1 /*
2 ** Copyright (C) 2003-2011 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 #include "sfconfig.h"
20
21 #include <stdlib.h>
22
23 #include "sndfile.h"
24 #include "sfendian.h"
25 #include "common.h"
26
27 /*============================================================================
28 ** Rule number 1 is to only apply dither when going from a larger bitwidth
29 ** to a smaller bitwidth. This can happen on both read and write.
30 **
31 ** Need to apply dither on all conversions marked X below.
32 **
33 ** Dither on write:
34 **
35 ** Input
36 ** | short int float double
37 ** --------+-----------------------------------------------
38 ** O 8 bit | X X X X
39 ** u 16 bit | none X X X
40 ** t 24 bit | none X X X
41 ** p 32 bit | none none X X
42 ** u float | none none none none
43 ** t double | none none none none
44 **
45 ** Dither on read:
46 **
47 ** Input
48 ** O | 8 bit 16 bit 24 bit 32 bit float double
49 ** u --------+-------------------------------------------------
50 ** t short | none none X X X X
51 ** p int | none none none X X X
52 ** u float | none none none none none none
53 ** t double | none none none none none none
54 */
55
56 #define SFE_DITHER_BAD_PTR 666
57 #define SFE_DITHER_BAD_TYPE 667
58
59 typedef struct
60 { int read_short_dither_bits, read_int_dither_bits ;
61 int write_short_dither_bits, write_int_dither_bits ;
62 double read_float_dither_scale, read_double_dither_bits ;
63 double write_float_dither_scale, write_double_dither_bits ;
64
65 sf_count_t (*read_short) (SF_PRIVATE *psf, short *ptr, sf_count_t len) ;
66 sf_count_t (*read_int) (SF_PRIVATE *psf, int *ptr, sf_count_t len) ;
67 sf_count_t (*read_float) (SF_PRIVATE *psf, float *ptr, sf_count_t len) ;
68 sf_count_t (*read_double) (SF_PRIVATE *psf, double *ptr, sf_count_t len) ;
69
70 sf_count_t (*write_short) (SF_PRIVATE *psf, const short *ptr, sf_count_t len) ;
71 sf_count_t (*write_int) (SF_PRIVATE *psf, const int *ptr, sf_count_t len) ;
72 sf_count_t (*write_float) (SF_PRIVATE *psf, const float *ptr, sf_count_t len) ;
73 sf_count_t (*write_double) (SF_PRIVATE *psf, const double *ptr, sf_count_t len) ;
74
75 double buffer [SF_BUFFER_LEN / sizeof (double)] ;
76 } DITHER_DATA ;
77
78 static sf_count_t dither_read_short (SF_PRIVATE *psf, short *ptr, sf_count_t len) ;
79 static sf_count_t dither_read_int (SF_PRIVATE *psf, int *ptr, sf_count_t len) ;
80
81 static sf_count_t dither_write_short (SF_PRIVATE *psf, const short *ptr, sf_count_t len) ;
82 static sf_count_t dither_write_int (SF_PRIVATE *psf, const int *ptr, sf_count_t len) ;
83 static sf_count_t dither_write_float (SF_PRIVATE *psf, const float *ptr, sf_count_t len) ;
84 static sf_count_t dither_write_double (SF_PRIVATE *psf, const double *ptr, sf_count_t len) ;
85
86 int
dither_init(SF_PRIVATE * psf,int mode)87 dither_init (SF_PRIVATE *psf, int mode)
88 { DITHER_DATA *pdither ;
89
90 pdither = psf->dither ; /* This may be NULL. */
91
92 /* Turn off dither on read. */
93 if (mode == SFM_READ && psf->read_dither.type == SFD_NO_DITHER)
94 { if (pdither == NULL)
95 return 0 ; /* Dither is already off, so just return. */
96
97 if (pdither->read_short)
98 psf->read_short = pdither->read_short ;
99 if (pdither->read_int)
100 psf->read_int = pdither->read_int ;
101 if (pdither->read_float)
102 psf->read_float = pdither->read_float ;
103 if (pdither->read_double)
104 psf->read_double = pdither->read_double ;
105 return 0 ;
106 } ;
107
108 /* Turn off dither on write. */
109 if (mode == SFM_WRITE && psf->write_dither.type == SFD_NO_DITHER)
110 { if (pdither == NULL)
111 return 0 ; /* Dither is already off, so just return. */
112
113 if (pdither->write_short)
114 psf->write_short = pdither->write_short ;
115 if (pdither->write_int)
116 psf->write_int = pdither->write_int ;
117 if (pdither->write_float)
118 psf->write_float = pdither->write_float ;
119 if (pdither->write_double)
120 psf->write_double = pdither->write_double ;
121 return 0 ;
122 } ;
123
124 /* Turn on dither on read if asked. */
125 if (mode == SFM_READ && psf->read_dither.type != 0)
126 { if (pdither == NULL)
127 pdither = psf->dither = calloc (1, sizeof (DITHER_DATA)) ;
128 if (pdither == NULL)
129 return SFE_MALLOC_FAILED ;
130
131 switch (SF_CODEC (psf->sf.format))
132 { case SF_FORMAT_DOUBLE :
133 case SF_FORMAT_FLOAT :
134 pdither->read_int = psf->read_int ;
135 psf->read_int = dither_read_int ;
136 break ;
137
138 case SF_FORMAT_PCM_32 :
139 case SF_FORMAT_PCM_24 :
140 case SF_FORMAT_PCM_16 :
141 case SF_FORMAT_PCM_S8 :
142 case SF_FORMAT_PCM_U8 :
143 pdither->read_short = psf->read_short ;
144 psf->read_short = dither_read_short ;
145 break ;
146
147 default : break ;
148 } ;
149 } ;
150
151 /* Turn on dither on write if asked. */
152 if (mode == SFM_WRITE && psf->write_dither.type != 0)
153 { if (pdither == NULL)
154 pdither = psf->dither = calloc (1, sizeof (DITHER_DATA)) ;
155 if (pdither == NULL)
156 return SFE_MALLOC_FAILED ;
157
158 switch (SF_CODEC (psf->sf.format))
159 { case SF_FORMAT_DOUBLE :
160 case SF_FORMAT_FLOAT :
161 pdither->write_int = psf->write_int ;
162 psf->write_int = dither_write_int ;
163 break ;
164
165 case SF_FORMAT_PCM_32 :
166 case SF_FORMAT_PCM_24 :
167 case SF_FORMAT_PCM_16 :
168 case SF_FORMAT_PCM_S8 :
169 case SF_FORMAT_PCM_U8 :
170 break ;
171
172 default : break ;
173 } ;
174
175 pdither->write_short = psf->write_short ;
176 psf->write_short = dither_write_short ;
177
178 pdither->write_int = psf->write_int ;
179 psf->write_int = dither_write_int ;
180
181 pdither->write_float = psf->write_float ;
182 psf->write_float = dither_write_float ;
183
184 pdither->write_double = psf->write_double ;
185 psf->write_double = dither_write_double ;
186 } ;
187
188 return 0 ;
189 } /* dither_init */
190
191 /*==============================================================================
192 */
193
194 static void dither_short (const short *in, short *out, int frames, int channels) ;
195 static void dither_int (const int *in, int *out, int frames, int channels) ;
196
197 static void dither_float (const float *in, float *out, int frames, int channels) ;
198 static void dither_double (const double *in, double *out, int frames, int channels) ;
199
200 static sf_count_t
dither_read_short(SF_PRIVATE * UNUSED (psf),short * UNUSED (ptr),sf_count_t len)201 dither_read_short (SF_PRIVATE * UNUSED (psf), short * UNUSED (ptr), sf_count_t len)
202 {
203 return len ;
204 } /* dither_read_short */
205
206 static sf_count_t
dither_read_int(SF_PRIVATE * UNUSED (psf),int * UNUSED (ptr),sf_count_t len)207 dither_read_int (SF_PRIVATE * UNUSED (psf), int * UNUSED (ptr), sf_count_t len)
208 {
209 return len ;
210 } /* dither_read_int */
211
212 /*------------------------------------------------------------------------------
213 */
214
215 static sf_count_t
dither_write_short(SF_PRIVATE * psf,const short * ptr,sf_count_t len)216 dither_write_short (SF_PRIVATE *psf, const short *ptr, sf_count_t len)
217 { DITHER_DATA *pdither ;
218 int bufferlen, writecount, thiswrite ;
219 sf_count_t total = 0 ;
220
221 if ((pdither = psf->dither) == NULL)
222 { psf->error = SFE_DITHER_BAD_PTR ;
223 return 0 ;
224 } ;
225
226 switch (SF_CODEC (psf->sf.format))
227 { case SF_FORMAT_PCM_S8 :
228 case SF_FORMAT_PCM_U8 :
229 case SF_FORMAT_DPCM_8 :
230 break ;
231
232 default :
233 return pdither->write_short (psf, ptr, len) ;
234 } ;
235
236 bufferlen = sizeof (pdither->buffer) / (sizeof (short)) ;
237
238 while (len > 0)
239 { writecount = (len >= bufferlen) ? bufferlen : (int) len ;
240 writecount /= psf->sf.channels ;
241 writecount *= psf->sf.channels ;
242
243 dither_short (ptr, (short*) pdither->buffer, writecount / psf->sf.channels, psf->sf.channels) ;
244
245 thiswrite = pdither->write_short (psf, (short*) pdither->buffer, writecount) ;
246 total += thiswrite ;
247 len -= thiswrite ;
248 if (thiswrite < writecount)
249 break ;
250 } ;
251
252 return total ;
253 } /* dither_write_short */
254
255 static sf_count_t
dither_write_int(SF_PRIVATE * psf,const int * ptr,sf_count_t len)256 dither_write_int (SF_PRIVATE *psf, const int *ptr, sf_count_t len)
257 { DITHER_DATA *pdither ;
258 int bufferlen, writecount, thiswrite ;
259 sf_count_t total = 0 ;
260
261 if ((pdither = psf->dither) == NULL)
262 { psf->error = SFE_DITHER_BAD_PTR ;
263 return 0 ;
264 } ;
265
266 switch (SF_CODEC (psf->sf.format))
267 { case SF_FORMAT_PCM_S8 :
268 case SF_FORMAT_PCM_U8 :
269 case SF_FORMAT_PCM_16 :
270 case SF_FORMAT_PCM_24 :
271 break ;
272
273 case SF_FORMAT_DPCM_8 :
274 case SF_FORMAT_DPCM_16 :
275 break ;
276
277 default :
278 return pdither->write_int (psf, ptr, len) ;
279 } ;
280
281
282 bufferlen = sizeof (pdither->buffer) / (sizeof (int)) ;
283
284 while (len > 0)
285 { writecount = (len >= bufferlen) ? bufferlen : (int) len ;
286 writecount /= psf->sf.channels ;
287 writecount *= psf->sf.channels ;
288
289 dither_int (ptr, (int*) pdither->buffer, writecount / psf->sf.channels, psf->sf.channels) ;
290
291 thiswrite = pdither->write_int (psf, (int*) pdither->buffer, writecount) ;
292 total += thiswrite ;
293 len -= thiswrite ;
294 if (thiswrite < writecount)
295 break ;
296 } ;
297
298 return total ;
299 } /* dither_write_int */
300
301 static sf_count_t
dither_write_float(SF_PRIVATE * psf,const float * ptr,sf_count_t len)302 dither_write_float (SF_PRIVATE *psf, const float *ptr, sf_count_t len)
303 { DITHER_DATA *pdither ;
304 int bufferlen, writecount, thiswrite ;
305 sf_count_t total = 0 ;
306
307 if ((pdither = psf->dither) == NULL)
308 { psf->error = SFE_DITHER_BAD_PTR ;
309 return 0 ;
310 } ;
311
312 switch (SF_CODEC (psf->sf.format))
313 { case SF_FORMAT_PCM_S8 :
314 case SF_FORMAT_PCM_U8 :
315 case SF_FORMAT_PCM_16 :
316 case SF_FORMAT_PCM_24 :
317 break ;
318
319 case SF_FORMAT_DPCM_8 :
320 case SF_FORMAT_DPCM_16 :
321 break ;
322
323 default :
324 return pdither->write_float (psf, ptr, len) ;
325 } ;
326
327 bufferlen = sizeof (pdither->buffer) / (sizeof (float)) ;
328
329 while (len > 0)
330 { writecount = (len >= bufferlen) ? bufferlen : (float) len ;
331 writecount /= psf->sf.channels ;
332 writecount *= psf->sf.channels ;
333
334 dither_float (ptr, (float*) pdither->buffer, writecount / psf->sf.channels, psf->sf.channels) ;
335
336 thiswrite = pdither->write_float (psf, (float*) pdither->buffer, writecount) ;
337 total += thiswrite ;
338 len -= thiswrite ;
339 if (thiswrite < writecount)
340 break ;
341 } ;
342
343 return total ;
344 } /* dither_write_float */
345
346 static sf_count_t
dither_write_double(SF_PRIVATE * psf,const double * ptr,sf_count_t len)347 dither_write_double (SF_PRIVATE *psf, const double *ptr, sf_count_t len)
348 { DITHER_DATA *pdither ;
349 int bufferlen, writecount, thiswrite ;
350 sf_count_t total = 0 ;
351
352 if ((pdither = psf->dither) == NULL)
353 { psf->error = SFE_DITHER_BAD_PTR ;
354 return 0 ;
355 } ;
356
357 switch (SF_CODEC (psf->sf.format))
358 { case SF_FORMAT_PCM_S8 :
359 case SF_FORMAT_PCM_U8 :
360 case SF_FORMAT_PCM_16 :
361 case SF_FORMAT_PCM_24 :
362 break ;
363
364 case SF_FORMAT_DPCM_8 :
365 case SF_FORMAT_DPCM_16 :
366 break ;
367
368 default :
369 return pdither->write_double (psf, ptr, len) ;
370 } ;
371
372
373 bufferlen = sizeof (pdither->buffer) / sizeof (double) ;
374
375 while (len > 0)
376 { writecount = (len >= bufferlen) ? bufferlen : (double) len ;
377 writecount /= psf->sf.channels ;
378 writecount *= psf->sf.channels ;
379
380 dither_double (ptr, (double*) pdither->buffer, writecount / psf->sf.channels, psf->sf.channels) ;
381
382 thiswrite = pdither->write_double (psf, (double*) pdither->buffer, writecount) ;
383 total += thiswrite ;
384 len -= thiswrite ;
385 if (thiswrite < writecount)
386 break ;
387 } ;
388
389 return total ;
390 } /* dither_write_double */
391
392 /*==============================================================================
393 */
394
395 static void
dither_short(const short * in,short * out,int frames,int channels)396 dither_short (const short *in, short *out, int frames, int channels)
397 { int ch, k ;
398
399 for (ch = 0 ; ch < channels ; ch++)
400 for (k = ch ; k < channels * frames ; k += channels)
401 out [k] = in [k] ;
402
403 } /* dither_short */
404
405 static void
dither_int(const int * in,int * out,int frames,int channels)406 dither_int (const int *in, int *out, int frames, int channels)
407 { int ch, k ;
408
409 for (ch = 0 ; ch < channels ; ch++)
410 for (k = ch ; k < channels * frames ; k += channels)
411 out [k] = in [k] ;
412
413 } /* dither_int */
414
415 static void
dither_float(const float * in,float * out,int frames,int channels)416 dither_float (const float *in, float *out, int frames, int channels)
417 { int ch, k ;
418
419 for (ch = 0 ; ch < channels ; ch++)
420 for (k = ch ; k < channels * frames ; k += channels)
421 out [k] = in [k] ;
422
423 } /* dither_float */
424
425 static void
dither_double(const double * in,double * out,int frames,int channels)426 dither_double (const double *in, double *out, int frames, int channels)
427 { int ch, k ;
428
429 for (ch = 0 ; ch < channels ; ch++)
430 for (k = ch ; k < channels * frames ; k += channels)
431 out [k] = in [k] ;
432
433 } /* dither_double */
434
435 /*==============================================================================
436 */
437 #if 0
438
439 /*
440 ** Not made public because this (maybe) requires storage of state information.
441 **
442 ** Also maybe need separate state info for each channel!!!!
443 */
444
445 int
446 DO_NOT_USE_sf_dither_short (const SF_DITHER_INFO *dither, const short *in, short *out, int frames, int channels)
447 { int ch, k ;
448
449 if (! dither)
450 return SFE_DITHER_BAD_PTR ;
451
452 switch (dither->type & SFD_TYPEMASK)
453 { case SFD_WHITE :
454 case SFD_TRIANGULAR_PDF :
455 for (ch = 0 ; ch < channels ; ch++)
456 for (k = ch ; k < channels * frames ; k += channels)
457 out [k] = in [k] ;
458 break ;
459
460 default :
461 return SFE_DITHER_BAD_TYPE ;
462 } ;
463
464 return 0 ;
465 } /* DO_NOT_USE_sf_dither_short */
466
467 int
468 DO_NOT_USE_sf_dither_int (const SF_DITHER_INFO *dither, const int *in, int *out, int frames, int channels)
469 { int ch, k ;
470
471 if (! dither)
472 return SFE_DITHER_BAD_PTR ;
473
474 switch (dither->type & SFD_TYPEMASK)
475 { case SFD_WHITE :
476 case SFD_TRIANGULAR_PDF :
477 for (ch = 0 ; ch < channels ; ch++)
478 for (k = ch ; k < channels * frames ; k += channels)
479 out [k] = in [k] ;
480 break ;
481
482 default :
483 return SFE_DITHER_BAD_TYPE ;
484 } ;
485
486 return 0 ;
487 } /* DO_NOT_USE_sf_dither_int */
488
489 int
490 DO_NOT_USE_sf_dither_float (const SF_DITHER_INFO *dither, const float *in, float *out, int frames, int channels)
491 { int ch, k ;
492
493 if (! dither)
494 return SFE_DITHER_BAD_PTR ;
495
496 switch (dither->type & SFD_TYPEMASK)
497 { case SFD_WHITE :
498 case SFD_TRIANGULAR_PDF :
499 for (ch = 0 ; ch < channels ; ch++)
500 for (k = ch ; k < channels * frames ; k += channels)
501 out [k] = in [k] ;
502 break ;
503
504 default :
505 return SFE_DITHER_BAD_TYPE ;
506 } ;
507
508 return 0 ;
509 } /* DO_NOT_USE_sf_dither_float */
510
511 int
512 DO_NOT_USE_sf_dither_double (const SF_DITHER_INFO *dither, const double *in, double *out, int frames, int channels)
513 { int ch, k ;
514
515 if (! dither)
516 return SFE_DITHER_BAD_PTR ;
517
518 switch (dither->type & SFD_TYPEMASK)
519 { case SFD_WHITE :
520 case SFD_TRIANGULAR_PDF :
521 for (ch = 0 ; ch < channels ; ch++)
522 for (k = ch ; k < channels * frames ; k += channels)
523 out [k] = in [k] ;
524 break ;
525
526 default :
527 return SFE_DITHER_BAD_TYPE ;
528 } ;
529
530 return 0 ;
531 } /* DO_NOT_USE_sf_dither_double */
532
533 #endif
534
535