1/*
2 * ATRAC3+ compatible decoder
3 *
4 * Copyright (c) 2010-2013 Maxim Poliakovski
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23/**
24 * @file
25 * Bitstream parser for ATRAC3+ decoder.
26 */
27
28#include "libavutil/avassert.h"
29#include "avcodec.h"
30#include "get_bits.h"
31#include "atrac3plus.h"
32#include "atrac3plus_data.h"
33
34static VLCElem tables_data[154276];
35static VLC wl_vlc_tabs[4];
36static VLC sf_vlc_tabs[8];
37static VLC ct_vlc_tabs[4];
38static VLC spec_vlc_tabs[112];
39static VLC gain_vlc_tabs[11];
40static VLC tone_vlc_tabs[7];
41
42/**
43 * Generate canonical VLC table from given descriptor.
44 *
45 * @param[in]     cb          ptr to codebook descriptor
46 * @param[in,out] xlat        ptr to ptr to translation table
47 * @param[in,out] tab_offset  starting offset to the generated vlc table
48 * @param[out]    out_vlc     ptr to vlc table to be generated
49 */
50static av_cold void build_canonical_huff(const uint8_t *cb, const uint8_t **xlat,
51                                         int *tab_offset, VLC *out_vlc)
52{
53    int i, max_len;
54    uint8_t bits[256];
55    int index = 0;
56
57    for (int b = 1; b <= 12; b++) {
58        for (i = *cb++; i > 0; i--) {
59            av_assert0(index < 256);
60            bits[index]  = b;
61            index++;
62        }
63    }
64    max_len = bits[index - 1];
65
66    out_vlc->table = &tables_data[*tab_offset];
67    out_vlc->table_allocated = 1 << max_len;
68
69    ff_init_vlc_from_lengths(out_vlc, max_len, index, bits, 1,
70                             *xlat, 1, 1, 0, INIT_VLC_USE_NEW_STATIC, NULL);
71
72    *tab_offset += 1 << max_len;
73    *xlat       += index;
74}
75
76av_cold void ff_atrac3p_init_vlcs(void)
77{
78    int i, tab_offset = 0;
79    const uint8_t *xlats;
80
81    xlats = atrac3p_wl_ct_xlats;
82    for (int i = 0; i < 4; i++) {
83        build_canonical_huff(atrac3p_wl_cbs[i], &xlats,
84                             &tab_offset, &wl_vlc_tabs[i]);
85        build_canonical_huff(atrac3p_ct_cbs[i], &xlats,
86                             &tab_offset, &ct_vlc_tabs[i]);
87    }
88
89    xlats = atrac3p_sf_xlats;
90    for (int i = 0; i < 8; i++)
91        build_canonical_huff(atrac3p_sf_cbs[i], &xlats,
92                             &tab_offset, &sf_vlc_tabs[i]);
93
94    /* build huffman tables for spectrum decoding */
95    xlats = atrac3p_spectra_xlats;
96    for (i = 0; i < 112; i++) {
97        if (atrac3p_spectra_cbs[i][0] >= 0)
98            build_canonical_huff(atrac3p_spectra_cbs[i],
99                                 &xlats, &tab_offset, &spec_vlc_tabs[i]);
100        else /* Reuse already initialized VLC table */
101            spec_vlc_tabs[i] = spec_vlc_tabs[-atrac3p_spectra_cbs[i][0]];
102    }
103
104    /* build huffman tables for gain data decoding */
105    xlats = atrac3p_gain_xlats;
106    for (i = 0; i < 11; i++)
107        build_canonical_huff(atrac3p_gain_cbs[i], &xlats,
108                             &tab_offset, &gain_vlc_tabs[i]);
109
110    /* build huffman tables for tone decoding */
111    xlats = atrac3p_tone_xlats;
112    for (i = 0; i < 7; i++)
113        build_canonical_huff(atrac3p_tone_cbs[i], &xlats,
114                             &tab_offset, &tone_vlc_tabs[i]);
115}
116
117/**
118 * Decode number of coded quantization units.
119 *
120 * @param[in]     gb            the GetBit context
121 * @param[in,out] chan          ptr to the channel parameters
122 * @param[in,out] ctx           ptr to the channel unit context
123 * @param[in]     avctx         ptr to the AVCodecContext
124 * @return result code: 0 = OK, otherwise - error code
125 */
126static int num_coded_units(GetBitContext *gb, Atrac3pChanParams *chan,
127                           Atrac3pChanUnitCtx *ctx, AVCodecContext *avctx)
128{
129    chan->fill_mode = get_bits(gb, 2);
130    if (!chan->fill_mode) {
131        chan->num_coded_vals = ctx->num_quant_units;
132    } else {
133        chan->num_coded_vals = get_bits(gb, 5);
134        if (chan->num_coded_vals > ctx->num_quant_units) {
135            av_log(avctx, AV_LOG_ERROR,
136                   "Invalid number of transmitted units!\n");
137            return AVERROR_INVALIDDATA;
138        }
139
140        if (chan->fill_mode == 3)
141            chan->split_point = get_bits(gb, 2) + (chan->ch_num << 1) + 1;
142    }
143
144    return 0;
145}
146
147/**
148 * Add weighting coefficients to the decoded word-length information.
149 *
150 * @param[in,out] ctx           ptr to the channel unit context
151 * @param[in,out] chan          ptr to the channel parameters
152 * @param[in]     wtab_idx      index of the table of weights
153 * @param[in]     avctx         ptr to the AVCodecContext
154 * @return result code: 0 = OK, otherwise - error code
155 */
156static int add_wordlen_weights(Atrac3pChanUnitCtx *ctx,
157                               Atrac3pChanParams *chan, int wtab_idx,
158                               AVCodecContext *avctx)
159{
160    int i;
161    const int8_t *weights_tab =
162        &atrac3p_wl_weights[chan->ch_num * 3 + wtab_idx - 1][0];
163
164    for (i = 0; i < ctx->num_quant_units; i++) {
165        chan->qu_wordlen[i] += weights_tab[i];
166        if (chan->qu_wordlen[i] < 0 || chan->qu_wordlen[i] > 7) {
167            av_log(avctx, AV_LOG_ERROR,
168                   "WL index out of range: pos=%d, val=%d!\n",
169                   i, chan->qu_wordlen[i]);
170            return AVERROR_INVALIDDATA;
171        }
172    }
173
174    return 0;
175}
176
177/**
178 * Subtract weighting coefficients from decoded scalefactors.
179 *
180 * @param[in,out] ctx           ptr to the channel unit context
181 * @param[in,out] chan          ptr to the channel parameters
182 * @param[in]     wtab_idx      index of table of weights
183 * @param[in]     avctx         ptr to the AVCodecContext
184 * @return result code: 0 = OK, otherwise - error code
185 */
186static int subtract_sf_weights(Atrac3pChanUnitCtx *ctx,
187                               Atrac3pChanParams *chan, int wtab_idx,
188                               AVCodecContext *avctx)
189{
190    int i;
191    const int8_t *weights_tab = &atrac3p_sf_weights[wtab_idx - 1][0];
192
193    for (i = 0; i < ctx->used_quant_units; i++) {
194        chan->qu_sf_idx[i] -= weights_tab[i];
195        if (chan->qu_sf_idx[i] < 0 || chan->qu_sf_idx[i] > 63) {
196            av_log(avctx, AV_LOG_ERROR,
197                   "SF index out of range: pos=%d, val=%d!\n",
198                   i, chan->qu_sf_idx[i]);
199            return AVERROR_INVALIDDATA;
200        }
201    }
202
203    return 0;
204}
205
206/**
207 * Unpack vector quantization tables.
208 *
209 * @param[in]    start_val    start value for the unpacked table
210 * @param[in]    shape_vec    ptr to table to unpack
211 * @param[out]   dst          ptr to output array
212 * @param[in]    num_values   number of values to unpack
213 */
214static inline void unpack_vq_shape(int start_val, const int8_t *shape_vec,
215                                   int *dst, int num_values)
216{
217    int i;
218
219    if (num_values) {
220        dst[0] = dst[1] = dst[2] = start_val;
221        for (i = 3; i < num_values; i++)
222            dst[i] = start_val - shape_vec[atrac3p_qu_num_to_seg[i] - 1];
223    }
224}
225
226#define UNPACK_SF_VQ_SHAPE(gb, dst, num_vals)                            \
227    start_val = get_bits((gb), 6);                                       \
228    unpack_vq_shape(start_val, &atrac3p_sf_shapes[get_bits((gb), 6)][0], \
229                    (dst), (num_vals))
230
231/**
232 * Decode word length for each quantization unit of a channel.
233 *
234 * @param[in]     gb            the GetBit context
235 * @param[in,out] ctx           ptr to the channel unit context
236 * @param[in]     ch_num        channel to process
237 * @param[in]     avctx         ptr to the AVCodecContext
238 * @return result code: 0 = OK, otherwise - error code
239 */
240static int decode_channel_wordlen(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
241                                  int ch_num, AVCodecContext *avctx)
242{
243    int i, weight_idx = 0, delta, diff, pos, delta_bits, min_val, flag,
244        ret, start_val;
245    VLC *vlc_tab;
246    Atrac3pChanParams *chan     = &ctx->channels[ch_num];
247    Atrac3pChanParams *ref_chan = &ctx->channels[0];
248
249    chan->fill_mode = 0;
250
251    switch (get_bits(gb, 2)) { /* switch according to coding mode */
252    case 0: /* coded using constant number of bits */
253        for (i = 0; i < ctx->num_quant_units; i++)
254            chan->qu_wordlen[i] = get_bits(gb, 3);
255        break;
256    case 1:
257        if (ch_num) {
258            if ((ret = num_coded_units(gb, chan, ctx, avctx)) < 0)
259                return ret;
260
261            if (chan->num_coded_vals) {
262                vlc_tab = &wl_vlc_tabs[get_bits(gb, 2)];
263
264                for (i = 0; i < chan->num_coded_vals; i++) {
265                    delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
266                    chan->qu_wordlen[i] = (ref_chan->qu_wordlen[i] + delta) & 7;
267                }
268            }
269        } else {
270            weight_idx = get_bits(gb, 2);
271            if ((ret = num_coded_units(gb, chan, ctx, avctx)) < 0)
272                return ret;
273
274            if (chan->num_coded_vals) {
275                pos = get_bits(gb, 5);
276                if (pos > chan->num_coded_vals) {
277                    av_log(avctx, AV_LOG_ERROR,
278                           "WL mode 1: invalid position!\n");
279                    return AVERROR_INVALIDDATA;
280                }
281
282                delta_bits = get_bits(gb, 2);
283                min_val    = get_bits(gb, 3);
284
285                for (i = 0; i < pos; i++)
286                    chan->qu_wordlen[i] = get_bits(gb, 3);
287
288                for (i = pos; i < chan->num_coded_vals; i++)
289                    chan->qu_wordlen[i] = (min_val + get_bitsz(gb, delta_bits)) & 7;
290            }
291        }
292        break;
293    case 2:
294        if ((ret = num_coded_units(gb, chan, ctx, avctx)) < 0)
295            return ret;
296
297        if (ch_num && chan->num_coded_vals) {
298            vlc_tab = &wl_vlc_tabs[get_bits(gb, 2)];
299            delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
300            chan->qu_wordlen[0] = (ref_chan->qu_wordlen[0] + delta) & 7;
301
302            for (i = 1; i < chan->num_coded_vals; i++) {
303                diff = ref_chan->qu_wordlen[i] - ref_chan->qu_wordlen[i - 1];
304                delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
305                chan->qu_wordlen[i] = (chan->qu_wordlen[i - 1] + diff + delta) & 7;
306            }
307        } else if (chan->num_coded_vals) {
308            flag    = get_bits(gb, 1);
309            vlc_tab = &wl_vlc_tabs[get_bits(gb, 1)];
310
311            start_val = get_bits(gb, 3);
312            unpack_vq_shape(start_val,
313                            &atrac3p_wl_shapes[start_val][get_bits(gb, 4)][0],
314                            chan->qu_wordlen, chan->num_coded_vals);
315
316            if (!flag) {
317                for (i = 0; i < chan->num_coded_vals; i++) {
318                    delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
319                    chan->qu_wordlen[i] = (chan->qu_wordlen[i] + delta) & 7;
320                }
321            } else {
322                for (i = 0; i < (chan->num_coded_vals & - 2); i += 2)
323                    if (!get_bits1(gb)) {
324                        chan->qu_wordlen[i]     = (chan->qu_wordlen[i] +
325                                                   get_vlc2(gb, vlc_tab->table,
326                                                            vlc_tab->bits, 1)) & 7;
327                        chan->qu_wordlen[i + 1] = (chan->qu_wordlen[i + 1] +
328                                                   get_vlc2(gb, vlc_tab->table,
329                                                            vlc_tab->bits, 1)) & 7;
330                    }
331
332                if (chan->num_coded_vals & 1)
333                    chan->qu_wordlen[i] = (chan->qu_wordlen[i] +
334                                           get_vlc2(gb, vlc_tab->table,
335                                                    vlc_tab->bits, 1)) & 7;
336            }
337        }
338        break;
339    case 3:
340        weight_idx = get_bits(gb, 2);
341        if ((ret = num_coded_units(gb, chan, ctx, avctx)) < 0)
342            return ret;
343
344        if (chan->num_coded_vals) {
345            vlc_tab = &wl_vlc_tabs[get_bits(gb, 2)];
346
347            /* first coefficient is coded directly */
348            chan->qu_wordlen[0] = get_bits(gb, 3);
349
350            for (i = 1; i < chan->num_coded_vals; i++) {
351                delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
352                chan->qu_wordlen[i] = (chan->qu_wordlen[i - 1] + delta) & 7;
353            }
354        }
355        break;
356    }
357
358    if (chan->fill_mode == 2) {
359        for (i = chan->num_coded_vals; i < ctx->num_quant_units; i++)
360            chan->qu_wordlen[i] = ch_num ? get_bits1(gb) : 1;
361    } else if (chan->fill_mode == 3) {
362        pos = ch_num ? chan->num_coded_vals + chan->split_point
363                     : ctx->num_quant_units - chan->split_point;
364        if (pos > FF_ARRAY_ELEMS(chan->qu_wordlen)) {
365            av_log(avctx, AV_LOG_ERROR, "Split point beyond array\n");
366            pos = FF_ARRAY_ELEMS(chan->qu_wordlen);
367        }
368        for (i = chan->num_coded_vals; i < pos; i++)
369            chan->qu_wordlen[i] = 1;
370    }
371
372    if (weight_idx)
373        return add_wordlen_weights(ctx, chan, weight_idx, avctx);
374
375    return 0;
376}
377
378/**
379 * Decode scale factor indexes for each quant unit of a channel.
380 *
381 * @param[in]     gb            the GetBit context
382 * @param[in,out] ctx           ptr to the channel unit context
383 * @param[in]     ch_num        channel to process
384 * @param[in]     avctx         ptr to the AVCodecContext
385 * @return result code: 0 = OK, otherwise - error code
386 */
387static int decode_channel_sf_idx(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
388                                 int ch_num, AVCodecContext *avctx)
389{
390    int i, weight_idx = 0, delta, diff, num_long_vals,
391        delta_bits, min_val, vlc_sel, start_val;
392    VLC *vlc_tab;
393    Atrac3pChanParams *chan     = &ctx->channels[ch_num];
394    Atrac3pChanParams *ref_chan = &ctx->channels[0];
395
396    switch (get_bits(gb, 2)) { /* switch according to coding mode */
397    case 0: /* coded using constant number of bits */
398        for (i = 0; i < ctx->used_quant_units; i++)
399            chan->qu_sf_idx[i] = get_bits(gb, 6);
400        break;
401    case 1:
402        if (ch_num) {
403            vlc_tab = &sf_vlc_tabs[get_bits(gb, 2)];
404
405            for (i = 0; i < ctx->used_quant_units; i++) {
406                delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
407                chan->qu_sf_idx[i] = (ref_chan->qu_sf_idx[i] + delta) & 0x3F;
408            }
409        } else {
410            weight_idx = get_bits(gb, 2);
411            if (weight_idx == 3) {
412                UNPACK_SF_VQ_SHAPE(gb, chan->qu_sf_idx, ctx->used_quant_units);
413
414                num_long_vals = get_bits(gb, 5);
415                delta_bits    = get_bits(gb, 2);
416                min_val       = get_bits(gb, 4) - 7;
417
418                for (i = 0; i < num_long_vals; i++)
419                    chan->qu_sf_idx[i] = (chan->qu_sf_idx[i] +
420                                          get_bits(gb, 4) - 7) & 0x3F;
421
422                /* all others are: min_val + delta */
423                for (i = num_long_vals; i < ctx->used_quant_units; i++)
424                    chan->qu_sf_idx[i] = (chan->qu_sf_idx[i] + min_val +
425                                          get_bitsz(gb, delta_bits)) & 0x3F;
426            } else {
427                num_long_vals = get_bits(gb, 5);
428                delta_bits    = get_bits(gb, 3);
429                min_val       = get_bits(gb, 6);
430                if (num_long_vals > ctx->used_quant_units || delta_bits == 7) {
431                    av_log(avctx, AV_LOG_ERROR,
432                           "SF mode 1: invalid parameters!\n");
433                    return AVERROR_INVALIDDATA;
434                }
435
436                /* read full-precision SF indexes */
437                for (i = 0; i < num_long_vals; i++)
438                    chan->qu_sf_idx[i] = get_bits(gb, 6);
439
440                /* all others are: min_val + delta */
441                for (i = num_long_vals; i < ctx->used_quant_units; i++)
442                    chan->qu_sf_idx[i] = (min_val +
443                                          get_bitsz(gb, delta_bits)) & 0x3F;
444            }
445        }
446        break;
447    case 2:
448        if (ch_num) {
449            vlc_tab = &sf_vlc_tabs[get_bits(gb, 2)];
450
451            delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
452            chan->qu_sf_idx[0] = (ref_chan->qu_sf_idx[0] + delta) & 0x3F;
453
454            for (i = 1; i < ctx->used_quant_units; i++) {
455                diff  = ref_chan->qu_sf_idx[i] - ref_chan->qu_sf_idx[i - 1];
456                delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
457                chan->qu_sf_idx[i] = (chan->qu_sf_idx[i - 1] + diff + delta) & 0x3F;
458            }
459        } else {
460            vlc_tab = &sf_vlc_tabs[get_bits(gb, 2) + 4];
461
462            UNPACK_SF_VQ_SHAPE(gb, chan->qu_sf_idx, ctx->used_quant_units);
463
464            for (i = 0; i < ctx->used_quant_units; i++) {
465                delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
466                chan->qu_sf_idx[i] = (chan->qu_sf_idx[i] +
467                                      sign_extend(delta, 4)) & 0x3F;
468            }
469        }
470        break;
471    case 3:
472        if (ch_num) {
473            /* copy coefficients from reference channel */
474            for (i = 0; i < ctx->used_quant_units; i++)
475                chan->qu_sf_idx[i] = ref_chan->qu_sf_idx[i];
476        } else {
477            weight_idx = get_bits(gb, 2);
478            vlc_sel    = get_bits(gb, 2);
479            vlc_tab    = &sf_vlc_tabs[vlc_sel];
480
481            if (weight_idx == 3) {
482                vlc_tab = &sf_vlc_tabs[vlc_sel + 4];
483
484                UNPACK_SF_VQ_SHAPE(gb, chan->qu_sf_idx, ctx->used_quant_units);
485
486                diff               = (get_bits(gb, 4)    + 56)   & 0x3F;
487                chan->qu_sf_idx[0] = (chan->qu_sf_idx[0] + diff) & 0x3F;
488
489                for (i = 1; i < ctx->used_quant_units; i++) {
490                    delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
491                    diff               = (diff + sign_extend(delta, 4)) & 0x3F;
492                    chan->qu_sf_idx[i] = (diff + chan->qu_sf_idx[i])    & 0x3F;
493                }
494            } else {
495                /* 1st coefficient is coded directly */
496                chan->qu_sf_idx[0] = get_bits(gb, 6);
497
498                for (i = 1; i < ctx->used_quant_units; i++) {
499                    delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
500                    chan->qu_sf_idx[i] = (chan->qu_sf_idx[i - 1] + delta) & 0x3F;
501                }
502            }
503        }
504        break;
505    }
506
507    if (weight_idx && weight_idx < 3)
508        return subtract_sf_weights(ctx, chan, weight_idx, avctx);
509
510    return 0;
511}
512
513/**
514 * Decode word length information for each channel.
515 *
516 * @param[in]     gb            the GetBit context
517 * @param[in,out] ctx           ptr to the channel unit context
518 * @param[in]     num_channels  number of channels to process
519 * @param[in]     avctx         ptr to the AVCodecContext
520 * @return result code: 0 = OK, otherwise - error code
521 */
522static int decode_quant_wordlen(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
523                                int num_channels, AVCodecContext *avctx)
524{
525    int ch_num, i, ret;
526
527    for (ch_num = 0; ch_num < num_channels; ch_num++) {
528        memset(ctx->channels[ch_num].qu_wordlen, 0,
529               sizeof(ctx->channels[ch_num].qu_wordlen));
530
531        if ((ret = decode_channel_wordlen(gb, ctx, ch_num, avctx)) < 0)
532            return ret;
533    }
534
535    /* scan for last non-zero coeff in both channels and
536     * set number of quant units having coded spectrum */
537    for (i = ctx->num_quant_units - 1; i >= 0; i--)
538        if (ctx->channels[0].qu_wordlen[i] ||
539            (num_channels == 2 && ctx->channels[1].qu_wordlen[i]))
540            break;
541    ctx->used_quant_units = i + 1;
542
543    return 0;
544}
545
546/**
547 * Decode scale factor indexes for each channel.
548 *
549 * @param[in]     gb            the GetBit context
550 * @param[in,out] ctx           ptr to the channel unit context
551 * @param[in]     num_channels  number of channels to process
552 * @param[in]     avctx         ptr to the AVCodecContext
553 * @return result code: 0 = OK, otherwise - error code
554 */
555static int decode_scale_factors(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
556                                int num_channels, AVCodecContext *avctx)
557{
558    int ch_num, ret;
559
560    if (!ctx->used_quant_units)
561        return 0;
562
563    for (ch_num = 0; ch_num < num_channels; ch_num++) {
564        memset(ctx->channels[ch_num].qu_sf_idx, 0,
565               sizeof(ctx->channels[ch_num].qu_sf_idx));
566
567        if ((ret = decode_channel_sf_idx(gb, ctx, ch_num, avctx)) < 0)
568            return ret;
569    }
570
571    return 0;
572}
573
574/**
575 * Decode number of code table values.
576 *
577 * @param[in]     gb            the GetBit context
578 * @param[in,out] ctx           ptr to the channel unit context
579 * @param[in]     avctx         ptr to the AVCodecContext
580 * @return result code: 0 = OK, otherwise - error code
581 */
582static int get_num_ct_values(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
583                             AVCodecContext *avctx)
584{
585    int num_coded_vals;
586
587    if (get_bits1(gb)) {
588        num_coded_vals = get_bits(gb, 5);
589        if (num_coded_vals > ctx->used_quant_units) {
590            av_log(avctx, AV_LOG_ERROR,
591                   "Invalid number of code table indexes: %d!\n", num_coded_vals);
592            return AVERROR_INVALIDDATA;
593        }
594        return num_coded_vals;
595    } else
596        return ctx->used_quant_units;
597}
598
599#define DEC_CT_IDX_COMMON(OP)                                           \
600    num_vals = get_num_ct_values(gb, ctx, avctx);                       \
601    if (num_vals < 0)                                                   \
602        return num_vals;                                                \
603                                                                        \
604    for (i = 0; i < num_vals; i++) {                                    \
605        if (chan->qu_wordlen[i]) {                                      \
606            chan->qu_tab_idx[i] = OP;                                   \
607        } else if (ch_num && ref_chan->qu_wordlen[i])                   \
608            /* get clone master flag */                                 \
609            chan->qu_tab_idx[i] = get_bits1(gb);                        \
610    }
611
612#define CODING_DIRECT get_bits(gb, num_bits)
613
614#define CODING_VLC get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1)
615
616#define CODING_VLC_DELTA                                                \
617    (!i) ? CODING_VLC                                                   \
618         : (pred + get_vlc2(gb, delta_vlc->table,                       \
619                            delta_vlc->bits, 1)) & mask;                \
620    pred = chan->qu_tab_idx[i]
621
622#define CODING_VLC_DIFF                                                 \
623    (ref_chan->qu_tab_idx[i] +                                          \
624     get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1)) & mask
625
626/**
627 * Decode code table indexes for each quant unit of a channel.
628 *
629 * @param[in]     gb            the GetBit context
630 * @param[in,out] ctx           ptr to the channel unit context
631 * @param[in]     ch_num        channel to process
632 * @param[in]     avctx         ptr to the AVCodecContext
633 * @return result code: 0 = OK, otherwise - error code
634 */
635static int decode_channel_code_tab(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
636                                   int ch_num, AVCodecContext *avctx)
637{
638    int i, num_vals, num_bits, pred;
639    int mask = ctx->use_full_table ? 7 : 3; /* mask for modular arithmetic */
640    VLC *vlc_tab, *delta_vlc;
641    Atrac3pChanParams *chan     = &ctx->channels[ch_num];
642    Atrac3pChanParams *ref_chan = &ctx->channels[0];
643
644    chan->table_type = get_bits1(gb);
645
646    switch (get_bits(gb, 2)) { /* switch according to coding mode */
647    case 0: /* directly coded */
648        num_bits = ctx->use_full_table + 2;
649        DEC_CT_IDX_COMMON(CODING_DIRECT);
650        break;
651    case 1: /* entropy-coded */
652        vlc_tab = ctx->use_full_table ? &ct_vlc_tabs[1]
653                                      : ct_vlc_tabs;
654        DEC_CT_IDX_COMMON(CODING_VLC);
655        break;
656    case 2: /* entropy-coded delta */
657        if (ctx->use_full_table) {
658            vlc_tab   = &ct_vlc_tabs[1];
659            delta_vlc = &ct_vlc_tabs[2];
660        } else {
661            vlc_tab   = ct_vlc_tabs;
662            delta_vlc = ct_vlc_tabs;
663        }
664        pred = 0;
665        DEC_CT_IDX_COMMON(CODING_VLC_DELTA);
666        break;
667    case 3: /* entropy-coded difference to master */
668        if (ch_num) {
669            vlc_tab = ctx->use_full_table ? &ct_vlc_tabs[3]
670                                          : ct_vlc_tabs;
671            DEC_CT_IDX_COMMON(CODING_VLC_DIFF);
672        }
673        break;
674    }
675
676    return 0;
677}
678
679/**
680 * Decode code table indexes for each channel.
681 *
682 * @param[in]     gb            the GetBit context
683 * @param[in,out] ctx           ptr to the channel unit context
684 * @param[in]     num_channels  number of channels to process
685 * @param[in]     avctx         ptr to the AVCodecContext
686 * @return result code: 0 = OK, otherwise - error code
687 */
688static int decode_code_table_indexes(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
689                                     int num_channels, AVCodecContext *avctx)
690{
691    int ch_num, ret;
692
693    if (!ctx->used_quant_units)
694        return 0;
695
696    ctx->use_full_table = get_bits1(gb);
697
698    for (ch_num = 0; ch_num < num_channels; ch_num++) {
699        memset(ctx->channels[ch_num].qu_tab_idx, 0,
700               sizeof(ctx->channels[ch_num].qu_tab_idx));
701
702        if ((ret = decode_channel_code_tab(gb, ctx, ch_num, avctx)) < 0)
703            return ret;
704    }
705
706    return 0;
707}
708
709/**
710 * Decode huffman-coded spectral lines for a given quant unit.
711 *
712 * This is a generalized version for all known coding modes.
713 * Its speed can be improved by creating separate functions for each mode.
714 *
715 * @param[in]   gb          the GetBit context
716 * @param[in]   tab         code table telling how to decode spectral lines
717 * @param[in]   vlc_tab     ptr to the huffman table associated with the code table
718 * @param[out]  out         pointer to buffer where decoded data should be stored
719 * @param[in]   num_specs   number of spectral lines to decode
720 */
721static void decode_qu_spectra(GetBitContext *gb, const Atrac3pSpecCodeTab *tab,
722                              VLC *vlc_tab, int16_t *out, const int num_specs)
723{
724    int i, j, pos, cf;
725    int group_size = tab->group_size;
726    int num_coeffs = tab->num_coeffs;
727    int bits       = tab->bits;
728    int is_signed  = tab->is_signed;
729    unsigned val;
730
731    for (pos = 0; pos < num_specs;) {
732        if (group_size == 1 || get_bits1(gb)) {
733            for (j = 0; j < group_size; j++) {
734                val = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
735
736                for (i = 0; i < num_coeffs; i++) {
737                    cf = av_mod_uintp2(val, bits);
738                    if (is_signed)
739                        cf = sign_extend(cf, bits);
740                    else if (cf && get_bits1(gb))
741                        cf = -cf;
742
743                    out[pos++] = cf;
744                    val      >>= bits;
745                }
746            }
747        } else /* group skipped */
748            pos += group_size * num_coeffs;
749    }
750}
751
752/**
753 * Decode huffman-coded IMDCT spectrum for all channels.
754 *
755 * @param[in]     gb            the GetBit context
756 * @param[in,out] ctx           ptr to the channel unit context
757 * @param[in]     num_channels  number of channels to process
758 * @param[in]     avctx         ptr to the AVCodecContext
759 */
760static void decode_spectrum(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
761                            int num_channels, AVCodecContext *avctx)
762{
763    int i, ch_num, qu, wordlen, codetab, tab_index, num_specs;
764    const Atrac3pSpecCodeTab *tab;
765    Atrac3pChanParams *chan;
766
767    for (ch_num = 0; ch_num < num_channels; ch_num++) {
768        chan = &ctx->channels[ch_num];
769
770        memset(chan->spectrum, 0, sizeof(chan->spectrum));
771
772        /* set power compensation level to disabled */
773        memset(chan->power_levs, ATRAC3P_POWER_COMP_OFF, sizeof(chan->power_levs));
774
775        for (qu = 0; qu < ctx->used_quant_units; qu++) {
776            num_specs = ff_atrac3p_qu_to_spec_pos[qu + 1] -
777                        ff_atrac3p_qu_to_spec_pos[qu];
778
779            wordlen = chan->qu_wordlen[qu];
780            codetab = chan->qu_tab_idx[qu];
781            if (wordlen) {
782                if (!ctx->use_full_table)
783                    codetab = atrac3p_ct_restricted_to_full[chan->table_type][wordlen - 1][codetab];
784
785                tab_index = (chan->table_type * 8 + codetab) * 7 + wordlen - 1;
786                tab       = &atrac3p_spectra_tabs[tab_index];
787
788                decode_qu_spectra(gb, tab, &spec_vlc_tabs[tab_index],
789                                  &chan->spectrum[ff_atrac3p_qu_to_spec_pos[qu]],
790                                  num_specs);
791            } else if (ch_num && ctx->channels[0].qu_wordlen[qu] && !codetab) {
792                /* copy coefficients from master */
793                memcpy(&chan->spectrum[ff_atrac3p_qu_to_spec_pos[qu]],
794                       &ctx->channels[0].spectrum[ff_atrac3p_qu_to_spec_pos[qu]],
795                       num_specs *
796                       sizeof(chan->spectrum[ff_atrac3p_qu_to_spec_pos[qu]]));
797                chan->qu_wordlen[qu] = ctx->channels[0].qu_wordlen[qu];
798            }
799        }
800
801        /* Power compensation levels only present in the bitstream
802         * if there are more than 2 quant units. The lowest two units
803         * correspond to the frequencies 0...351 Hz, whose shouldn't
804         * be affected by the power compensation. */
805        if (ctx->used_quant_units > 2) {
806            num_specs = atrac3p_subband_to_num_powgrps[ctx->num_coded_subbands - 1];
807            for (i = 0; i < num_specs; i++)
808                chan->power_levs[i] = get_bits(gb, 4);
809        }
810    }
811}
812
813/**
814 * Retrieve specified amount of flag bits from the input bitstream.
815 * The data can be shortened in the case of the following two common conditions:
816 * if all bits are zero then only one signal bit = 0 will be stored,
817 * if all bits are ones then two signal bits = 1,0 will be stored.
818 * Otherwise, all necessary bits will be directly stored
819 * prefixed by two signal bits = 1,1.
820 *
821 * @param[in]   gb              ptr to the GetBitContext
822 * @param[out]  out             where to place decoded flags
823 * @param[in]   num_flags       number of flags to process
824 * @return: 0 = all flag bits are zero, 1 = there is at least one non-zero flag bit
825 */
826static int get_subband_flags(GetBitContext *gb, uint8_t *out, int num_flags)
827{
828    int i, result;
829
830    memset(out, 0, num_flags);
831
832    result = get_bits1(gb);
833    if (result) {
834        if (get_bits1(gb))
835            for (i = 0; i < num_flags; i++)
836                out[i] = get_bits1(gb);
837        else
838            memset(out, 1, num_flags);
839    }
840
841    return result;
842}
843
844/**
845 * Decode mdct window shape flags for all channels.
846 *
847 * @param[in]     gb            the GetBit context
848 * @param[in,out] ctx           ptr to the channel unit context
849 * @param[in]     num_channels  number of channels to process
850 */
851static void decode_window_shape(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
852                                int num_channels)
853{
854    int ch_num;
855
856    for (ch_num = 0; ch_num < num_channels; ch_num++)
857        get_subband_flags(gb, ctx->channels[ch_num].wnd_shape,
858                          ctx->num_subbands);
859}
860
861/**
862 * Decode number of gain control points.
863 *
864 * @param[in]     gb              the GetBit context
865 * @param[in,out] ctx             ptr to the channel unit context
866 * @param[in]     ch_num          channel to process
867 * @param[in]     coded_subbands  number of subbands to process
868 * @return result code: 0 = OK, otherwise - error code
869 */
870static int decode_gainc_npoints(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
871                                int ch_num, int coded_subbands)
872{
873    int i, delta, delta_bits, min_val;
874    Atrac3pChanParams *chan     = &ctx->channels[ch_num];
875    Atrac3pChanParams *ref_chan = &ctx->channels[0];
876
877    switch (get_bits(gb, 2)) { /* switch according to coding mode */
878    case 0: /* fixed-length coding */
879        for (i = 0; i < coded_subbands; i++)
880            chan->gain_data[i].num_points = get_bits(gb, 3);
881        break;
882    case 1: /* variable-length coding */
883        for (i = 0; i < coded_subbands; i++)
884            chan->gain_data[i].num_points =
885                get_vlc2(gb, gain_vlc_tabs[0].table,
886                         gain_vlc_tabs[0].bits, 1);
887        break;
888    case 2:
889        if (ch_num) { /* VLC modulo delta to master channel */
890            for (i = 0; i < coded_subbands; i++) {
891                delta = get_vlc2(gb, gain_vlc_tabs[1].table,
892                                 gain_vlc_tabs[1].bits, 1);
893                chan->gain_data[i].num_points =
894                    (ref_chan->gain_data[i].num_points + delta) & 7;
895            }
896        } else { /* VLC modulo delta to previous */
897            chan->gain_data[0].num_points =
898                get_vlc2(gb, gain_vlc_tabs[0].table,
899                         gain_vlc_tabs[0].bits, 1);
900
901            for (i = 1; i < coded_subbands; i++) {
902                delta = get_vlc2(gb, gain_vlc_tabs[1].table,
903                                 gain_vlc_tabs[1].bits, 1);
904                chan->gain_data[i].num_points =
905                    (chan->gain_data[i - 1].num_points + delta) & 7;
906            }
907        }
908        break;
909    case 3:
910        if (ch_num) { /* copy data from master channel */
911            for (i = 0; i < coded_subbands; i++)
912                chan->gain_data[i].num_points =
913                    ref_chan->gain_data[i].num_points;
914        } else { /* shorter delta to min */
915            delta_bits = get_bits(gb, 2);
916            min_val    = get_bits(gb, 3);
917
918            for (i = 0; i < coded_subbands; i++) {
919                chan->gain_data[i].num_points = min_val + get_bitsz(gb, delta_bits);
920                if (chan->gain_data[i].num_points > 7)
921                    return AVERROR_INVALIDDATA;
922            }
923        }
924    }
925
926    return 0;
927}
928
929/**
930 * Implements coding mode 3 (slave) for gain compensation levels.
931 *
932 * @param[out]   dst   ptr to the output array
933 * @param[in]    ref   ptr to the reference channel
934 */
935static inline void gainc_level_mode3s(AtracGainInfo *dst, AtracGainInfo *ref)
936{
937    int i;
938
939    for (i = 0; i < dst->num_points; i++)
940        dst->lev_code[i] = (i >= ref->num_points) ? 7 : ref->lev_code[i];
941}
942
943/**
944 * Implements coding mode 1 (master) for gain compensation levels.
945 *
946 * @param[in]     gb     the GetBit context
947 * @param[in]     ctx    ptr to the channel unit context
948 * @param[out]    dst    ptr to the output array
949 */
950static inline void gainc_level_mode1m(GetBitContext *gb,
951                                      Atrac3pChanUnitCtx *ctx,
952                                      AtracGainInfo *dst)
953{
954    int i, delta;
955
956    if (dst->num_points > 0)
957        dst->lev_code[0] = get_vlc2(gb, gain_vlc_tabs[2].table,
958                                    gain_vlc_tabs[2].bits, 1);
959
960    for (i = 1; i < dst->num_points; i++) {
961        delta = get_vlc2(gb, gain_vlc_tabs[3].table,
962                         gain_vlc_tabs[3].bits, 1);
963        dst->lev_code[i] = (dst->lev_code[i - 1] + delta) & 0xF;
964    }
965}
966
967/**
968 * Decode level code for each gain control point.
969 *
970 * @param[in]     gb              the GetBit context
971 * @param[in,out] ctx             ptr to the channel unit context
972 * @param[in]     ch_num          channel to process
973 * @param[in]     coded_subbands  number of subbands to process
974 * @return result code: 0 = OK, otherwise - error code
975 */
976static int decode_gainc_levels(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
977                               int ch_num, int coded_subbands)
978{
979    int sb, i, delta, delta_bits, min_val, pred;
980    Atrac3pChanParams *chan     = &ctx->channels[ch_num];
981    Atrac3pChanParams *ref_chan = &ctx->channels[0];
982
983    switch (get_bits(gb, 2)) { /* switch according to coding mode */
984    case 0: /* fixed-length coding */
985        for (sb = 0; sb < coded_subbands; sb++)
986            for (i = 0; i < chan->gain_data[sb].num_points; i++)
987                chan->gain_data[sb].lev_code[i] = get_bits(gb, 4);
988        break;
989    case 1:
990        if (ch_num) { /* VLC modulo delta to master channel */
991            for (sb = 0; sb < coded_subbands; sb++)
992                for (i = 0; i < chan->gain_data[sb].num_points; i++) {
993                    delta = get_vlc2(gb, gain_vlc_tabs[5].table,
994                                     gain_vlc_tabs[5].bits, 1);
995                    pred = (i >= ref_chan->gain_data[sb].num_points)
996                           ? 7 : ref_chan->gain_data[sb].lev_code[i];
997                    chan->gain_data[sb].lev_code[i] = (pred + delta) & 0xF;
998                }
999        } else { /* VLC modulo delta to previous */
1000            for (sb = 0; sb < coded_subbands; sb++)
1001                gainc_level_mode1m(gb, ctx, &chan->gain_data[sb]);
1002        }
1003        break;
1004    case 2:
1005        if (ch_num) { /* VLC modulo delta to previous or clone master */
1006            for (sb = 0; sb < coded_subbands; sb++)
1007                if (chan->gain_data[sb].num_points > 0) {
1008                    if (get_bits1(gb))
1009                        gainc_level_mode1m(gb, ctx, &chan->gain_data[sb]);
1010                    else
1011                        gainc_level_mode3s(&chan->gain_data[sb],
1012                                           &ref_chan->gain_data[sb]);
1013                }
1014        } else { /* VLC modulo delta to lev_codes of previous subband */
1015            if (chan->gain_data[0].num_points > 0)
1016                gainc_level_mode1m(gb, ctx, &chan->gain_data[0]);
1017
1018            for (sb = 1; sb < coded_subbands; sb++)
1019                for (i = 0; i < chan->gain_data[sb].num_points; i++) {
1020                    delta = get_vlc2(gb, gain_vlc_tabs[4].table,
1021                                     gain_vlc_tabs[4].bits, 1);
1022                    pred = (i >= chan->gain_data[sb - 1].num_points)
1023                           ? 7 : chan->gain_data[sb - 1].lev_code[i];
1024                    chan->gain_data[sb].lev_code[i] = (pred + delta) & 0xF;
1025                }
1026        }
1027        break;
1028    case 3:
1029        if (ch_num) { /* clone master */
1030            for (sb = 0; sb < coded_subbands; sb++)
1031                gainc_level_mode3s(&chan->gain_data[sb],
1032                                   &ref_chan->gain_data[sb]);
1033        } else { /* shorter delta to min */
1034            delta_bits = get_bits(gb, 2);
1035            min_val    = get_bits(gb, 4);
1036
1037            for (sb = 0; sb < coded_subbands; sb++)
1038                for (i = 0; i < chan->gain_data[sb].num_points; i++) {
1039                    chan->gain_data[sb].lev_code[i] = min_val + get_bitsz(gb, delta_bits);
1040                    if (chan->gain_data[sb].lev_code[i] > 15)
1041                        return AVERROR_INVALIDDATA;
1042                }
1043        }
1044        break;
1045    }
1046
1047    return 0;
1048}
1049
1050/**
1051 * Implements coding mode 0 for gain compensation locations.
1052 *
1053 * @param[in]     gb     the GetBit context
1054 * @param[in]     ctx    ptr to the channel unit context
1055 * @param[out]    dst    ptr to the output array
1056 * @param[in]     pos    position of the value to be processed
1057 */
1058static inline void gainc_loc_mode0(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
1059                                   AtracGainInfo *dst, int pos)
1060{
1061    int delta_bits;
1062
1063    if (!pos || dst->loc_code[pos - 1] < 15)
1064        dst->loc_code[pos] = get_bits(gb, 5);
1065    else if (dst->loc_code[pos - 1] >= 30)
1066        dst->loc_code[pos] = 31;
1067    else {
1068        delta_bits         = av_log2(30 - dst->loc_code[pos - 1]) + 1;
1069        dst->loc_code[pos] = dst->loc_code[pos - 1] +
1070                             get_bits(gb, delta_bits) + 1;
1071    }
1072}
1073
1074/**
1075 * Implements coding mode 1 for gain compensation locations.
1076 *
1077 * @param[in]     gb     the GetBit context
1078 * @param[in]     ctx    ptr to the channel unit context
1079 * @param[out]    dst    ptr to the output array
1080 */
1081static inline void gainc_loc_mode1(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
1082                                   AtracGainInfo *dst)
1083{
1084    int i;
1085    VLC *tab;
1086
1087    if (dst->num_points > 0) {
1088        /* 1st coefficient is stored directly */
1089        dst->loc_code[0] = get_bits(gb, 5);
1090
1091        for (i = 1; i < dst->num_points; i++) {
1092            /* switch VLC according to the curve direction
1093             * (ascending/descending) */
1094            tab              = (dst->lev_code[i] <= dst->lev_code[i - 1])
1095                               ? &gain_vlc_tabs[7]
1096                               : &gain_vlc_tabs[9];
1097            dst->loc_code[i] = dst->loc_code[i - 1] +
1098                               get_vlc2(gb, tab->table, tab->bits, 1);
1099        }
1100    }
1101}
1102
1103/**
1104 * Decode location code for each gain control point.
1105 *
1106 * @param[in]     gb              the GetBit context
1107 * @param[in,out] ctx             ptr to the channel unit context
1108 * @param[in]     ch_num          channel to process
1109 * @param[in]     coded_subbands  number of subbands to process
1110 * @param[in]     avctx           ptr to the AVCodecContext
1111 * @return result code: 0 = OK, otherwise - error code
1112 */
1113static int decode_gainc_loc_codes(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
1114                                  int ch_num, int coded_subbands,
1115                                  AVCodecContext *avctx)
1116{
1117    int sb, i, delta, delta_bits, min_val, pred, more_than_ref;
1118    AtracGainInfo *dst, *ref;
1119    VLC *tab;
1120    Atrac3pChanParams *chan     = &ctx->channels[ch_num];
1121    Atrac3pChanParams *ref_chan = &ctx->channels[0];
1122
1123    switch (get_bits(gb, 2)) { /* switch according to coding mode */
1124    case 0: /* sequence of numbers in ascending order */
1125        for (sb = 0; sb < coded_subbands; sb++)
1126            for (i = 0; i < chan->gain_data[sb].num_points; i++)
1127                gainc_loc_mode0(gb, ctx, &chan->gain_data[sb], i);
1128        break;
1129    case 1:
1130        if (ch_num) {
1131            for (sb = 0; sb < coded_subbands; sb++) {
1132                if (chan->gain_data[sb].num_points <= 0)
1133                    continue;
1134                dst = &chan->gain_data[sb];
1135                ref = &ref_chan->gain_data[sb];
1136
1137                /* 1st value is vlc-coded modulo delta to master */
1138                delta = get_vlc2(gb, gain_vlc_tabs[10].table,
1139                                 gain_vlc_tabs[10].bits, 1);
1140                pred = ref->num_points > 0 ? ref->loc_code[0] : 0;
1141                dst->loc_code[0] = (pred + delta) & 0x1F;
1142
1143                for (i = 1; i < dst->num_points; i++) {
1144                    more_than_ref = i >= ref->num_points;
1145                    if (dst->lev_code[i] > dst->lev_code[i - 1]) {
1146                        /* ascending curve */
1147                        if (more_than_ref) {
1148                            delta =
1149                                get_vlc2(gb, gain_vlc_tabs[9].table,
1150                                         gain_vlc_tabs[9].bits, 1);
1151                            dst->loc_code[i] = dst->loc_code[i - 1] + delta;
1152                        } else {
1153                            if (get_bits1(gb))
1154                                gainc_loc_mode0(gb, ctx, dst, i);  // direct coding
1155                            else
1156                                dst->loc_code[i] = ref->loc_code[i];  // clone master
1157                        }
1158                    } else { /* descending curve */
1159                        tab   = more_than_ref ? &gain_vlc_tabs[7]
1160                                              : &gain_vlc_tabs[10];
1161                        delta = get_vlc2(gb, tab->table, tab->bits, 1);
1162                        if (more_than_ref)
1163                            dst->loc_code[i] = dst->loc_code[i - 1] + delta;
1164                        else
1165                            dst->loc_code[i] = (ref->loc_code[i] + delta) & 0x1F;
1166                    }
1167                }
1168            }
1169        } else /* VLC delta to previous */
1170            for (sb = 0; sb < coded_subbands; sb++)
1171                gainc_loc_mode1(gb, ctx, &chan->gain_data[sb]);
1172        break;
1173    case 2:
1174        if (ch_num) {
1175            for (sb = 0; sb < coded_subbands; sb++) {
1176                if (chan->gain_data[sb].num_points <= 0)
1177                    continue;
1178                dst = &chan->gain_data[sb];
1179                ref = &ref_chan->gain_data[sb];
1180                if (dst->num_points > ref->num_points || get_bits1(gb))
1181                    gainc_loc_mode1(gb, ctx, dst);
1182                else /* clone master for the whole subband */
1183                    for (i = 0; i < chan->gain_data[sb].num_points; i++)
1184                        dst->loc_code[i] = ref->loc_code[i];
1185            }
1186        } else {
1187            /* data for the first subband is coded directly */
1188            for (i = 0; i < chan->gain_data[0].num_points; i++)
1189                gainc_loc_mode0(gb, ctx, &chan->gain_data[0], i);
1190
1191            for (sb = 1; sb < coded_subbands; sb++) {
1192                if (chan->gain_data[sb].num_points <= 0)
1193                    continue;
1194                dst = &chan->gain_data[sb];
1195
1196                /* 1st value is vlc-coded modulo delta to the corresponding
1197                 * value of the previous subband if any or zero */
1198                delta = get_vlc2(gb, gain_vlc_tabs[6].table,
1199                                 gain_vlc_tabs[6].bits, 1);
1200                pred             = dst[-1].num_points > 0
1201                                   ? dst[-1].loc_code[0] : 0;
1202                dst->loc_code[0] = (pred + delta) & 0x1F;
1203
1204                for (i = 1; i < dst->num_points; i++) {
1205                    more_than_ref = i >= dst[-1].num_points;
1206                    /* Select VLC table according to curve direction and
1207                     * presence of prediction. */
1208                    tab = &gain_vlc_tabs[(dst->lev_code[i] > dst->lev_code[i - 1]) *
1209                                                   2 + more_than_ref + 6];
1210                    delta = get_vlc2(gb, tab->table, tab->bits, 1);
1211                    if (more_than_ref)
1212                        dst->loc_code[i] = dst->loc_code[i - 1] + delta;
1213                    else
1214                        dst->loc_code[i] = (dst[-1].loc_code[i] + delta) & 0x1F;
1215                }
1216            }
1217        }
1218        break;
1219    case 3:
1220        if (ch_num) { /* clone master or direct or direct coding */
1221            for (sb = 0; sb < coded_subbands; sb++)
1222                for (i = 0; i < chan->gain_data[sb].num_points; i++) {
1223                    if (i >= ref_chan->gain_data[sb].num_points)
1224                        gainc_loc_mode0(gb, ctx, &chan->gain_data[sb], i);
1225                    else
1226                        chan->gain_data[sb].loc_code[i] =
1227                            ref_chan->gain_data[sb].loc_code[i];
1228                }
1229        } else { /* shorter delta to min */
1230            delta_bits = get_bits(gb, 2) + 1;
1231            min_val    = get_bits(gb, 5);
1232
1233            for (sb = 0; sb < coded_subbands; sb++)
1234                for (i = 0; i < chan->gain_data[sb].num_points; i++)
1235                    chan->gain_data[sb].loc_code[i] = min_val + i +
1236                                                      get_bits(gb, delta_bits);
1237        }
1238        break;
1239    }
1240
1241    /* Validate decoded information */
1242    for (sb = 0; sb < coded_subbands; sb++) {
1243        dst = &chan->gain_data[sb];
1244        for (i = 0; i < chan->gain_data[sb].num_points; i++) {
1245            if (dst->loc_code[i] < 0 || dst->loc_code[i] > 31 ||
1246                (i && dst->loc_code[i] <= dst->loc_code[i - 1])) {
1247                av_log(avctx, AV_LOG_ERROR,
1248                       "Invalid gain location: ch=%d, sb=%d, pos=%d, val=%d\n",
1249                       ch_num, sb, i, dst->loc_code[i]);
1250                return AVERROR_INVALIDDATA;
1251            }
1252        }
1253    }
1254
1255    return 0;
1256}
1257
1258/**
1259 * Decode gain control data for all channels.
1260 *
1261 * @param[in]     gb            the GetBit context
1262 * @param[in,out] ctx           ptr to the channel unit context
1263 * @param[in]     num_channels  number of channels to process
1264 * @param[in]     avctx         ptr to the AVCodecContext
1265 * @return result code: 0 = OK, otherwise - error code
1266 */
1267static int decode_gainc_data(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
1268                             int num_channels, AVCodecContext *avctx)
1269{
1270    int ch_num, coded_subbands, sb, ret;
1271
1272    for (ch_num = 0; ch_num < num_channels; ch_num++) {
1273        memset(ctx->channels[ch_num].gain_data, 0,
1274               sizeof(*ctx->channels[ch_num].gain_data) * ATRAC3P_SUBBANDS);
1275
1276        if (get_bits1(gb)) { /* gain control data present? */
1277            coded_subbands = get_bits(gb, 4) + 1;
1278            if (get_bits1(gb)) /* is high band gain data replication on? */
1279                ctx->channels[ch_num].num_gain_subbands = get_bits(gb, 4) + 1;
1280            else
1281                ctx->channels[ch_num].num_gain_subbands = coded_subbands;
1282
1283            if ((ret = decode_gainc_npoints(gb, ctx, ch_num, coded_subbands)) < 0 ||
1284                (ret = decode_gainc_levels(gb, ctx, ch_num, coded_subbands))  < 0 ||
1285                (ret = decode_gainc_loc_codes(gb, ctx, ch_num, coded_subbands, avctx)) < 0)
1286                return ret;
1287
1288            if (coded_subbands > 0) { /* propagate gain data if requested */
1289                for (sb = coded_subbands; sb < ctx->channels[ch_num].num_gain_subbands; sb++)
1290                    ctx->channels[ch_num].gain_data[sb] =
1291                        ctx->channels[ch_num].gain_data[sb - 1];
1292            }
1293        } else {
1294            ctx->channels[ch_num].num_gain_subbands = 0;
1295        }
1296    }
1297
1298    return 0;
1299}
1300
1301/**
1302 * Decode envelope for all tones of a channel.
1303 *
1304 * @param[in]     gb                the GetBit context
1305 * @param[in,out] ctx               ptr to the channel unit context
1306 * @param[in]     ch_num            channel to process
1307 * @param[in]     band_has_tones    ptr to an array of per-band-flags:
1308 *                                  1 - tone data present
1309 */
1310static void decode_tones_envelope(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
1311                                  int ch_num, int band_has_tones[])
1312{
1313    int sb;
1314    Atrac3pWavesData *dst = ctx->channels[ch_num].tones_info;
1315    Atrac3pWavesData *ref = ctx->channels[0].tones_info;
1316
1317    if (!ch_num || !get_bits1(gb)) { /* mode 0: fixed-length coding */
1318        for (sb = 0; sb < ctx->waves_info->num_tone_bands; sb++) {
1319            if (!band_has_tones[sb])
1320                continue;
1321            dst[sb].pend_env.has_start_point = get_bits1(gb);
1322            dst[sb].pend_env.start_pos       = dst[sb].pend_env.has_start_point
1323                                               ? get_bits(gb, 5) : -1;
1324            dst[sb].pend_env.has_stop_point  = get_bits1(gb);
1325            dst[sb].pend_env.stop_pos        = dst[sb].pend_env.has_stop_point
1326                                               ? get_bits(gb, 5) : 32;
1327        }
1328    } else { /* mode 1(slave only): copy master */
1329        for (sb = 0; sb < ctx->waves_info->num_tone_bands; sb++) {
1330            if (!band_has_tones[sb])
1331                continue;
1332            dst[sb].pend_env.has_start_point = ref[sb].pend_env.has_start_point;
1333            dst[sb].pend_env.has_stop_point  = ref[sb].pend_env.has_stop_point;
1334            dst[sb].pend_env.start_pos       = ref[sb].pend_env.start_pos;
1335            dst[sb].pend_env.stop_pos        = ref[sb].pend_env.stop_pos;
1336        }
1337    }
1338}
1339
1340/**
1341 * Decode number of tones for each subband of a channel.
1342 *
1343 * @param[in]     gb                the GetBit context
1344 * @param[in,out] ctx               ptr to the channel unit context
1345 * @param[in]     ch_num            channel to process
1346 * @param[in]     band_has_tones    ptr to an array of per-band-flags:
1347 *                                  1 - tone data present
1348 * @param[in]     avctx             ptr to the AVCodecContext
1349 * @return result code: 0 = OK, otherwise - error code
1350 */
1351static int decode_band_numwavs(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
1352                               int ch_num, int band_has_tones[],
1353                               AVCodecContext *avctx)
1354{
1355    int mode, sb, delta;
1356    Atrac3pWavesData *dst = ctx->channels[ch_num].tones_info;
1357    Atrac3pWavesData *ref = ctx->channels[0].tones_info;
1358
1359    mode = get_bits(gb, ch_num + 1);
1360    switch (mode) {
1361    case 0: /** fixed-length coding */
1362        for (sb = 0; sb < ctx->waves_info->num_tone_bands; sb++)
1363            if (band_has_tones[sb])
1364                dst[sb].num_wavs = get_bits(gb, 4);
1365        break;
1366    case 1: /** variable-length coding */
1367        for (sb = 0; sb < ctx->waves_info->num_tone_bands; sb++)
1368            if (band_has_tones[sb])
1369                dst[sb].num_wavs =
1370                    get_vlc2(gb, tone_vlc_tabs[1].table,
1371                             tone_vlc_tabs[1].bits, 1);
1372        break;
1373    case 2: /** VLC modulo delta to master (slave only) */
1374        for (sb = 0; sb < ctx->waves_info->num_tone_bands; sb++)
1375            if (band_has_tones[sb]) {
1376                delta = get_vlc2(gb, tone_vlc_tabs[2].table,
1377                                 tone_vlc_tabs[2].bits, 1);
1378                delta = sign_extend(delta, 3);
1379                dst[sb].num_wavs = (ref[sb].num_wavs + delta) & 0xF;
1380            }
1381        break;
1382    case 3: /** copy master (slave only) */
1383        for (sb = 0; sb < ctx->waves_info->num_tone_bands; sb++)
1384            if (band_has_tones[sb])
1385                dst[sb].num_wavs = ref[sb].num_wavs;
1386        break;
1387    }
1388
1389    /** initialize start tone index for each subband */
1390    for (sb = 0; sb < ctx->waves_info->num_tone_bands; sb++)
1391        if (band_has_tones[sb]) {
1392            if (ctx->waves_info->tones_index + dst[sb].num_wavs > 48) {
1393                av_log(avctx, AV_LOG_ERROR,
1394                       "Too many tones: %d (max. 48), frame: %d!\n",
1395                       ctx->waves_info->tones_index + dst[sb].num_wavs,
1396                       avctx->frame_number);
1397                return AVERROR_INVALIDDATA;
1398            }
1399            dst[sb].start_index           = ctx->waves_info->tones_index;
1400            ctx->waves_info->tones_index += dst[sb].num_wavs;
1401        }
1402
1403    return 0;
1404}
1405
1406/**
1407 * Decode frequency information for each subband of a channel.
1408 *
1409 * @param[in]     gb                the GetBit context
1410 * @param[in,out] ctx               ptr to the channel unit context
1411 * @param[in]     ch_num            channel to process
1412 * @param[in]     band_has_tones    ptr to an array of per-band-flags:
1413 *                                  1 - tone data present
1414 */
1415static void decode_tones_frequency(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
1416                                   int ch_num, int band_has_tones[])
1417{
1418    int sb, i, direction, nbits, pred, delta;
1419    Atrac3pWaveParam *iwav, *owav;
1420    Atrac3pWavesData *dst = ctx->channels[ch_num].tones_info;
1421    Atrac3pWavesData *ref = ctx->channels[0].tones_info;
1422
1423    if (!ch_num || !get_bits1(gb)) { /* mode 0: fixed-length coding */
1424        for (sb = 0; sb < ctx->waves_info->num_tone_bands; sb++) {
1425            if (!band_has_tones[sb] || !dst[sb].num_wavs)
1426                continue;
1427            iwav      = &ctx->waves_info->waves[dst[sb].start_index];
1428            direction = (dst[sb].num_wavs > 1) ? get_bits1(gb) : 0;
1429            if (direction) { /** packed numbers in descending order */
1430                if (dst[sb].num_wavs)
1431                    iwav[dst[sb].num_wavs - 1].freq_index = get_bits(gb, 10);
1432                for (i = dst[sb].num_wavs - 2; i >= 0 ; i--) {
1433                    nbits = av_log2(iwav[i+1].freq_index) + 1;
1434                    iwav[i].freq_index = get_bits(gb, nbits);
1435                }
1436            } else { /** packed numbers in ascending order */
1437                for (i = 0; i < dst[sb].num_wavs; i++) {
1438                    if (!i || iwav[i - 1].freq_index < 512)
1439                        iwav[i].freq_index = get_bits(gb, 10);
1440                    else {
1441                        nbits = av_log2(1023 - iwav[i - 1].freq_index) + 1;
1442                        iwav[i].freq_index = get_bits(gb, nbits) +
1443                                             1024 - (1 << nbits);
1444                    }
1445                }
1446            }
1447        }
1448    } else { /* mode 1: VLC modulo delta to master (slave only) */
1449        for (sb = 0; sb < ctx->waves_info->num_tone_bands; sb++) {
1450            if (!band_has_tones[sb] || !dst[sb].num_wavs)
1451                continue;
1452            iwav = &ctx->waves_info->waves[ref[sb].start_index];
1453            owav = &ctx->waves_info->waves[dst[sb].start_index];
1454            for (i = 0; i < dst[sb].num_wavs; i++) {
1455                delta = get_vlc2(gb, tone_vlc_tabs[6].table,
1456                                 tone_vlc_tabs[6].bits, 1);
1457                delta = sign_extend(delta, 8);
1458                pred  = (i < ref[sb].num_wavs) ? iwav[i].freq_index :
1459                        (ref[sb].num_wavs ? iwav[ref[sb].num_wavs - 1].freq_index : 0);
1460                owav[i].freq_index = (pred + delta) & 0x3FF;
1461            }
1462        }
1463    }
1464}
1465
1466/**
1467 * Decode amplitude information for each subband of a channel.
1468 *
1469 * @param[in]     gb                the GetBit context
1470 * @param[in,out] ctx               ptr to the channel unit context
1471 * @param[in]     ch_num            channel to process
1472 * @param[in]     band_has_tones    ptr to an array of per-band-flags:
1473 *                                  1 - tone data present
1474 */
1475static void decode_tones_amplitude(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
1476                                   int ch_num, int band_has_tones[])
1477{
1478    int mode, sb, j, i, diff, maxdiff, fi, delta, pred;
1479    Atrac3pWaveParam *wsrc, *wref;
1480    int refwaves[48] = { 0 };
1481    Atrac3pWavesData *dst = ctx->channels[ch_num].tones_info;
1482    Atrac3pWavesData *ref = ctx->channels[0].tones_info;
1483
1484    if (ch_num) {
1485        for (sb = 0; sb < ctx->waves_info->num_tone_bands; sb++) {
1486            if (!band_has_tones[sb] || !dst[sb].num_wavs)
1487                continue;
1488            wsrc = &ctx->waves_info->waves[dst[sb].start_index];
1489            wref = &ctx->waves_info->waves[ref[sb].start_index];
1490            for (j = 0; j < dst[sb].num_wavs; j++) {
1491                for (i = 0, fi = 0, maxdiff = 1024; i < ref[sb].num_wavs; i++) {
1492                    diff = FFABS(wsrc[j].freq_index - wref[i].freq_index);
1493                    if (diff < maxdiff) {
1494                        maxdiff = diff;
1495                        fi      = i;
1496                    }
1497                }
1498
1499                if (maxdiff < 8)
1500                    refwaves[dst[sb].start_index + j] = fi + ref[sb].start_index;
1501                else if (j < ref[sb].num_wavs)
1502                    refwaves[dst[sb].start_index + j] = j + ref[sb].start_index;
1503                else
1504                    refwaves[dst[sb].start_index + j] = -1;
1505            }
1506        }
1507    }
1508
1509    mode = get_bits(gb, ch_num + 1);
1510
1511    switch (mode) {
1512    case 0: /** fixed-length coding */
1513        for (sb = 0; sb < ctx->waves_info->num_tone_bands; sb++) {
1514            if (!band_has_tones[sb] || !dst[sb].num_wavs)
1515                continue;
1516            if (ctx->waves_info->amplitude_mode)
1517                for (i = 0; i < dst[sb].num_wavs; i++)
1518                    ctx->waves_info->waves[dst[sb].start_index + i].amp_sf = get_bits(gb, 6);
1519            else
1520                ctx->waves_info->waves[dst[sb].start_index].amp_sf = get_bits(gb, 6);
1521        }
1522        break;
1523    case 1: /** min + VLC delta */
1524        for (sb = 0; sb < ctx->waves_info->num_tone_bands; sb++) {
1525            if (!band_has_tones[sb] || !dst[sb].num_wavs)
1526                continue;
1527            if (ctx->waves_info->amplitude_mode)
1528                for (i = 0; i < dst[sb].num_wavs; i++)
1529                    ctx->waves_info->waves[dst[sb].start_index + i].amp_sf =
1530                        get_vlc2(gb, tone_vlc_tabs[3].table,
1531                                 tone_vlc_tabs[3].bits, 1) + 20;
1532            else
1533                ctx->waves_info->waves[dst[sb].start_index].amp_sf =
1534                    get_vlc2(gb, tone_vlc_tabs[4].table,
1535                             tone_vlc_tabs[4].bits, 1) + 24;
1536        }
1537        break;
1538    case 2: /** VLC modulo delta to master (slave only) */
1539        for (sb = 0; sb < ctx->waves_info->num_tone_bands; sb++) {
1540            if (!band_has_tones[sb] || !dst[sb].num_wavs)
1541                continue;
1542            for (i = 0; i < dst[sb].num_wavs; i++) {
1543                delta = get_vlc2(gb, tone_vlc_tabs[5].table,
1544                                 tone_vlc_tabs[5].bits, 1);
1545                delta = sign_extend(delta, 5);
1546                pred  = refwaves[dst[sb].start_index + i] >= 0 ?
1547                        ctx->waves_info->waves[refwaves[dst[sb].start_index + i]].amp_sf : 34;
1548                ctx->waves_info->waves[dst[sb].start_index + i].amp_sf = (pred + delta) & 0x3F;
1549            }
1550        }
1551        break;
1552    case 3: /** clone master (slave only) */
1553        for (sb = 0; sb < ctx->waves_info->num_tone_bands; sb++) {
1554            if (!band_has_tones[sb])
1555                continue;
1556            for (i = 0; i < dst[sb].num_wavs; i++)
1557                ctx->waves_info->waves[dst[sb].start_index + i].amp_sf =
1558                    refwaves[dst[sb].start_index + i] >= 0
1559                    ? ctx->waves_info->waves[refwaves[dst[sb].start_index + i]].amp_sf
1560                    : 32;
1561        }
1562        break;
1563    }
1564}
1565
1566/**
1567 * Decode phase information for each subband of a channel.
1568 *
1569 * @param[in]     gb                the GetBit context
1570 * @param[in,out] ctx               ptr to the channel unit context
1571 * @param[in]     ch_num            channel to process
1572 * @param[in]     band_has_tones    ptr to an array of per-band-flags:
1573 *                                  1 - tone data present
1574 */
1575static void decode_tones_phase(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
1576                               int ch_num, int band_has_tones[])
1577{
1578    int sb, i;
1579    Atrac3pWaveParam *wparam;
1580    Atrac3pWavesData *dst = ctx->channels[ch_num].tones_info;
1581
1582    for (sb = 0; sb < ctx->waves_info->num_tone_bands; sb++) {
1583        if (!band_has_tones[sb])
1584            continue;
1585        wparam = &ctx->waves_info->waves[dst[sb].start_index];
1586        for (i = 0; i < dst[sb].num_wavs; i++)
1587            wparam[i].phase_index = get_bits(gb, 5);
1588    }
1589}
1590
1591/**
1592 * Decode tones info for all channels.
1593 *
1594 * @param[in]     gb            the GetBit context
1595 * @param[in,out] ctx           ptr to the channel unit context
1596 * @param[in]     num_channels  number of channels to process
1597 * @param[in]     avctx         ptr to the AVCodecContext
1598 * @return result code: 0 = OK, otherwise - error code
1599 */
1600static int decode_tones_info(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
1601                             int num_channels, AVCodecContext *avctx)
1602{
1603    int ch_num, i, ret;
1604    int band_has_tones[16];
1605
1606    for (ch_num = 0; ch_num < num_channels; ch_num++)
1607        memset(ctx->channels[ch_num].tones_info, 0,
1608               sizeof(*ctx->channels[ch_num].tones_info) * ATRAC3P_SUBBANDS);
1609
1610    ctx->waves_info->tones_present = get_bits1(gb);
1611    if (!ctx->waves_info->tones_present)
1612        return 0;
1613
1614    memset(ctx->waves_info->waves, 0, sizeof(ctx->waves_info->waves));
1615
1616    ctx->waves_info->amplitude_mode = get_bits1(gb);
1617    if (!ctx->waves_info->amplitude_mode) {
1618        avpriv_report_missing_feature(avctx, "GHA amplitude mode 0");
1619        return AVERROR_PATCHWELCOME;
1620    }
1621
1622    ctx->waves_info->num_tone_bands =
1623        get_vlc2(gb, tone_vlc_tabs[0].table,
1624                 tone_vlc_tabs[0].bits, 1) + 1;
1625
1626    if (num_channels == 2) {
1627        get_subband_flags(gb, ctx->waves_info->tone_sharing, ctx->waves_info->num_tone_bands);
1628        get_subband_flags(gb, ctx->waves_info->tone_master,  ctx->waves_info->num_tone_bands);
1629        get_subband_flags(gb, ctx->waves_info->invert_phase, ctx->waves_info->num_tone_bands);
1630    }
1631
1632    ctx->waves_info->tones_index = 0;
1633
1634    for (ch_num = 0; ch_num < num_channels; ch_num++) {
1635        for (i = 0; i < ctx->waves_info->num_tone_bands; i++)
1636            band_has_tones[i] = !ch_num ? 1 : !ctx->waves_info->tone_sharing[i];
1637
1638        decode_tones_envelope(gb, ctx, ch_num, band_has_tones);
1639        if ((ret = decode_band_numwavs(gb, ctx, ch_num, band_has_tones,
1640                                       avctx)) < 0)
1641            return ret;
1642
1643        decode_tones_frequency(gb, ctx, ch_num, band_has_tones);
1644        decode_tones_amplitude(gb, ctx, ch_num, band_has_tones);
1645        decode_tones_phase(gb, ctx, ch_num, band_has_tones);
1646    }
1647
1648    if (num_channels == 2) {
1649        for (i = 0; i < ctx->waves_info->num_tone_bands; i++) {
1650            if (ctx->waves_info->tone_sharing[i])
1651                ctx->channels[1].tones_info[i] = ctx->channels[0].tones_info[i];
1652
1653            if (ctx->waves_info->tone_master[i])
1654                FFSWAP(Atrac3pWavesData, ctx->channels[0].tones_info[i],
1655                       ctx->channels[1].tones_info[i]);
1656        }
1657    }
1658
1659    return 0;
1660}
1661
1662int ff_atrac3p_decode_channel_unit(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
1663                                   int num_channels, AVCodecContext *avctx)
1664{
1665    int ret;
1666
1667    /* parse sound header */
1668    ctx->num_quant_units = get_bits(gb, 5) + 1;
1669    if (ctx->num_quant_units > 28 && ctx->num_quant_units < 32) {
1670        av_log(avctx, AV_LOG_ERROR,
1671               "Invalid number of quantization units: %d!\n",
1672               ctx->num_quant_units);
1673        return AVERROR_INVALIDDATA;
1674    }
1675
1676    ctx->mute_flag = get_bits1(gb);
1677
1678    /* decode various sound parameters */
1679    if ((ret = decode_quant_wordlen(gb, ctx, num_channels, avctx)) < 0)
1680        return ret;
1681
1682    ctx->num_subbands       = atrac3p_qu_to_subband[ctx->num_quant_units - 1] + 1;
1683    ctx->num_coded_subbands = ctx->used_quant_units
1684                              ? atrac3p_qu_to_subband[ctx->used_quant_units - 1] + 1
1685                              : 0;
1686
1687    if ((ret = decode_scale_factors(gb, ctx, num_channels, avctx)) < 0)
1688        return ret;
1689
1690    if ((ret = decode_code_table_indexes(gb, ctx, num_channels, avctx)) < 0)
1691        return ret;
1692
1693    decode_spectrum(gb, ctx, num_channels, avctx);
1694
1695    if (num_channels == 2) {
1696        get_subband_flags(gb, ctx->swap_channels, ctx->num_coded_subbands);
1697        get_subband_flags(gb, ctx->negate_coeffs, ctx->num_coded_subbands);
1698    }
1699
1700    decode_window_shape(gb, ctx, num_channels);
1701
1702    if ((ret = decode_gainc_data(gb, ctx, num_channels, avctx)) < 0)
1703        return ret;
1704
1705    if ((ret = decode_tones_info(gb, ctx, num_channels, avctx)) < 0)
1706        return ret;
1707
1708    /* decode global noise info */
1709    ctx->noise_present = get_bits1(gb);
1710    if (ctx->noise_present) {
1711        ctx->noise_level_index = get_bits(gb, 4);
1712        ctx->noise_table_index = get_bits(gb, 4);
1713    }
1714
1715    return 0;
1716}
1717