1104 | #ifdef DEBUG_CONVERT |
| 1105 | fprintf(stderr, "Converting audio rate / 2\n"); |
| 1106 | #endif |
| 1107 | src = cvt->buf; |
| 1108 | dst = cvt->buf; |
| 1109 | switch (format & 0xFF) { |
| 1110 | case 8: |
| 1111 | for ( i=cvt->len_cvt/4; i; --i ) { |
| 1112 | dst[0] = src[0]; |
| 1113 | dst[1] = src[1]; |
| 1114 | src += 4; |
| 1115 | dst += 2; |
| 1116 | } |
| 1117 | break; |
| 1118 | case 16: |
| 1119 | for ( i=cvt->len_cvt/8; i; --i ) { |
| 1120 | dst[0] = src[0]; |
| 1121 | dst[1] = src[1]; |
| 1122 | dst[2] = src[2]; |
| 1123 | dst[3] = src[3]; |
| 1124 | src += 8; |
| 1125 | dst += 4; |
| 1126 | } |
| 1127 | break; |
| 1128 | } |
| 1129 | cvt->len_cvt /= 2; |
| 1130 | if ( cvt->filters[++cvt->filter_index] ) { |
| 1131 | cvt->filters[cvt->filter_index](cvt, format); |
| 1132 | } |
| 1133 | } |
| 1134 | |
| 1135 | |
| 1136 | /* Convert rate down by multiple of 2, for quad */ |
| 1137 | void SDLCALL SDL_RateDIV2_c4(SDL_AudioCVT *cvt, Uint16 format) |
| 1138 | { |
| 1139 | int i; |
| 1140 | Uint8 *src, *dst; |
| 1141 | |
| 1142 | #ifdef DEBUG_CONVERT |
| 1143 | fprintf(stderr, "Converting audio rate / 2\n"); |
| 1144 | #endif |
| 1145 | src = cvt->buf; |
| 1146 | dst = cvt->buf; |
| 1147 | switch (format & 0xFF) { |
| 1148 | case 8: |
| 1149 | for ( i=cvt->len_cvt/8; i; --i ) { |
| 1150 | dst[0] = src[0]; |
| 1151 | dst[1] = src[1]; |
| 1152 | dst[2] = src[2]; |
| 1153 | dst[3] = src[3]; |
| 1154 | src += 8; |
| 1155 | dst += 4; |
| 1156 | } |
| 1157 | break; |
| 1158 | case 16: |
| 1159 | for ( i=cvt->len_cvt/16; i; --i ) { |
| 1160 | dst[0] = src[0]; |
| 1161 | dst[1] = src[1]; |
| 1162 | dst[2] = src[2]; |
| 1163 | dst[3] = src[3]; |
| 1164 | dst[4] = src[4]; |
| 1165 | dst[5] = src[5]; |
| 1166 | dst[6] = src[6]; |
| 1167 | dst[7] = src[7]; |
| 1168 | src += 16; |
| 1169 | dst += 8; |
| 1170 | } |
| 1171 | break; |
| 1172 | } |
| 1173 | cvt->len_cvt /= 2; |
| 1174 | if ( cvt->filters[++cvt->filter_index] ) { |
| 1175 | cvt->filters[cvt->filter_index](cvt, format); |
| 1176 | } |
| 1177 | } |
| 1178 | |
| 1179 | /* Convert rate down by multiple of 2, for 5.1 */ |
| 1180 | void SDLCALL SDL_RateDIV2_c6(SDL_AudioCVT *cvt, Uint16 format) |
| 1181 | { |
| 1182 | int i; |
| 1183 | Uint8 *src, *dst; |
| 1184 | |
| 1185 | #ifdef DEBUG_CONVERT |
| 1186 | fprintf(stderr, "Converting audio rate / 2\n"); |
| 1187 | #endif |
| 1188 | src = cvt->buf; |
| 1189 | dst = cvt->buf; |
| 1190 | switch (format & 0xFF) { |
| 1191 | case 8: |
| 1192 | for ( i=cvt->len_cvt/12; i; --i ) { |
| 1193 | dst[0] = src[0]; |
| 1194 | dst[1] = src[1]; |
| 1195 | dst[2] = src[2]; |
| 1196 | dst[3] = src[3]; |
| 1197 | dst[4] = src[4]; |
| 1198 | dst[5] = src[5]; |
| 1199 | src += 12; |
| 1200 | dst += 6; |
| 1201 | } |
| 1202 | break; |
| 1203 | case 16: |
| 1204 | for ( i=cvt->len_cvt/24; i; --i ) { |
| 1205 | dst[0] = src[0]; |
| 1206 | dst[1] = src[1]; |
| 1207 | dst[2] = src[2]; |
| 1208 | dst[3] = src[3]; |
| 1209 | dst[4] = src[4]; |
| 1210 | dst[5] = src[5]; |
| 1211 | dst[6] = src[6]; |
| 1212 | dst[7] = src[7]; |
| 1213 | dst[8] = src[8]; |
| 1214 | dst[9] = src[9]; |
| 1215 | dst[10] = src[10]; |
| 1216 | dst[11] = src[11]; |
| 1217 | src += 24; |
| 1218 | dst += 12; |
| 1219 | } |
| 1220 | break; |
| 1221 | } |
| 1222 | cvt->len_cvt /= 2; |
| 1223 | if ( cvt->filters[++cvt->filter_index] ) { |
| 1224 | cvt->filters[cvt->filter_index](cvt, format); |
| 1225 | } |
| 1226 | } |
| 1227 | |
| 1228 | /* Very slow rate conversion routine */ |
| 1229 | void SDLCALL SDL_RateSLOW(SDL_AudioCVT *cvt, Uint16 format) |
| 1230 | { |
| 1231 | double ipos; |
| 1232 | int i, clen; |
| 1233 | |
| 1234 | #ifdef DEBUG_CONVERT |
| 1235 | fprintf(stderr, "Converting audio rate * %4.4f\n", 1.0/cvt->rate_incr); |
| 1236 | #endif |
| 1237 | clen = (int)((double)cvt->len_cvt / cvt->rate_incr); |
| 1238 | if ( cvt->rate_incr > 1.0 ) { |
| 1239 | switch (format & 0xFF) { |
| 1240 | case 8: { |
| 1241 | Uint8 *output; |
| 1242 | |
| 1243 | output = cvt->buf; |
| 1244 | ipos = 0.0; |
| 1245 | for ( i=clen; i; --i ) { |
| 1246 | *output = cvt->buf[(int)ipos]; |
| 1247 | ipos += cvt->rate_incr; |
| 1248 | output += 1; |
| 1249 | } |
| 1250 | } |
| 1251 | break; |
| 1252 | |
| 1253 | case 16: { |
| 1254 | Uint16 *output; |
| 1255 | |
| 1256 | clen &= ~1; |
| 1257 | output = (Uint16 *)cvt->buf; |
| 1258 | ipos = 0.0; |
| 1259 | for ( i=clen/2; i; --i ) { |
| 1260 | *output=((Uint16 *)cvt->buf)[(int)ipos]; |
| 1261 | ipos += cvt->rate_incr; |
| 1262 | output += 1; |
| 1263 | } |
| 1264 | } |
| 1265 | break; |
| 1266 | } |
| 1267 | } else { |
| 1268 | switch (format & 0xFF) { |
| 1269 | case 8: { |
| 1270 | Uint8 *output; |
| 1271 | |
| 1272 | output = cvt->buf+clen; |
| 1273 | ipos = (double)cvt->len_cvt; |
| 1274 | for ( i=clen; i; --i ) { |
| 1275 | ipos -= cvt->rate_incr; |
| 1276 | output -= 1; |
| 1277 | *output = cvt->buf[(int)ipos]; |
| 1278 | } |
| 1279 | } |
| 1280 | break; |
| 1281 | |
| 1282 | case 16: { |
| 1283 | Uint16 *output; |
| 1284 | |
| 1285 | clen &= ~1; |
| 1286 | output = (Uint16 *)(cvt->buf+clen); |
| 1287 | ipos = (double)cvt->len_cvt/2; |
| 1288 | for ( i=clen/2; i; --i ) { |
| 1289 | ipos -= cvt->rate_incr; |
| 1290 | output -= 1; |
| 1291 | *output=((Uint16 *)cvt->buf)[(int)ipos]; |
| 1292 | } |
| 1293 | } |
| 1294 | break; |
| 1295 | } |
| 1296 | } |
| 1297 | cvt->len_cvt = clen; |
| 1298 | if ( cvt->filters[++cvt->filter_index] ) { |
| 1299 | cvt->filters[cvt->filter_index](cvt, format); |
| 1300 | } |
| 1301 | } |
| 1302 | |
| 1303 | int SDL_ConvertAudio(SDL_AudioCVT *cvt) |
| 1304 | { |
| 1305 | /* Make sure there's data to convert */ |
| 1306 | if ( cvt->buf == NULL ) { |
| 1307 | SDL_SetError("No buffer allocated for conversion"); |
| 1308 | return(-1); |
| 1309 | } |
| 1310 | /* Return okay if no conversion is necessary */ |
| 1311 | cvt->len_cvt = cvt->len; |
| 1312 | if ( cvt->filters[0] == NULL ) { |
| 1313 | return(0); |
| 1314 | } |
| 1315 | |
| 1316 | /* Set up the conversion and go! */ |
| 1317 | cvt->filter_index = 0; |
| 1318 | cvt->filters[0](cvt, cvt->src_format); |
| 1319 | return(0); |
| 1320 | } |
| 1321 | |
| 1322 | /* Creates a set of audio filters to convert from one format to another. |
| 1323 | Returns -1 if the format conversion is not supported, or 1 if the |
| 1324 | audio filter is set up. |
| 1325 | */ |
| 1326 | |
| 1327 | int SDL_BuildAudioCVT(SDL_AudioCVT *cvt, |
| 1328 | Uint16 src_format, Uint8 src_channels, int src_rate, |
| 1329 | Uint16 dst_format, Uint8 dst_channels, int dst_rate) |
| 1330 | { |
| 1331 | /*printf("Build format %04x->%04x, channels %u->%u, rate %d->%d\n", |
| 1332 | src_format, dst_format, src_channels, dst_channels, src_rate, dst_rate);*/ |
| 1333 | /* Start off with no conversion necessary */ |
| 1334 | cvt->needed = 0; |
| 1335 | cvt->filter_index = 0; |
| 1336 | cvt->filters[0] = NULL; |
| 1337 | cvt->len_mult = 1; |
| 1338 | cvt->len_ratio = 1.0; |
| 1339 | |
| 1340 | /* First filter: Endian conversion from src to dst */ |
| 1341 | if ( (src_format & 0x1000) != (dst_format & 0x1000) |
| 1342 | && ((src_format & 0xff) == 16) && ((dst_format & 0xff) == 16)) { |
| 1343 | cvt->filters[cvt->filter_index++] = SDL_ConvertEndian; |
| 1344 | } |
| 1345 | |
| 1346 | /* Second filter: Sign conversion -- signed/unsigned */ |
| 1347 | if ( (src_format & 0x8000) != (dst_format & 0x8000) ) { |
| 1348 | cvt->filters[cvt->filter_index++] = SDL_ConvertSign; |
| 1349 | } |
| 1350 | |
| 1351 | /* Next filter: Convert 16 bit <--> 8 bit PCM */ |
| 1352 | if ( (src_format & 0xFF) != (dst_format & 0xFF) ) { |
| 1353 | switch (dst_format&0x10FF) { |
| 1354 | case AUDIO_U8: |
| 1355 | cvt->filters[cvt->filter_index++] = |
| 1356 | SDL_Convert8; |
| 1357 | cvt->len_ratio /= 2; |
| 1358 | break; |
| 1359 | case AUDIO_U16LSB: |
| 1360 | cvt->filters[cvt->filter_index++] = |
| 1361 | SDL_Convert16LSB; |
| 1362 | cvt->len_mult *= 2; |
| 1363 | cvt->len_ratio *= 2; |
| 1364 | break; |
| 1365 | case AUDIO_U16MSB: |
| 1366 | cvt->filters[cvt->filter_index++] = |
| 1367 | SDL_Convert16MSB; |
| 1368 | cvt->len_mult *= 2; |
| 1369 | cvt->len_ratio *= 2; |
| 1370 | break; |
| 1371 | } |
| 1372 | } |
| 1373 | |
| 1374 | /* Last filter: Mono/Stereo conversion */ |
| 1375 | if ( src_channels != dst_channels ) { |
| 1376 | if ( (src_channels == 1) && (dst_channels > 1) ) { |
| 1377 | cvt->filters[cvt->filter_index++] = |
| 1378 | SDL_ConvertStereo; |
| 1379 | cvt->len_mult *= 2; |
| 1380 | src_channels = 2; |
| 1381 | cvt->len_ratio *= 2; |
| 1382 | } |
| 1383 | if ( (src_channels == 2) && |
| 1384 | (dst_channels == 6) ) { |
| 1385 | cvt->filters[cvt->filter_index++] = |
| 1386 | SDL_ConvertSurround; |
| 1387 | src_channels = 6; |
| 1388 | cvt->len_mult *= 3; |
| 1389 | cvt->len_ratio *= 3; |
| 1390 | } |
| 1391 | if ( (src_channels == 2) && |
| 1392 | (dst_channels == 4) ) { |
| 1393 | cvt->filters[cvt->filter_index++] = |
| 1394 | SDL_ConvertSurround_4; |
| 1395 | src_channels = 4; |
| 1396 | cvt->len_mult *= 2; |
| 1397 | cvt->len_ratio *= 2; |
| 1398 | } |
| 1399 | while ( (src_channels*2) <= dst_channels ) { |
| 1400 | cvt->filters[cvt->filter_index++] = |
| 1401 | SDL_ConvertStereo; |
| 1402 | cvt->len_mult *= 2; |
| 1403 | src_channels *= 2; |
| 1404 | cvt->len_ratio *= 2; |
| 1405 | } |
| 1406 | if ( (src_channels == 6) && |
| 1407 | (dst_channels <= 2) ) { |
| 1408 | cvt->filters[cvt->filter_index++] = |
| 1409 | SDL_ConvertStrip; |
| 1410 | src_channels = 2; |
| 1411 | cvt->len_ratio /= 3; |
| 1412 | } |
| 1413 | if ( (src_channels == 6) && |
| 1414 | (dst_channels == 4) ) { |
| 1415 | cvt->filters[cvt->filter_index++] = |
| 1416 | SDL_ConvertStrip_2; |
| 1417 | src_channels = 4; |
| 1418 | cvt->len_ratio /= 2; |
| 1419 | } |
| 1420 | /* This assumes that 4 channel audio is in the format: |
| 1421 | Left {front/back} + Right {front/back} |
| 1422 | so converting to L/R stereo works properly. |
| 1423 | */ |
| 1424 | while ( ((src_channels%2) == 0) && |
| 1425 | ((src_channels/2) >= dst_channels) ) { |
| 1426 | cvt->filters[cvt->filter_index++] = |
| 1427 | SDL_ConvertMono; |
| 1428 | src_channels /= 2; |
| 1429 | cvt->len_ratio /= 2; |
| 1430 | } |
| 1431 | if ( src_channels != dst_channels ) { |
| 1432 | /* Uh oh.. */; |
| 1433 | } |
| 1434 | } |
| 1435 | |
| 1436 | /* Do rate conversion */ |
| 1437 | cvt->rate_incr = 0.0; |
| 1438 | if ( (src_rate/100) != (dst_rate/100) ) { |
| 1439 | Uint32 hi_rate, lo_rate; |
| 1440 | int len_mult; |
| 1441 | double len_ratio; |
| 1442 | void (SDLCALL *rate_cvt)(SDL_AudioCVT *cvt, Uint16 format); |
| 1443 | |
| 1444 | if ( src_rate > dst_rate ) { |
| 1445 | hi_rate = src_rate; |
| 1446 | lo_rate = dst_rate; |
| 1447 | switch (src_channels) { |
| 1448 | case 1: rate_cvt = SDL_RateDIV2; break; |
| 1449 | case 2: rate_cvt = SDL_RateDIV2_c2; break; |
| 1450 | case 4: rate_cvt = SDL_RateDIV2_c4; break; |
| 1451 | case 6: rate_cvt = SDL_RateDIV2_c6; break; |
| 1452 | default: return -1; |
| 1453 | } |
| 1454 | len_mult = 1; |
| 1455 | len_ratio = 0.5; |
| 1456 | } else { |
| 1457 | hi_rate = dst_rate; |
| 1458 | lo_rate = src_rate; |
| 1459 | switch (src_channels) { |
| 1460 | case 1: rate_cvt = SDL_RateMUL2; break; |
| 1461 | case 2: rate_cvt = SDL_RateMUL2_c2; break; |
| 1462 | case 4: rate_cvt = SDL_RateMUL2_c4; break; |
| 1463 | case 6: rate_cvt = SDL_RateMUL2_c6; break; |
| 1464 | default: return -1; |
| 1465 | } |
| 1466 | len_mult = 2; |
| 1467 | len_ratio = 2.0; |
| 1468 | } |
| 1469 | /* If hi_rate = lo_rate*2^x then conversion is easy */ |
| 1470 | while ( ((lo_rate*2)/100) <= (hi_rate/100) ) { |
| 1471 | cvt->filters[cvt->filter_index++] = rate_cvt; |
| 1472 | cvt->len_mult *= len_mult; |
| 1473 | lo_rate *= 2; |
| 1474 | cvt->len_ratio *= len_ratio; |
| 1475 | } |
| 1476 | /* We may need a slow conversion here to finish up */ |
| 1477 | if ( (lo_rate/100) != (hi_rate/100) ) { |
| 1478 | #if 1 |
| 1479 | /* The problem with this is that if the input buffer is |
| 1480 | say 1K, and the conversion rate is say 1.1, then the |
| 1481 | output buffer is 1.1K, which may not be an acceptable |
| 1482 | buffer size for the audio driver (not a power of 2) |
| 1483 | */ |
| 1484 | /* For now, punt and hope the rate distortion isn't great. |
| 1485 | */ |
| 1486 | #else |
| 1487 | if ( src_rate < dst_rate ) { |
| 1488 | cvt->rate_incr = (double)lo_rate/hi_rate; |
| 1489 | cvt->len_mult *= 2; |
| 1490 | cvt->len_ratio /= cvt->rate_incr; |
| 1491 | } else { |
| 1492 | cvt->rate_incr = (double)hi_rate/lo_rate; |
| 1493 | cvt->len_ratio *= cvt->rate_incr; |
| 1494 | } |
| 1495 | cvt->filters[cvt->filter_index++] = SDL_RateSLOW; |
| 1496 | #endif |
| 1497 | } |
| 1498 | } |
| 1499 | |
| 1500 | /* Set up the filter information */ |
| 1501 | if ( cvt->filter_index != 0 ) { |
| 1502 | cvt->needed = 1; |
| 1503 | cvt->src_format = src_format; |
| 1504 | cvt->dst_format = dst_format; |
| 1505 | cvt->len = 0; |
| 1506 | cvt->buf = NULL; |
| 1507 | cvt->filters[cvt->filter_index] = NULL; |
| 1508 | } |
| 1509 | return(cvt->needed); |
| 1510 | } |