2 ** Copyright (C) 2002-2005 Erik de Castro Lopo <erikd@mega-nerd.com>
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.
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.
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.
19 /*===========================================================================
20 ** Delta Word Variable Width
22 ** This decoder and encoder were implemented using information found in this
23 ** document : http://home.swbell.net/rubywand/R011SNDFMTS.TXT
25 ** According to the document, the algorithm "was invented 1991 by Magnus
26 ** Lidstrom and is copyright 1993 by NuEdge Development".
37 #include "float_cast.h"
41 { int dwm_maxsize, bit_width, max_delta, span ;
43 int bit_count, bits, last_delta_width, last_sample ;
46 unsigned char buffer [256] ;
50 /*============================================================================================
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) ;
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) ;
63 static sf_count_t dwvw_seek (SF_PRIVATE *psf, int mode, sf_count_t offset) ;
64 static int dwvw_close (SF_PRIVATE *psf) ;
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) ;
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) ;
73 /*============================================================================================
74 ** DWVW initialisation function.
78 dwvw_init (SF_PRIVATE *psf, int bitwidth)
79 { DWVW_PRIVATE *pdwvw ;
81 if (psf->fdata != NULL)
82 { psf_log_printf (psf, "*** psf->fdata is not NULL.\n") ;
87 return SFE_DWVW_BAD_BITWIDTH ;
89 if (psf->mode == SFM_RDWR)
90 return SFE_BAD_MODE_RW ;
92 if ((pdwvw = calloc (1, sizeof (DWVW_PRIVATE))) == NULL)
93 return SFE_MALLOC_FAILED ;
95 psf->fdata = (void*) pdwvw ;
97 pdwvw->bit_width = bitwidth ;
98 pdwvw->dwm_maxsize = bitwidth / 2 ;
99 pdwvw->max_delta = 1 << (bitwidth - 1) ;
100 pdwvw->span = 1 << bitwidth ;
102 dwvw_read_reset (pdwvw) ;
104 if (psf->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 ;
111 if (psf->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 ;
118 psf->codec_close = dwvw_close ;
119 psf->seek = dwvw_seek ;
121 /* FIXME : This is bogus. */
122 psf->sf.frames = SF_COUNT_MAX ;
123 psf->datalength = psf->sf.frames ;
124 /* EMXIF : This is bogus. */
129 /*--------------------------------------------------------------------------------------------
133 dwvw_close (SF_PRIVATE *psf)
134 { DWVW_PRIVATE *pdwvw ;
136 if (psf->fdata == NULL)
138 pdwvw = (DWVW_PRIVATE*) psf->fdata ;
140 if (psf->mode == SFM_WRITE)
141 { static int last_values [12] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } ;
143 /* Write 8 zero samples to fully flush output. */
144 dwvw_encode_data (psf, pdwvw, last_values, 12) ;
146 /* Write the last buffer worth of data to disk. */
147 psf_fwrite (pdwvw->b.buffer, 1, pdwvw->b.index, psf) ;
149 if (psf->write_header)
150 psf->write_header (psf, SF_TRUE) ;
157 dwvw_seek (SF_PRIVATE *psf, int mode, sf_count_t offset)
158 { DWVW_PRIVATE *pdwvw ;
163 { psf->error = SFE_INTERNAL ;
164 return PSF_SEEK_ERROR ;
167 pdwvw = (DWVW_PRIVATE*) psf->fdata ;
170 { psf_fseek (psf, psf->dataoffset, SEEK_SET) ;
171 dwvw_read_reset (pdwvw) ;
175 psf->error = SFE_BAD_SEEK ;
176 return PSF_SEEK_ERROR ;
180 /*==============================================================================
184 dwvw_read_s (SF_PRIVATE *psf, short *ptr, sf_count_t len)
185 { DWVW_PRIVATE *pdwvw ;
187 int k, bufferlen, readcount = 0, count ;
188 sf_count_t total = 0 ;
192 pdwvw = (DWVW_PRIVATE*) psf->fdata ;
195 bufferlen = ARRAY_LEN (psf->u.ibuf) ;
197 { readcount = (len >= bufferlen) ? bufferlen : len ;
198 count = dwvw_decode_data (psf, pdwvw, iptr, readcount) ;
199 for (k = 0 ; k < readcount ; k++)
200 ptr [total + k] = iptr [k] >> 16 ;
204 if (count != readcount)
212 dwvw_read_i (SF_PRIVATE *psf, int *ptr, sf_count_t len)
213 { DWVW_PRIVATE *pdwvw ;
214 int readcount, count ;
215 sf_count_t total = 0 ;
219 pdwvw = (DWVW_PRIVATE*) psf->fdata ;
222 { readcount = (len > 0x10000000) ? 0x10000000 : (int) len ;
224 count = dwvw_decode_data (psf, pdwvw, ptr, readcount) ;
229 if (count != readcount)
237 dwvw_read_f (SF_PRIVATE *psf, float *ptr, sf_count_t len)
238 { DWVW_PRIVATE *pdwvw ;
240 int k, bufferlen, readcount = 0, count ;
241 sf_count_t total = 0 ;
246 pdwvw = (DWVW_PRIVATE*) psf->fdata ;
248 normfact = (psf->norm_float == SF_TRUE) ? 1.0 / ((float) 0x80000000) : 1.0 ;
251 bufferlen = ARRAY_LEN (psf->u.ibuf) ;
253 { readcount = (len >= bufferlen) ? bufferlen : len ;
254 count = dwvw_decode_data (psf, pdwvw, iptr, readcount) ;
255 for (k = 0 ; k < readcount ; k++)
256 ptr [total + k] = normfact * (float) (iptr [k]) ;
260 if (count != readcount)
268 dwvw_read_d (SF_PRIVATE *psf, double *ptr, sf_count_t len)
269 { DWVW_PRIVATE *pdwvw ;
271 int k, bufferlen, readcount = 0, count ;
272 sf_count_t total = 0 ;
277 pdwvw = (DWVW_PRIVATE*) psf->fdata ;
279 normfact = (psf->norm_double == SF_TRUE) ? 1.0 / ((double) 0x80000000) : 1.0 ;
282 bufferlen = ARRAY_LEN (psf->u.ibuf) ;
284 { readcount = (len >= bufferlen) ? bufferlen : len ;
285 count = dwvw_decode_data (psf, pdwvw, iptr, readcount) ;
286 for (k = 0 ; k < readcount ; k++)
287 ptr [total + k] = normfact * (double) (iptr [k]) ;
291 if (count != readcount)
299 dwvw_decode_data (SF_PRIVATE *psf, DWVW_PRIVATE *pdwvw, int *ptr, int len)
301 int delta_width_modifier, delta_width, delta_negative, delta, sample ;
303 /* Restore state from last decode call. */
304 delta_width = pdwvw->last_delta_width ;
305 sample = pdwvw->last_sample ;
307 for (count = 0 ; count < len ; count++)
308 { /* If bit_count parameter is zero get the delta_width_modifier. */
309 delta_width_modifier = dwvw_decode_load_bits (psf, pdwvw, -1) ;
311 /* Check for end of input bit stream. Break loop if end. */
312 if (delta_width_modifier < 0)
315 if (delta_width_modifier && dwvw_decode_load_bits (psf, pdwvw, 1))
316 delta_width_modifier = - delta_width_modifier ;
318 /* Calculate the current word width. */
319 delta_width = (delta_width + delta_width_modifier + pdwvw->bit_width) % pdwvw->bit_width ;
321 /* Load the delta. */
324 { delta = dwvw_decode_load_bits (psf, pdwvw, delta_width - 1) | (1 << (delta_width - 1)) ;
325 delta_negative = dwvw_decode_load_bits (psf, pdwvw, 1) ;
326 if (delta == pdwvw->max_delta - 1)
327 delta += dwvw_decode_load_bits (psf, pdwvw, 1) ;
332 /* Calculate the sample */
335 if (sample >= pdwvw->max_delta)
336 sample -= pdwvw->span ;
337 else if (sample < - pdwvw->max_delta)
338 sample += pdwvw->span ;
340 /* Store the sample justifying to the most significant bit. */
341 ptr [count] = sample << (32 - pdwvw->bit_width) ;
343 if (pdwvw->b.end == 0 && pdwvw->bit_count == 0)
347 pdwvw->last_delta_width = delta_width ;
348 pdwvw->last_sample = sample ;
350 pdwvw->samplecount += count ;
353 } /* dwvw_decode_data */
356 dwvw_decode_load_bits (SF_PRIVATE *psf, DWVW_PRIVATE *pdwvw, int bit_count)
357 { int output = 0, get_dwm = SF_FALSE ;
360 ** Depending on the value of parameter bit_count, either get the
361 ** required number of bits (ie bit_count > 0) or the
362 ** delta_width_modifier (otherwise).
366 { get_dwm = SF_TRUE ;
367 /* modify bit_count to ensure we have enought bits for finding dwm. */
368 bit_count = pdwvw->dwm_maxsize ;
371 /* Load bits in bit reseviour. */
372 while (pdwvw->bit_count < bit_count)
373 { if (pdwvw->b.index >= pdwvw->b.end)
374 { pdwvw->b.end = psf_fread (pdwvw->b.buffer, 1, sizeof (pdwvw->b.buffer), psf) ;
378 /* Check for end of input stream. */
379 if (bit_count < 8 && pdwvw->b.end == 0)
382 pdwvw->bits = (pdwvw->bits << 8) ;
384 if (pdwvw->b.index < pdwvw->b.end)
385 { pdwvw->bits |= pdwvw->b.buffer [pdwvw->b.index] ;
388 pdwvw->bit_count += 8 ;
391 /* If asked to get bits do so. */
393 { output = (pdwvw->bits >> (pdwvw->bit_count - bit_count)) & ((1 << bit_count) - 1) ;
394 pdwvw->bit_count -= bit_count ;
398 /* Otherwise must have been asked to get delta_width_modifier. */
399 while (output < (pdwvw->dwm_maxsize))
400 { pdwvw->bit_count -= 1 ;
401 if (pdwvw->bits & (1 << pdwvw->bit_count))
407 } /* dwvw_decode_load_bits */
410 dwvw_read_reset (DWVW_PRIVATE *pdwvw)
411 { pdwvw->samplecount = 0 ;
414 pdwvw->bit_count = 0 ;
416 pdwvw->last_delta_width = 0 ;
417 pdwvw->last_sample = 0 ;
418 } /* dwvw_read_reset */
421 dwvw_encode_store_bits (SF_PRIVATE *psf, DWVW_PRIVATE *pdwvw, int data, int new_bits)
424 /* Shift the bits into the resevoir. */
425 pdwvw->bits = (pdwvw->bits << new_bits) | (data & ((1 << new_bits) - 1)) ;
426 pdwvw->bit_count += new_bits ;
428 /* Transfer bit to buffer. */
429 while (pdwvw->bit_count >= 8)
430 { byte = pdwvw->bits >> (pdwvw->bit_count - 8) ;
431 pdwvw->bit_count -= 8 ;
432 pdwvw->b.buffer [pdwvw->b.index] = byte & 0xFF ;
436 if (pdwvw->b.index > SIGNED_SIZEOF (pdwvw->b.buffer) - 4)
437 { psf_fwrite (pdwvw->b.buffer, 1, pdwvw->b.index, psf) ;
442 } /* dwvw_encode_store_bits */
445 /* Debigging routine. */
447 dump_bits (DWVW_PRIVATE *pdwvw)
450 for (k = 0 ; k < 10 && k < pdwvw->b.index ; k++)
453 { putchar (mask & pdwvw->b.buffer [k] ? '1' : '0') ;
459 for (k = pdwvw->bit_count - 1 ; k >= 0 ; k --)
460 putchar (pdwvw->bits & (1 << k) ? '1' : '0') ;
466 #define HIGHEST_BIT(x,count) \
476 dwvw_encode_data (SF_PRIVATE *psf, DWVW_PRIVATE *pdwvw, const int *ptr, int len)
478 int delta_width_modifier, delta, delta_negative, delta_width, extra_bit ;
480 for (count = 0 ; count < len ; count++)
481 { delta = (ptr [count] >> (32 - pdwvw->bit_width)) - pdwvw->last_sample ;
483 /* Calculate extra_bit if needed. */
486 if (delta < -pdwvw->max_delta)
487 delta = pdwvw->max_delta + (delta % pdwvw->max_delta) ;
488 else if (delta == -pdwvw->max_delta)
491 delta = pdwvw->max_delta - 1 ;
493 else if (delta > pdwvw->max_delta)
494 { delta_negative = 1 ;
495 delta = pdwvw->span - delta ;
496 delta = abs (delta) ;
498 else if (delta == pdwvw->max_delta)
500 delta = pdwvw->max_delta - 1 ;
503 { delta_negative = 1 ;
504 delta = abs (delta) ;
507 if (delta == pdwvw->max_delta - 1 && extra_bit == -1)
510 /* Find width in bits of delta */
511 HIGHEST_BIT (delta, delta_width) ;
513 /* Calculate the delta_width_modifier */
514 delta_width_modifier = (delta_width - pdwvw->last_delta_width) % pdwvw->bit_width ;
515 if (delta_width_modifier > pdwvw->dwm_maxsize)
516 delta_width_modifier -= pdwvw->bit_width ;
517 if (delta_width_modifier < -pdwvw->dwm_maxsize)
518 delta_width_modifier += pdwvw->bit_width ;
520 /* Write delta_width_modifier zeros, followed by terminating '1'. */
521 dwvw_encode_store_bits (psf, pdwvw, 0, abs (delta_width_modifier)) ;
522 if (abs (delta_width_modifier) != pdwvw->dwm_maxsize)
523 dwvw_encode_store_bits (psf, pdwvw, 1, 1) ;
525 /* Write delta_width_modifier sign. */
526 if (delta_width_modifier < 0)
527 dwvw_encode_store_bits (psf, pdwvw, 1, 1) ;
528 if (delta_width_modifier > 0)
529 dwvw_encode_store_bits (psf, pdwvw, 0, 1) ;
531 /* Write delta and delta sign bit. */
533 { dwvw_encode_store_bits (psf, pdwvw, delta, abs (delta_width) - 1) ;
534 dwvw_encode_store_bits (psf, pdwvw, (delta_negative ? 1 : 0), 1) ;
537 /* Write extra bit!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! */
539 dwvw_encode_store_bits (psf, pdwvw, extra_bit, 1) ;
541 pdwvw->last_sample = ptr [count] >> (32 - pdwvw->bit_width) ;
542 pdwvw->last_delta_width = delta_width ;
545 pdwvw->samplecount += count ;
548 } /* dwvw_encode_data */
551 dwvw_write_s (SF_PRIVATE *psf, const short *ptr, sf_count_t len)
552 { DWVW_PRIVATE *pdwvw ;
554 int k, bufferlen, writecount = 0, count ;
555 sf_count_t total = 0 ;
559 pdwvw = (DWVW_PRIVATE*) psf->fdata ;
562 bufferlen = ARRAY_LEN (psf->u.ibuf) ;
564 { writecount = (len >= bufferlen) ? bufferlen : len ;
565 for (k = 0 ; k < writecount ; k++)
566 iptr [k] = ptr [total + k] << 16 ;
567 count = dwvw_encode_data (psf, pdwvw, iptr, writecount) ;
571 if (count != writecount)
579 dwvw_write_i (SF_PRIVATE *psf, const int *ptr, sf_count_t len)
580 { DWVW_PRIVATE *pdwvw ;
581 int writecount, count ;
582 sf_count_t total = 0 ;
586 pdwvw = (DWVW_PRIVATE*) psf->fdata ;
589 { writecount = (len > 0x10000000) ? 0x10000000 : (int) len ;
591 count = dwvw_encode_data (psf, pdwvw, ptr, writecount) ;
596 if (count != writecount)
604 dwvw_write_f (SF_PRIVATE *psf, const float *ptr, sf_count_t len)
605 { DWVW_PRIVATE *pdwvw ;
607 int k, bufferlen, writecount = 0, count ;
608 sf_count_t total = 0 ;
613 pdwvw = (DWVW_PRIVATE*) psf->fdata ;
615 normfact = (psf->norm_float == SF_TRUE) ? (1.0 * 0x7FFFFFFF) : 1.0 ;
618 bufferlen = ARRAY_LEN (psf->u.ibuf) ;
620 { writecount = (len >= bufferlen) ? bufferlen : len ;
621 for (k = 0 ; k < writecount ; k++)
622 iptr [k] = lrintf (normfact * ptr [total + k]) ;
623 count = dwvw_encode_data (psf, pdwvw, iptr, writecount) ;
627 if (count != writecount)
635 dwvw_write_d (SF_PRIVATE *psf, const double *ptr, sf_count_t len)
636 { DWVW_PRIVATE *pdwvw ;
638 int k, bufferlen, writecount = 0, count ;
639 sf_count_t total = 0 ;
644 pdwvw = (DWVW_PRIVATE*) psf->fdata ;
646 normfact = (psf->norm_double == SF_TRUE) ? (1.0 * 0x7FFFFFFF) : 1.0 ;
649 bufferlen = ARRAY_LEN (psf->u.ibuf) ;
651 { writecount = (len >= bufferlen) ? bufferlen : len ;
652 for (k = 0 ; k < writecount ; k++)
653 iptr [k] = lrint (normfact * ptr [total + k]) ;
654 count = dwvw_encode_data (psf, pdwvw, iptr, writecount) ;
658 if (count != writecount)
666 ** Do not edit or modify anything in this comment block.
667 ** The arch-tag line is a file identity tag for the GNU Arch
668 ** revision control system.
670 ** arch-tag: 1ca09552-b01f-4d7f-9bcf-612f834fe41d