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1/*
2** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
3** Copyright (C) 2003-2005 M. Bakker, Nero AG, http://www.nero.com
4**
5** This program is free software; you can redistribute it and/or modify
6** it under the terms of the GNU General Public License as published by
7** the Free Software Foundation; either version 2 of the License, or
8** (at your option) any later version.
9**
10** This program 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
13** GNU General Public License for more details.
14**
15** You should have received a copy of the GNU General Public License
16** along with this program; if not, write to the Free Software
17** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18**
19** Any non-GPL usage of this software or parts of this software is strictly
20** forbidden.
21**
22** The "appropriate copyright message" mentioned in section 2c of the GPLv2
23** must read: "Code from FAAD2 is copyright (c) Nero AG, www.nero.com"
24**
25** Commercial non-GPL licensing of this software is possible.
26** For more info contact Nero AG through Mpeg4AAClicense@nero.com.
27**
28** $Id: rvlc.c,v 1.21 2007/11/01 12:33:34 menno Exp $
29**/
30
31/* RVLC scalefactor decoding
32 *
33 * RVLC works like this:
34 * 1. Only symmetric huffman codewords are used
35 * 2. Total length of the scalefactor data is stored in the bitsream
36 * 3. Scalefactors are DPCM coded
37 * 4. Next to the starting value for DPCM the ending value is also stored
38 *
39 * With all this it is possible to read the scalefactor data from 2 sides.
40 * If there is a bit error in the scalefactor data it is possible to start
41 * decoding from the other end of the data, to find all but 1 scalefactor.
42 */
43#include <stdlib.h>
44#include "common.h"
45#include "structs.h"
46
47
48#include "syntax.h"
49#include "bits.h"
50#include "rvlc.h"
51
52
53#ifdef ERROR_RESILIENCE
54
55//#define PRINT_RVLC
56
57/* static function declarations */
58static uint8_t rvlc_decode_sf_forward(ic_stream *ics,
59 bitfile *ld_sf,
60 bitfile *ld_esc,
61 uint8_t *is_used);
62#if 0
63static uint8_t rvlc_decode_sf_reverse(ic_stream *ics,
64 bitfile *ld_sf,
65 bitfile *ld_esc,
66 uint8_t is_used);
67#endif
68static int8_t rvlc_huffman_sf(bitfile *ld_sf, bitfile *ld_esc,
69 int8_t direction);
70static int8_t rvlc_huffman_esc(bitfile *ld_esc, int8_t direction);
71
72
73uint8_t rvlc_scale_factor_data(ic_stream *ics, bitfile *ld)
74{
75 uint8_t bits = 9;
76
77 ics->sf_concealment = faad_get1bit(ld
78 DEBUGVAR(1, 149, "rvlc_scale_factor_data(): sf_concealment"));
79 ics->rev_global_gain = (uint8_t)faad_getbits(ld, 8
80 DEBUGVAR(1, 150, "rvlc_scale_factor_data(): rev_global_gain"));
81
82 if (ics->window_sequence == EIGHT_SHORT_SEQUENCE) {
83 bits = 11;
84 }
85
86 /* the number of bits used for the huffman codewords */
87 ics->length_of_rvlc_sf = (uint16_t)faad_getbits(ld, bits
88 DEBUGVAR(1, 151, "rvlc_scale_factor_data(): length_of_rvlc_sf"));
89
90 if (ics->noise_used) {
91 ics->dpcm_noise_nrg = (uint16_t)faad_getbits(ld, 9
92 DEBUGVAR(1, 152, "rvlc_scale_factor_data(): dpcm_noise_nrg"));
93
94 ics->length_of_rvlc_sf -= 9;
95 }
96
97 ics->sf_escapes_present = faad_get1bit(ld
98 DEBUGVAR(1, 153, "rvlc_scale_factor_data(): sf_escapes_present"));
99
100 if (ics->sf_escapes_present) {
101 ics->length_of_rvlc_escapes = (uint8_t)faad_getbits(ld, 8
102 DEBUGVAR(1, 154, "rvlc_scale_factor_data(): length_of_rvlc_escapes"));
103 }
104
105 if (ics->noise_used) {
106 ics->dpcm_noise_last_position = (uint16_t)faad_getbits(ld, 9
107 DEBUGVAR(1, 155, "rvlc_scale_factor_data(): dpcm_noise_last_position"));
108 }
109
110 return 0;
111}
112
113uint8_t rvlc_decode_scale_factors(ic_stream *ics, bitfile *ld)
114{
115 uint8_t result;
116 uint8_t intensity_used = 0;
117 uint8_t *rvlc_sf_buffer = NULL;
118 uint8_t *rvlc_esc_buffer = NULL;
119 bitfile ld_rvlc_sf, ld_rvlc_esc;
120 // bitfile ld_rvlc_sf_rev, ld_rvlc_esc_rev;
121
122 if (ics->length_of_rvlc_sf > 0) {
123 /* We read length_of_rvlc_sf bits here to put it in a
124 seperate bitfile.
125 */
126 rvlc_sf_buffer = faad_getbitbuffer(ld, ics->length_of_rvlc_sf
127 DEBUGVAR(1, 156, "rvlc_decode_scale_factors(): bitbuffer: length_of_rvlc_sf"));
128
129 faad_initbits(&ld_rvlc_sf, (void*)rvlc_sf_buffer, bit2byte(ics->length_of_rvlc_sf));
130 // faad_initbits_rev(&ld_rvlc_sf_rev, (void*)rvlc_sf_buffer,
131 // ics->length_of_rvlc_sf);
132 }
133
134 if (ics->sf_escapes_present) {
135 /* We read length_of_rvlc_escapes bits here to put it in a
136 seperate bitfile.
137 */
138 rvlc_esc_buffer = faad_getbitbuffer(ld, ics->length_of_rvlc_escapes
139 DEBUGVAR(1, 157, "rvlc_decode_scale_factors(): bitbuffer: length_of_rvlc_escapes"));
140
141 faad_initbits(&ld_rvlc_esc, (void*)rvlc_esc_buffer, bit2byte(ics->length_of_rvlc_escapes));
142 // faad_initbits_rev(&ld_rvlc_esc_rev, (void*)rvlc_esc_buffer,
143 // ics->length_of_rvlc_escapes);
144 }
145
146 /* decode the rvlc scale factors and escapes */
147 result = rvlc_decode_sf_forward(ics, &ld_rvlc_sf,
148 &ld_rvlc_esc, &intensity_used);
149 // result = rvlc_decode_sf_reverse(ics, &ld_rvlc_sf_rev,
150 // &ld_rvlc_esc_rev, intensity_used);
151
152
153 if (rvlc_esc_buffer) {
154 faad_free(rvlc_esc_buffer);
155 }
156 if (rvlc_sf_buffer) {
157 faad_free(rvlc_sf_buffer);
158 }
159
160 if (ics->length_of_rvlc_sf > 0) {
161 faad_endbits(&ld_rvlc_sf);
162 }
163 if (ics->sf_escapes_present) {
164 faad_endbits(&ld_rvlc_esc);
165 }
166
167 return result;
168}
169
170static uint8_t rvlc_decode_sf_forward(ic_stream *ics, bitfile *ld_sf, bitfile *ld_esc,
171 uint8_t *intensity_used)
172{
173 int8_t g, sfb;
174 int8_t t = 0;
175 int8_t error = 0;
176 int8_t noise_pcm_flag = 1;
177
178 int16_t scale_factor = ics->global_gain;
179 int16_t is_position = 0;
180 int16_t noise_energy = ics->global_gain - 90 - 256;
181
182#ifdef PRINT_RVLC
183 printf("\nglobal_gain: %d\n", ics->global_gain);
184#endif
185
186 for (g = 0; g < ics->num_window_groups; g++) {
187 for (sfb = 0; sfb < ics->max_sfb; sfb++) {
188 if (error) {
189 ics->scale_factors[g][sfb] = 0;
190 } else {
191 switch (ics->sfb_cb[g][sfb]) {
192 case ZERO_HCB: /* zero book */
193 ics->scale_factors[g][sfb] = 0;
194 break;
195 case INTENSITY_HCB: /* intensity books */
196 case INTENSITY_HCB2:
197
198 *intensity_used = 1;
199
200 /* decode intensity position */
201 t = rvlc_huffman_sf(ld_sf, ld_esc, +1);
202
203 is_position += t;
204 ics->scale_factors[g][sfb] = is_position;
205
206 break;
207 case NOISE_HCB: /* noise books */
208
209 /* decode noise energy */
210 if (noise_pcm_flag) {
211 int16_t n = ics->dpcm_noise_nrg;
212 noise_pcm_flag = 0;
213 noise_energy += n;
214 } else {
215 t = rvlc_huffman_sf(ld_sf, ld_esc, +1);
216 noise_energy += t;
217 }
218
219 ics->scale_factors[g][sfb] = noise_energy;
220
221 break;
222 default: /* spectral books */
223
224 /* decode scale factor */
225 t = rvlc_huffman_sf(ld_sf, ld_esc, +1);
226
227 scale_factor += t;
228 if (scale_factor < 0) {
229 return 4;
230 }
231
232 ics->scale_factors[g][sfb] = scale_factor;
233
234 break;
235 }
236#ifdef PRINT_RVLC
237 printf("%3d:%4d%4d\n", sfb, ics->sfb_cb[g][sfb],
238 ics->scale_factors[g][sfb]);
239#endif
240 if (t == 99) {
241 error = 1;
242 }
243 }
244 }
245 }
246#ifdef PRINT_RVLC
247 printf("\n\n");
248#endif
249
250 return 0;
251}
252
253#if 0 // not used right now, doesn't work correctly yet
254static uint8_t rvlc_decode_sf_reverse(ic_stream *ics, bitfile *ld_sf, bitfile *ld_esc,
255 uint8_t intensity_used)
256{
257 int8_t g, sfb;
258 int8_t t = 0;
259 int8_t error = 0;
260 int8_t noise_pcm_flag = 1, is_pcm_flag = 1, sf_pcm_flag = 1;
261
262 int16_t scale_factor = ics->rev_global_gain;
263 int16_t is_position = 0;
264 int16_t noise_energy = ics->rev_global_gain;
265
266#ifdef PRINT_RVLC
267 printf("\nrev_global_gain: %d\n", ics->rev_global_gain);
268#endif
269
270 if (intensity_used) {
271 is_position = rvlc_huffman_sf(ld_sf, ld_esc, -1);
272#ifdef PRINT_RVLC
273 printf("is_position: %d\n", is_position);
274#endif
275 }
276
277 for (g = ics->num_window_groups - 1; g >= 0; g--) {
278 for (sfb = ics->max_sfb - 1; sfb >= 0; sfb--) {
279 if (error) {
280 ics->scale_factors[g][sfb] = 0;
281 } else {
282 switch (ics->sfb_cb[g][sfb]) {
283 case ZERO_HCB: /* zero book */
284 ics->scale_factors[g][sfb] = 0;
285 break;
286 case INTENSITY_HCB: /* intensity books */
287 case INTENSITY_HCB2:
288
289 if (is_pcm_flag) {
290 is_pcm_flag = 0;
291 ics->scale_factors[g][sfb] = is_position;
292 } else {
293 t = rvlc_huffman_sf(ld_sf, ld_esc, -1);
294 is_position -= t;
295
296 ics->scale_factors[g][sfb] = (uint8_t)is_position;
297 }
298 break;
299 case NOISE_HCB: /* noise books */
300
301 /* decode noise energy */
302 if (noise_pcm_flag) {
303 noise_pcm_flag = 0;
304 noise_energy = ics->dpcm_noise_last_position;
305 } else {
306 t = rvlc_huffman_sf(ld_sf, ld_esc, -1);
307 noise_energy -= t;
308 }
309
310 ics->scale_factors[g][sfb] = (uint8_t)noise_energy;
311 break;
312 default: /* spectral books */
313
314 if (sf_pcm_flag || (sfb == 0)) {
315 sf_pcm_flag = 0;
316 if (sfb == 0) {
317 scale_factor = ics->global_gain;
318 }
319 } else {
320 /* decode scale factor */
321 t = rvlc_huffman_sf(ld_sf, ld_esc, -1);
322 scale_factor -= t;
323 }
324
325 if (scale_factor < 0) {
326 return 4;
327 }
328
329 ics->scale_factors[g][sfb] = (uint8_t)scale_factor;
330 break;
331 }
332#ifdef PRINT_RVLC
333 printf("%3d:%4d%4d\n", sfb, ics->sfb_cb[g][sfb],
334 ics->scale_factors[g][sfb]);
335#endif
336 if (t == 99) {
337 error = 1;
338 }
339 }
340 }
341 }
342
343#ifdef PRINT_RVLC
344 printf("\n\n");
345#endif
346
347 return 0;
348}
349#endif
350
351/* index == 99 means not allowed codeword */
352static rvlc_huff_table book_rvlc[] = {
353 /*index length codeword */
354 { 0, 1, 0 }, /* 0 */
355 { -1, 3, 5 }, /* 101 */
356 { 1, 3, 7 }, /* 111 */
357 { -2, 4, 9 }, /* 1001 */
358 { -3, 5, 17 }, /* 10001 */
359 { 2, 5, 27 }, /* 11011 */
360 { -4, 6, 33 }, /* 100001 */
361 { 99, 6, 50 }, /* 110010 */
362 { 3, 6, 51 }, /* 110011 */
363 { 99, 6, 52 }, /* 110100 */
364 { -7, 7, 65 }, /* 1000001 */
365 { 99, 7, 96 }, /* 1100000 */
366 { 99, 7, 98 }, /* 1100010 */
367 { 7, 7, 99 }, /* 1100011 */
368 { 4, 7, 107 }, /* 1101011 */
369 { -5, 8, 129 }, /* 10000001 */
370 { 99, 8, 194 }, /* 11000010 */
371 { 5, 8, 195 }, /* 11000011 */
372 { 99, 8, 212 }, /* 11010100 */
373 { 99, 9, 256 }, /* 100000000 */
374 { -6, 9, 257 }, /* 100000001 */
375 { 99, 9, 426 }, /* 110101010 */
376 { 6, 9, 427 }, /* 110101011 */
377 { 99, 10, 0 } /* Shouldn't come this far */
378};
379
380static rvlc_huff_table book_escape[] = {
381 /*index length codeword */
382 { 1, 2, 0 },
383 { 0, 2, 2 },
384 { 3, 3, 2 },
385 { 2, 3, 6 },
386 { 4, 4, 14 },
387 { 7, 5, 13 },
388 { 6, 5, 15 },
389 { 5, 5, 31 },
390 { 11, 6, 24 },
391 { 10, 6, 25 },
392 { 9, 6, 29 },
393 { 8, 6, 61 },
394 { 13, 7, 56 },
395 { 12, 7, 120 },
396 { 15, 8, 114 },
397 { 14, 8, 242 },
398 { 17, 9, 230 },
399 { 16, 9, 486 },
400 { 19, 10, 463 },
401 { 18, 10, 974 },
402 { 22, 11, 925 },
403 { 20, 11, 1950 },
404 { 21, 11, 1951 },
405 { 23, 12, 1848 },
406 { 25, 13, 3698 },
407 { 24, 14, 7399 },
408 { 26, 15, 14797 },
409 { 49, 19, 236736 },
410 { 50, 19, 236737 },
411 { 51, 19, 236738 },
412 { 52, 19, 236739 },
413 { 53, 19, 236740 },
414 { 27, 20, 473482 },
415 { 28, 20, 473483 },
416 { 29, 20, 473484 },
417 { 30, 20, 473485 },
418 { 31, 20, 473486 },
419 { 32, 20, 473487 },
420 { 33, 20, 473488 },
421 { 34, 20, 473489 },
422 { 35, 20, 473490 },
423 { 36, 20, 473491 },
424 { 37, 20, 473492 },
425 { 38, 20, 473493 },
426 { 39, 20, 473494 },
427 { 40, 20, 473495 },
428 { 41, 20, 473496 },
429 { 42, 20, 473497 },
430 { 43, 20, 473498 },
431 { 44, 20, 473499 },
432 { 45, 20, 473500 },
433 { 46, 20, 473501 },
434 { 47, 20, 473502 },
435 { 48, 20, 473503 },
436 { 99, 21, 0 } /* Shouldn't come this far */
437};
438
439static int8_t rvlc_huffman_sf(bitfile *ld_sf, bitfile *ld_esc,
440 int8_t direction)
441{
442 uint8_t i, j;
443 int8_t index;
444 uint32_t cw;
445 rvlc_huff_table *h = book_rvlc;
446
447 i = h->len;
448 if (direction > 0) {
449 cw = faad_getbits(ld_sf, i DEBUGVAR(1, 0, ""));
450 } else {
451 cw = faad_getbits_rev(ld_sf, i DEBUGVAR(1, 0, ""));
452 }
453
454 while ((cw != h->cw)
455 && (i < 10)) {
456 h++;
457 j = h->len - i;
458 i += j;
459 cw <<= j;
460 if (direction > 0) {
461 cw |= faad_getbits(ld_sf, j DEBUGVAR(1, 0, ""));
462 } else {
463 cw |= faad_getbits_rev(ld_sf, j DEBUGVAR(1, 0, ""));
464 }
465 }
466
467 index = h->index;
468
469 if (index == +ESC_VAL) {
470 int8_t esc = rvlc_huffman_esc(ld_esc, direction);
471 if (esc == 99) {
472 return 99;
473 }
474 index += esc;
475#ifdef PRINT_RVLC
476 printf("esc: %d - ", esc);
477#endif
478 }
479 if (index == -ESC_VAL) {
480 int8_t esc = rvlc_huffman_esc(ld_esc, direction);
481 if (esc == 99) {
482 return 99;
483 }
484 index -= esc;
485#ifdef PRINT_RVLC
486 printf("esc: %d - ", esc);
487#endif
488 }
489
490 return index;
491}
492
493static int8_t rvlc_huffman_esc(bitfile *ld,
494 int8_t direction)
495{
496 uint8_t i, j;
497 uint32_t cw;
498 rvlc_huff_table *h = book_escape;
499
500 i = h->len;
501 if (direction > 0) {
502 cw = faad_getbits(ld, i DEBUGVAR(1, 0, ""));
503 } else {
504 cw = faad_getbits_rev(ld, i DEBUGVAR(1, 0, ""));
505 }
506
507 while ((cw != h->cw)
508 && (i < 21)) {
509 h++;
510 j = h->len - i;
511 i += j;
512 cw <<= j;
513 if (direction > 0) {
514 cw |= faad_getbits(ld, j DEBUGVAR(1, 0, ""));
515 } else {
516 cw |= faad_getbits_rev(ld, j DEBUGVAR(1, 0, ""));
517 }
518 }
519
520 return h->index;
521}
522
523#endif
524
525
generated by cgit at 2024-05-18 20:42:54 (GMT)