1/*
2 * QDM2 compatible decoder
3 * Copyright (c) 2003 Ewald Snel
4 * Copyright (c) 2005 Benjamin Larsson
5 * Copyright (c) 2005 Alex Beregszaszi
6 * Copyright (c) 2005 Roberto Togni
7 *
8 * This file is part of FFmpeg.
9 *
10 * FFmpeg is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU Lesser General Public
12 * License as published by the Free Software Foundation; either
13 * version 2.1 of the License, or (at your option) any later version.
14 *
15 * FFmpeg is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18 * Lesser General Public License for more details.
19 *
20 * You should have received a copy of the GNU Lesser General Public
21 * License along with FFmpeg; if not, write to the Free Software
22 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 */
24
25/**
26 * @file
27 * QDM2 decoder
28 * @author Ewald Snel, Benjamin Larsson, Alex Beregszaszi, Roberto Togni
29 *
30 * The decoder is not perfect yet, there are still some distortions
31 * especially on files encoded with 16 or 8 subbands.
32 */
33
34#include <math.h>
35#include <stddef.h>
36#include <stdio.h>
37
38#define BITSTREAM_READER_LE
39#include "libavutil/channel_layout.h"
40#include "avcodec.h"
41#include "get_bits.h"
42#include "internal.h"
43#include "rdft.h"
44#include "mpegaudiodsp.h"
45#include "mpegaudio.h"
46
47#include "qdm2data.h"
48#include "qdm2_tablegen.h"
49
50#undef NDEBUG
51#include <assert.h>
52
53
54#define QDM2_LIST_ADD(list, size, packet) \
55do { \
56      if (size > 0) { \
57    list[size - 1].next = &list[size]; \
58      } \
59      list[size].packet = packet; \
60      list[size].next = NULL; \
61      size++; \
62} while(0)
63
64// Result is 8, 16 or 30
65#define QDM2_SB_USED(sub_sampling) (((sub_sampling) >= 2) ? 30 : 8 << (sub_sampling))
66
67#define FIX_NOISE_IDX(noise_idx) \
68  if ((noise_idx) >= 3840) \
69    (noise_idx) -= 3840; \
70
71#define SB_DITHERING_NOISE(sb,noise_idx) (noise_table[(noise_idx)++] * sb_noise_attenuation[(sb)])
72
73#define SAMPLES_NEEDED \
74     av_log (NULL,AV_LOG_INFO,"This file triggers some untested code. Please contact the developers.\n");
75
76#define SAMPLES_NEEDED_2(why) \
77     av_log (NULL,AV_LOG_INFO,"This file triggers some missing code. Please contact the developers.\nPosition: %s\n",why);
78
79#define QDM2_MAX_FRAME_SIZE 512
80
81typedef int8_t sb_int8_array[2][30][64];
82
83/**
84 * Subpacket
85 */
86typedef struct {
87    int type;            ///< subpacket type
88    unsigned int size;   ///< subpacket size
89    const uint8_t *data; ///< pointer to subpacket data (points to input data buffer, it's not a private copy)
90} QDM2SubPacket;
91
92/**
93 * A node in the subpacket list
94 */
95typedef struct QDM2SubPNode {
96    QDM2SubPacket *packet;      ///< packet
97    struct QDM2SubPNode *next; ///< pointer to next packet in the list, NULL if leaf node
98} QDM2SubPNode;
99
100typedef struct {
101    float re;
102    float im;
103} QDM2Complex;
104
105typedef struct {
106    float level;
107    QDM2Complex *complex;
108    const float *table;
109    int   phase;
110    int   phase_shift;
111    int   duration;
112    short time_index;
113    short cutoff;
114} FFTTone;
115
116typedef struct {
117    int16_t sub_packet;
118    uint8_t channel;
119    int16_t offset;
120    int16_t exp;
121    uint8_t phase;
122} FFTCoefficient;
123
124typedef struct {
125    DECLARE_ALIGNED(32, QDM2Complex, complex)[MPA_MAX_CHANNELS][256];
126} QDM2FFT;
127
128/**
129 * QDM2 decoder context
130 */
131typedef struct {
132    /// Parameters from codec header, do not change during playback
133    int nb_channels;         ///< number of channels
134    int channels;            ///< number of channels
135    int group_size;          ///< size of frame group (16 frames per group)
136    int fft_size;            ///< size of FFT, in complex numbers
137    int checksum_size;       ///< size of data block, used also for checksum
138
139    /// Parameters built from header parameters, do not change during playback
140    int group_order;         ///< order of frame group
141    int fft_order;           ///< order of FFT (actually fftorder+1)
142    int frame_size;          ///< size of data frame
143    int frequency_range;
144    int sub_sampling;        ///< subsampling: 0=25%, 1=50%, 2=100% */
145    int coeff_per_sb_select; ///< selector for "num. of coeffs. per subband" tables. Can be 0, 1, 2
146    int cm_table_select;     ///< selector for "coding method" tables. Can be 0, 1 (from init: 0-4)
147
148    /// Packets and packet lists
149    QDM2SubPacket sub_packets[16];      ///< the packets themselves
150    QDM2SubPNode sub_packet_list_A[16]; ///< list of all packets
151    QDM2SubPNode sub_packet_list_B[16]; ///< FFT packets B are on list
152    int sub_packets_B;                  ///< number of packets on 'B' list
153    QDM2SubPNode sub_packet_list_C[16]; ///< packets with errors?
154    QDM2SubPNode sub_packet_list_D[16]; ///< DCT packets
155
156    /// FFT and tones
157    FFTTone fft_tones[1000];
158    int fft_tone_start;
159    int fft_tone_end;
160    FFTCoefficient fft_coefs[1000];
161    int fft_coefs_index;
162    int fft_coefs_min_index[5];
163    int fft_coefs_max_index[5];
164    int fft_level_exp[6];
165    RDFTContext rdft_ctx;
166    QDM2FFT fft;
167
168    /// I/O data
169    const uint8_t *compressed_data;
170    int compressed_size;
171    float output_buffer[QDM2_MAX_FRAME_SIZE * MPA_MAX_CHANNELS * 2];
172
173    /// Synthesis filter
174    MPADSPContext mpadsp;
175    DECLARE_ALIGNED(32, float, synth_buf)[MPA_MAX_CHANNELS][512*2];
176    int synth_buf_offset[MPA_MAX_CHANNELS];
177    DECLARE_ALIGNED(32, float, sb_samples)[MPA_MAX_CHANNELS][128][SBLIMIT];
178    DECLARE_ALIGNED(32, float, samples)[MPA_MAX_CHANNELS * MPA_FRAME_SIZE];
179
180    /// Mixed temporary data used in decoding
181    float tone_level[MPA_MAX_CHANNELS][30][64];
182    int8_t coding_method[MPA_MAX_CHANNELS][30][64];
183    int8_t quantized_coeffs[MPA_MAX_CHANNELS][10][8];
184    int8_t tone_level_idx_base[MPA_MAX_CHANNELS][30][8];
185    int8_t tone_level_idx_hi1[MPA_MAX_CHANNELS][3][8][8];
186    int8_t tone_level_idx_mid[MPA_MAX_CHANNELS][26][8];
187    int8_t tone_level_idx_hi2[MPA_MAX_CHANNELS][26];
188    int8_t tone_level_idx[MPA_MAX_CHANNELS][30][64];
189    int8_t tone_level_idx_temp[MPA_MAX_CHANNELS][30][64];
190
191    // Flags
192    int has_errors;         ///< packet has errors
193    int superblocktype_2_3; ///< select fft tables and some algorithm based on superblock type
194    int do_synth_filter;    ///< used to perform or skip synthesis filter
195
196    int sub_packet;
197    int noise_idx; ///< index for dithering noise table
198} QDM2Context;
199
200
201static VLC vlc_tab_level;
202static VLC vlc_tab_diff;
203static VLC vlc_tab_run;
204static VLC fft_level_exp_alt_vlc;
205static VLC fft_level_exp_vlc;
206static VLC fft_stereo_exp_vlc;
207static VLC fft_stereo_phase_vlc;
208static VLC vlc_tab_tone_level_idx_hi1;
209static VLC vlc_tab_tone_level_idx_mid;
210static VLC vlc_tab_tone_level_idx_hi2;
211static VLC vlc_tab_type30;
212static VLC vlc_tab_type34;
213static VLC vlc_tab_fft_tone_offset[5];
214
215static const uint16_t qdm2_vlc_offs[] = {
216    0,260,566,598,894,1166,1230,1294,1678,1950,2214,2278,2310,2570,2834,3124,3448,3838,
217};
218
219static const int switchtable[23] = {
220    0, 5, 1, 5, 5, 5, 5, 5, 2, 5, 5, 5, 5, 5, 5, 5, 3, 5, 5, 5, 5, 5, 4
221};
222
223static av_cold void qdm2_init_vlc(void)
224{
225    static VLC_TYPE qdm2_table[3838][2];
226
227    vlc_tab_level.table           = &qdm2_table[qdm2_vlc_offs[0]];
228    vlc_tab_level.table_allocated = qdm2_vlc_offs[1] - qdm2_vlc_offs[0];
229    init_vlc(&vlc_tab_level, 8, 24,
230             vlc_tab_level_huffbits, 1, 1,
231             vlc_tab_level_huffcodes, 2, 2,
232             INIT_VLC_USE_NEW_STATIC | INIT_VLC_LE);
233
234    vlc_tab_diff.table           = &qdm2_table[qdm2_vlc_offs[1]];
235    vlc_tab_diff.table_allocated = qdm2_vlc_offs[2] - qdm2_vlc_offs[1];
236    init_vlc(&vlc_tab_diff, 8, 37,
237             vlc_tab_diff_huffbits, 1, 1,
238             vlc_tab_diff_huffcodes, 2, 2,
239             INIT_VLC_USE_NEW_STATIC | INIT_VLC_LE);
240
241    vlc_tab_run.table           = &qdm2_table[qdm2_vlc_offs[2]];
242    vlc_tab_run.table_allocated = qdm2_vlc_offs[3] - qdm2_vlc_offs[2];
243    init_vlc(&vlc_tab_run, 5, 6,
244             vlc_tab_run_huffbits, 1, 1,
245             vlc_tab_run_huffcodes, 1, 1,
246             INIT_VLC_USE_NEW_STATIC | INIT_VLC_LE);
247
248    fft_level_exp_alt_vlc.table           = &qdm2_table[qdm2_vlc_offs[3]];
249    fft_level_exp_alt_vlc.table_allocated = qdm2_vlc_offs[4] -
250                                            qdm2_vlc_offs[3];
251    init_vlc(&fft_level_exp_alt_vlc, 8, 28,
252             fft_level_exp_alt_huffbits, 1, 1,
253             fft_level_exp_alt_huffcodes, 2, 2,
254             INIT_VLC_USE_NEW_STATIC | INIT_VLC_LE);
255
256    fft_level_exp_vlc.table           = &qdm2_table[qdm2_vlc_offs[4]];
257    fft_level_exp_vlc.table_allocated = qdm2_vlc_offs[5] - qdm2_vlc_offs[4];
258    init_vlc(&fft_level_exp_vlc, 8, 20,
259             fft_level_exp_huffbits, 1, 1,
260             fft_level_exp_huffcodes, 2, 2,
261             INIT_VLC_USE_NEW_STATIC | INIT_VLC_LE);
262
263    fft_stereo_exp_vlc.table           = &qdm2_table[qdm2_vlc_offs[5]];
264    fft_stereo_exp_vlc.table_allocated = qdm2_vlc_offs[6] -
265                                         qdm2_vlc_offs[5];
266    init_vlc(&fft_stereo_exp_vlc, 6, 7,
267             fft_stereo_exp_huffbits, 1, 1,
268             fft_stereo_exp_huffcodes, 1, 1,
269             INIT_VLC_USE_NEW_STATIC | INIT_VLC_LE);
270
271    fft_stereo_phase_vlc.table           = &qdm2_table[qdm2_vlc_offs[6]];
272    fft_stereo_phase_vlc.table_allocated = qdm2_vlc_offs[7] -
273                                           qdm2_vlc_offs[6];
274    init_vlc(&fft_stereo_phase_vlc, 6, 9,
275             fft_stereo_phase_huffbits, 1, 1,
276             fft_stereo_phase_huffcodes, 1, 1,
277             INIT_VLC_USE_NEW_STATIC | INIT_VLC_LE);
278
279    vlc_tab_tone_level_idx_hi1.table =
280        &qdm2_table[qdm2_vlc_offs[7]];
281    vlc_tab_tone_level_idx_hi1.table_allocated = qdm2_vlc_offs[8] -
282                                                 qdm2_vlc_offs[7];
283    init_vlc(&vlc_tab_tone_level_idx_hi1, 8, 20,
284             vlc_tab_tone_level_idx_hi1_huffbits, 1, 1,
285             vlc_tab_tone_level_idx_hi1_huffcodes, 2, 2,
286             INIT_VLC_USE_NEW_STATIC | INIT_VLC_LE);
287
288    vlc_tab_tone_level_idx_mid.table =
289        &qdm2_table[qdm2_vlc_offs[8]];
290    vlc_tab_tone_level_idx_mid.table_allocated = qdm2_vlc_offs[9] -
291                                                 qdm2_vlc_offs[8];
292    init_vlc(&vlc_tab_tone_level_idx_mid, 8, 24,
293             vlc_tab_tone_level_idx_mid_huffbits, 1, 1,
294             vlc_tab_tone_level_idx_mid_huffcodes, 2, 2,
295             INIT_VLC_USE_NEW_STATIC | INIT_VLC_LE);
296
297    vlc_tab_tone_level_idx_hi2.table =
298        &qdm2_table[qdm2_vlc_offs[9]];
299    vlc_tab_tone_level_idx_hi2.table_allocated = qdm2_vlc_offs[10] -
300                                                 qdm2_vlc_offs[9];
301    init_vlc(&vlc_tab_tone_level_idx_hi2, 8, 24,
302             vlc_tab_tone_level_idx_hi2_huffbits, 1, 1,
303             vlc_tab_tone_level_idx_hi2_huffcodes, 2, 2,
304             INIT_VLC_USE_NEW_STATIC | INIT_VLC_LE);
305
306    vlc_tab_type30.table           = &qdm2_table[qdm2_vlc_offs[10]];
307    vlc_tab_type30.table_allocated = qdm2_vlc_offs[11] - qdm2_vlc_offs[10];
308    init_vlc(&vlc_tab_type30, 6, 9,
309             vlc_tab_type30_huffbits, 1, 1,
310             vlc_tab_type30_huffcodes, 1, 1,
311             INIT_VLC_USE_NEW_STATIC | INIT_VLC_LE);
312
313    vlc_tab_type34.table           = &qdm2_table[qdm2_vlc_offs[11]];
314    vlc_tab_type34.table_allocated = qdm2_vlc_offs[12] - qdm2_vlc_offs[11];
315    init_vlc(&vlc_tab_type34, 5, 10,
316             vlc_tab_type34_huffbits, 1, 1,
317             vlc_tab_type34_huffcodes, 1, 1,
318             INIT_VLC_USE_NEW_STATIC | INIT_VLC_LE);
319
320    vlc_tab_fft_tone_offset[0].table =
321        &qdm2_table[qdm2_vlc_offs[12]];
322    vlc_tab_fft_tone_offset[0].table_allocated = qdm2_vlc_offs[13] -
323                                                 qdm2_vlc_offs[12];
324    init_vlc(&vlc_tab_fft_tone_offset[0], 8, 23,
325             vlc_tab_fft_tone_offset_0_huffbits, 1, 1,
326             vlc_tab_fft_tone_offset_0_huffcodes, 2, 2,
327             INIT_VLC_USE_NEW_STATIC | INIT_VLC_LE);
328
329    vlc_tab_fft_tone_offset[1].table =
330        &qdm2_table[qdm2_vlc_offs[13]];
331    vlc_tab_fft_tone_offset[1].table_allocated = qdm2_vlc_offs[14] -
332                                                 qdm2_vlc_offs[13];
333    init_vlc(&vlc_tab_fft_tone_offset[1], 8, 28,
334             vlc_tab_fft_tone_offset_1_huffbits, 1, 1,
335             vlc_tab_fft_tone_offset_1_huffcodes, 2, 2,
336             INIT_VLC_USE_NEW_STATIC | INIT_VLC_LE);
337
338    vlc_tab_fft_tone_offset[2].table =
339        &qdm2_table[qdm2_vlc_offs[14]];
340    vlc_tab_fft_tone_offset[2].table_allocated = qdm2_vlc_offs[15] -
341                                                 qdm2_vlc_offs[14];
342    init_vlc(&vlc_tab_fft_tone_offset[2], 8, 32,
343             vlc_tab_fft_tone_offset_2_huffbits, 1, 1,
344             vlc_tab_fft_tone_offset_2_huffcodes, 2, 2,
345             INIT_VLC_USE_NEW_STATIC | INIT_VLC_LE);
346
347    vlc_tab_fft_tone_offset[3].table =
348        &qdm2_table[qdm2_vlc_offs[15]];
349    vlc_tab_fft_tone_offset[3].table_allocated = qdm2_vlc_offs[16] -
350                                                 qdm2_vlc_offs[15];
351    init_vlc(&vlc_tab_fft_tone_offset[3], 8, 35,
352             vlc_tab_fft_tone_offset_3_huffbits, 1, 1,
353             vlc_tab_fft_tone_offset_3_huffcodes, 2, 2,
354             INIT_VLC_USE_NEW_STATIC | INIT_VLC_LE);
355
356    vlc_tab_fft_tone_offset[4].table =
357        &qdm2_table[qdm2_vlc_offs[16]];
358    vlc_tab_fft_tone_offset[4].table_allocated = qdm2_vlc_offs[17] -
359                                                 qdm2_vlc_offs[16];
360    init_vlc(&vlc_tab_fft_tone_offset[4], 8, 38,
361             vlc_tab_fft_tone_offset_4_huffbits, 1, 1,
362             vlc_tab_fft_tone_offset_4_huffcodes, 2, 2,
363             INIT_VLC_USE_NEW_STATIC | INIT_VLC_LE);
364}
365
366static int qdm2_get_vlc(GetBitContext *gb, VLC *vlc, int flag, int depth)
367{
368    int value;
369
370    value = get_vlc2(gb, vlc->table, vlc->bits, depth);
371
372    /* stage-2, 3 bits exponent escape sequence */
373    if (value-- == 0)
374        value = get_bits(gb, get_bits(gb, 3) + 1);
375
376    /* stage-3, optional */
377    if (flag) {
378        int tmp;
379
380        if (value >= 60) {
381            av_log(NULL, AV_LOG_ERROR, "value %d in qdm2_get_vlc too large\n", value);
382            return 0;
383        }
384
385        tmp= vlc_stage3_values[value];
386
387        if ((value & ~3) > 0)
388            tmp += get_bits(gb, (value >> 2));
389        value = tmp;
390    }
391
392    return value;
393}
394
395static int qdm2_get_se_vlc(VLC *vlc, GetBitContext *gb, int depth)
396{
397    int value = qdm2_get_vlc(gb, vlc, 0, depth);
398
399    return (value & 1) ? ((value + 1) >> 1) : -(value >> 1);
400}
401
402/**
403 * QDM2 checksum
404 *
405 * @param data      pointer to data to be checksum'ed
406 * @param length    data length
407 * @param value     checksum value
408 *
409 * @return          0 if checksum is OK
410 */
411static uint16_t qdm2_packet_checksum(const uint8_t *data, int length, int value)
412{
413    int i;
414
415    for (i = 0; i < length; i++)
416        value -= data[i];
417
418    return (uint16_t)(value & 0xffff);
419}
420
421/**
422 * Fill a QDM2SubPacket structure with packet type, size, and data pointer.
423 *
424 * @param gb            bitreader context
425 * @param sub_packet    packet under analysis
426 */
427static void qdm2_decode_sub_packet_header(GetBitContext *gb,
428                                          QDM2SubPacket *sub_packet)
429{
430    sub_packet->type = get_bits(gb, 8);
431
432    if (sub_packet->type == 0) {
433        sub_packet->size = 0;
434        sub_packet->data = NULL;
435    } else {
436        sub_packet->size = get_bits(gb, 8);
437
438        if (sub_packet->type & 0x80) {
439            sub_packet->size <<= 8;
440            sub_packet->size  |= get_bits(gb, 8);
441            sub_packet->type  &= 0x7f;
442        }
443
444        if (sub_packet->type == 0x7f)
445            sub_packet->type |= (get_bits(gb, 8) << 8);
446
447        // FIXME: this depends on bitreader-internal data
448        sub_packet->data = &gb->buffer[get_bits_count(gb) / 8];
449    }
450
451    av_log(NULL, AV_LOG_DEBUG, "Subpacket: type=%d size=%d start_offs=%x\n",
452           sub_packet->type, sub_packet->size, get_bits_count(gb) / 8);
453}
454
455/**
456 * Return node pointer to first packet of requested type in list.
457 *
458 * @param list    list of subpackets to be scanned
459 * @param type    type of searched subpacket
460 * @return        node pointer for subpacket if found, else NULL
461 */
462static QDM2SubPNode *qdm2_search_subpacket_type_in_list(QDM2SubPNode *list,
463                                                        int type)
464{
465    while (list != NULL && list->packet != NULL) {
466        if (list->packet->type == type)
467            return list;
468        list = list->next;
469    }
470    return NULL;
471}
472
473/**
474 * Replace 8 elements with their average value.
475 * Called by qdm2_decode_superblock before starting subblock decoding.
476 *
477 * @param q       context
478 */
479static void average_quantized_coeffs(QDM2Context *q)
480{
481    int i, j, n, ch, sum;
482
483    n = coeff_per_sb_for_avg[q->coeff_per_sb_select][QDM2_SB_USED(q->sub_sampling) - 1] + 1;
484
485    for (ch = 0; ch < q->nb_channels; ch++)
486        for (i = 0; i < n; i++) {
487            sum = 0;
488
489            for (j = 0; j < 8; j++)
490                sum += q->quantized_coeffs[ch][i][j];
491
492            sum /= 8;
493            if (sum > 0)
494                sum--;
495
496            for (j = 0; j < 8; j++)
497                q->quantized_coeffs[ch][i][j] = sum;
498        }
499}
500
501/**
502 * Build subband samples with noise weighted by q->tone_level.
503 * Called by synthfilt_build_sb_samples.
504 *
505 * @param q     context
506 * @param sb    subband index
507 */
508static void build_sb_samples_from_noise(QDM2Context *q, int sb)
509{
510    int ch, j;
511
512    FIX_NOISE_IDX(q->noise_idx);
513
514    if (!q->nb_channels)
515        return;
516
517    for (ch = 0; ch < q->nb_channels; ch++) {
518        for (j = 0; j < 64; j++) {
519            q->sb_samples[ch][j * 2][sb] =
520                SB_DITHERING_NOISE(sb, q->noise_idx) * q->tone_level[ch][sb][j];
521            q->sb_samples[ch][j * 2 + 1][sb] =
522                SB_DITHERING_NOISE(sb, q->noise_idx) * q->tone_level[ch][sb][j];
523        }
524    }
525}
526
527/**
528 * Called while processing data from subpackets 11 and 12.
529 * Used after making changes to coding_method array.
530 *
531 * @param sb               subband index
532 * @param channels         number of channels
533 * @param coding_method    q->coding_method[0][0][0]
534 */
535static int fix_coding_method_array(int sb, int channels,
536                                   sb_int8_array coding_method)
537{
538    int j, k;
539    int ch;
540    int run, case_val;
541
542    for (ch = 0; ch < channels; ch++) {
543        for (j = 0; j < 64; ) {
544            if (coding_method[ch][sb][j] < 8)
545                return -1;
546            if ((coding_method[ch][sb][j] - 8) > 22) {
547                run      = 1;
548                case_val = 8;
549            } else {
550                switch (switchtable[coding_method[ch][sb][j] - 8]) {
551                case 0: run  = 10;
552                    case_val = 10;
553                    break;
554                case 1: run  = 1;
555                    case_val = 16;
556                    break;
557                case 2: run  = 5;
558                    case_val = 24;
559                    break;
560                case 3: run  = 3;
561                    case_val = 30;
562                    break;
563                case 4: run  = 1;
564                    case_val = 30;
565                    break;
566                case 5: run  = 1;
567                    case_val = 8;
568                    break;
569                default: run = 1;
570                    case_val = 8;
571                    break;
572                }
573            }
574            for (k = 0; k < run; k++) {
575                if (j + k < 128) {
576                    if (coding_method[ch][sb + (j + k) / 64][(j + k) % 64] > coding_method[ch][sb][j]) {
577                        if (k > 0) {
578                            SAMPLES_NEEDED
579                            //not debugged, almost never used
580                            memset(&coding_method[ch][sb][j + k], case_val,
581                                   k *sizeof(int8_t));
582                            memset(&coding_method[ch][sb][j + k], case_val,
583                                   3 * sizeof(int8_t));
584                        }
585                    }
586                }
587            }
588            j += run;
589        }
590    }
591    return 0;
592}
593
594/**
595 * Related to synthesis filter
596 * Called by process_subpacket_10
597 *
598 * @param q       context
599 * @param flag    1 if called after getting data from subpacket 10, 0 if no subpacket 10
600 */
601static void fill_tone_level_array(QDM2Context *q, int flag)
602{
603    int i, sb, ch, sb_used;
604    int tmp, tab;
605
606    for (ch = 0; ch < q->nb_channels; ch++)
607        for (sb = 0; sb < 30; sb++)
608            for (i = 0; i < 8; i++) {
609                if ((tab=coeff_per_sb_for_dequant[q->coeff_per_sb_select][sb]) < (last_coeff[q->coeff_per_sb_select] - 1))
610                    tmp = q->quantized_coeffs[ch][tab + 1][i] * dequant_table[q->coeff_per_sb_select][tab + 1][sb]+
611                          q->quantized_coeffs[ch][tab][i] * dequant_table[q->coeff_per_sb_select][tab][sb];
612                else
613                    tmp = q->quantized_coeffs[ch][tab][i] * dequant_table[q->coeff_per_sb_select][tab][sb];
614                if(tmp < 0)
615                    tmp += 0xff;
616                q->tone_level_idx_base[ch][sb][i] = (tmp / 256) & 0xff;
617            }
618
619    sb_used = QDM2_SB_USED(q->sub_sampling);
620
621    if ((q->superblocktype_2_3 != 0) && !flag) {
622        for (sb = 0; sb < sb_used; sb++)
623            for (ch = 0; ch < q->nb_channels; ch++)
624                for (i = 0; i < 64; i++) {
625                    q->tone_level_idx[ch][sb][i] = q->tone_level_idx_base[ch][sb][i / 8];
626                    if (q->tone_level_idx[ch][sb][i] < 0)
627                        q->tone_level[ch][sb][i] = 0;
628                    else
629                        q->tone_level[ch][sb][i] = fft_tone_level_table[0][q->tone_level_idx[ch][sb][i] & 0x3f];
630                }
631    } else {
632        tab = q->superblocktype_2_3 ? 0 : 1;
633        for (sb = 0; sb < sb_used; sb++) {
634            if ((sb >= 4) && (sb <= 23)) {
635                for (ch = 0; ch < q->nb_channels; ch++)
636                    for (i = 0; i < 64; i++) {
637                        tmp = q->tone_level_idx_base[ch][sb][i / 8] -
638                              q->tone_level_idx_hi1[ch][sb / 8][i / 8][i % 8] -
639                              q->tone_level_idx_mid[ch][sb - 4][i / 8] -
640                              q->tone_level_idx_hi2[ch][sb - 4];
641                        q->tone_level_idx[ch][sb][i] = tmp & 0xff;
642                        if ((tmp < 0) || (!q->superblocktype_2_3 && !tmp))
643                            q->tone_level[ch][sb][i] = 0;
644                        else
645                            q->tone_level[ch][sb][i] = fft_tone_level_table[tab][tmp & 0x3f];
646                }
647            } else {
648                if (sb > 4) {
649                    for (ch = 0; ch < q->nb_channels; ch++)
650                        for (i = 0; i < 64; i++) {
651                            tmp = q->tone_level_idx_base[ch][sb][i / 8] -
652                                  q->tone_level_idx_hi1[ch][2][i / 8][i % 8] -
653                                  q->tone_level_idx_hi2[ch][sb - 4];
654                            q->tone_level_idx[ch][sb][i] = tmp & 0xff;
655                            if ((tmp < 0) || (!q->superblocktype_2_3 && !tmp))
656                                q->tone_level[ch][sb][i] = 0;
657                            else
658                                q->tone_level[ch][sb][i] = fft_tone_level_table[tab][tmp & 0x3f];
659                    }
660                } else {
661                    for (ch = 0; ch < q->nb_channels; ch++)
662                        for (i = 0; i < 64; i++) {
663                            tmp = q->tone_level_idx[ch][sb][i] = q->tone_level_idx_base[ch][sb][i / 8];
664                            if ((tmp < 0) || (!q->superblocktype_2_3 && !tmp))
665                                q->tone_level[ch][sb][i] = 0;
666                            else
667                                q->tone_level[ch][sb][i] = fft_tone_level_table[tab][tmp & 0x3f];
668                        }
669                }
670            }
671        }
672    }
673}
674
675/**
676 * Related to synthesis filter
677 * Called by process_subpacket_11
678 * c is built with data from subpacket 11
679 * Most of this function is used only if superblock_type_2_3 == 0,
680 * never seen it in samples.
681 *
682 * @param tone_level_idx
683 * @param tone_level_idx_temp
684 * @param coding_method        q->coding_method[0][0][0]
685 * @param nb_channels          number of channels
686 * @param c                    coming from subpacket 11, passed as 8*c
687 * @param superblocktype_2_3   flag based on superblock packet type
688 * @param cm_table_select      q->cm_table_select
689 */
690static void fill_coding_method_array(sb_int8_array tone_level_idx,
691                                     sb_int8_array tone_level_idx_temp,
692                                     sb_int8_array coding_method,
693                                     int nb_channels,
694                                     int c, int superblocktype_2_3,
695                                     int cm_table_select)
696{
697    int ch, sb, j;
698    int tmp, acc, esp_40, comp;
699    int add1, add2, add3, add4;
700    int64_t multres;
701
702    if (!superblocktype_2_3) {
703        /* This case is untested, no samples available */
704        avpriv_request_sample(NULL, "!superblocktype_2_3");
705        return;
706        for (ch = 0; ch < nb_channels; ch++)
707            for (sb = 0; sb < 30; sb++) {
708                for (j = 1; j < 63; j++) {  // The loop only iterates to 63 so the code doesn't overflow the buffer
709                    add1 = tone_level_idx[ch][sb][j] - 10;
710                    if (add1 < 0)
711                        add1 = 0;
712                    add2 = add3 = add4 = 0;
713                    if (sb > 1) {
714                        add2 = tone_level_idx[ch][sb - 2][j] + tone_level_idx_offset_table[sb][0] - 6;
715                        if (add2 < 0)
716                            add2 = 0;
717                    }
718                    if (sb > 0) {
719                        add3 = tone_level_idx[ch][sb - 1][j] + tone_level_idx_offset_table[sb][1] - 6;
720                        if (add3 < 0)
721                            add3 = 0;
722                    }
723                    if (sb < 29) {
724                        add4 = tone_level_idx[ch][sb + 1][j] + tone_level_idx_offset_table[sb][3] - 6;
725                        if (add4 < 0)
726                            add4 = 0;
727                    }
728                    tmp = tone_level_idx[ch][sb][j + 1] * 2 - add4 - add3 - add2 - add1;
729                    if (tmp < 0)
730                        tmp = 0;
731                    tone_level_idx_temp[ch][sb][j + 1] = tmp & 0xff;
732                }
733                tone_level_idx_temp[ch][sb][0] = tone_level_idx_temp[ch][sb][1];
734            }
735            acc = 0;
736            for (ch = 0; ch < nb_channels; ch++)
737                for (sb = 0; sb < 30; sb++)
738                    for (j = 0; j < 64; j++)
739                        acc += tone_level_idx_temp[ch][sb][j];
740
741            multres = 0x66666667LL * (acc * 10);
742            esp_40 = (multres >> 32) / 8 + ((multres & 0xffffffff) >> 31);
743            for (ch = 0;  ch < nb_channels; ch++)
744                for (sb = 0; sb < 30; sb++)
745                    for (j = 0; j < 64; j++) {
746                        comp = tone_level_idx_temp[ch][sb][j]* esp_40 * 10;
747                        if (comp < 0)
748                            comp += 0xff;
749                        comp /= 256; // signed shift
750                        switch(sb) {
751                            case 0:
752                                if (comp < 30)
753                                    comp = 30;
754                                comp += 15;
755                                break;
756                            case 1:
757                                if (comp < 24)
758                                    comp = 24;
759                                comp += 10;
760                                break;
761                            case 2:
762                            case 3:
763                            case 4:
764                                if (comp < 16)
765                                    comp = 16;
766                        }
767                        if (comp <= 5)
768                            tmp = 0;
769                        else if (comp <= 10)
770                            tmp = 10;
771                        else if (comp <= 16)
772                            tmp = 16;
773                        else if (comp <= 24)
774                            tmp = -1;
775                        else
776                            tmp = 0;
777                        coding_method[ch][sb][j] = ((tmp & 0xfffa) + 30 )& 0xff;
778                    }
779            for (sb = 0; sb < 30; sb++)
780                fix_coding_method_array(sb, nb_channels, coding_method);
781            for (ch = 0; ch < nb_channels; ch++)
782                for (sb = 0; sb < 30; sb++)
783                    for (j = 0; j < 64; j++)
784                        if (sb >= 10) {
785                            if (coding_method[ch][sb][j] < 10)
786                                coding_method[ch][sb][j] = 10;
787                        } else {
788                            if (sb >= 2) {
789                                if (coding_method[ch][sb][j] < 16)
790                                    coding_method[ch][sb][j] = 16;
791                            } else {
792                                if (coding_method[ch][sb][j] < 30)
793                                    coding_method[ch][sb][j] = 30;
794                            }
795                        }
796    } else { // superblocktype_2_3 != 0
797        for (ch = 0; ch < nb_channels; ch++)
798            for (sb = 0; sb < 30; sb++)
799                for (j = 0; j < 64; j++)
800                    coding_method[ch][sb][j] = coding_method_table[cm_table_select][sb];
801    }
802}
803
804/**
805 *
806 * Called by process_subpacket_11 to process more data from subpacket 11
807 * with sb 0-8.
808 * Called by process_subpacket_12 to process data from subpacket 12 with
809 * sb 8-sb_used.
810 *
811 * @param q         context
812 * @param gb        bitreader context
813 * @param length    packet length in bits
814 * @param sb_min    lower subband processed (sb_min included)
815 * @param sb_max    higher subband processed (sb_max excluded)
816 */
817static int synthfilt_build_sb_samples(QDM2Context *q, GetBitContext *gb,
818                                       int length, int sb_min, int sb_max)
819{
820    int sb, j, k, n, ch, run, channels;
821    int joined_stereo, zero_encoding;
822    int type34_first;
823    float type34_div = 0;
824    float type34_predictor;
825    float samples[10];
826    int sign_bits[16] = {0};
827
828    if (length == 0) {
829        // If no data use noise
830        for (sb=sb_min; sb < sb_max; sb++)
831            build_sb_samples_from_noise(q, sb);
832
833        return 0;
834    }
835
836    for (sb = sb_min; sb < sb_max; sb++) {
837        channels = q->nb_channels;
838
839        if (q->nb_channels <= 1 || sb < 12)
840            joined_stereo = 0;
841        else if (sb >= 24)
842            joined_stereo = 1;
843        else
844            joined_stereo = (get_bits_left(gb) >= 1) ? get_bits1(gb) : 0;
845
846        if (joined_stereo) {
847            if (get_bits_left(gb) >= 16)
848                for (j = 0; j < 16; j++)
849                    sign_bits[j] = get_bits1(gb);
850
851            for (j = 0; j < 64; j++)
852                if (q->coding_method[1][sb][j] > q->coding_method[0][sb][j])
853                    q->coding_method[0][sb][j] = q->coding_method[1][sb][j];
854
855            if (fix_coding_method_array(sb, q->nb_channels,
856                                            q->coding_method)) {
857                av_log(NULL, AV_LOG_ERROR, "coding method invalid\n");
858                build_sb_samples_from_noise(q, sb);
859                continue;
860            }
861            channels = 1;
862        }
863
864        for (ch = 0; ch < channels; ch++) {
865            FIX_NOISE_IDX(q->noise_idx);
866            zero_encoding = (get_bits_left(gb) >= 1) ? get_bits1(gb) : 0;
867            type34_predictor = 0.0;
868            type34_first = 1;
869
870            for (j = 0; j < 128; ) {
871                switch (q->coding_method[ch][sb][j / 2]) {
872                    case 8:
873                        if (get_bits_left(gb) >= 10) {
874                            if (zero_encoding) {
875                                for (k = 0; k < 5; k++) {
876                                    if ((j + 2 * k) >= 128)
877                                        break;
878                                    samples[2 * k] = get_bits1(gb) ? dequant_1bit[joined_stereo][2 * get_bits1(gb)] : 0;
879                                }
880                            } else {
881                                n = get_bits(gb, 8);
882                                if (n >= 243) {
883                                    av_log(NULL, AV_LOG_ERROR, "Invalid 8bit codeword\n");
884                                    return AVERROR_INVALIDDATA;
885                                }
886
887                                for (k = 0; k < 5; k++)
888                                    samples[2 * k] = dequant_1bit[joined_stereo][random_dequant_index[n][k]];
889                            }
890                            for (k = 0; k < 5; k++)
891                                samples[2 * k + 1] = SB_DITHERING_NOISE(sb,q->noise_idx);
892                        } else {
893                            for (k = 0; k < 10; k++)
894                                samples[k] = SB_DITHERING_NOISE(sb,q->noise_idx);
895                        }
896                        run = 10;
897                        break;
898
899                    case 10:
900                        if (get_bits_left(gb) >= 1) {
901                            float f = 0.81;
902
903                            if (get_bits1(gb))
904                                f = -f;
905                            f -= noise_samples[((sb + 1) * (j +5 * ch + 1)) & 127] * 9.0 / 40.0;
906                            samples[0] = f;
907                        } else {
908                            samples[0] = SB_DITHERING_NOISE(sb,q->noise_idx);
909                        }
910                        run = 1;
911                        break;
912
913                    case 16:
914                        if (get_bits_left(gb) >= 10) {
915                            if (zero_encoding) {
916                                for (k = 0; k < 5; k++) {
917                                    if ((j + k) >= 128)
918                                        break;
919                                    samples[k] = (get_bits1(gb) == 0) ? 0 : dequant_1bit[joined_stereo][2 * get_bits1(gb)];
920                                }
921                            } else {
922                                n = get_bits (gb, 8);
923                                if (n >= 243) {
924                                    av_log(NULL, AV_LOG_ERROR, "Invalid 8bit codeword\n");
925                                    return AVERROR_INVALIDDATA;
926                                }
927
928                                for (k = 0; k < 5; k++)
929                                    samples[k] = dequant_1bit[joined_stereo][random_dequant_index[n][k]];
930                            }
931                        } else {
932                            for (k = 0; k < 5; k++)
933                                samples[k] = SB_DITHERING_NOISE(sb,q->noise_idx);
934                        }
935                        run = 5;
936                        break;
937
938                    case 24:
939                        if (get_bits_left(gb) >= 7) {
940                            n = get_bits(gb, 7);
941                            if (n >= 125) {
942                                av_log(NULL, AV_LOG_ERROR, "Invalid 7bit codeword\n");
943                                return AVERROR_INVALIDDATA;
944                            }
945
946                            for (k = 0; k < 3; k++)
947                                samples[k] = (random_dequant_type24[n][k] - 2.0) * 0.5;
948                        } else {
949                            for (k = 0; k < 3; k++)
950                                samples[k] = SB_DITHERING_NOISE(sb,q->noise_idx);
951                        }
952                        run = 3;
953                        break;
954
955                    case 30:
956                        if (get_bits_left(gb) >= 4) {
957                            unsigned index = qdm2_get_vlc(gb, &vlc_tab_type30, 0, 1);
958                            if (index >= FF_ARRAY_ELEMS(type30_dequant)) {
959                                av_log(NULL, AV_LOG_ERROR, "index %d out of type30_dequant array\n", index);
960                                return AVERROR_INVALIDDATA;
961                            }
962                            samples[0] = type30_dequant[index];
963                        } else
964                            samples[0] = SB_DITHERING_NOISE(sb,q->noise_idx);
965
966                        run = 1;
967                        break;
968
969                    case 34:
970                        if (get_bits_left(gb) >= 7) {
971                            if (type34_first) {
972                                type34_div = (float)(1 << get_bits(gb, 2));
973                                samples[0] = ((float)get_bits(gb, 5) - 16.0) / 15.0;
974                                type34_predictor = samples[0];
975                                type34_first = 0;
976                            } else {
977                                unsigned index = qdm2_get_vlc(gb, &vlc_tab_type34, 0, 1);
978                                if (index >= FF_ARRAY_ELEMS(type34_delta)) {
979                                    av_log(NULL, AV_LOG_ERROR, "index %d out of type34_delta array\n", index);
980                                    return AVERROR_INVALIDDATA;
981                                }
982                                samples[0] = type34_delta[index] / type34_div + type34_predictor;
983                                type34_predictor = samples[0];
984                            }
985                        } else {
986                            samples[0] = SB_DITHERING_NOISE(sb,q->noise_idx);
987                        }
988                        run = 1;
989                        break;
990
991                    default:
992                        samples[0] = SB_DITHERING_NOISE(sb,q->noise_idx);
993                        run = 1;
994                        break;
995                }
996
997                if (joined_stereo) {
998                    for (k = 0; k < run && j + k < 128; k++) {
999                        q->sb_samples[0][j + k][sb] =
1000                            q->tone_level[0][sb][(j + k) / 2] * samples[k];
1001                        if (q->nb_channels == 2) {
1002                            if (sign_bits[(j + k) / 8])
1003                                q->sb_samples[1][j + k][sb] =
1004                                    q->tone_level[1][sb][(j + k) / 2] * -samples[k];
1005                            else
1006                                q->sb_samples[1][j + k][sb] =
1007                                    q->tone_level[1][sb][(j + k) / 2] * samples[k];
1008                        }
1009                    }
1010                } else {
1011                    for (k = 0; k < run; k++)
1012                        if ((j + k) < 128)
1013                            q->sb_samples[ch][j + k][sb] = q->tone_level[ch][sb][(j + k)/2] * samples[k];
1014                }
1015
1016                j += run;
1017            } // j loop
1018        } // channel loop
1019    } // subband loop
1020    return 0;
1021}
1022
1023/**
1024 * Init the first element of a channel in quantized_coeffs with data
1025 * from packet 10 (quantized_coeffs[ch][0]).
1026 * This is similar to process_subpacket_9, but for a single channel
1027 * and for element [0]
1028 * same VLC tables as process_subpacket_9 are used.
1029 *
1030 * @param quantized_coeffs    pointer to quantized_coeffs[ch][0]
1031 * @param gb        bitreader context
1032 */
1033static int init_quantized_coeffs_elem0(int8_t *quantized_coeffs,
1034                                        GetBitContext *gb)
1035{
1036    int i, k, run, level, diff;
1037
1038    if (get_bits_left(gb) < 16)
1039        return -1;
1040    level = qdm2_get_vlc(gb, &vlc_tab_level, 0, 2);
1041
1042    quantized_coeffs[0] = level;
1043
1044    for (i = 0; i < 7; ) {
1045        if (get_bits_left(gb) < 16)
1046            return -1;
1047        run = qdm2_get_vlc(gb, &vlc_tab_run, 0, 1) + 1;
1048
1049        if (i + run >= 8)
1050            return -1;
1051
1052        if (get_bits_left(gb) < 16)
1053            return -1;
1054        diff = qdm2_get_se_vlc(&vlc_tab_diff, gb, 2);
1055
1056        for (k = 1; k <= run; k++)
1057            quantized_coeffs[i + k] = (level + ((k * diff) / run));
1058
1059        level += diff;
1060        i += run;
1061    }
1062    return 0;
1063}
1064
1065/**
1066 * Related to synthesis filter, process data from packet 10
1067 * Init part of quantized_coeffs via function init_quantized_coeffs_elem0
1068 * Init tone_level_idx_hi1, tone_level_idx_hi2, tone_level_idx_mid with
1069 * data from packet 10
1070 *
1071 * @param q         context
1072 * @param gb        bitreader context
1073 */
1074static void init_tone_level_dequantization(QDM2Context *q, GetBitContext *gb)
1075{
1076    int sb, j, k, n, ch;
1077
1078    for (ch = 0; ch < q->nb_channels; ch++) {
1079        init_quantized_coeffs_elem0(q->quantized_coeffs[ch][0], gb);
1080
1081        if (get_bits_left(gb) < 16) {
1082            memset(q->quantized_coeffs[ch][0], 0, 8);
1083            break;
1084        }
1085    }
1086
1087    n = q->sub_sampling + 1;
1088
1089    for (sb = 0; sb < n; sb++)
1090        for (ch = 0; ch < q->nb_channels; ch++)
1091            for (j = 0; j < 8; j++) {
1092                if (get_bits_left(gb) < 1)
1093                    break;
1094                if (get_bits1(gb)) {
1095                    for (k=0; k < 8; k++) {
1096                        if (get_bits_left(gb) < 16)
1097                            break;
1098                        q->tone_level_idx_hi1[ch][sb][j][k] = qdm2_get_vlc(gb, &vlc_tab_tone_level_idx_hi1, 0, 2);
1099                    }
1100                } else {
1101                    for (k=0; k < 8; k++)
1102                        q->tone_level_idx_hi1[ch][sb][j][k] = 0;
1103                }
1104            }
1105
1106    n = QDM2_SB_USED(q->sub_sampling) - 4;
1107
1108    for (sb = 0; sb < n; sb++)
1109        for (ch = 0; ch < q->nb_channels; ch++) {
1110            if (get_bits_left(gb) < 16)
1111                break;
1112            q->tone_level_idx_hi2[ch][sb] = qdm2_get_vlc(gb, &vlc_tab_tone_level_idx_hi2, 0, 2);
1113            if (sb > 19)
1114                q->tone_level_idx_hi2[ch][sb] -= 16;
1115            else
1116                for (j = 0; j < 8; j++)
1117                    q->tone_level_idx_mid[ch][sb][j] = -16;
1118        }
1119
1120    n = QDM2_SB_USED(q->sub_sampling) - 5;
1121
1122    for (sb = 0; sb < n; sb++)
1123        for (ch = 0; ch < q->nb_channels; ch++)
1124            for (j = 0; j < 8; j++) {
1125                if (get_bits_left(gb) < 16)
1126                    break;
1127                q->tone_level_idx_mid[ch][sb][j] = qdm2_get_vlc(gb, &vlc_tab_tone_level_idx_mid, 0, 2) - 32;
1128            }
1129}
1130
1131/**
1132 * Process subpacket 9, init quantized_coeffs with data from it
1133 *
1134 * @param q       context
1135 * @param node    pointer to node with packet
1136 */
1137static int process_subpacket_9(QDM2Context *q, QDM2SubPNode *node)
1138{
1139    GetBitContext gb;
1140    int i, j, k, n, ch, run, level, diff;
1141
1142    init_get_bits(&gb, node->packet->data, node->packet->size * 8);
1143
1144    n = coeff_per_sb_for_avg[q->coeff_per_sb_select][QDM2_SB_USED(q->sub_sampling) - 1] + 1;
1145
1146    for (i = 1; i < n; i++)
1147        for (ch = 0; ch < q->nb_channels; ch++) {
1148            level = qdm2_get_vlc(&gb, &vlc_tab_level, 0, 2);
1149            q->quantized_coeffs[ch][i][0] = level;
1150
1151            for (j = 0; j < (8 - 1); ) {
1152                run  = qdm2_get_vlc(&gb, &vlc_tab_run, 0, 1) + 1;
1153                diff = qdm2_get_se_vlc(&vlc_tab_diff, &gb, 2);
1154
1155                if (j + run >= 8)
1156                    return -1;
1157
1158                for (k = 1; k <= run; k++)
1159                    q->quantized_coeffs[ch][i][j + k] = (level + ((k * diff) / run));
1160
1161                level += diff;
1162                j     += run;
1163            }
1164        }
1165
1166    for (ch = 0; ch < q->nb_channels; ch++)
1167        for (i = 0; i < 8; i++)
1168            q->quantized_coeffs[ch][0][i] = 0;
1169
1170    return 0;
1171}
1172
1173/**
1174 * Process subpacket 10 if not null, else
1175 *
1176 * @param q         context
1177 * @param node      pointer to node with packet
1178 */
1179static void process_subpacket_10(QDM2Context *q, QDM2SubPNode *node)
1180{
1181    GetBitContext gb;
1182
1183    if (node) {
1184        init_get_bits(&gb, node->packet->data, node->packet->size * 8);
1185        init_tone_level_dequantization(q, &gb);
1186        fill_tone_level_array(q, 1);
1187    } else {
1188        fill_tone_level_array(q, 0);
1189    }
1190}
1191
1192/**
1193 * Process subpacket 11
1194 *
1195 * @param q         context
1196 * @param node      pointer to node with packet
1197 */
1198static void process_subpacket_11(QDM2Context *q, QDM2SubPNode *node)
1199{
1200    GetBitContext gb;
1201    int length = 0;
1202
1203    if (node) {
1204        length = node->packet->size * 8;
1205        init_get_bits(&gb, node->packet->data, length);
1206    }
1207
1208    if (length >= 32) {
1209        int c = get_bits(&gb, 13);
1210
1211        if (c > 3)
1212            fill_coding_method_array(q->tone_level_idx,
1213                                     q->tone_level_idx_temp, q->coding_method,
1214                                     q->nb_channels, 8 * c,
1215                                     q->superblocktype_2_3, q->cm_table_select);
1216    }
1217
1218    synthfilt_build_sb_samples(q, &gb, length, 0, 8);
1219}
1220
1221/**
1222 * Process subpacket 12
1223 *
1224 * @param q         context
1225 * @param node      pointer to node with packet
1226 */
1227static void process_subpacket_12(QDM2Context *q, QDM2SubPNode *node)
1228{
1229    GetBitContext gb;
1230    int length = 0;
1231
1232    if (node) {
1233        length = node->packet->size * 8;
1234        init_get_bits(&gb, node->packet->data, length);
1235    }
1236
1237    synthfilt_build_sb_samples(q, &gb, length, 8, QDM2_SB_USED(q->sub_sampling));
1238}
1239
1240/**
1241 * Process new subpackets for synthesis filter
1242 *
1243 * @param q       context
1244 * @param list    list with synthesis filter packets (list D)
1245 */
1246static void process_synthesis_subpackets(QDM2Context *q, QDM2SubPNode *list)
1247{
1248    QDM2SubPNode *nodes[4];
1249
1250    nodes[0] = qdm2_search_subpacket_type_in_list(list, 9);
1251    if (nodes[0] != NULL)
1252        process_subpacket_9(q, nodes[0]);
1253
1254    nodes[1] = qdm2_search_subpacket_type_in_list(list, 10);
1255    if (nodes[1] != NULL)
1256        process_subpacket_10(q, nodes[1]);
1257    else
1258        process_subpacket_10(q, NULL);
1259
1260    nodes[2] = qdm2_search_subpacket_type_in_list(list, 11);
1261    if (nodes[0] != NULL && nodes[1] != NULL && nodes[2] != NULL)
1262        process_subpacket_11(q, nodes[2]);
1263    else
1264        process_subpacket_11(q, NULL);
1265
1266    nodes[3] = qdm2_search_subpacket_type_in_list(list, 12);
1267    if (nodes[0] != NULL && nodes[1] != NULL && nodes[3] != NULL)
1268        process_subpacket_12(q, nodes[3]);
1269    else
1270        process_subpacket_12(q, NULL);
1271}
1272
1273/**
1274 * Decode superblock, fill packet lists.
1275 *
1276 * @param q    context
1277 */
1278static void qdm2_decode_super_block(QDM2Context *q)
1279{
1280    GetBitContext gb;
1281    QDM2SubPacket header, *packet;
1282    int i, packet_bytes, sub_packet_size, sub_packets_D;
1283    unsigned int next_index = 0;
1284
1285    memset(q->tone_level_idx_hi1, 0, sizeof(q->tone_level_idx_hi1));
1286    memset(q->tone_level_idx_mid, 0, sizeof(q->tone_level_idx_mid));
1287    memset(q->tone_level_idx_hi2, 0, sizeof(q->tone_level_idx_hi2));
1288
1289    q->sub_packets_B = 0;
1290    sub_packets_D    = 0;
1291
1292    average_quantized_coeffs(q); // average elements in quantized_coeffs[max_ch][10][8]
1293
1294    init_get_bits(&gb, q->compressed_data, q->compressed_size * 8);
1295    qdm2_decode_sub_packet_header(&gb, &header);
1296
1297    if (header.type < 2 || header.type >= 8) {
1298        q->has_errors = 1;
1299        av_log(NULL, AV_LOG_ERROR, "bad superblock type\n");
1300        return;
1301    }
1302
1303    q->superblocktype_2_3 = (header.type == 2 || header.type == 3);
1304    packet_bytes          = (q->compressed_size - get_bits_count(&gb) / 8);
1305
1306    init_get_bits(&gb, header.data, header.size * 8);
1307
1308    if (header.type == 2 || header.type == 4 || header.type == 5) {
1309        int csum = 257 * get_bits(&gb, 8);
1310        csum += 2 * get_bits(&gb, 8);
1311
1312        csum = qdm2_packet_checksum(q->compressed_data, q->checksum_size, csum);
1313
1314        if (csum != 0) {
1315            q->has_errors = 1;
1316            av_log(NULL, AV_LOG_ERROR, "bad packet checksum\n");
1317            return;
1318        }
1319    }
1320
1321    q->sub_packet_list_B[0].packet = NULL;
1322    q->sub_packet_list_D[0].packet = NULL;
1323
1324    for (i = 0; i < 6; i++)
1325        if (--q->fft_level_exp[i] < 0)
1326            q->fft_level_exp[i] = 0;
1327
1328    for (i = 0; packet_bytes > 0; i++) {
1329        int j;
1330
1331        if (i >= FF_ARRAY_ELEMS(q->sub_packet_list_A)) {
1332            SAMPLES_NEEDED_2("too many packet bytes");
1333            return;
1334        }
1335
1336        q->sub_packet_list_A[i].next = NULL;
1337
1338        if (i > 0) {
1339            q->sub_packet_list_A[i - 1].next = &q->sub_packet_list_A[i];
1340
1341            /* seek to next block */
1342            init_get_bits(&gb, header.data, header.size * 8);
1343            skip_bits(&gb, next_index * 8);
1344
1345            if (next_index >= header.size)
1346                break;
1347        }
1348
1349        /* decode subpacket */
1350        packet = &q->sub_packets[i];
1351        qdm2_decode_sub_packet_header(&gb, packet);
1352        next_index      = packet->size + get_bits_count(&gb) / 8;
1353        sub_packet_size = ((packet->size > 0xff) ? 1 : 0) + packet->size + 2;
1354
1355        if (packet->type == 0)
1356            break;
1357
1358        if (sub_packet_size > packet_bytes) {
1359            if (packet->type != 10 && packet->type != 11 && packet->type != 12)
1360                break;
1361            packet->size += packet_bytes - sub_packet_size;
1362        }
1363
1364        packet_bytes -= sub_packet_size;
1365
1366        /* add subpacket to 'all subpackets' list */
1367        q->sub_packet_list_A[i].packet = packet;
1368
1369        /* add subpacket to related list */
1370        if (packet->type == 8) {
1371            SAMPLES_NEEDED_2("packet type 8");
1372            return;
1373        } else if (packet->type >= 9 && packet->type <= 12) {
1374            /* packets for MPEG Audio like Synthesis Filter */
1375            QDM2_LIST_ADD(q->sub_packet_list_D, sub_packets_D, packet);
1376        } else if (packet->type == 13) {
1377            for (j = 0; j < 6; j++)
1378                q->fft_level_exp[j] = get_bits(&gb, 6);
1379        } else if (packet->type == 14) {
1380            for (j = 0; j < 6; j++)
1381                q->fft_level_exp[j] = qdm2_get_vlc(&gb, &fft_level_exp_vlc, 0, 2);
1382        } else if (packet->type == 15) {
1383            SAMPLES_NEEDED_2("packet type 15")
1384            return;
1385        } else if (packet->type >= 16 && packet->type < 48 &&
1386                   !fft_subpackets[packet->type - 16]) {
1387            /* packets for FFT */
1388            QDM2_LIST_ADD(q->sub_packet_list_B, q->sub_packets_B, packet);
1389        }
1390    } // Packet bytes loop
1391
1392    if (q->sub_packet_list_D[0].packet != NULL) {
1393        process_synthesis_subpackets(q, q->sub_packet_list_D);
1394        q->do_synth_filter = 1;
1395    } else if (q->do_synth_filter) {
1396        process_subpacket_10(q, NULL);
1397        process_subpacket_11(q, NULL);
1398        process_subpacket_12(q, NULL);
1399    }
1400}
1401
1402static void qdm2_fft_init_coefficient(QDM2Context *q, int sub_packet,
1403                                      int offset, int duration, int channel,
1404                                      int exp, int phase)
1405{
1406    if (q->fft_coefs_min_index[duration] < 0)
1407        q->fft_coefs_min_index[duration] = q->fft_coefs_index;
1408
1409    q->fft_coefs[q->fft_coefs_index].sub_packet =
1410        ((sub_packet >= 16) ? (sub_packet - 16) : sub_packet);
1411    q->fft_coefs[q->fft_coefs_index].channel = channel;
1412    q->fft_coefs[q->fft_coefs_index].offset  = offset;
1413    q->fft_coefs[q->fft_coefs_index].exp     = exp;
1414    q->fft_coefs[q->fft_coefs_index].phase   = phase;
1415    q->fft_coefs_index++;
1416}
1417
1418static void qdm2_fft_decode_tones(QDM2Context *q, int duration,
1419                                  GetBitContext *gb, int b)
1420{
1421    int channel, stereo, phase, exp;
1422    int local_int_4, local_int_8, stereo_phase, local_int_10;
1423    int local_int_14, stereo_exp, local_int_20, local_int_28;
1424    int n, offset;
1425
1426    local_int_4  = 0;
1427    local_int_28 = 0;
1428    local_int_20 = 2;
1429    local_int_8  = (4 - duration);
1430    local_int_10 = 1 << (q->group_order - duration - 1);
1431    offset       = 1;
1432
1433    while (get_bits_left(gb)>0) {
1434        if (q->superblocktype_2_3) {
1435            while ((n = qdm2_get_vlc(gb, &vlc_tab_fft_tone_offset[local_int_8], 1, 2)) < 2) {
1436                if (get_bits_left(gb)<0) {
1437                    if(local_int_4 < q->group_size)
1438                        av_log(NULL, AV_LOG_ERROR, "overread in qdm2_fft_decode_tones()\n");
1439                    return;
1440                }
1441                offset = 1;
1442                if (n == 0) {
1443                    local_int_4  += local_int_10;
1444                    local_int_28 += (1 << local_int_8);
1445                } else {
1446                    local_int_4  += 8 * local_int_10;
1447                    local_int_28 += (8 << local_int_8);
1448                }
1449            }
1450            offset += (n - 2);
1451        } else {
1452            offset += qdm2_get_vlc(gb, &vlc_tab_fft_tone_offset[local_int_8], 1, 2);
1453            while (offset >= (local_int_10 - 1)) {
1454                offset       += (1 - (local_int_10 - 1));
1455                local_int_4  += local_int_10;
1456                local_int_28 += (1 << local_int_8);
1457            }
1458        }
1459
1460        if (local_int_4 >= q->group_size)
1461            return;
1462
1463        local_int_14 = (offset >> local_int_8);
1464        if (local_int_14 >= FF_ARRAY_ELEMS(fft_level_index_table))
1465            return;
1466
1467        if (q->nb_channels > 1) {
1468            channel = get_bits1(gb);
1469            stereo  = get_bits1(gb);
1470        } else {
1471            channel = 0;
1472            stereo  = 0;
1473        }
1474
1475        exp  = qdm2_get_vlc(gb, (b ? &fft_level_exp_vlc : &fft_level_exp_alt_vlc), 0, 2);
1476        exp += q->fft_level_exp[fft_level_index_table[local_int_14]];
1477        exp  = (exp < 0) ? 0 : exp;
1478
1479        phase        = get_bits(gb, 3);
1480        stereo_exp   = 0;
1481        stereo_phase = 0;
1482
1483        if (stereo) {
1484            stereo_exp   = (exp - qdm2_get_vlc(gb, &fft_stereo_exp_vlc, 0, 1));
1485            stereo_phase = (phase - qdm2_get_vlc(gb, &fft_stereo_phase_vlc, 0, 1));
1486            if (stereo_phase < 0)
1487                stereo_phase += 8;
1488        }
1489
1490        if (q->frequency_range > (local_int_14 + 1)) {
1491            int sub_packet = (local_int_20 + local_int_28);
1492
1493            qdm2_fft_init_coefficient(q, sub_packet, offset, duration,
1494                                      channel, exp, phase);
1495            if (stereo)
1496                qdm2_fft_init_coefficient(q, sub_packet, offset, duration,
1497                                          1 - channel,
1498                                          stereo_exp, stereo_phase);
1499        }
1500        offset++;
1501    }
1502}
1503
1504static void qdm2_decode_fft_packets(QDM2Context *q)
1505{
1506    int i, j, min, max, value, type, unknown_flag;
1507    GetBitContext gb;
1508
1509    if (q->sub_packet_list_B[0].packet == NULL)
1510        return;
1511
1512    /* reset minimum indexes for FFT coefficients */
1513    q->fft_coefs_index = 0;
1514    for (i = 0; i < 5; i++)
1515        q->fft_coefs_min_index[i] = -1;
1516
1517    /* process subpackets ordered by type, largest type first */
1518    for (i = 0, max = 256; i < q->sub_packets_B; i++) {
1519        QDM2SubPacket *packet = NULL;
1520
1521        /* find subpacket with largest type less than max */
1522        for (j = 0, min = 0; j < q->sub_packets_B; j++) {
1523            value = q->sub_packet_list_B[j].packet->type;
1524            if (value > min && value < max) {
1525                min    = value;
1526                packet = q->sub_packet_list_B[j].packet;
1527            }
1528        }
1529
1530        max = min;
1531
1532        /* check for errors (?) */
1533        if (!packet)
1534            return;
1535
1536        if (i == 0 &&
1537            (packet->type < 16 || packet->type >= 48 ||
1538             fft_subpackets[packet->type - 16]))
1539            return;
1540
1541        /* decode FFT tones */
1542        init_get_bits(&gb, packet->data, packet->size * 8);
1543
1544        if (packet->type >= 32 && packet->type < 48 && !fft_subpackets[packet->type - 16])
1545            unknown_flag = 1;
1546        else
1547            unknown_flag = 0;
1548
1549        type = packet->type;
1550
1551        if ((type >= 17 && type < 24) || (type >= 33 && type < 40)) {
1552            int duration = q->sub_sampling + 5 - (type & 15);
1553
1554            if (duration >= 0 && duration < 4)
1555                qdm2_fft_decode_tones(q, duration, &gb, unknown_flag);
1556        } else if (type == 31) {
1557            for (j = 0; j < 4; j++)
1558                qdm2_fft_decode_tones(q, j, &gb, unknown_flag);
1559        } else if (type == 46) {
1560            for (j = 0; j < 6; j++)
1561                q->fft_level_exp[j] = get_bits(&gb, 6);
1562            for (j = 0; j < 4; j++)
1563                qdm2_fft_decode_tones(q, j, &gb, unknown_flag);
1564        }
1565    } // Loop on B packets
1566
1567    /* calculate maximum indexes for FFT coefficients */
1568    for (i = 0, j = -1; i < 5; i++)
1569        if (q->fft_coefs_min_index[i] >= 0) {
1570            if (j >= 0)
1571                q->fft_coefs_max_index[j] = q->fft_coefs_min_index[i];
1572            j = i;
1573        }
1574    if (j >= 0)
1575        q->fft_coefs_max_index[j] = q->fft_coefs_index;
1576}
1577
1578static void qdm2_fft_generate_tone(QDM2Context *q, FFTTone *tone)
1579{
1580    float level, f[6];
1581    int i;
1582    QDM2Complex c;
1583    const double iscale = 2.0 * M_PI / 512.0;
1584
1585    tone->phase += tone->phase_shift;
1586
1587    /* calculate current level (maximum amplitude) of tone */
1588    level = fft_tone_envelope_table[tone->duration][tone->time_index] * tone->level;
1589    c.im  = level * sin(tone->phase * iscale);
1590    c.re  = level * cos(tone->phase * iscale);
1591
1592    /* generate FFT coefficients for tone */
1593    if (tone->duration >= 3 || tone->cutoff >= 3) {
1594        tone->complex[0].im += c.im;
1595        tone->complex[0].re += c.re;
1596        tone->complex[1].im -= c.im;
1597        tone->complex[1].re -= c.re;
1598    } else {
1599        f[1] = -tone->table[4];
1600        f[0] = tone->table[3] - tone->table[0];
1601        f[2] = 1.0 - tone->table[2] - tone->table[3];
1602        f[3] = tone->table[1] + tone->table[4] - 1.0;
1603        f[4] = tone->table[0] - tone->table[1];
1604        f[5] = tone->table[2];
1605        for (i = 0; i < 2; i++) {
1606            tone->complex[fft_cutoff_index_table[tone->cutoff][i]].re +=
1607                c.re * f[i];
1608            tone->complex[fft_cutoff_index_table[tone->cutoff][i]].im +=
1609                c.im * ((tone->cutoff <= i) ? -f[i] : f[i]);
1610        }
1611        for (i = 0; i < 4; i++) {
1612            tone->complex[i].re += c.re * f[i + 2];
1613            tone->complex[i].im += c.im * f[i + 2];
1614        }
1615    }
1616
1617    /* copy the tone if it has not yet died out */
1618    if (++tone->time_index < ((1 << (5 - tone->duration)) - 1)) {
1619        memcpy(&q->fft_tones[q->fft_tone_end], tone, sizeof(FFTTone));
1620        q->fft_tone_end = (q->fft_tone_end + 1) % 1000;
1621    }
1622}
1623
1624static void qdm2_fft_tone_synthesizer(QDM2Context *q, int sub_packet)
1625{
1626    int i, j, ch;
1627    const double iscale = 0.25 * M_PI;
1628
1629    for (ch = 0; ch < q->channels; ch++) {
1630        memset(q->fft.complex[ch], 0, q->fft_size * sizeof(QDM2Complex));
1631    }
1632
1633
1634    /* apply FFT tones with duration 4 (1 FFT period) */
1635    if (q->fft_coefs_min_index[4] >= 0)
1636        for (i = q->fft_coefs_min_index[4]; i < q->fft_coefs_max_index[4]; i++) {
1637            float level;
1638            QDM2Complex c;
1639
1640            if (q->fft_coefs[i].sub_packet != sub_packet)
1641                break;
1642
1643            ch = (q->channels == 1) ? 0 : q->fft_coefs[i].channel;
1644            level = (q->fft_coefs[i].exp < 0) ? 0.0 : fft_tone_level_table[q->superblocktype_2_3 ? 0 : 1][q->fft_coefs[i].exp & 63];
1645
1646            c.re = level * cos(q->fft_coefs[i].phase * iscale);
1647            c.im = level * sin(q->fft_coefs[i].phase * iscale);
1648            q->fft.complex[ch][q->fft_coefs[i].offset + 0].re += c.re;
1649            q->fft.complex[ch][q->fft_coefs[i].offset + 0].im += c.im;
1650            q->fft.complex[ch][q->fft_coefs[i].offset + 1].re -= c.re;
1651            q->fft.complex[ch][q->fft_coefs[i].offset + 1].im -= c.im;
1652        }
1653
1654    /* generate existing FFT tones */
1655    for (i = q->fft_tone_end; i != q->fft_tone_start; ) {
1656        qdm2_fft_generate_tone(q, &q->fft_tones[q->fft_tone_start]);
1657        q->fft_tone_start = (q->fft_tone_start + 1) % 1000;
1658    }
1659
1660    /* create and generate new FFT tones with duration 0 (long) to 3 (short) */
1661    for (i = 0; i < 4; i++)
1662        if (q->fft_coefs_min_index[i] >= 0) {
1663            for (j = q->fft_coefs_min_index[i]; j < q->fft_coefs_max_index[i]; j++) {
1664                int offset, four_i;
1665                FFTTone tone;
1666
1667                if (q->fft_coefs[j].sub_packet != sub_packet)
1668                    break;
1669
1670                four_i = (4 - i);
1671                offset = q->fft_coefs[j].offset >> four_i;
1672                ch = (q->channels == 1) ? 0 : q->fft_coefs[j].channel;
1673
1674                if (offset < q->frequency_range) {
1675                    if (offset < 2)
1676                        tone.cutoff = offset;
1677                    else
1678                        tone.cutoff = (offset >= 60) ? 3 : 2;
1679
1680                    tone.level = (q->fft_coefs[j].exp < 0) ? 0.0 : fft_tone_level_table[q->superblocktype_2_3 ? 0 : 1][q->fft_coefs[j].exp & 63];
1681                    tone.complex = &q->fft.complex[ch][offset];
1682                    tone.table = fft_tone_sample_table[i][q->fft_coefs[j].offset - (offset << four_i)];
1683                    tone.phase = 64 * q->fft_coefs[j].phase - (offset << 8) - 128;
1684                    tone.phase_shift = (2 * q->fft_coefs[j].offset + 1) << (7 - four_i);
1685                    tone.duration = i;
1686                    tone.time_index = 0;
1687
1688                    qdm2_fft_generate_tone(q, &tone);
1689                }
1690            }
1691            q->fft_coefs_min_index[i] = j;
1692        }
1693}
1694
1695static void qdm2_calculate_fft(QDM2Context *q, int channel, int sub_packet)
1696{
1697    const float gain = (q->channels == 1 && q->nb_channels == 2) ? 0.5f : 1.0f;
1698    float *out       = q->output_buffer + channel;
1699    int i;
1700    q->fft.complex[channel][0].re *= 2.0f;
1701    q->fft.complex[channel][0].im  = 0.0f;
1702    q->rdft_ctx.rdft_calc(&q->rdft_ctx, (FFTSample *)q->fft.complex[channel]);
1703    /* add samples to output buffer */
1704    for (i = 0; i < FFALIGN(q->fft_size, 8); i++) {
1705        out[0]           += q->fft.complex[channel][i].re * gain;
1706        out[q->channels] += q->fft.complex[channel][i].im * gain;
1707        out              += 2 * q->channels;
1708    }
1709}
1710
1711/**
1712 * @param q        context
1713 * @param index    subpacket number
1714 */
1715static void qdm2_synthesis_filter(QDM2Context *q, int index)
1716{
1717    int i, k, ch, sb_used, sub_sampling, dither_state = 0;
1718
1719    /* copy sb_samples */
1720    sb_used = QDM2_SB_USED(q->sub_sampling);
1721
1722    for (ch = 0; ch < q->channels; ch++)
1723        for (i = 0; i < 8; i++)
1724            for (k = sb_used; k < SBLIMIT; k++)
1725                q->sb_samples[ch][(8 * index) + i][k] = 0;
1726
1727    for (ch = 0; ch < q->nb_channels; ch++) {
1728        float *samples_ptr = q->samples + ch;
1729
1730        for (i = 0; i < 8; i++) {
1731            ff_mpa_synth_filter_float(&q->mpadsp,
1732                                      q->synth_buf[ch], &(q->synth_buf_offset[ch]),
1733                                      ff_mpa_synth_window_float, &dither_state,
1734                                      samples_ptr, q->nb_channels,
1735                                      q->sb_samples[ch][(8 * index) + i]);
1736            samples_ptr += 32 * q->nb_channels;
1737        }
1738    }
1739
1740    /* add samples to output buffer */
1741    sub_sampling = (4 >> q->sub_sampling);
1742
1743    for (ch = 0; ch < q->channels; ch++)
1744        for (i = 0; i < q->frame_size; i++)
1745            q->output_buffer[q->channels * i + ch] += (1 << 23) * q->samples[q->nb_channels * sub_sampling * i + ch];
1746}
1747
1748/**
1749 * Init static data (does not depend on specific file)
1750 *
1751 * @param q    context
1752 */
1753static av_cold void qdm2_init_static_data(void) {
1754    static int done;
1755
1756    if(done)
1757        return;
1758
1759    qdm2_init_vlc();
1760    ff_mpa_synth_init_float(ff_mpa_synth_window_float);
1761    softclip_table_init();
1762    rnd_table_init();
1763    init_noise_samples();
1764
1765    done = 1;
1766}
1767
1768/**
1769 * Init parameters from codec extradata
1770 */
1771static av_cold int qdm2_decode_init(AVCodecContext *avctx)
1772{
1773    QDM2Context *s = avctx->priv_data;
1774    uint8_t *extradata;
1775    int extradata_size;
1776    int tmp_val, tmp, size;
1777
1778    qdm2_init_static_data();
1779
1780    /* extradata parsing
1781
1782    Structure:
1783    wave {
1784        frma (QDM2)
1785        QDCA
1786        QDCP
1787    }
1788
1789    32  size (including this field)
1790    32  tag (=frma)
1791    32  type (=QDM2 or QDMC)
1792
1793    32  size (including this field, in bytes)
1794    32  tag (=QDCA) // maybe mandatory parameters
1795    32  unknown (=1)
1796    32  channels (=2)
1797    32  samplerate (=44100)
1798    32  bitrate (=96000)
1799    32  block size (=4096)
1800    32  frame size (=256) (for one channel)
1801    32  packet size (=1300)
1802
1803    32  size (including this field, in bytes)
1804    32  tag (=QDCP) // maybe some tuneable parameters
1805    32  float1 (=1.0)
1806    32  zero ?
1807    32  float2 (=1.0)
1808    32  float3 (=1.0)
1809    32  unknown (27)
1810    32  unknown (8)
1811    32  zero ?
1812    */
1813
1814    if (!avctx->extradata || (avctx->extradata_size < 48)) {
1815        av_log(avctx, AV_LOG_ERROR, "extradata missing or truncated\n");
1816        return -1;
1817    }
1818
1819    extradata      = avctx->extradata;
1820    extradata_size = avctx->extradata_size;
1821
1822    while (extradata_size > 7) {
1823        if (!memcmp(extradata, "frmaQDM", 7))
1824            break;
1825        extradata++;
1826        extradata_size--;
1827    }
1828
1829    if (extradata_size < 12) {
1830        av_log(avctx, AV_LOG_ERROR, "not enough extradata (%i)\n",
1831               extradata_size);
1832        return -1;
1833    }
1834
1835    if (memcmp(extradata, "frmaQDM", 7)) {
1836        av_log(avctx, AV_LOG_ERROR, "invalid headers, QDM? not found\n");
1837        return -1;
1838    }
1839
1840    if (extradata[7] == 'C') {
1841//        s->is_qdmc = 1;
1842        av_log(avctx, AV_LOG_ERROR, "stream is QDMC version 1, which is not supported\n");
1843        return -1;
1844    }
1845
1846    extradata += 8;
1847    extradata_size -= 8;
1848
1849    size = AV_RB32(extradata);
1850
1851    if(size > extradata_size){
1852        av_log(avctx, AV_LOG_ERROR, "extradata size too small, %i < %i\n",
1853               extradata_size, size);
1854        return -1;
1855    }
1856
1857    extradata += 4;
1858    av_log(avctx, AV_LOG_DEBUG, "size: %d\n", size);
1859    if (AV_RB32(extradata) != MKBETAG('Q','D','C','A')) {
1860        av_log(avctx, AV_LOG_ERROR, "invalid extradata, expecting QDCA\n");
1861        return -1;
1862    }
1863
1864    extradata += 8;
1865
1866    avctx->channels = s->nb_channels = s->channels = AV_RB32(extradata);
1867    extradata += 4;
1868    if (s->channels <= 0 || s->channels > MPA_MAX_CHANNELS) {
1869        av_log(avctx, AV_LOG_ERROR, "Invalid number of channels\n");
1870        return AVERROR_INVALIDDATA;
1871    }
1872    avctx->channel_layout = avctx->channels == 2 ? AV_CH_LAYOUT_STEREO :
1873                                                   AV_CH_LAYOUT_MONO;
1874
1875    avctx->sample_rate = AV_RB32(extradata);
1876    extradata += 4;
1877
1878    avctx->bit_rate = AV_RB32(extradata);
1879    extradata += 4;
1880
1881    s->group_size = AV_RB32(extradata);
1882    extradata += 4;
1883
1884    s->fft_size = AV_RB32(extradata);
1885    extradata += 4;
1886
1887    s->checksum_size = AV_RB32(extradata);
1888    if (s->checksum_size >= 1U << 28) {
1889        av_log(avctx, AV_LOG_ERROR, "data block size too large (%u)\n", s->checksum_size);
1890        return AVERROR_INVALIDDATA;
1891    }
1892
1893    s->fft_order = av_log2(s->fft_size) + 1;
1894
1895    // something like max decodable tones
1896    s->group_order = av_log2(s->group_size) + 1;
1897    s->frame_size = s->group_size / 16; // 16 iterations per super block
1898
1899    if (s->frame_size > QDM2_MAX_FRAME_SIZE)
1900        return AVERROR_INVALIDDATA;
1901
1902    s->sub_sampling = s->fft_order - 7;
1903    s->frequency_range = 255 / (1 << (2 - s->sub_sampling));
1904
1905    switch ((s->sub_sampling * 2 + s->channels - 1)) {
1906        case 0: tmp = 40; break;
1907        case 1: tmp = 48; break;
1908        case 2: tmp = 56; break;
1909        case 3: tmp = 72; break;
1910        case 4: tmp = 80; break;
1911        case 5: tmp = 100;break;
1912        default: tmp=s->sub_sampling; break;
1913    }
1914    tmp_val = 0;
1915    if ((tmp * 1000) < avctx->bit_rate)  tmp_val = 1;
1916    if ((tmp * 1440) < avctx->bit_rate)  tmp_val = 2;
1917    if ((tmp * 1760) < avctx->bit_rate)  tmp_val = 3;
1918    if ((tmp * 2240) < avctx->bit_rate)  tmp_val = 4;
1919    s->cm_table_select = tmp_val;
1920
1921    if (avctx->bit_rate <= 8000)
1922        s->coeff_per_sb_select = 0;
1923    else if (avctx->bit_rate < 16000)
1924        s->coeff_per_sb_select = 1;
1925    else
1926        s->coeff_per_sb_select = 2;
1927
1928    // Fail on unknown fft order
1929    if ((s->fft_order < 7) || (s->fft_order > 9)) {
1930        av_log(avctx, AV_LOG_ERROR, "Unknown FFT order (%d), contact the developers!\n", s->fft_order);
1931        return -1;
1932    }
1933    if (s->fft_size != (1 << (s->fft_order - 1))) {
1934        av_log(avctx, AV_LOG_ERROR, "FFT size %d not power of 2.\n", s->fft_size);
1935        return AVERROR_INVALIDDATA;
1936    }
1937
1938    ff_rdft_init(&s->rdft_ctx, s->fft_order, IDFT_C2R);
1939    ff_mpadsp_init(&s->mpadsp);
1940
1941    avctx->sample_fmt = AV_SAMPLE_FMT_S16;
1942
1943    return 0;
1944}
1945
1946static av_cold int qdm2_decode_close(AVCodecContext *avctx)
1947{
1948    QDM2Context *s = avctx->priv_data;
1949
1950    ff_rdft_end(&s->rdft_ctx);
1951
1952    return 0;
1953}
1954
1955static int qdm2_decode(QDM2Context *q, const uint8_t *in, int16_t *out)
1956{
1957    int ch, i;
1958    const int frame_size = (q->frame_size * q->channels);
1959
1960    if((unsigned)frame_size > FF_ARRAY_ELEMS(q->output_buffer)/2)
1961        return -1;
1962
1963    /* select input buffer */
1964    q->compressed_data = in;
1965    q->compressed_size = q->checksum_size;
1966
1967    /* copy old block, clear new block of output samples */
1968    memmove(q->output_buffer, &q->output_buffer[frame_size], frame_size * sizeof(float));
1969    memset(&q->output_buffer[frame_size], 0, frame_size * sizeof(float));
1970
1971    /* decode block of QDM2 compressed data */
1972    if (q->sub_packet == 0) {
1973        q->has_errors = 0; // zero it for a new super block
1974        av_log(NULL,AV_LOG_DEBUG,"Superblock follows\n");
1975        qdm2_decode_super_block(q);
1976    }
1977
1978    /* parse subpackets */
1979    if (!q->has_errors) {
1980        if (q->sub_packet == 2)
1981            qdm2_decode_fft_packets(q);
1982
1983        qdm2_fft_tone_synthesizer(q, q->sub_packet);
1984    }
1985
1986    /* sound synthesis stage 1 (FFT) */
1987    for (ch = 0; ch < q->channels; ch++) {
1988        qdm2_calculate_fft(q, ch, q->sub_packet);
1989
1990        if (!q->has_errors && q->sub_packet_list_C[0].packet != NULL) {
1991            SAMPLES_NEEDED_2("has errors, and C list is not empty")
1992            return -1;
1993        }
1994    }
1995
1996    /* sound synthesis stage 2 (MPEG audio like synthesis filter) */
1997    if (!q->has_errors && q->do_synth_filter)
1998        qdm2_synthesis_filter(q, q->sub_packet);
1999
2000    q->sub_packet = (q->sub_packet + 1) % 16;
2001
2002    /* clip and convert output float[] to 16bit signed samples */
2003    for (i = 0; i < frame_size; i++) {
2004        int value = (int)q->output_buffer[i];
2005
2006        if (value > SOFTCLIP_THRESHOLD)
2007            value = (value >  HARDCLIP_THRESHOLD) ?  32767 :  softclip_table[ value - SOFTCLIP_THRESHOLD];
2008        else if (value < -SOFTCLIP_THRESHOLD)
2009            value = (value < -HARDCLIP_THRESHOLD) ? -32767 : -softclip_table[-value - SOFTCLIP_THRESHOLD];
2010
2011        out[i] = value;
2012    }
2013
2014    return 0;
2015}
2016
2017static int qdm2_decode_frame(AVCodecContext *avctx, void *data,
2018                             int *got_frame_ptr, AVPacket *avpkt)
2019{
2020    AVFrame *frame     = data;
2021    const uint8_t *buf = avpkt->data;
2022    int buf_size = avpkt->size;
2023    QDM2Context *s = avctx->priv_data;
2024    int16_t *out;
2025    int i, ret;
2026
2027    if(!buf)
2028        return 0;
2029    if(buf_size < s->checksum_size)
2030        return -1;
2031
2032    /* get output buffer */
2033    frame->nb_samples = 16 * s->frame_size;
2034    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
2035        return ret;
2036    out = (int16_t *)frame->data[0];
2037
2038    for (i = 0; i < 16; i++) {
2039        if (qdm2_decode(s, buf, out) < 0)
2040            return -1;
2041        out += s->channels * s->frame_size;
2042    }
2043
2044    *got_frame_ptr = 1;
2045
2046    return s->checksum_size;
2047}
2048
2049AVCodec ff_qdm2_decoder = {
2050    .name             = "qdm2",
2051    .long_name        = NULL_IF_CONFIG_SMALL("QDesign Music Codec 2"),
2052    .type             = AVMEDIA_TYPE_AUDIO,
2053    .id               = AV_CODEC_ID_QDM2,
2054    .priv_data_size   = sizeof(QDM2Context),
2055    .init             = qdm2_decode_init,
2056    .close            = qdm2_decode_close,
2057    .decode           = qdm2_decode_frame,
2058    .capabilities     = CODEC_CAP_DR1,
2059};
2060