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 VLC_TYPE tables_data[154276][2];
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#define GET_DELTA(gb, delta_bits) \
43    ((delta_bits) ? get_bits((gb), (delta_bits)) : 0)
44
45/**
46 * Generate canonical VLC table from given descriptor.
47 *
48 * @param[in]     cb          ptr to codebook descriptor
49 * @param[in]     xlat        ptr to translation table or NULL
50 * @param[in,out] tab_offset  starting offset to the generated vlc table
51 * @param[out]    out_vlc     ptr to vlc table to be generated
52 */
53static av_cold void build_canonical_huff(const uint8_t *cb, const uint8_t *xlat,
54                                         int *tab_offset, VLC *out_vlc)
55{
56    int i, b;
57    uint16_t codes[256];
58    uint8_t bits[256];
59    unsigned code = 0;
60    int index = 0;
61    int min_len = *cb++; // get shortest codeword length
62    int max_len = *cb++; // get longest  codeword length
63
64    for (b = min_len; b <= max_len; b++) {
65        for (i = *cb++; i > 0; i--) {
66            av_assert0(index < 256);
67            bits[index]  = b;
68            codes[index] = code++;
69            index++;
70        }
71        code <<= 1;
72    }
73
74    out_vlc->table = &tables_data[*tab_offset];
75    out_vlc->table_allocated = 1 << max_len;
76
77    ff_init_vlc_sparse(out_vlc, max_len, index, bits, 1, 1, codes, 2, 2,
78                       xlat, 1, 1, INIT_VLC_USE_NEW_STATIC);
79
80    *tab_offset += 1 << max_len;
81}
82
83av_cold void ff_atrac3p_init_vlcs(void)
84{
85    int i, wl_vlc_offs, ct_vlc_offs, sf_vlc_offs, tab_offset;
86
87    static int wl_nb_bits[4]  = { 2, 3, 5, 5 };
88    static int wl_nb_codes[4] = { 3, 5, 8, 8 };
89    static const uint8_t *wl_bits[4] = {
90        atrac3p_wl_huff_bits1, atrac3p_wl_huff_bits2,
91        atrac3p_wl_huff_bits3, atrac3p_wl_huff_bits4
92    };
93    static const uint8_t *wl_codes[4] = {
94        atrac3p_wl_huff_code1, atrac3p_wl_huff_code2,
95        atrac3p_wl_huff_code3, atrac3p_wl_huff_code4
96    };
97    static const uint8_t *wl_xlats[4] = {
98        atrac3p_wl_huff_xlat1, atrac3p_wl_huff_xlat2, NULL, NULL
99    };
100
101    static int ct_nb_bits[4]  = { 3, 4, 4, 4 };
102    static int ct_nb_codes[4] = { 4, 8, 8, 8 };
103    static const uint8_t *ct_bits[4]  = {
104        atrac3p_ct_huff_bits1, atrac3p_ct_huff_bits2,
105        atrac3p_ct_huff_bits2, atrac3p_ct_huff_bits3
106    };
107    static const uint8_t *ct_codes[4] = {
108        atrac3p_ct_huff_code1, atrac3p_ct_huff_code2,
109        atrac3p_ct_huff_code2, atrac3p_ct_huff_code3
110    };
111    static const uint8_t *ct_xlats[4] = {
112        NULL, NULL, atrac3p_ct_huff_xlat1, NULL
113    };
114
115    static int sf_nb_bits[8]  = {  9,  9,  9,  9,  6,  6,  7,  7 };
116    static int sf_nb_codes[8] = { 64, 64, 64, 64, 16, 16, 16, 16 };
117    static const uint8_t  *sf_bits[8]  = {
118        atrac3p_sf_huff_bits1, atrac3p_sf_huff_bits1, atrac3p_sf_huff_bits2,
119        atrac3p_sf_huff_bits3, atrac3p_sf_huff_bits4, atrac3p_sf_huff_bits4,
120        atrac3p_sf_huff_bits5, atrac3p_sf_huff_bits6
121    };
122    static const uint16_t *sf_codes[8] = {
123        atrac3p_sf_huff_code1, atrac3p_sf_huff_code1, atrac3p_sf_huff_code2,
124        atrac3p_sf_huff_code3, atrac3p_sf_huff_code4, atrac3p_sf_huff_code4,
125        atrac3p_sf_huff_code5, atrac3p_sf_huff_code6
126    };
127    static const uint8_t  *sf_xlats[8] = {
128        atrac3p_sf_huff_xlat1, atrac3p_sf_huff_xlat2, NULL, NULL,
129        atrac3p_sf_huff_xlat4, atrac3p_sf_huff_xlat5, NULL, NULL
130    };
131
132    static const uint8_t *gain_cbs[11] = {
133        atrac3p_huff_gain_npoints1_cb, atrac3p_huff_gain_npoints1_cb,
134        atrac3p_huff_gain_lev1_cb, atrac3p_huff_gain_lev2_cb,
135        atrac3p_huff_gain_lev3_cb, atrac3p_huff_gain_lev4_cb,
136        atrac3p_huff_gain_loc3_cb, atrac3p_huff_gain_loc1_cb,
137        atrac3p_huff_gain_loc4_cb, atrac3p_huff_gain_loc2_cb,
138        atrac3p_huff_gain_loc5_cb
139    };
140    static const uint8_t *gain_xlats[11] = {
141        NULL, atrac3p_huff_gain_npoints2_xlat, atrac3p_huff_gain_lev1_xlat,
142        atrac3p_huff_gain_lev2_xlat, atrac3p_huff_gain_lev3_xlat,
143        atrac3p_huff_gain_lev4_xlat, atrac3p_huff_gain_loc3_xlat,
144        atrac3p_huff_gain_loc1_xlat, atrac3p_huff_gain_loc4_xlat,
145        atrac3p_huff_gain_loc2_xlat, atrac3p_huff_gain_loc5_xlat
146    };
147
148    static const uint8_t *tone_cbs[7] = {
149        atrac3p_huff_tonebands_cb,  atrac3p_huff_numwavs1_cb,
150        atrac3p_huff_numwavs2_cb,   atrac3p_huff_wav_ampsf1_cb,
151        atrac3p_huff_wav_ampsf2_cb, atrac3p_huff_wav_ampsf3_cb,
152        atrac3p_huff_freq_cb
153    };
154    static const uint8_t *tone_xlats[7] = {
155        NULL, NULL, atrac3p_huff_numwavs2_xlat, atrac3p_huff_wav_ampsf1_xlat,
156        atrac3p_huff_wav_ampsf2_xlat, atrac3p_huff_wav_ampsf3_xlat,
157        atrac3p_huff_freq_xlat
158    };
159
160    for (i = 0, wl_vlc_offs = 0, ct_vlc_offs = 2508; i < 4; i++) {
161        wl_vlc_tabs[i].table = &tables_data[wl_vlc_offs];
162        wl_vlc_tabs[i].table_allocated = 1 << wl_nb_bits[i];
163        ct_vlc_tabs[i].table = &tables_data[ct_vlc_offs];
164        ct_vlc_tabs[i].table_allocated = 1 << ct_nb_bits[i];
165
166        ff_init_vlc_sparse(&wl_vlc_tabs[i], wl_nb_bits[i], wl_nb_codes[i],
167                           wl_bits[i],  1, 1,
168                           wl_codes[i], 1, 1,
169                           wl_xlats[i], 1, 1,
170                           INIT_VLC_USE_NEW_STATIC);
171
172        ff_init_vlc_sparse(&ct_vlc_tabs[i], ct_nb_bits[i], ct_nb_codes[i],
173                           ct_bits[i],  1, 1,
174                           ct_codes[i], 1, 1,
175                           ct_xlats[i], 1, 1,
176                           INIT_VLC_USE_NEW_STATIC);
177
178        wl_vlc_offs += wl_vlc_tabs[i].table_allocated;
179        ct_vlc_offs += ct_vlc_tabs[i].table_allocated;
180    }
181
182    for (i = 0, sf_vlc_offs = 76; i < 8; i++) {
183        sf_vlc_tabs[i].table = &tables_data[sf_vlc_offs];
184        sf_vlc_tabs[i].table_allocated = 1 << sf_nb_bits[i];
185
186        ff_init_vlc_sparse(&sf_vlc_tabs[i], sf_nb_bits[i], sf_nb_codes[i],
187                           sf_bits[i],  1, 1,
188                           sf_codes[i], 2, 2,
189                           sf_xlats[i], 1, 1,
190                           INIT_VLC_USE_NEW_STATIC);
191        sf_vlc_offs += sf_vlc_tabs[i].table_allocated;
192    }
193
194    tab_offset = 2564;
195
196    /* build huffman tables for spectrum decoding */
197    for (i = 0; i < 112; i++) {
198        if (atrac3p_spectra_tabs[i].cb)
199            build_canonical_huff(atrac3p_spectra_tabs[i].cb,
200                                 atrac3p_spectra_tabs[i].xlat,
201                                 &tab_offset, &spec_vlc_tabs[i]);
202        else
203            spec_vlc_tabs[i].table = 0;
204    }
205
206    /* build huffman tables for gain data decoding */
207    for (i = 0; i < 11; i++)
208        build_canonical_huff(gain_cbs[i], gain_xlats[i], &tab_offset, &gain_vlc_tabs[i]);
209
210    /* build huffman tables for tone decoding */
211    for (i = 0; i < 7; i++)
212        build_canonical_huff(tone_cbs[i], tone_xlats[i], &tab_offset, &tone_vlc_tabs[i]);
213}
214
215/**
216 * Decode number of coded quantization units.
217 *
218 * @param[in]     gb            the GetBit context
219 * @param[in,out] chan          ptr to the channel parameters
220 * @param[in,out] ctx           ptr to the channel unit context
221 * @param[in]     avctx         ptr to the AVCodecContext
222 * @return result code: 0 = OK, otherwise - error code
223 */
224static int num_coded_units(GetBitContext *gb, Atrac3pChanParams *chan,
225                           Atrac3pChanUnitCtx *ctx, AVCodecContext *avctx)
226{
227    chan->fill_mode = get_bits(gb, 2);
228    if (!chan->fill_mode) {
229        chan->num_coded_vals = ctx->num_quant_units;
230    } else {
231        chan->num_coded_vals = get_bits(gb, 5);
232        if (chan->num_coded_vals > ctx->num_quant_units) {
233            av_log(avctx, AV_LOG_ERROR,
234                   "Invalid number of transmitted units!\n");
235            return AVERROR_INVALIDDATA;
236        }
237
238        if (chan->fill_mode == 3)
239            chan->split_point = get_bits(gb, 2) + (chan->ch_num << 1) + 1;
240    }
241
242    return 0;
243}
244
245/**
246 * Add weighting coefficients to the decoded word-length information.
247 *
248 * @param[in,out] ctx           ptr to the channel unit context
249 * @param[in,out] chan          ptr to the channel parameters
250 * @param[in]     wtab_idx      index of the table of weights
251 * @param[in]     avctx         ptr to the AVCodecContext
252 * @return result code: 0 = OK, otherwise - error code
253 */
254static int add_wordlen_weights(Atrac3pChanUnitCtx *ctx,
255                               Atrac3pChanParams *chan, int wtab_idx,
256                               AVCodecContext *avctx)
257{
258    int i;
259    const int8_t *weights_tab =
260        &atrac3p_wl_weights[chan->ch_num * 3 + wtab_idx - 1][0];
261
262    for (i = 0; i < ctx->num_quant_units; i++) {
263        chan->qu_wordlen[i] += weights_tab[i];
264        if (chan->qu_wordlen[i] < 0 || chan->qu_wordlen[i] > 7) {
265            av_log(avctx, AV_LOG_ERROR,
266                   "WL index out of range: pos=%d, val=%d!\n",
267                   i, chan->qu_wordlen[i]);
268            return AVERROR_INVALIDDATA;
269        }
270    }
271
272    return 0;
273}
274
275/**
276 * Subtract weighting coefficients from decoded scalefactors.
277 *
278 * @param[in,out] ctx           ptr to the channel unit context
279 * @param[in,out] chan          ptr to the channel parameters
280 * @param[in]     wtab_idx      index of table of weights
281 * @param[in]     avctx         ptr to the AVCodecContext
282 * @return result code: 0 = OK, otherwise - error code
283 */
284static int subtract_sf_weights(Atrac3pChanUnitCtx *ctx,
285                               Atrac3pChanParams *chan, int wtab_idx,
286                               AVCodecContext *avctx)
287{
288    int i;
289    const int8_t *weights_tab = &atrac3p_sf_weights[wtab_idx - 1][0];
290
291    for (i = 0; i < ctx->used_quant_units; i++) {
292        chan->qu_sf_idx[i] -= weights_tab[i];
293        if (chan->qu_sf_idx[i] < 0 || chan->qu_sf_idx[i] > 63) {
294            av_log(avctx, AV_LOG_ERROR,
295                   "SF index out of range: pos=%d, val=%d!\n",
296                   i, chan->qu_sf_idx[i]);
297            return AVERROR_INVALIDDATA;
298        }
299    }
300
301    return 0;
302}
303
304/**
305 * Unpack vector quantization tables.
306 *
307 * @param[in]    start_val    start value for the unpacked table
308 * @param[in]    shape_vec    ptr to table to unpack
309 * @param[out]   dst          ptr to output array
310 * @param[in]    num_values   number of values to unpack
311 */
312static inline void unpack_vq_shape(int start_val, const int8_t *shape_vec,
313                                   int *dst, int num_values)
314{
315    int i;
316
317    if (num_values) {
318        dst[0] = dst[1] = dst[2] = start_val;
319        for (i = 3; i < num_values; i++)
320            dst[i] = start_val - shape_vec[atrac3p_qu_num_to_seg[i] - 1];
321    }
322}
323
324#define UNPACK_SF_VQ_SHAPE(gb, dst, num_vals)                            \
325    start_val = get_bits((gb), 6);                                       \
326    unpack_vq_shape(start_val, &atrac3p_sf_shapes[get_bits((gb), 6)][0], \
327                    (dst), (num_vals))
328
329/**
330 * Decode word length for each quantization unit of a channel.
331 *
332 * @param[in]     gb            the GetBit context
333 * @param[in,out] ctx           ptr to the channel unit context
334 * @param[in]     ch_num        channel to process
335 * @param[in]     avctx         ptr to the AVCodecContext
336 * @return result code: 0 = OK, otherwise - error code
337 */
338static int decode_channel_wordlen(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
339                                  int ch_num, AVCodecContext *avctx)
340{
341    int i, weight_idx = 0, delta, diff, pos, delta_bits, min_val, flag,
342        ret, start_val;
343    VLC *vlc_tab;
344    Atrac3pChanParams *chan     = &ctx->channels[ch_num];
345    Atrac3pChanParams *ref_chan = &ctx->channels[0];
346
347    chan->fill_mode = 0;
348
349    switch (get_bits(gb, 2)) { /* switch according to coding mode */
350    case 0: /* coded using constant number of bits */
351        for (i = 0; i < ctx->num_quant_units; i++)
352            chan->qu_wordlen[i] = get_bits(gb, 3);
353        break;
354    case 1:
355        if (ch_num) {
356            if ((ret = num_coded_units(gb, chan, ctx, avctx)) < 0)
357                return ret;
358
359            if (chan->num_coded_vals) {
360                vlc_tab = &wl_vlc_tabs[get_bits(gb, 2)];
361
362                for (i = 0; i < chan->num_coded_vals; i++) {
363                    delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
364                    chan->qu_wordlen[i] = (ref_chan->qu_wordlen[i] + delta) & 7;
365                }
366            }
367        } else {
368            weight_idx = get_bits(gb, 2);
369            if ((ret = num_coded_units(gb, chan, ctx, avctx)) < 0)
370                return ret;
371
372            if (chan->num_coded_vals) {
373                pos = get_bits(gb, 5);
374                if (pos > chan->num_coded_vals) {
375                    av_log(avctx, AV_LOG_ERROR,
376                           "WL mode 1: invalid position!\n");
377                    return AVERROR_INVALIDDATA;
378                }
379
380                delta_bits = get_bits(gb, 2);
381                min_val    = get_bits(gb, 3);
382
383                for (i = 0; i < pos; i++)
384                    chan->qu_wordlen[i] = get_bits(gb, 3);
385
386                for (i = pos; i < chan->num_coded_vals; i++)
387                    chan->qu_wordlen[i] = (min_val + GET_DELTA(gb, delta_bits)) & 7;
388            }
389        }
390        break;
391    case 2:
392        if ((ret = num_coded_units(gb, chan, ctx, avctx)) < 0)
393            return ret;
394
395        if (ch_num && chan->num_coded_vals) {
396            vlc_tab = &wl_vlc_tabs[get_bits(gb, 2)];
397            delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
398            chan->qu_wordlen[0] = (ref_chan->qu_wordlen[0] + delta) & 7;
399
400            for (i = 1; i < chan->num_coded_vals; i++) {
401                diff = ref_chan->qu_wordlen[i] - ref_chan->qu_wordlen[i - 1];
402                delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
403                chan->qu_wordlen[i] = (chan->qu_wordlen[i - 1] + diff + delta) & 7;
404            }
405        } else if (chan->num_coded_vals) {
406            flag    = get_bits(gb, 1);
407            vlc_tab = &wl_vlc_tabs[get_bits(gb, 1)];
408
409            start_val = get_bits(gb, 3);
410            unpack_vq_shape(start_val,
411                            &atrac3p_wl_shapes[start_val][get_bits(gb, 4)][0],
412                            chan->qu_wordlen, chan->num_coded_vals);
413
414            if (!flag) {
415                for (i = 0; i < chan->num_coded_vals; i++) {
416                    delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
417                    chan->qu_wordlen[i] = (chan->qu_wordlen[i] + delta) & 7;
418                }
419            } else {
420                for (i = 0; i < (chan->num_coded_vals & - 2); i += 2)
421                    if (!get_bits1(gb)) {
422                        chan->qu_wordlen[i]     = (chan->qu_wordlen[i] +
423                                                   get_vlc2(gb, vlc_tab->table,
424                                                            vlc_tab->bits, 1)) & 7;
425                        chan->qu_wordlen[i + 1] = (chan->qu_wordlen[i + 1] +
426                                                   get_vlc2(gb, vlc_tab->table,
427                                                            vlc_tab->bits, 1)) & 7;
428                    }
429
430                if (chan->num_coded_vals & 1)
431                    chan->qu_wordlen[i] = (chan->qu_wordlen[i] +
432                                           get_vlc2(gb, vlc_tab->table,
433                                                    vlc_tab->bits, 1)) & 7;
434            }
435        }
436        break;
437    case 3:
438        weight_idx = get_bits(gb, 2);
439        if ((ret = num_coded_units(gb, chan, ctx, avctx)) < 0)
440            return ret;
441
442        if (chan->num_coded_vals) {
443            vlc_tab = &wl_vlc_tabs[get_bits(gb, 2)];
444
445            /* first coefficient is coded directly */
446            chan->qu_wordlen[0] = get_bits(gb, 3);
447
448            for (i = 1; i < chan->num_coded_vals; i++) {
449                delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
450                chan->qu_wordlen[i] = (chan->qu_wordlen[i - 1] + delta) & 7;
451            }
452        }
453        break;
454    }
455
456    if (chan->fill_mode == 2) {
457        for (i = chan->num_coded_vals; i < ctx->num_quant_units; i++)
458            chan->qu_wordlen[i] = ch_num ? get_bits1(gb) : 1;
459    } else if (chan->fill_mode == 3) {
460        pos = ch_num ? chan->num_coded_vals + chan->split_point
461                     : ctx->num_quant_units - chan->split_point;
462        for (i = chan->num_coded_vals; i < pos; i++)
463            chan->qu_wordlen[i] = 1;
464    }
465
466    if (weight_idx)
467        return add_wordlen_weights(ctx, chan, weight_idx, avctx);
468
469    return 0;
470}
471
472/**
473 * Decode scale factor indexes for each quant unit of a channel.
474 *
475 * @param[in]     gb            the GetBit context
476 * @param[in,out] ctx           ptr to the channel unit context
477 * @param[in]     ch_num        channel to process
478 * @param[in]     avctx         ptr to the AVCodecContext
479 * @return result code: 0 = OK, otherwise - error code
480 */
481static int decode_channel_sf_idx(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
482                                 int ch_num, AVCodecContext *avctx)
483{
484    int i, weight_idx = 0, delta, diff, num_long_vals,
485        delta_bits, min_val, vlc_sel, start_val;
486    VLC *vlc_tab;
487    Atrac3pChanParams *chan     = &ctx->channels[ch_num];
488    Atrac3pChanParams *ref_chan = &ctx->channels[0];
489
490    switch (get_bits(gb, 2)) { /* switch according to coding mode */
491    case 0: /* coded using constant number of bits */
492        for (i = 0; i < ctx->used_quant_units; i++)
493            chan->qu_sf_idx[i] = get_bits(gb, 6);
494        break;
495    case 1:
496        if (ch_num) {
497            vlc_tab = &sf_vlc_tabs[get_bits(gb, 2)];
498
499            for (i = 0; i < ctx->used_quant_units; i++) {
500                delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
501                chan->qu_sf_idx[i] = (ref_chan->qu_sf_idx[i] + delta) & 0x3F;
502            }
503        } else {
504            weight_idx = get_bits(gb, 2);
505            if (weight_idx == 3) {
506                UNPACK_SF_VQ_SHAPE(gb, chan->qu_sf_idx, ctx->used_quant_units);
507
508                num_long_vals = get_bits(gb, 5);
509                delta_bits    = get_bits(gb, 2);
510                min_val       = get_bits(gb, 4) - 7;
511
512                for (i = 0; i < num_long_vals; i++)
513                    chan->qu_sf_idx[i] = (chan->qu_sf_idx[i] +
514                                          get_bits(gb, 4) - 7) & 0x3F;
515
516                /* all others are: min_val + delta */
517                for (i = num_long_vals; i < ctx->used_quant_units; i++)
518                    chan->qu_sf_idx[i] = (chan->qu_sf_idx[i] + min_val +
519                                          GET_DELTA(gb, delta_bits)) & 0x3F;
520            } else {
521                num_long_vals = get_bits(gb, 5);
522                delta_bits    = get_bits(gb, 3);
523                min_val       = get_bits(gb, 6);
524                if (num_long_vals > ctx->used_quant_units || delta_bits == 7) {
525                    av_log(avctx, AV_LOG_ERROR,
526                           "SF mode 1: invalid parameters!\n");
527                    return AVERROR_INVALIDDATA;
528                }
529
530                /* read full-precision SF indexes */
531                for (i = 0; i < num_long_vals; i++)
532                    chan->qu_sf_idx[i] = get_bits(gb, 6);
533
534                /* all others are: min_val + delta */
535                for (i = num_long_vals; i < ctx->used_quant_units; i++)
536                    chan->qu_sf_idx[i] = (min_val +
537                                          GET_DELTA(gb, delta_bits)) & 0x3F;
538            }
539        }
540        break;
541    case 2:
542        if (ch_num) {
543            vlc_tab = &sf_vlc_tabs[get_bits(gb, 2)];
544
545            delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
546            chan->qu_sf_idx[0] = (ref_chan->qu_sf_idx[0] + delta) & 0x3F;
547
548            for (i = 1; i < ctx->used_quant_units; i++) {
549                diff  = ref_chan->qu_sf_idx[i] - ref_chan->qu_sf_idx[i - 1];
550                delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
551                chan->qu_sf_idx[i] = (chan->qu_sf_idx[i - 1] + diff + delta) & 0x3F;
552            }
553        } else {
554            vlc_tab = &sf_vlc_tabs[get_bits(gb, 2) + 4];
555
556            UNPACK_SF_VQ_SHAPE(gb, chan->qu_sf_idx, ctx->used_quant_units);
557
558            for (i = 0; i < ctx->used_quant_units; i++) {
559                delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
560                chan->qu_sf_idx[i] = (chan->qu_sf_idx[i] +
561                                      sign_extend(delta, 4)) & 0x3F;
562            }
563        }
564        break;
565    case 3:
566        if (ch_num) {
567            /* copy coefficients from reference channel */
568            for (i = 0; i < ctx->used_quant_units; i++)
569                chan->qu_sf_idx[i] = ref_chan->qu_sf_idx[i];
570        } else {
571            weight_idx = get_bits(gb, 2);
572            vlc_sel    = get_bits(gb, 2);
573            vlc_tab    = &sf_vlc_tabs[vlc_sel];
574
575            if (weight_idx == 3) {
576                vlc_tab = &sf_vlc_tabs[vlc_sel + 4];
577
578                UNPACK_SF_VQ_SHAPE(gb, chan->qu_sf_idx, ctx->used_quant_units);
579
580                diff               = (get_bits(gb, 4)    + 56)   & 0x3F;
581                chan->qu_sf_idx[0] = (chan->qu_sf_idx[0] + diff) & 0x3F;
582
583                for (i = 1; i < ctx->used_quant_units; i++) {
584                    delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
585                    diff               = (diff + sign_extend(delta, 4)) & 0x3F;
586                    chan->qu_sf_idx[i] = (diff + chan->qu_sf_idx[i])    & 0x3F;
587                }
588            } else {
589                /* 1st coefficient is coded directly */
590                chan->qu_sf_idx[0] = get_bits(gb, 6);
591
592                for (i = 1; i < ctx->used_quant_units; i++) {
593                    delta = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
594                    chan->qu_sf_idx[i] = (chan->qu_sf_idx[i - 1] + delta) & 0x3F;
595                }
596            }
597        }
598        break;
599    }
600
601    if (weight_idx && weight_idx < 3)
602        return subtract_sf_weights(ctx, chan, weight_idx, avctx);
603
604    return 0;
605}
606
607/**
608 * Decode word length information for each channel.
609 *
610 * @param[in]     gb            the GetBit context
611 * @param[in,out] ctx           ptr to the channel unit context
612 * @param[in]     num_channels  number of channels to process
613 * @param[in]     avctx         ptr to the AVCodecContext
614 * @return result code: 0 = OK, otherwise - error code
615 */
616static int decode_quant_wordlen(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
617                                int num_channels, AVCodecContext *avctx)
618{
619    int ch_num, i, ret;
620
621    for (ch_num = 0; ch_num < num_channels; ch_num++) {
622        memset(ctx->channels[ch_num].qu_wordlen, 0,
623               sizeof(ctx->channels[ch_num].qu_wordlen));
624
625        if ((ret = decode_channel_wordlen(gb, ctx, ch_num, avctx)) < 0)
626            return ret;
627    }
628
629    /* scan for last non-zero coeff in both channels and
630     * set number of quant units having coded spectrum */
631    for (i = ctx->num_quant_units - 1; i >= 0; i--)
632        if (ctx->channels[0].qu_wordlen[i] ||
633            (num_channels == 2 && ctx->channels[1].qu_wordlen[i]))
634            break;
635    ctx->used_quant_units = i + 1;
636
637    return 0;
638}
639
640/**
641 * Decode scale factor indexes for each channel.
642 *
643 * @param[in]     gb            the GetBit context
644 * @param[in,out] ctx           ptr to the channel unit context
645 * @param[in]     num_channels  number of channels to process
646 * @param[in]     avctx         ptr to the AVCodecContext
647 * @return result code: 0 = OK, otherwise - error code
648 */
649static int decode_scale_factors(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
650                                int num_channels, AVCodecContext *avctx)
651{
652    int ch_num, ret;
653
654    if (!ctx->used_quant_units)
655        return 0;
656
657    for (ch_num = 0; ch_num < num_channels; ch_num++) {
658        memset(ctx->channels[ch_num].qu_sf_idx, 0,
659               sizeof(ctx->channels[ch_num].qu_sf_idx));
660
661        if ((ret = decode_channel_sf_idx(gb, ctx, ch_num, avctx)) < 0)
662            return ret;
663    }
664
665    return 0;
666}
667
668/**
669 * Decode number of code table values.
670 *
671 * @param[in]     gb            the GetBit context
672 * @param[in,out] ctx           ptr to the channel unit context
673 * @param[in]     avctx         ptr to the AVCodecContext
674 * @return result code: 0 = OK, otherwise - error code
675 */
676static int get_num_ct_values(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
677                             AVCodecContext *avctx)
678{
679    int num_coded_vals;
680
681    if (get_bits1(gb)) {
682        num_coded_vals = get_bits(gb, 5);
683        if (num_coded_vals > ctx->used_quant_units) {
684            av_log(avctx, AV_LOG_ERROR,
685                   "Invalid number of code table indexes: %d!\n", num_coded_vals);
686            return AVERROR_INVALIDDATA;
687        }
688        return num_coded_vals;
689    } else
690        return ctx->used_quant_units;
691}
692
693#define DEC_CT_IDX_COMMON(OP)                                           \
694    num_vals = get_num_ct_values(gb, ctx, avctx);                       \
695    if (num_vals < 0)                                                   \
696        return num_vals;                                                \
697                                                                        \
698    for (i = 0; i < num_vals; i++) {                                    \
699        if (chan->qu_wordlen[i]) {                                      \
700            chan->qu_tab_idx[i] = OP;                                   \
701        } else if (ch_num && ref_chan->qu_wordlen[i])                   \
702            /* get clone master flag */                                 \
703            chan->qu_tab_idx[i] = get_bits1(gb);                        \
704    }
705
706#define CODING_DIRECT get_bits(gb, num_bits)
707
708#define CODING_VLC get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1)
709
710#define CODING_VLC_DELTA                                                \
711    (!i) ? CODING_VLC                                                   \
712         : (pred + get_vlc2(gb, delta_vlc->table,                       \
713                            delta_vlc->bits, 1)) & mask;                \
714    pred = chan->qu_tab_idx[i]
715
716#define CODING_VLC_DIFF                                                 \
717    (ref_chan->qu_tab_idx[i] +                                          \
718     get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1)) & mask
719
720/**
721 * Decode code table indexes for each quant unit of a channel.
722 *
723 * @param[in]     gb            the GetBit context
724 * @param[in,out] ctx           ptr to the channel unit context
725 * @param[in]     ch_num        channel to process
726 * @param[in]     avctx         ptr to the AVCodecContext
727 * @return result code: 0 = OK, otherwise - error code
728 */
729static int decode_channel_code_tab(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
730                                   int ch_num, AVCodecContext *avctx)
731{
732    int i, num_vals, num_bits, pred;
733    int mask = ctx->use_full_table ? 7 : 3; /* mask for modular arithmetic */
734    VLC *vlc_tab, *delta_vlc;
735    Atrac3pChanParams *chan     = &ctx->channels[ch_num];
736    Atrac3pChanParams *ref_chan = &ctx->channels[0];
737
738    chan->table_type = get_bits1(gb);
739
740    switch (get_bits(gb, 2)) { /* switch according to coding mode */
741    case 0: /* directly coded */
742        num_bits = ctx->use_full_table + 2;
743        DEC_CT_IDX_COMMON(CODING_DIRECT);
744        break;
745    case 1: /* entropy-coded */
746        vlc_tab = ctx->use_full_table ? &ct_vlc_tabs[1]
747                                      : ct_vlc_tabs;
748        DEC_CT_IDX_COMMON(CODING_VLC);
749        break;
750    case 2: /* entropy-coded delta */
751        if (ctx->use_full_table) {
752            vlc_tab   = &ct_vlc_tabs[1];
753            delta_vlc = &ct_vlc_tabs[2];
754        } else {
755            vlc_tab   = ct_vlc_tabs;
756            delta_vlc = ct_vlc_tabs;
757        }
758        pred = 0;
759        DEC_CT_IDX_COMMON(CODING_VLC_DELTA);
760        break;
761    case 3: /* entropy-coded difference to master */
762        if (ch_num) {
763            vlc_tab = ctx->use_full_table ? &ct_vlc_tabs[3]
764                                          : ct_vlc_tabs;
765            DEC_CT_IDX_COMMON(CODING_VLC_DIFF);
766        }
767        break;
768    }
769
770    return 0;
771}
772
773/**
774 * Decode code table indexes for each channel.
775 *
776 * @param[in]     gb            the GetBit context
777 * @param[in,out] ctx           ptr to the channel unit context
778 * @param[in]     num_channels  number of channels to process
779 * @param[in]     avctx         ptr to the AVCodecContext
780 * @return result code: 0 = OK, otherwise - error code
781 */
782static int decode_code_table_indexes(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
783                                     int num_channels, AVCodecContext *avctx)
784{
785    int ch_num, ret;
786
787    if (!ctx->used_quant_units)
788        return 0;
789
790    ctx->use_full_table = get_bits1(gb);
791
792    for (ch_num = 0; ch_num < num_channels; ch_num++) {
793        memset(ctx->channels[ch_num].qu_tab_idx, 0,
794               sizeof(ctx->channels[ch_num].qu_tab_idx));
795
796        if ((ret = decode_channel_code_tab(gb, ctx, ch_num, avctx)) < 0)
797            return ret;
798    }
799
800    return 0;
801}
802
803/**
804 * Decode huffman-coded spectral lines for a given quant unit.
805 *
806 * This is a generalized version for all known coding modes.
807 * Its speed can be improved by creating separate functions for each mode.
808 *
809 * @param[in]   gb          the GetBit context
810 * @param[in]   tab         code table telling how to decode spectral lines
811 * @param[in]   vlc_tab     ptr to the huffman table associated with the code table
812 * @param[out]  out         pointer to buffer where decoded data should be stored
813 * @param[in]   num_specs   number of spectral lines to decode
814 */
815static void decode_qu_spectra(GetBitContext *gb, const Atrac3pSpecCodeTab *tab,
816                              VLC *vlc_tab, int16_t *out, const int num_specs)
817{
818    int i, j, pos, cf;
819    int group_size = tab->group_size;
820    int num_coeffs = tab->num_coeffs;
821    int bits       = tab->bits;
822    int is_signed  = tab->is_signed;
823    unsigned val, mask = (1 << bits) - 1;
824
825    for (pos = 0; pos < num_specs;) {
826        if (group_size == 1 || get_bits1(gb)) {
827            for (j = 0; j < group_size; j++) {
828                val = get_vlc2(gb, vlc_tab->table, vlc_tab->bits, 1);
829
830                for (i = 0; i < num_coeffs; i++) {
831                    cf = val & mask;
832                    if (is_signed)
833                        cf = sign_extend(cf, bits);
834                    else if (cf && get_bits1(gb))
835                        cf = -cf;
836
837                    out[pos++] = cf;
838                    val      >>= bits;
839                }
840            }
841        } else /* group skipped */
842            pos += group_size * num_coeffs;
843    }
844}
845
846/**
847 * Decode huffman-coded IMDCT spectrum for all channels.
848 *
849 * @param[in]     gb            the GetBit context
850 * @param[in,out] ctx           ptr to the channel unit context
851 * @param[in]     num_channels  number of channels to process
852 * @param[in]     avctx         ptr to the AVCodecContext
853 */
854static void decode_spectrum(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
855                            int num_channels, AVCodecContext *avctx)
856{
857    int i, ch_num, qu, wordlen, codetab, tab_index, num_specs;
858    const Atrac3pSpecCodeTab *tab;
859    Atrac3pChanParams *chan;
860
861    for (ch_num = 0; ch_num < num_channels; ch_num++) {
862        chan = &ctx->channels[ch_num];
863
864        memset(chan->spectrum, 0, sizeof(chan->spectrum));
865
866        /* set power compensation level to disabled */
867        memset(chan->power_levs, ATRAC3P_POWER_COMP_OFF, sizeof(chan->power_levs));
868
869        for (qu = 0; qu < ctx->used_quant_units; qu++) {
870            num_specs = ff_atrac3p_qu_to_spec_pos[qu + 1] -
871                        ff_atrac3p_qu_to_spec_pos[qu];
872
873            wordlen = chan->qu_wordlen[qu];
874            codetab = chan->qu_tab_idx[qu];
875            if (wordlen) {
876                if (!ctx->use_full_table)
877                    codetab = atrac3p_ct_restricted_to_full[chan->table_type][wordlen - 1][codetab];
878
879                tab_index = (chan->table_type * 8 + codetab) * 7 + wordlen - 1;
880                tab       = &atrac3p_spectra_tabs[tab_index];
881
882                /* this allows reusing VLC tables */
883                if (tab->redirect >= 0)
884                    tab_index = tab->redirect;
885
886                decode_qu_spectra(gb, tab, &spec_vlc_tabs[tab_index],
887                                  &chan->spectrum[ff_atrac3p_qu_to_spec_pos[qu]],
888                                  num_specs);
889            } else if (ch_num && ctx->channels[0].qu_wordlen[qu] && !codetab) {
890                /* copy coefficients from master */
891                memcpy(&chan->spectrum[ff_atrac3p_qu_to_spec_pos[qu]],
892                       &ctx->channels[0].spectrum[ff_atrac3p_qu_to_spec_pos[qu]],
893                       num_specs *
894                       sizeof(chan->spectrum[ff_atrac3p_qu_to_spec_pos[qu]]));
895                chan->qu_wordlen[qu] = ctx->channels[0].qu_wordlen[qu];
896            }
897        }
898
899        /* Power compensation levels only present in the bitstream
900         * if there are more than 2 quant units. The lowest two units
901         * correspond to the frequencies 0...351 Hz, whose shouldn't
902         * be affected by the power compensation. */
903        if (ctx->used_quant_units > 2) {
904            num_specs = atrac3p_subband_to_num_powgrps[ctx->num_coded_subbands - 1];
905            for (i = 0; i < num_specs; i++)
906                chan->power_levs[i] = get_bits(gb, 4);
907        }
908    }
909}
910
911/**
912 * Retrieve specified amount of flag bits from the input bitstream.
913 * The data can be shortened in the case of the following two common conditions:
914 * if all bits are zero then only one signal bit = 0 will be stored,
915 * if all bits are ones then two signal bits = 1,0 will be stored.
916 * Otherwise, all necessary bits will be directly stored
917 * prefixed by two signal bits = 1,1.
918 *
919 * @param[in]   gb              ptr to the GetBitContext
920 * @param[out]  out             where to place decoded flags
921 * @param[in]   num_flags       number of flags to process
922 * @return: 0 = all flag bits are zero, 1 = there is at least one non-zero flag bit
923 */
924static int get_subband_flags(GetBitContext *gb, uint8_t *out, int num_flags)
925{
926    int i, result;
927
928    memset(out, 0, num_flags);
929
930    result = get_bits1(gb);
931    if (result) {
932        if (get_bits1(gb))
933            for (i = 0; i < num_flags; i++)
934                out[i] = get_bits1(gb);
935        else
936            memset(out, 1, num_flags);
937    }
938
939    return result;
940}
941
942/**
943 * Decode mdct window shape flags for all channels.
944 *
945 * @param[in]     gb            the GetBit context
946 * @param[in,out] ctx           ptr to the channel unit context
947 * @param[in]     num_channels  number of channels to process
948 */
949static void decode_window_shape(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
950                                int num_channels)
951{
952    int ch_num;
953
954    for (ch_num = 0; ch_num < num_channels; ch_num++)
955        get_subband_flags(gb, ctx->channels[ch_num].wnd_shape,
956                          ctx->num_subbands);
957}
958
959/**
960 * Decode number of gain control points.
961 *
962 * @param[in]     gb              the GetBit context
963 * @param[in,out] ctx             ptr to the channel unit context
964 * @param[in]     ch_num          channel to process
965 * @param[in]     coded_subbands  number of subbands to process
966 * @return result code: 0 = OK, otherwise - error code
967 */
968static int decode_gainc_npoints(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
969                                int ch_num, int coded_subbands)
970{
971    int i, delta, delta_bits, min_val;
972    Atrac3pChanParams *chan     = &ctx->channels[ch_num];
973    Atrac3pChanParams *ref_chan = &ctx->channels[0];
974
975    switch (get_bits(gb, 2)) { /* switch according to coding mode */
976    case 0: /* fixed-length coding */
977        for (i = 0; i < coded_subbands; i++)
978            chan->gain_data[i].num_points = get_bits(gb, 3);
979        break;
980    case 1: /* variable-length coding */
981        for (i = 0; i < coded_subbands; i++)
982            chan->gain_data[i].num_points =
983                get_vlc2(gb, gain_vlc_tabs[0].table,
984                         gain_vlc_tabs[0].bits, 1);
985        break;
986    case 2:
987        if (ch_num) { /* VLC modulo delta to master channel */
988            for (i = 0; i < coded_subbands; i++) {
989                delta = get_vlc2(gb, gain_vlc_tabs[1].table,
990                                 gain_vlc_tabs[1].bits, 1);
991                chan->gain_data[i].num_points =
992                    (ref_chan->gain_data[i].num_points + delta) & 7;
993            }
994        } else { /* VLC modulo delta to previous */
995            chan->gain_data[0].num_points =
996                get_vlc2(gb, gain_vlc_tabs[0].table,
997                         gain_vlc_tabs[0].bits, 1);
998
999            for (i = 1; i < coded_subbands; i++) {
1000                delta = get_vlc2(gb, gain_vlc_tabs[1].table,
1001                                 gain_vlc_tabs[1].bits, 1);
1002                chan->gain_data[i].num_points =
1003                    (chan->gain_data[i - 1].num_points + delta) & 7;
1004            }
1005        }
1006        break;
1007    case 3:
1008        if (ch_num) { /* copy data from master channel */
1009            for (i = 0; i < coded_subbands; i++)
1010                chan->gain_data[i].num_points =
1011                    ref_chan->gain_data[i].num_points;
1012        } else { /* shorter delta to min */
1013            delta_bits = get_bits(gb, 2);
1014            min_val    = get_bits(gb, 3);
1015
1016            for (i = 0; i < coded_subbands; i++) {
1017                chan->gain_data[i].num_points = min_val + GET_DELTA(gb, delta_bits);
1018                if (chan->gain_data[i].num_points > 7)
1019                    return AVERROR_INVALIDDATA;
1020            }
1021        }
1022    }
1023
1024    return 0;
1025}
1026
1027/**
1028 * Implements coding mode 3 (slave) for gain compensation levels.
1029 *
1030 * @param[out]   dst   ptr to the output array
1031 * @param[in]    ref   ptr to the reference channel
1032 */
1033static inline void gainc_level_mode3s(AtracGainInfo *dst, AtracGainInfo *ref)
1034{
1035    int i;
1036
1037    for (i = 0; i < dst->num_points; i++)
1038        dst->lev_code[i] = (i >= ref->num_points) ? 7 : ref->lev_code[i];
1039}
1040
1041/**
1042 * Implements coding mode 1 (master) for gain compensation levels.
1043 *
1044 * @param[in]     gb     the GetBit context
1045 * @param[in]     ctx    ptr to the channel unit context
1046 * @param[out]    dst    ptr to the output array
1047 */
1048static inline void gainc_level_mode1m(GetBitContext *gb,
1049                                      Atrac3pChanUnitCtx *ctx,
1050                                      AtracGainInfo *dst)
1051{
1052    int i, delta;
1053
1054    if (dst->num_points > 0)
1055        dst->lev_code[0] = get_vlc2(gb, gain_vlc_tabs[2].table,
1056                                    gain_vlc_tabs[2].bits, 1);
1057
1058    for (i = 1; i < dst->num_points; i++) {
1059        delta = get_vlc2(gb, gain_vlc_tabs[3].table,
1060                         gain_vlc_tabs[3].bits, 1);
1061        dst->lev_code[i] = (dst->lev_code[i - 1] + delta) & 0xF;
1062    }
1063}
1064
1065/**
1066 * Decode level code for each gain control point.
1067 *
1068 * @param[in]     gb              the GetBit context
1069 * @param[in,out] ctx             ptr to the channel unit context
1070 * @param[in]     ch_num          channel to process
1071 * @param[in]     coded_subbands  number of subbands to process
1072 * @return result code: 0 = OK, otherwise - error code
1073 */
1074static int decode_gainc_levels(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
1075                               int ch_num, int coded_subbands)
1076{
1077    int sb, i, delta, delta_bits, min_val, pred;
1078    Atrac3pChanParams *chan     = &ctx->channels[ch_num];
1079    Atrac3pChanParams *ref_chan = &ctx->channels[0];
1080
1081    switch (get_bits(gb, 2)) { /* switch according to coding mode */
1082    case 0: /* fixed-length coding */
1083        for (sb = 0; sb < coded_subbands; sb++)
1084            for (i = 0; i < chan->gain_data[sb].num_points; i++)
1085                chan->gain_data[sb].lev_code[i] = get_bits(gb, 4);
1086        break;
1087    case 1:
1088        if (ch_num) { /* VLC modulo delta to master channel */
1089            for (sb = 0; sb < coded_subbands; sb++)
1090                for (i = 0; i < chan->gain_data[sb].num_points; i++) {
1091                    delta = get_vlc2(gb, gain_vlc_tabs[5].table,
1092                                     gain_vlc_tabs[5].bits, 1);
1093                    pred = (i >= ref_chan->gain_data[sb].num_points)
1094                           ? 7 : ref_chan->gain_data[sb].lev_code[i];
1095                    chan->gain_data[sb].lev_code[i] = (pred + delta) & 0xF;
1096                }
1097        } else { /* VLC modulo delta to previous */
1098            for (sb = 0; sb < coded_subbands; sb++)
1099                gainc_level_mode1m(gb, ctx, &chan->gain_data[sb]);
1100        }
1101        break;
1102    case 2:
1103        if (ch_num) { /* VLC modulo delta to previous or clone master */
1104            for (sb = 0; sb < coded_subbands; sb++)
1105                if (chan->gain_data[sb].num_points > 0) {
1106                    if (get_bits1(gb))
1107                        gainc_level_mode1m(gb, ctx, &chan->gain_data[sb]);
1108                    else
1109                        gainc_level_mode3s(&chan->gain_data[sb],
1110                                           &ref_chan->gain_data[sb]);
1111                }
1112        } else { /* VLC modulo delta to lev_codes of previous subband */
1113            if (chan->gain_data[0].num_points > 0)
1114                gainc_level_mode1m(gb, ctx, &chan->gain_data[0]);
1115
1116            for (sb = 1; sb < coded_subbands; sb++)
1117                for (i = 0; i < chan->gain_data[sb].num_points; i++) {
1118                    delta = get_vlc2(gb, gain_vlc_tabs[4].table,
1119                                     gain_vlc_tabs[4].bits, 1);
1120                    pred = (i >= chan->gain_data[sb - 1].num_points)
1121                           ? 7 : chan->gain_data[sb - 1].lev_code[i];
1122                    chan->gain_data[sb].lev_code[i] = (pred + delta) & 0xF;
1123                }
1124        }
1125        break;
1126    case 3:
1127        if (ch_num) { /* clone master */
1128            for (sb = 0; sb < coded_subbands; sb++)
1129                gainc_level_mode3s(&chan->gain_data[sb],
1130                                   &ref_chan->gain_data[sb]);
1131        } else { /* shorter delta to min */
1132            delta_bits = get_bits(gb, 2);
1133            min_val    = get_bits(gb, 4);
1134
1135            for (sb = 0; sb < coded_subbands; sb++)
1136                for (i = 0; i < chan->gain_data[sb].num_points; i++) {
1137                    chan->gain_data[sb].lev_code[i] = min_val + GET_DELTA(gb, delta_bits);
1138                    if (chan->gain_data[sb].lev_code[i] > 15)
1139                        return AVERROR_INVALIDDATA;
1140                }
1141        }
1142        break;
1143    }
1144
1145    return 0;
1146}
1147
1148/**
1149 * Implements coding mode 0 for gain compensation locations.
1150 *
1151 * @param[in]     gb     the GetBit context
1152 * @param[in]     ctx    ptr to the channel unit context
1153 * @param[out]    dst    ptr to the output array
1154 * @param[in]     pos    position of the value to be processed
1155 */
1156static inline void gainc_loc_mode0(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
1157                                   AtracGainInfo *dst, int pos)
1158{
1159    int delta_bits;
1160
1161    if (!pos || dst->loc_code[pos - 1] < 15)
1162        dst->loc_code[pos] = get_bits(gb, 5);
1163    else if (dst->loc_code[pos - 1] >= 30)
1164        dst->loc_code[pos] = 31;
1165    else {
1166        delta_bits         = av_log2(30 - dst->loc_code[pos - 1]) + 1;
1167        dst->loc_code[pos] = dst->loc_code[pos - 1] +
1168                             get_bits(gb, delta_bits) + 1;
1169    }
1170}
1171
1172/**
1173 * Implements coding mode 1 for gain compensation locations.
1174 *
1175 * @param[in]     gb     the GetBit context
1176 * @param[in]     ctx    ptr to the channel unit context
1177 * @param[out]    dst    ptr to the output array
1178 */
1179static inline void gainc_loc_mode1(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
1180                                   AtracGainInfo *dst)
1181{
1182    int i;
1183    VLC *tab;
1184
1185    if (dst->num_points > 0) {
1186        /* 1st coefficient is stored directly */
1187        dst->loc_code[0] = get_bits(gb, 5);
1188
1189        for (i = 1; i < dst->num_points; i++) {
1190            /* switch VLC according to the curve direction
1191             * (ascending/descending) */
1192            tab              = (dst->lev_code[i] <= dst->lev_code[i - 1])
1193                               ? &gain_vlc_tabs[7]
1194                               : &gain_vlc_tabs[9];
1195            dst->loc_code[i] = dst->loc_code[i - 1] +
1196                               get_vlc2(gb, tab->table, tab->bits, 1);
1197        }
1198    }
1199}
1200
1201/**
1202 * Decode location code for each gain control point.
1203 *
1204 * @param[in]     gb              the GetBit context
1205 * @param[in,out] ctx             ptr to the channel unit context
1206 * @param[in]     ch_num          channel to process
1207 * @param[in]     coded_subbands  number of subbands to process
1208 * @param[in]     avctx           ptr to the AVCodecContext
1209 * @return result code: 0 = OK, otherwise - error code
1210 */
1211static int decode_gainc_loc_codes(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
1212                                  int ch_num, int coded_subbands,
1213                                  AVCodecContext *avctx)
1214{
1215    int sb, i, delta, delta_bits, min_val, pred, more_than_ref;
1216    AtracGainInfo *dst, *ref;
1217    VLC *tab;
1218    Atrac3pChanParams *chan     = &ctx->channels[ch_num];
1219    Atrac3pChanParams *ref_chan = &ctx->channels[0];
1220
1221    switch (get_bits(gb, 2)) { /* switch according to coding mode */
1222    case 0: /* sequence of numbers in ascending order */
1223        for (sb = 0; sb < coded_subbands; sb++)
1224            for (i = 0; i < chan->gain_data[sb].num_points; i++)
1225                gainc_loc_mode0(gb, ctx, &chan->gain_data[sb], i);
1226        break;
1227    case 1:
1228        if (ch_num) {
1229            for (sb = 0; sb < coded_subbands; sb++) {
1230                if (chan->gain_data[sb].num_points <= 0)
1231                    continue;
1232                dst = &chan->gain_data[sb];
1233                ref = &ref_chan->gain_data[sb];
1234
1235                /* 1st value is vlc-coded modulo delta to master */
1236                delta = get_vlc2(gb, gain_vlc_tabs[10].table,
1237                                 gain_vlc_tabs[10].bits, 1);
1238                pred = ref->num_points > 0 ? ref->loc_code[0] : 0;
1239                dst->loc_code[0] = (pred + delta) & 0x1F;
1240
1241                for (i = 1; i < dst->num_points; i++) {
1242                    more_than_ref = i >= ref->num_points;
1243                    if (dst->lev_code[i] > dst->lev_code[i - 1]) {
1244                        /* ascending curve */
1245                        if (more_than_ref) {
1246                            delta =
1247                                get_vlc2(gb, gain_vlc_tabs[9].table,
1248                                         gain_vlc_tabs[9].bits, 1);
1249                            dst->loc_code[i] = dst->loc_code[i - 1] + delta;
1250                        } else {
1251                            if (get_bits1(gb))
1252                                gainc_loc_mode0(gb, ctx, dst, i);  // direct coding
1253                            else
1254                                dst->loc_code[i] = ref->loc_code[i];  // clone master
1255                        }
1256                    } else { /* descending curve */
1257                        tab   = more_than_ref ? &gain_vlc_tabs[7]
1258                                              : &gain_vlc_tabs[10];
1259                        delta = get_vlc2(gb, tab->table, tab->bits, 1);
1260                        if (more_than_ref)
1261                            dst->loc_code[i] = dst->loc_code[i - 1] + delta;
1262                        else
1263                            dst->loc_code[i] = (ref->loc_code[i] + delta) & 0x1F;
1264                    }
1265                }
1266            }
1267        } else /* VLC delta to previous */
1268            for (sb = 0; sb < coded_subbands; sb++)
1269                gainc_loc_mode1(gb, ctx, &chan->gain_data[sb]);
1270        break;
1271    case 2:
1272        if (ch_num) {
1273            for (sb = 0; sb < coded_subbands; sb++) {
1274                if (chan->gain_data[sb].num_points <= 0)
1275                    continue;
1276                dst = &chan->gain_data[sb];
1277                ref = &ref_chan->gain_data[sb];
1278                if (dst->num_points > ref->num_points || get_bits1(gb))
1279                    gainc_loc_mode1(gb, ctx, dst);
1280                else /* clone master for the whole subband */
1281                    for (i = 0; i < chan->gain_data[sb].num_points; i++)
1282                        dst->loc_code[i] = ref->loc_code[i];
1283            }
1284        } else {
1285            /* data for the first subband is coded directly */
1286            for (i = 0; i < chan->gain_data[0].num_points; i++)
1287                gainc_loc_mode0(gb, ctx, &chan->gain_data[0], i);
1288
1289            for (sb = 1; sb < coded_subbands; sb++) {
1290                if (chan->gain_data[sb].num_points <= 0)
1291                    continue;
1292                dst = &chan->gain_data[sb];
1293
1294                /* 1st value is vlc-coded modulo delta to the corresponding
1295                 * value of the previous subband if any or zero */
1296                delta = get_vlc2(gb, gain_vlc_tabs[6].table,
1297                                 gain_vlc_tabs[6].bits, 1);
1298                pred             = dst[-1].num_points > 0
1299                                   ? dst[-1].loc_code[0] : 0;
1300                dst->loc_code[0] = (pred + delta) & 0x1F;
1301
1302                for (i = 1; i < dst->num_points; i++) {
1303                    more_than_ref = i >= dst[-1].num_points;
1304                    /* Select VLC table according to curve direction and
1305                     * presence of prediction. */
1306                    tab = &gain_vlc_tabs[(dst->lev_code[i] > dst->lev_code[i - 1]) *
1307                                                   2 + more_than_ref + 6];
1308                    delta = get_vlc2(gb, tab->table, tab->bits, 1);
1309                    if (more_than_ref)
1310                        dst->loc_code[i] = dst->loc_code[i - 1] + delta;
1311                    else
1312                        dst->loc_code[i] = (dst[-1].loc_code[i] + delta) & 0x1F;
1313                }
1314            }
1315        }
1316        break;
1317    case 3:
1318        if (ch_num) { /* clone master or direct or direct coding */
1319            for (sb = 0; sb < coded_subbands; sb++)
1320                for (i = 0; i < chan->gain_data[sb].num_points; i++) {
1321                    if (i >= ref_chan->gain_data[sb].num_points)
1322                        gainc_loc_mode0(gb, ctx, &chan->gain_data[sb], i);
1323                    else
1324                        chan->gain_data[sb].loc_code[i] =
1325                            ref_chan->gain_data[sb].loc_code[i];
1326                }
1327        } else { /* shorter delta to min */
1328            delta_bits = get_bits(gb, 2) + 1;
1329            min_val    = get_bits(gb, 5);
1330
1331            for (sb = 0; sb < coded_subbands; sb++)
1332                for (i = 0; i < chan->gain_data[sb].num_points; i++)
1333                    chan->gain_data[sb].loc_code[i] = min_val + i +
1334                                                      get_bits(gb, delta_bits);
1335        }
1336        break;
1337    }
1338
1339    /* Validate decoded information */
1340    for (sb = 0; sb < coded_subbands; sb++) {
1341        dst = &chan->gain_data[sb];
1342        for (i = 0; i < chan->gain_data[sb].num_points; i++) {
1343            if (dst->loc_code[i] < 0 || dst->loc_code[i] > 31 ||
1344                (i && dst->loc_code[i] <= dst->loc_code[i - 1])) {
1345                av_log(avctx, AV_LOG_ERROR,
1346                       "Invalid gain location: ch=%d, sb=%d, pos=%d, val=%d\n",
1347                       ch_num, sb, i, dst->loc_code[i]);
1348                return AVERROR_INVALIDDATA;
1349            }
1350        }
1351    }
1352
1353    return 0;
1354}
1355
1356/**
1357 * Decode gain control data for all channels.
1358 *
1359 * @param[in]     gb            the GetBit context
1360 * @param[in,out] ctx           ptr to the channel unit context
1361 * @param[in]     num_channels  number of channels to process
1362 * @param[in]     avctx         ptr to the AVCodecContext
1363 * @return result code: 0 = OK, otherwise - error code
1364 */
1365static int decode_gainc_data(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
1366                             int num_channels, AVCodecContext *avctx)
1367{
1368    int ch_num, coded_subbands, sb, ret;
1369
1370    for (ch_num = 0; ch_num < num_channels; ch_num++) {
1371        memset(ctx->channels[ch_num].gain_data, 0,
1372               sizeof(*ctx->channels[ch_num].gain_data) * ATRAC3P_SUBBANDS);
1373
1374        if (get_bits1(gb)) { /* gain control data present? */
1375            coded_subbands = get_bits(gb, 4) + 1;
1376            if (get_bits1(gb)) /* is high band gain data replication on? */
1377                ctx->channels[ch_num].num_gain_subbands = get_bits(gb, 4) + 1;
1378            else
1379                ctx->channels[ch_num].num_gain_subbands = coded_subbands;
1380
1381            if ((ret = decode_gainc_npoints(gb, ctx, ch_num, coded_subbands)) < 0 ||
1382                (ret = decode_gainc_levels(gb, ctx, ch_num, coded_subbands))  < 0 ||
1383                (ret = decode_gainc_loc_codes(gb, ctx, ch_num, coded_subbands, avctx)) < 0)
1384                return ret;
1385
1386            if (coded_subbands > 0) { /* propagate gain data if requested */
1387                for (sb = coded_subbands; sb < ctx->channels[ch_num].num_gain_subbands; sb++)
1388                    ctx->channels[ch_num].gain_data[sb] =
1389                        ctx->channels[ch_num].gain_data[sb - 1];
1390            }
1391        } else {
1392            ctx->channels[ch_num].num_gain_subbands = 0;
1393        }
1394    }
1395
1396    return 0;
1397}
1398
1399/**
1400 * Decode envelope for all tones of a channel.
1401 *
1402 * @param[in]     gb                the GetBit context
1403 * @param[in,out] ctx               ptr to the channel unit context
1404 * @param[in]     ch_num            channel to process
1405 * @param[in]     band_has_tones    ptr to an array of per-band-flags:
1406 *                                  1 - tone data present
1407 */
1408static void decode_tones_envelope(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
1409                                  int ch_num, int band_has_tones[])
1410{
1411    int sb;
1412    Atrac3pWavesData *dst = ctx->channels[ch_num].tones_info;
1413    Atrac3pWavesData *ref = ctx->channels[0].tones_info;
1414
1415    if (!ch_num || !get_bits1(gb)) { /* mode 0: fixed-length coding */
1416        for (sb = 0; sb < ctx->waves_info->num_tone_bands; sb++) {
1417            if (!band_has_tones[sb])
1418                continue;
1419            dst[sb].pend_env.has_start_point = get_bits1(gb);
1420            dst[sb].pend_env.start_pos       = dst[sb].pend_env.has_start_point
1421                                               ? get_bits(gb, 5) : -1;
1422            dst[sb].pend_env.has_stop_point  = get_bits1(gb);
1423            dst[sb].pend_env.stop_pos        = dst[sb].pend_env.has_stop_point
1424                                               ? get_bits(gb, 5) : 32;
1425        }
1426    } else { /* mode 1(slave only): copy master */
1427        for (sb = 0; sb < ctx->waves_info->num_tone_bands; sb++) {
1428            if (!band_has_tones[sb])
1429                continue;
1430            dst[sb].pend_env.has_start_point = ref[sb].pend_env.has_start_point;
1431            dst[sb].pend_env.has_stop_point  = ref[sb].pend_env.has_stop_point;
1432            dst[sb].pend_env.start_pos       = ref[sb].pend_env.start_pos;
1433            dst[sb].pend_env.stop_pos        = ref[sb].pend_env.stop_pos;
1434        }
1435    }
1436}
1437
1438/**
1439 * Decode number of tones for each subband of a channel.
1440 *
1441 * @param[in]     gb                the GetBit context
1442 * @param[in,out] ctx               ptr to the channel unit context
1443 * @param[in]     ch_num            channel to process
1444 * @param[in]     band_has_tones    ptr to an array of per-band-flags:
1445 *                                  1 - tone data present
1446 * @param[in]     avctx             ptr to the AVCodecContext
1447 * @return result code: 0 = OK, otherwise - error code
1448 */
1449static int decode_band_numwavs(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
1450                               int ch_num, int band_has_tones[],
1451                               AVCodecContext *avctx)
1452{
1453    int mode, sb, delta;
1454    Atrac3pWavesData *dst = ctx->channels[ch_num].tones_info;
1455    Atrac3pWavesData *ref = ctx->channels[0].tones_info;
1456
1457    mode = get_bits(gb, ch_num + 1);
1458    switch (mode) {
1459    case 0: /** fixed-length coding */
1460        for (sb = 0; sb < ctx->waves_info->num_tone_bands; sb++)
1461            if (band_has_tones[sb])
1462                dst[sb].num_wavs = get_bits(gb, 4);
1463        break;
1464    case 1: /** variable-length coding */
1465        for (sb = 0; sb < ctx->waves_info->num_tone_bands; sb++)
1466            if (band_has_tones[sb])
1467                dst[sb].num_wavs =
1468                    get_vlc2(gb, tone_vlc_tabs[1].table,
1469                             tone_vlc_tabs[1].bits, 1);
1470        break;
1471    case 2: /** VLC modulo delta to master (slave only) */
1472        for (sb = 0; sb < ctx->waves_info->num_tone_bands; sb++)
1473            if (band_has_tones[sb]) {
1474                delta = get_vlc2(gb, tone_vlc_tabs[2].table,
1475                                 tone_vlc_tabs[2].bits, 1);
1476                delta = sign_extend(delta, 3);
1477                dst[sb].num_wavs = (ref[sb].num_wavs + delta) & 0xF;
1478            }
1479        break;
1480    case 3: /** copy master (slave only) */
1481        for (sb = 0; sb < ctx->waves_info->num_tone_bands; sb++)
1482            if (band_has_tones[sb])
1483                dst[sb].num_wavs = ref[sb].num_wavs;
1484        break;
1485    }
1486
1487    /** initialize start tone index for each subband */
1488    for (sb = 0; sb < ctx->waves_info->num_tone_bands; sb++)
1489        if (band_has_tones[sb]) {
1490            if (ctx->waves_info->tones_index + dst[sb].num_wavs > 48) {
1491                av_log(avctx, AV_LOG_ERROR,
1492                       "Too many tones: %d (max. 48), frame: %d!\n",
1493                       ctx->waves_info->tones_index + dst[sb].num_wavs,
1494                       avctx->frame_number);
1495                return AVERROR_INVALIDDATA;
1496            }
1497            dst[sb].start_index           = ctx->waves_info->tones_index;
1498            ctx->waves_info->tones_index += dst[sb].num_wavs;
1499        }
1500
1501    return 0;
1502}
1503
1504/**
1505 * Decode frequency information for each subband of a channel.
1506 *
1507 * @param[in]     gb                the GetBit context
1508 * @param[in,out] ctx               ptr to the channel unit context
1509 * @param[in]     ch_num            channel to process
1510 * @param[in]     band_has_tones    ptr to an array of per-band-flags:
1511 *                                  1 - tone data present
1512 */
1513static void decode_tones_frequency(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
1514                                   int ch_num, int band_has_tones[])
1515{
1516    int sb, i, direction, nbits, pred, delta;
1517    Atrac3pWaveParam *iwav, *owav;
1518    Atrac3pWavesData *dst = ctx->channels[ch_num].tones_info;
1519    Atrac3pWavesData *ref = ctx->channels[0].tones_info;
1520
1521    if (!ch_num || !get_bits1(gb)) { /* mode 0: fixed-length coding */
1522        for (sb = 0; sb < ctx->waves_info->num_tone_bands; sb++) {
1523            if (!band_has_tones[sb] || !dst[sb].num_wavs)
1524                continue;
1525            iwav      = &ctx->waves_info->waves[dst[sb].start_index];
1526            direction = (dst[sb].num_wavs > 1) ? get_bits1(gb) : 0;
1527            if (direction) { /** packed numbers in descending order */
1528                if (dst[sb].num_wavs)
1529                    iwav[dst[sb].num_wavs - 1].freq_index = get_bits(gb, 10);
1530                for (i = dst[sb].num_wavs - 2; i >= 0 ; i--) {
1531                    nbits = av_log2(iwav[i+1].freq_index) + 1;
1532                    iwav[i].freq_index = get_bits(gb, nbits);
1533                }
1534            } else { /** packed numbers in ascending order */
1535                for (i = 0; i < dst[sb].num_wavs; i++) {
1536                    if (!i || iwav[i - 1].freq_index < 512)
1537                        iwav[i].freq_index = get_bits(gb, 10);
1538                    else {
1539                        nbits = av_log2(1023 - iwav[i - 1].freq_index) + 1;
1540                        iwav[i].freq_index = get_bits(gb, nbits) +
1541                                             1024 - (1 << nbits);
1542                    }
1543                }
1544            }
1545        }
1546    } else { /* mode 1: VLC modulo delta to master (slave only) */
1547        for (sb = 0; sb < ctx->waves_info->num_tone_bands; sb++) {
1548            if (!band_has_tones[sb] || !dst[sb].num_wavs)
1549                continue;
1550            iwav = &ctx->waves_info->waves[ref[sb].start_index];
1551            owav = &ctx->waves_info->waves[dst[sb].start_index];
1552            for (i = 0; i < dst[sb].num_wavs; i++) {
1553                delta = get_vlc2(gb, tone_vlc_tabs[6].table,
1554                                 tone_vlc_tabs[6].bits, 1);
1555                delta = sign_extend(delta, 8);
1556                pred  = (i < ref[sb].num_wavs) ? iwav[i].freq_index :
1557                        (ref[sb].num_wavs ? iwav[ref[sb].num_wavs - 1].freq_index : 0);
1558                owav[i].freq_index = (pred + delta) & 0x3FF;
1559            }
1560        }
1561    }
1562}
1563
1564/**
1565 * Decode amplitude information for each subband of a channel.
1566 *
1567 * @param[in]     gb                the GetBit context
1568 * @param[in,out] ctx               ptr to the channel unit context
1569 * @param[in]     ch_num            channel to process
1570 * @param[in]     band_has_tones    ptr to an array of per-band-flags:
1571 *                                  1 - tone data present
1572 */
1573static void decode_tones_amplitude(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
1574                                   int ch_num, int band_has_tones[])
1575{
1576    int mode, sb, j, i, diff, maxdiff, fi, delta, pred;
1577    Atrac3pWaveParam *wsrc, *wref;
1578    int refwaves[48];
1579    Atrac3pWavesData *dst = ctx->channels[ch_num].tones_info;
1580    Atrac3pWavesData *ref = ctx->channels[0].tones_info;
1581
1582    if (ch_num) {
1583        for (sb = 0; sb < ctx->waves_info->num_tone_bands; sb++) {
1584            if (!band_has_tones[sb] || !dst[sb].num_wavs)
1585                continue;
1586            wsrc = &ctx->waves_info->waves[dst[sb].start_index];
1587            wref = &ctx->waves_info->waves[ref[sb].start_index];
1588            for (j = 0; j < dst[sb].num_wavs; j++) {
1589                for (i = 0, fi = 0, maxdiff = 1024; i < ref[sb].num_wavs; i++) {
1590                    diff = FFABS(wsrc[j].freq_index - wref[i].freq_index);
1591                    if (diff < maxdiff) {
1592                        maxdiff = diff;
1593                        fi      = i;
1594                    }
1595                }
1596
1597                if (maxdiff < 8)
1598                    refwaves[dst[sb].start_index + j] = fi + ref[sb].start_index;
1599                else if (j < ref[sb].num_wavs)
1600                    refwaves[dst[sb].start_index + j] = j + ref[sb].start_index;
1601                else
1602                    refwaves[dst[sb].start_index + j] = -1;
1603            }
1604        }
1605    }
1606
1607    mode = get_bits(gb, ch_num + 1);
1608
1609    switch (mode) {
1610    case 0: /** fixed-length coding */
1611        for (sb = 0; sb < ctx->waves_info->num_tone_bands; sb++) {
1612            if (!band_has_tones[sb] || !dst[sb].num_wavs)
1613                continue;
1614            if (ctx->waves_info->amplitude_mode)
1615                for (i = 0; i < dst[sb].num_wavs; i++)
1616                    ctx->waves_info->waves[dst[sb].start_index + i].amp_sf = get_bits(gb, 6);
1617            else
1618                ctx->waves_info->waves[dst[sb].start_index].amp_sf = get_bits(gb, 6);
1619        }
1620        break;
1621    case 1: /** min + VLC delta */
1622        for (sb = 0; sb < ctx->waves_info->num_tone_bands; sb++) {
1623            if (!band_has_tones[sb] || !dst[sb].num_wavs)
1624                continue;
1625            if (ctx->waves_info->amplitude_mode)
1626                for (i = 0; i < dst[sb].num_wavs; i++)
1627                    ctx->waves_info->waves[dst[sb].start_index + i].amp_sf =
1628                        get_vlc2(gb, tone_vlc_tabs[3].table,
1629                                 tone_vlc_tabs[3].bits, 1) + 20;
1630            else
1631                ctx->waves_info->waves[dst[sb].start_index].amp_sf =
1632                    get_vlc2(gb, tone_vlc_tabs[4].table,
1633                             tone_vlc_tabs[4].bits, 1) + 24;
1634        }
1635        break;
1636    case 2: /** VLC modulo delta to master (slave only) */
1637        for (sb = 0; sb < ctx->waves_info->num_tone_bands; sb++) {
1638            if (!band_has_tones[sb] || !dst[sb].num_wavs)
1639                continue;
1640            for (i = 0; i < dst[sb].num_wavs; i++) {
1641                delta = get_vlc2(gb, tone_vlc_tabs[5].table,
1642                                 tone_vlc_tabs[5].bits, 1);
1643                delta = sign_extend(delta, 5);
1644                pred  = refwaves[dst[sb].start_index + i] >= 0 ?
1645                        ctx->waves_info->waves[refwaves[dst[sb].start_index + i]].amp_sf : 34;
1646                ctx->waves_info->waves[dst[sb].start_index + i].amp_sf = (pred + delta) & 0x3F;
1647            }
1648        }
1649        break;
1650    case 3: /** clone master (slave only) */
1651        for (sb = 0; sb < ctx->waves_info->num_tone_bands; sb++) {
1652            if (!band_has_tones[sb])
1653                continue;
1654            for (i = 0; i < dst[sb].num_wavs; i++)
1655                ctx->waves_info->waves[dst[sb].start_index + i].amp_sf =
1656                    refwaves[dst[sb].start_index + i] >= 0
1657                    ? ctx->waves_info->waves[refwaves[dst[sb].start_index + i]].amp_sf
1658                    : 32;
1659        }
1660        break;
1661    }
1662}
1663
1664/**
1665 * Decode phase information for each subband of a channel.
1666 *
1667 * @param[in]     gb                the GetBit context
1668 * @param[in,out] ctx               ptr to the channel unit context
1669 * @param[in]     ch_num            channel to process
1670 * @param[in]     band_has_tones    ptr to an array of per-band-flags:
1671 *                                  1 - tone data present
1672 */
1673static void decode_tones_phase(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
1674                               int ch_num, int band_has_tones[])
1675{
1676    int sb, i;
1677    Atrac3pWaveParam *wparam;
1678    Atrac3pWavesData *dst = ctx->channels[ch_num].tones_info;
1679
1680    for (sb = 0; sb < ctx->waves_info->num_tone_bands; sb++) {
1681        if (!band_has_tones[sb])
1682            continue;
1683        wparam = &ctx->waves_info->waves[dst[sb].start_index];
1684        for (i = 0; i < dst[sb].num_wavs; i++)
1685            wparam[i].phase_index = get_bits(gb, 5);
1686    }
1687}
1688
1689/**
1690 * Decode tones info for all channels.
1691 *
1692 * @param[in]     gb            the GetBit context
1693 * @param[in,out] ctx           ptr to the channel unit context
1694 * @param[in]     num_channels  number of channels to process
1695 * @param[in]     avctx         ptr to the AVCodecContext
1696 * @return result code: 0 = OK, otherwise - error code
1697 */
1698static int decode_tones_info(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
1699                             int num_channels, AVCodecContext *avctx)
1700{
1701    int ch_num, i, ret;
1702    int band_has_tones[16];
1703
1704    for (ch_num = 0; ch_num < num_channels; ch_num++)
1705        memset(ctx->channels[ch_num].tones_info, 0,
1706               sizeof(*ctx->channels[ch_num].tones_info) * ATRAC3P_SUBBANDS);
1707
1708    ctx->waves_info->tones_present = get_bits1(gb);
1709    if (!ctx->waves_info->tones_present)
1710        return 0;
1711
1712    memset(ctx->waves_info->waves, 0, sizeof(ctx->waves_info->waves));
1713
1714    ctx->waves_info->amplitude_mode = get_bits1(gb);
1715    if (!ctx->waves_info->amplitude_mode) {
1716        avpriv_report_missing_feature(avctx, "GHA amplitude mode 0");
1717        return AVERROR_PATCHWELCOME;
1718    }
1719
1720    ctx->waves_info->num_tone_bands =
1721        get_vlc2(gb, tone_vlc_tabs[0].table,
1722                 tone_vlc_tabs[0].bits, 1) + 1;
1723
1724    if (num_channels == 2) {
1725        get_subband_flags(gb, ctx->waves_info->tone_sharing, ctx->waves_info->num_tone_bands);
1726        get_subband_flags(gb, ctx->waves_info->tone_master,  ctx->waves_info->num_tone_bands);
1727        if (get_subband_flags(gb, ctx->waves_info->phase_shift,
1728                              ctx->waves_info->num_tone_bands)) {
1729            avpriv_report_missing_feature(avctx, "GHA Phase shifting");
1730            return AVERROR_PATCHWELCOME;
1731        }
1732    }
1733
1734    ctx->waves_info->tones_index = 0;
1735
1736    for (ch_num = 0; ch_num < num_channels; ch_num++) {
1737        for (i = 0; i < ctx->waves_info->num_tone_bands; i++)
1738            band_has_tones[i] = !ch_num ? 1 : !ctx->waves_info->tone_sharing[i];
1739
1740        decode_tones_envelope(gb, ctx, ch_num, band_has_tones);
1741        if ((ret = decode_band_numwavs(gb, ctx, ch_num, band_has_tones,
1742                                       avctx)) < 0)
1743            return ret;
1744
1745        decode_tones_frequency(gb, ctx, ch_num, band_has_tones);
1746        decode_tones_amplitude(gb, ctx, ch_num, band_has_tones);
1747        decode_tones_phase(gb, ctx, ch_num, band_has_tones);
1748    }
1749
1750    if (num_channels == 2) {
1751        for (i = 0; i < ctx->waves_info->num_tone_bands; i++) {
1752            if (ctx->waves_info->tone_sharing[i])
1753                ctx->channels[1].tones_info[i] = ctx->channels[0].tones_info[i];
1754
1755            if (ctx->waves_info->tone_master[i])
1756                FFSWAP(Atrac3pWavesData, ctx->channels[0].tones_info[i],
1757                       ctx->channels[1].tones_info[i]);
1758        }
1759    }
1760
1761    return 0;
1762}
1763
1764int ff_atrac3p_decode_channel_unit(GetBitContext *gb, Atrac3pChanUnitCtx *ctx,
1765                                   int num_channels, AVCodecContext *avctx)
1766{
1767    int ret;
1768
1769    /* parse sound header */
1770    ctx->num_quant_units = get_bits(gb, 5) + 1;
1771    if (ctx->num_quant_units > 28 && ctx->num_quant_units < 32) {
1772        av_log(avctx, AV_LOG_ERROR,
1773               "Invalid number of quantization units: %d!\n",
1774               ctx->num_quant_units);
1775        return AVERROR_INVALIDDATA;
1776    }
1777
1778    ctx->mute_flag = get_bits1(gb);
1779
1780    /* decode various sound parameters */
1781    if ((ret = decode_quant_wordlen(gb, ctx, num_channels, avctx)) < 0)
1782        return ret;
1783
1784    ctx->num_subbands       = atrac3p_qu_to_subband[ctx->num_quant_units - 1] + 1;
1785    ctx->num_coded_subbands = ctx->used_quant_units
1786                              ? atrac3p_qu_to_subband[ctx->used_quant_units - 1] + 1
1787                              : 0;
1788
1789    if ((ret = decode_scale_factors(gb, ctx, num_channels, avctx)) < 0)
1790        return ret;
1791
1792    if ((ret = decode_code_table_indexes(gb, ctx, num_channels, avctx)) < 0)
1793        return ret;
1794
1795    decode_spectrum(gb, ctx, num_channels, avctx);
1796
1797    if (num_channels == 2) {
1798        get_subband_flags(gb, ctx->swap_channels, ctx->num_coded_subbands);
1799        get_subband_flags(gb, ctx->negate_coeffs, ctx->num_coded_subbands);
1800    }
1801
1802    decode_window_shape(gb, ctx, num_channels);
1803
1804    if ((ret = decode_gainc_data(gb, ctx, num_channels, avctx)) < 0)
1805        return ret;
1806
1807    if ((ret = decode_tones_info(gb, ctx, num_channels, avctx)) < 0)
1808        return ret;
1809
1810    /* decode global noise info */
1811    ctx->noise_present = get_bits1(gb);
1812    if (ctx->noise_present) {
1813        ctx->noise_level_index = get_bits(gb, 4);
1814        ctx->noise_table_index = get_bits(gb, 4);
1815    }
1816
1817    return 0;
1818}
1819