Alexandre Lision | 7c6f4a6 | 2013-09-05 13:27:01 -0400 | [diff] [blame] | 1 | /* |
| 2 | ** Copyright (C) 2002-2011 Erik de Castro Lopo <erikd@mega-nerd.com> |
| 3 | ** |
| 4 | ** This program is free software; you can redistribute it and/or modify |
| 5 | ** it under the terms of the GNU Lesser General Public License as published by |
| 6 | ** the Free Software Foundation; either version 2.1 of the License, or |
| 7 | ** (at your option) any later version. |
| 8 | ** |
| 9 | ** This program is distributed in the hope that it will be useful, |
| 10 | ** but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | ** GNU Lesser General Public License for more details. |
| 13 | ** |
| 14 | ** You should have received a copy of the GNU Lesser General Public License |
| 15 | ** along with this program; if not, write to the Free Software |
| 16 | ** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 17 | */ |
| 18 | |
| 19 | /*=========================================================================== |
| 20 | ** Delta Word Variable Width |
| 21 | ** |
| 22 | ** This decoder and encoder were implemented using information found in this |
| 23 | ** document : http://home.swbell.net/rubywand/R011SNDFMTS.TXT |
| 24 | ** |
| 25 | ** According to the document, the algorithm "was invented 1991 by Magnus |
| 26 | ** Lidstrom and is copyright 1993 by NuEdge Development". |
| 27 | */ |
| 28 | |
| 29 | #include "sfconfig.h" |
| 30 | |
| 31 | #include <stdio.h> |
| 32 | #include <stdlib.h> |
| 33 | #include <string.h> |
| 34 | #include <math.h> |
| 35 | |
| 36 | #include "sndfile.h" |
| 37 | #include "sfendian.h" |
| 38 | #include "common.h" |
| 39 | |
| 40 | typedef struct |
| 41 | { int dwm_maxsize, bit_width, max_delta, span ; |
| 42 | int samplecount ; |
| 43 | int bit_count, bits, last_delta_width, last_sample ; |
| 44 | struct |
| 45 | { int index, end ; |
| 46 | unsigned char buffer [256] ; |
| 47 | } b ; |
| 48 | } DWVW_PRIVATE ; |
| 49 | |
| 50 | /*============================================================================================ |
| 51 | */ |
| 52 | |
| 53 | static sf_count_t dwvw_read_s (SF_PRIVATE *psf, short *ptr, sf_count_t len) ; |
| 54 | static sf_count_t dwvw_read_i (SF_PRIVATE *psf, int *ptr, sf_count_t len) ; |
| 55 | static sf_count_t dwvw_read_f (SF_PRIVATE *psf, float *ptr, sf_count_t len) ; |
| 56 | static sf_count_t dwvw_read_d (SF_PRIVATE *psf, double *ptr, sf_count_t len) ; |
| 57 | |
| 58 | static sf_count_t dwvw_write_s (SF_PRIVATE *psf, const short *ptr, sf_count_t len) ; |
| 59 | static sf_count_t dwvw_write_i (SF_PRIVATE *psf, const int *ptr, sf_count_t len) ; |
| 60 | static sf_count_t dwvw_write_f (SF_PRIVATE *psf, const float *ptr, sf_count_t len) ; |
| 61 | static sf_count_t dwvw_write_d (SF_PRIVATE *psf, const double *ptr, sf_count_t len) ; |
| 62 | |
| 63 | static sf_count_t dwvw_seek (SF_PRIVATE *psf, int mode, sf_count_t offset) ; |
| 64 | static int dwvw_close (SF_PRIVATE *psf) ; |
| 65 | |
| 66 | static int dwvw_decode_data (SF_PRIVATE *psf, DWVW_PRIVATE *pdwvw, int *ptr, int len) ; |
| 67 | static int dwvw_decode_load_bits (SF_PRIVATE *psf, DWVW_PRIVATE *pdwvw, int bit_count) ; |
| 68 | |
| 69 | static int dwvw_encode_data (SF_PRIVATE *psf, DWVW_PRIVATE *pdwvw, const int *ptr, int len) ; |
| 70 | static void dwvw_encode_store_bits (SF_PRIVATE *psf, DWVW_PRIVATE *pdwvw, int data, int new_bits) ; |
| 71 | static void dwvw_read_reset (DWVW_PRIVATE *pdwvw) ; |
| 72 | |
| 73 | /*============================================================================================ |
| 74 | ** DWVW initialisation function. |
| 75 | */ |
| 76 | |
| 77 | int |
| 78 | dwvw_init (SF_PRIVATE *psf, int bitwidth) |
| 79 | { DWVW_PRIVATE *pdwvw ; |
| 80 | |
| 81 | if (psf->codec_data != NULL) |
| 82 | { psf_log_printf (psf, "*** psf->codec_data is not NULL.\n") ; |
| 83 | return SFE_INTERNAL ; |
| 84 | } ; |
| 85 | |
| 86 | if (bitwidth > 24) |
| 87 | return SFE_DWVW_BAD_BITWIDTH ; |
| 88 | |
| 89 | if (psf->file.mode == SFM_RDWR) |
| 90 | return SFE_BAD_MODE_RW ; |
| 91 | |
| 92 | if ((pdwvw = calloc (1, sizeof (DWVW_PRIVATE))) == NULL) |
| 93 | return SFE_MALLOC_FAILED ; |
| 94 | |
| 95 | psf->codec_data = (void*) pdwvw ; |
| 96 | |
| 97 | pdwvw->bit_width = bitwidth ; |
| 98 | pdwvw->dwm_maxsize = bitwidth / 2 ; |
| 99 | pdwvw->max_delta = 1 << (bitwidth - 1) ; |
| 100 | pdwvw->span = 1 << bitwidth ; |
| 101 | |
| 102 | dwvw_read_reset (pdwvw) ; |
| 103 | |
| 104 | if (psf->file.mode == SFM_READ) |
| 105 | { psf->read_short = dwvw_read_s ; |
| 106 | psf->read_int = dwvw_read_i ; |
| 107 | psf->read_float = dwvw_read_f ; |
| 108 | psf->read_double = dwvw_read_d ; |
| 109 | } ; |
| 110 | |
| 111 | if (psf->file.mode == SFM_WRITE) |
| 112 | { psf->write_short = dwvw_write_s ; |
| 113 | psf->write_int = dwvw_write_i ; |
| 114 | psf->write_float = dwvw_write_f ; |
| 115 | psf->write_double = dwvw_write_d ; |
| 116 | } ; |
| 117 | |
| 118 | psf->codec_close = dwvw_close ; |
| 119 | psf->seek = dwvw_seek ; |
| 120 | |
| 121 | /* FIXME : This is bogus. */ |
| 122 | psf->sf.frames = SF_COUNT_MAX ; |
| 123 | psf->datalength = psf->sf.frames ; |
| 124 | /* EMXIF : This is bogus. */ |
| 125 | |
| 126 | return 0 ; |
| 127 | } /* dwvw_init */ |
| 128 | |
| 129 | /*-------------------------------------------------------------------------------------------- |
| 130 | */ |
| 131 | |
| 132 | static int |
| 133 | dwvw_close (SF_PRIVATE *psf) |
| 134 | { DWVW_PRIVATE *pdwvw ; |
| 135 | |
| 136 | if (psf->codec_data == NULL) |
| 137 | return 0 ; |
| 138 | pdwvw = (DWVW_PRIVATE*) psf->codec_data ; |
| 139 | |
| 140 | if (psf->file.mode == SFM_WRITE) |
| 141 | { static int last_values [12] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } ; |
| 142 | |
| 143 | /* Write 8 zero samples to fully flush output. */ |
| 144 | dwvw_encode_data (psf, pdwvw, last_values, 12) ; |
| 145 | |
| 146 | /* Write the last buffer worth of data to disk. */ |
| 147 | psf_fwrite (pdwvw->b.buffer, 1, pdwvw->b.index, psf) ; |
| 148 | |
| 149 | if (psf->write_header) |
| 150 | psf->write_header (psf, SF_TRUE) ; |
| 151 | } ; |
| 152 | |
| 153 | return 0 ; |
| 154 | } /* dwvw_close */ |
| 155 | |
| 156 | static sf_count_t |
| 157 | dwvw_seek (SF_PRIVATE *psf, int UNUSED (mode), sf_count_t offset) |
| 158 | { DWVW_PRIVATE *pdwvw ; |
| 159 | |
| 160 | if (! psf->codec_data) |
| 161 | { psf->error = SFE_INTERNAL ; |
| 162 | return PSF_SEEK_ERROR ; |
| 163 | } ; |
| 164 | |
| 165 | pdwvw = (DWVW_PRIVATE*) psf->codec_data ; |
| 166 | |
| 167 | if (offset == 0) |
| 168 | { psf_fseek (psf, psf->dataoffset, SEEK_SET) ; |
| 169 | dwvw_read_reset (pdwvw) ; |
| 170 | return 0 ; |
| 171 | } ; |
| 172 | |
| 173 | psf->error = SFE_BAD_SEEK ; |
| 174 | return PSF_SEEK_ERROR ; |
| 175 | } /* dwvw_seek */ |
| 176 | |
| 177 | |
| 178 | /*============================================================================== |
| 179 | */ |
| 180 | |
| 181 | static sf_count_t |
| 182 | dwvw_read_s (SF_PRIVATE *psf, short *ptr, sf_count_t len) |
| 183 | { DWVW_PRIVATE *pdwvw ; |
| 184 | int *iptr ; |
| 185 | int k, bufferlen, readcount = 0, count ; |
| 186 | sf_count_t total = 0 ; |
| 187 | |
| 188 | if (! psf->codec_data) |
| 189 | return 0 ; |
| 190 | pdwvw = (DWVW_PRIVATE*) psf->codec_data ; |
| 191 | |
| 192 | iptr = psf->u.ibuf ; |
| 193 | bufferlen = ARRAY_LEN (psf->u.ibuf) ; |
| 194 | while (len > 0) |
| 195 | { readcount = (len >= bufferlen) ? bufferlen : len ; |
| 196 | count = dwvw_decode_data (psf, pdwvw, iptr, readcount) ; |
| 197 | for (k = 0 ; k < readcount ; k++) |
| 198 | ptr [total + k] = iptr [k] >> 16 ; |
| 199 | |
| 200 | total += count ; |
| 201 | len -= readcount ; |
| 202 | if (count != readcount) |
| 203 | break ; |
| 204 | } ; |
| 205 | |
| 206 | return total ; |
| 207 | } /* dwvw_read_s */ |
| 208 | |
| 209 | static sf_count_t |
| 210 | dwvw_read_i (SF_PRIVATE *psf, int *ptr, sf_count_t len) |
| 211 | { DWVW_PRIVATE *pdwvw ; |
| 212 | int readcount, count ; |
| 213 | sf_count_t total = 0 ; |
| 214 | |
| 215 | if (! psf->codec_data) |
| 216 | return 0 ; |
| 217 | pdwvw = (DWVW_PRIVATE*) psf->codec_data ; |
| 218 | |
| 219 | while (len > 0) |
| 220 | { readcount = (len > 0x10000000) ? 0x10000000 : (int) len ; |
| 221 | |
| 222 | count = dwvw_decode_data (psf, pdwvw, ptr, readcount) ; |
| 223 | |
| 224 | total += count ; |
| 225 | len -= count ; |
| 226 | |
| 227 | if (count != readcount) |
| 228 | break ; |
| 229 | } ; |
| 230 | |
| 231 | return total ; |
| 232 | } /* dwvw_read_i */ |
| 233 | |
| 234 | static sf_count_t |
| 235 | dwvw_read_f (SF_PRIVATE *psf, float *ptr, sf_count_t len) |
| 236 | { DWVW_PRIVATE *pdwvw ; |
| 237 | int *iptr ; |
| 238 | int k, bufferlen, readcount = 0, count ; |
| 239 | sf_count_t total = 0 ; |
| 240 | float normfact ; |
| 241 | |
| 242 | if (! psf->codec_data) |
| 243 | return 0 ; |
| 244 | pdwvw = (DWVW_PRIVATE*) psf->codec_data ; |
| 245 | |
| 246 | normfact = (psf->norm_float == SF_TRUE) ? 1.0 / ((float) 0x80000000) : 1.0 ; |
| 247 | |
| 248 | iptr = psf->u.ibuf ; |
| 249 | bufferlen = ARRAY_LEN (psf->u.ibuf) ; |
| 250 | while (len > 0) |
| 251 | { readcount = (len >= bufferlen) ? bufferlen : len ; |
| 252 | count = dwvw_decode_data (psf, pdwvw, iptr, readcount) ; |
| 253 | for (k = 0 ; k < readcount ; k++) |
| 254 | ptr [total + k] = normfact * (float) (iptr [k]) ; |
| 255 | |
| 256 | total += count ; |
| 257 | len -= readcount ; |
| 258 | if (count != readcount) |
| 259 | break ; |
| 260 | } ; |
| 261 | |
| 262 | return total ; |
| 263 | } /* dwvw_read_f */ |
| 264 | |
| 265 | static sf_count_t |
| 266 | dwvw_read_d (SF_PRIVATE *psf, double *ptr, sf_count_t len) |
| 267 | { DWVW_PRIVATE *pdwvw ; |
| 268 | int *iptr ; |
| 269 | int k, bufferlen, readcount = 0, count ; |
| 270 | sf_count_t total = 0 ; |
| 271 | double normfact ; |
| 272 | |
| 273 | if (! psf->codec_data) |
| 274 | return 0 ; |
| 275 | pdwvw = (DWVW_PRIVATE*) psf->codec_data ; |
| 276 | |
| 277 | normfact = (psf->norm_double == SF_TRUE) ? 1.0 / ((double) 0x80000000) : 1.0 ; |
| 278 | |
| 279 | iptr = psf->u.ibuf ; |
| 280 | bufferlen = ARRAY_LEN (psf->u.ibuf) ; |
| 281 | while (len > 0) |
| 282 | { readcount = (len >= bufferlen) ? bufferlen : len ; |
| 283 | count = dwvw_decode_data (psf, pdwvw, iptr, readcount) ; |
| 284 | for (k = 0 ; k < readcount ; k++) |
| 285 | ptr [total + k] = normfact * (double) (iptr [k]) ; |
| 286 | |
| 287 | total += count ; |
| 288 | len -= readcount ; |
| 289 | if (count != readcount) |
| 290 | break ; |
| 291 | } ; |
| 292 | |
| 293 | return total ; |
| 294 | } /* dwvw_read_d */ |
| 295 | |
| 296 | static int |
| 297 | dwvw_decode_data (SF_PRIVATE *psf, DWVW_PRIVATE *pdwvw, int *ptr, int len) |
| 298 | { int count ; |
| 299 | int delta_width_modifier, delta_width, delta_negative, delta, sample ; |
| 300 | |
| 301 | /* Restore state from last decode call. */ |
| 302 | delta_width = pdwvw->last_delta_width ; |
| 303 | sample = pdwvw->last_sample ; |
| 304 | |
| 305 | for (count = 0 ; count < len ; count++) |
| 306 | { /* If bit_count parameter is zero get the delta_width_modifier. */ |
| 307 | delta_width_modifier = dwvw_decode_load_bits (psf, pdwvw, -1) ; |
| 308 | |
| 309 | /* Check for end of input bit stream. Break loop if end. */ |
| 310 | if (delta_width_modifier < 0) |
| 311 | break ; |
| 312 | |
| 313 | if (delta_width_modifier && dwvw_decode_load_bits (psf, pdwvw, 1)) |
| 314 | delta_width_modifier = - delta_width_modifier ; |
| 315 | |
| 316 | /* Calculate the current word width. */ |
| 317 | delta_width = (delta_width + delta_width_modifier + pdwvw->bit_width) % pdwvw->bit_width ; |
| 318 | |
| 319 | /* Load the delta. */ |
| 320 | delta = 0 ; |
| 321 | if (delta_width) |
| 322 | { delta = dwvw_decode_load_bits (psf, pdwvw, delta_width - 1) | (1 << (delta_width - 1)) ; |
| 323 | delta_negative = dwvw_decode_load_bits (psf, pdwvw, 1) ; |
| 324 | if (delta == pdwvw->max_delta - 1) |
| 325 | delta += dwvw_decode_load_bits (psf, pdwvw, 1) ; |
| 326 | if (delta_negative) |
| 327 | delta = -delta ; |
| 328 | } ; |
| 329 | |
| 330 | /* Calculate the sample */ |
| 331 | sample += delta ; |
| 332 | |
| 333 | if (sample >= pdwvw->max_delta) |
| 334 | sample -= pdwvw->span ; |
| 335 | else if (sample < - pdwvw->max_delta) |
| 336 | sample += pdwvw->span ; |
| 337 | |
| 338 | /* Store the sample justifying to the most significant bit. */ |
| 339 | ptr [count] = sample << (32 - pdwvw->bit_width) ; |
| 340 | |
| 341 | if (pdwvw->b.end == 0 && pdwvw->bit_count == 0) |
| 342 | break ; |
| 343 | } ; |
| 344 | |
| 345 | pdwvw->last_delta_width = delta_width ; |
| 346 | pdwvw->last_sample = sample ; |
| 347 | |
| 348 | pdwvw->samplecount += count ; |
| 349 | |
| 350 | return count ; |
| 351 | } /* dwvw_decode_data */ |
| 352 | |
| 353 | static int |
| 354 | dwvw_decode_load_bits (SF_PRIVATE *psf, DWVW_PRIVATE *pdwvw, int bit_count) |
| 355 | { int output = 0, get_dwm = SF_FALSE ; |
| 356 | |
| 357 | /* |
| 358 | ** Depending on the value of parameter bit_count, either get the |
| 359 | ** required number of bits (ie bit_count > 0) or the |
| 360 | ** delta_width_modifier (otherwise). |
| 361 | */ |
| 362 | |
| 363 | if (bit_count < 0) |
| 364 | { get_dwm = SF_TRUE ; |
| 365 | /* modify bit_count to ensure we have enought bits for finding dwm. */ |
| 366 | bit_count = pdwvw->dwm_maxsize ; |
| 367 | } ; |
| 368 | |
| 369 | /* Load bits in bit reseviour. */ |
| 370 | while (pdwvw->bit_count < bit_count) |
| 371 | { if (pdwvw->b.index >= pdwvw->b.end) |
| 372 | { pdwvw->b.end = psf_fread (pdwvw->b.buffer, 1, sizeof (pdwvw->b.buffer), psf) ; |
| 373 | pdwvw->b.index = 0 ; |
| 374 | } ; |
| 375 | |
| 376 | /* Check for end of input stream. */ |
| 377 | if (bit_count < 8 && pdwvw->b.end == 0) |
| 378 | return -1 ; |
| 379 | |
| 380 | pdwvw->bits = (pdwvw->bits << 8) ; |
| 381 | |
| 382 | if (pdwvw->b.index < pdwvw->b.end) |
| 383 | { pdwvw->bits |= pdwvw->b.buffer [pdwvw->b.index] ; |
| 384 | pdwvw->b.index ++ ; |
| 385 | } ; |
| 386 | pdwvw->bit_count += 8 ; |
| 387 | } ; |
| 388 | |
| 389 | /* If asked to get bits do so. */ |
| 390 | if (! get_dwm) |
| 391 | { output = (pdwvw->bits >> (pdwvw->bit_count - bit_count)) & ((1 << bit_count) - 1) ; |
| 392 | pdwvw->bit_count -= bit_count ; |
| 393 | return output ; |
| 394 | } ; |
| 395 | |
| 396 | /* Otherwise must have been asked to get delta_width_modifier. */ |
| 397 | while (output < (pdwvw->dwm_maxsize)) |
| 398 | { pdwvw->bit_count -= 1 ; |
| 399 | if (pdwvw->bits & (1 << pdwvw->bit_count)) |
| 400 | break ; |
| 401 | output += 1 ; |
| 402 | } ; |
| 403 | |
| 404 | return output ; |
| 405 | } /* dwvw_decode_load_bits */ |
| 406 | |
| 407 | static void |
| 408 | dwvw_read_reset (DWVW_PRIVATE *pdwvw) |
| 409 | { pdwvw->samplecount = 0 ; |
| 410 | pdwvw->b.index = 0 ; |
| 411 | pdwvw->b.end = 0 ; |
| 412 | pdwvw->bit_count = 0 ; |
| 413 | pdwvw->bits = 0 ; |
| 414 | pdwvw->last_delta_width = 0 ; |
| 415 | pdwvw->last_sample = 0 ; |
| 416 | } /* dwvw_read_reset */ |
| 417 | |
| 418 | static void |
| 419 | dwvw_encode_store_bits (SF_PRIVATE *psf, DWVW_PRIVATE *pdwvw, int data, int new_bits) |
| 420 | { int byte ; |
| 421 | |
| 422 | /* Shift the bits into the resevoir. */ |
| 423 | pdwvw->bits = (pdwvw->bits << new_bits) | (data & ((1 << new_bits) - 1)) ; |
| 424 | pdwvw->bit_count += new_bits ; |
| 425 | |
| 426 | /* Transfer bit to buffer. */ |
| 427 | while (pdwvw->bit_count >= 8) |
| 428 | { byte = pdwvw->bits >> (pdwvw->bit_count - 8) ; |
| 429 | pdwvw->bit_count -= 8 ; |
| 430 | pdwvw->b.buffer [pdwvw->b.index] = byte & 0xFF ; |
| 431 | pdwvw->b.index ++ ; |
| 432 | } ; |
| 433 | |
| 434 | if (pdwvw->b.index > SIGNED_SIZEOF (pdwvw->b.buffer) - 4) |
| 435 | { psf_fwrite (pdwvw->b.buffer, 1, pdwvw->b.index, psf) ; |
| 436 | pdwvw->b.index = 0 ; |
| 437 | } ; |
| 438 | |
| 439 | return ; |
| 440 | } /* dwvw_encode_store_bits */ |
| 441 | |
| 442 | #if 0 |
| 443 | /* Debigging routine. */ |
| 444 | static void |
| 445 | dump_bits (DWVW_PRIVATE *pdwvw) |
| 446 | { int k, mask ; |
| 447 | |
| 448 | for (k = 0 ; k < 10 && k < pdwvw->b.index ; k++) |
| 449 | { mask = 0x80 ; |
| 450 | while (mask) |
| 451 | { putchar (mask & pdwvw->b.buffer [k] ? '1' : '0') ; |
| 452 | mask >>= 1 ; |
| 453 | } ; |
| 454 | putchar (' ') ; |
| 455 | } |
| 456 | |
| 457 | for (k = pdwvw->bit_count - 1 ; k >= 0 ; k --) |
| 458 | putchar (pdwvw->bits & (1 << k) ? '1' : '0') ; |
| 459 | |
| 460 | putchar ('\n') ; |
| 461 | } /* dump_bits */ |
| 462 | #endif |
| 463 | |
| 464 | #define HIGHEST_BIT(x,count) \ |
| 465 | { int y = x ; \ |
| 466 | (count) = 0 ; \ |
| 467 | while (y) \ |
| 468 | { (count) ++ ; \ |
| 469 | y >>= 1 ; \ |
| 470 | } ; \ |
| 471 | } ; |
| 472 | |
| 473 | static int |
| 474 | dwvw_encode_data (SF_PRIVATE *psf, DWVW_PRIVATE *pdwvw, const int *ptr, int len) |
| 475 | { int count ; |
| 476 | int delta_width_modifier, delta, delta_negative, delta_width, extra_bit ; |
| 477 | |
| 478 | for (count = 0 ; count < len ; count++) |
| 479 | { delta = (ptr [count] >> (32 - pdwvw->bit_width)) - pdwvw->last_sample ; |
| 480 | |
| 481 | /* Calculate extra_bit if needed. */ |
| 482 | extra_bit = -1 ; |
| 483 | delta_negative = 0 ; |
| 484 | if (delta < -pdwvw->max_delta) |
| 485 | delta = pdwvw->max_delta + (delta % pdwvw->max_delta) ; |
| 486 | else if (delta == -pdwvw->max_delta) |
| 487 | { extra_bit = 1 ; |
| 488 | delta_negative = 1 ; |
| 489 | delta = pdwvw->max_delta - 1 ; |
| 490 | } |
| 491 | else if (delta > pdwvw->max_delta) |
| 492 | { delta_negative = 1 ; |
| 493 | delta = pdwvw->span - delta ; |
| 494 | delta = abs (delta) ; |
| 495 | } |
| 496 | else if (delta == pdwvw->max_delta) |
| 497 | { extra_bit = 1 ; |
| 498 | delta = pdwvw->max_delta - 1 ; |
| 499 | } |
| 500 | else if (delta < 0) |
| 501 | { delta_negative = 1 ; |
| 502 | delta = abs (delta) ; |
| 503 | } ; |
| 504 | |
| 505 | if (delta == pdwvw->max_delta - 1 && extra_bit == -1) |
| 506 | extra_bit = 0 ; |
| 507 | |
| 508 | /* Find width in bits of delta */ |
| 509 | HIGHEST_BIT (delta, delta_width) ; |
| 510 | |
| 511 | /* Calculate the delta_width_modifier */ |
| 512 | delta_width_modifier = (delta_width - pdwvw->last_delta_width) % pdwvw->bit_width ; |
| 513 | if (delta_width_modifier > pdwvw->dwm_maxsize) |
| 514 | delta_width_modifier -= pdwvw->bit_width ; |
| 515 | if (delta_width_modifier < -pdwvw->dwm_maxsize) |
| 516 | delta_width_modifier += pdwvw->bit_width ; |
| 517 | |
| 518 | /* Write delta_width_modifier zeros, followed by terminating '1'. */ |
| 519 | dwvw_encode_store_bits (psf, pdwvw, 0, abs (delta_width_modifier)) ; |
| 520 | if (abs (delta_width_modifier) != pdwvw->dwm_maxsize) |
| 521 | dwvw_encode_store_bits (psf, pdwvw, 1, 1) ; |
| 522 | |
| 523 | /* Write delta_width_modifier sign. */ |
| 524 | if (delta_width_modifier < 0) |
| 525 | dwvw_encode_store_bits (psf, pdwvw, 1, 1) ; |
| 526 | if (delta_width_modifier > 0) |
| 527 | dwvw_encode_store_bits (psf, pdwvw, 0, 1) ; |
| 528 | |
| 529 | /* Write delta and delta sign bit. */ |
| 530 | if (delta_width) |
| 531 | { dwvw_encode_store_bits (psf, pdwvw, delta, abs (delta_width) - 1) ; |
| 532 | dwvw_encode_store_bits (psf, pdwvw, (delta_negative ? 1 : 0), 1) ; |
| 533 | } ; |
| 534 | |
| 535 | /* Write extra bit!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! */ |
| 536 | if (extra_bit >= 0) |
| 537 | dwvw_encode_store_bits (psf, pdwvw, extra_bit, 1) ; |
| 538 | |
| 539 | pdwvw->last_sample = ptr [count] >> (32 - pdwvw->bit_width) ; |
| 540 | pdwvw->last_delta_width = delta_width ; |
| 541 | } ; |
| 542 | |
| 543 | pdwvw->samplecount += count ; |
| 544 | |
| 545 | return count ; |
| 546 | } /* dwvw_encode_data */ |
| 547 | |
| 548 | static sf_count_t |
| 549 | dwvw_write_s (SF_PRIVATE *psf, const short *ptr, sf_count_t len) |
| 550 | { DWVW_PRIVATE *pdwvw ; |
| 551 | int *iptr ; |
| 552 | int k, bufferlen, writecount = 0, count ; |
| 553 | sf_count_t total = 0 ; |
| 554 | |
| 555 | if (! psf->codec_data) |
| 556 | return 0 ; |
| 557 | pdwvw = (DWVW_PRIVATE*) psf->codec_data ; |
| 558 | |
| 559 | iptr = psf->u.ibuf ; |
| 560 | bufferlen = ARRAY_LEN (psf->u.ibuf) ; |
| 561 | while (len > 0) |
| 562 | { writecount = (len >= bufferlen) ? bufferlen : len ; |
| 563 | for (k = 0 ; k < writecount ; k++) |
| 564 | iptr [k] = ptr [total + k] << 16 ; |
| 565 | count = dwvw_encode_data (psf, pdwvw, iptr, writecount) ; |
| 566 | |
| 567 | total += count ; |
| 568 | len -= writecount ; |
| 569 | if (count != writecount) |
| 570 | break ; |
| 571 | } ; |
| 572 | |
| 573 | return total ; |
| 574 | } /* dwvw_write_s */ |
| 575 | |
| 576 | static sf_count_t |
| 577 | dwvw_write_i (SF_PRIVATE *psf, const int *ptr, sf_count_t len) |
| 578 | { DWVW_PRIVATE *pdwvw ; |
| 579 | int writecount, count ; |
| 580 | sf_count_t total = 0 ; |
| 581 | |
| 582 | if (! psf->codec_data) |
| 583 | return 0 ; |
| 584 | pdwvw = (DWVW_PRIVATE*) psf->codec_data ; |
| 585 | |
| 586 | while (len > 0) |
| 587 | { writecount = (len > 0x10000000) ? 0x10000000 : (int) len ; |
| 588 | |
| 589 | count = dwvw_encode_data (psf, pdwvw, ptr, writecount) ; |
| 590 | |
| 591 | total += count ; |
| 592 | len -= count ; |
| 593 | |
| 594 | if (count != writecount) |
| 595 | break ; |
| 596 | } ; |
| 597 | |
| 598 | return total ; |
| 599 | } /* dwvw_write_i */ |
| 600 | |
| 601 | static sf_count_t |
| 602 | dwvw_write_f (SF_PRIVATE *psf, const float *ptr, sf_count_t len) |
| 603 | { DWVW_PRIVATE *pdwvw ; |
| 604 | int *iptr ; |
| 605 | int k, bufferlen, writecount = 0, count ; |
| 606 | sf_count_t total = 0 ; |
| 607 | float normfact ; |
| 608 | |
| 609 | if (! psf->codec_data) |
| 610 | return 0 ; |
| 611 | pdwvw = (DWVW_PRIVATE*) psf->codec_data ; |
| 612 | |
| 613 | normfact = (psf->norm_float == SF_TRUE) ? (1.0 * 0x7FFFFFFF) : 1.0 ; |
| 614 | |
| 615 | iptr = psf->u.ibuf ; |
| 616 | bufferlen = ARRAY_LEN (psf->u.ibuf) ; |
| 617 | while (len > 0) |
| 618 | { writecount = (len >= bufferlen) ? bufferlen : len ; |
| 619 | for (k = 0 ; k < writecount ; k++) |
| 620 | iptr [k] = lrintf (normfact * ptr [total + k]) ; |
| 621 | count = dwvw_encode_data (psf, pdwvw, iptr, writecount) ; |
| 622 | |
| 623 | total += count ; |
| 624 | len -= writecount ; |
| 625 | if (count != writecount) |
| 626 | break ; |
| 627 | } ; |
| 628 | |
| 629 | return total ; |
| 630 | } /* dwvw_write_f */ |
| 631 | |
| 632 | static sf_count_t |
| 633 | dwvw_write_d (SF_PRIVATE *psf, const double *ptr, sf_count_t len) |
| 634 | { DWVW_PRIVATE *pdwvw ; |
| 635 | int *iptr ; |
| 636 | int k, bufferlen, writecount = 0, count ; |
| 637 | sf_count_t total = 0 ; |
| 638 | double normfact ; |
| 639 | |
| 640 | if (! psf->codec_data) |
| 641 | return 0 ; |
| 642 | pdwvw = (DWVW_PRIVATE*) psf->codec_data ; |
| 643 | |
| 644 | normfact = (psf->norm_double == SF_TRUE) ? (1.0 * 0x7FFFFFFF) : 1.0 ; |
| 645 | |
| 646 | iptr = psf->u.ibuf ; |
| 647 | bufferlen = ARRAY_LEN (psf->u.ibuf) ; |
| 648 | while (len > 0) |
| 649 | { writecount = (len >= bufferlen) ? bufferlen : len ; |
| 650 | for (k = 0 ; k < writecount ; k++) |
| 651 | iptr [k] = lrint (normfact * ptr [total + k]) ; |
| 652 | count = dwvw_encode_data (psf, pdwvw, iptr, writecount) ; |
| 653 | |
| 654 | total += count ; |
| 655 | len -= writecount ; |
| 656 | if (count != writecount) |
| 657 | break ; |
| 658 | } ; |
| 659 | |
| 660 | return total ; |
| 661 | } /* dwvw_write_d */ |
| 662 | |