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 libavcodec/qdm2.c
27 * QDM2 decoder
28 * @author Ewald Snel, Benjamin Larsson, Alex Beregszaszi, Roberto Togni
29 * The decoder is not perfect yet, there are still some distortions
30 * especially on files encoded with 16 or 8 subbands.
31 */
32
33#include <math.h>
34#include <stddef.h>
35#include <stdio.h>
36
37#define ALT_BITSTREAM_READER_LE
38#include "avcodec.h"
39#include "bitstream.h"
40#include "dsputil.h"
41#include "mpegaudio.h"
42
43#include "qdm2data.h"
44
45#undef NDEBUG
46#include <assert.h>
47
48
49#define SOFTCLIP_THRESHOLD 27600
50#define HARDCLIP_THRESHOLD 35716
51
52
53#define QDM2_LIST_ADD(list, size, packet) \
54do { \
55      if (size > 0) { \
56    list[size - 1].next = &list[size]; \
57      } \
58      list[size].packet = packet; \
59      list[size].next = NULL; \
60      size++; \
61} while(0)
62
63// Result is 8, 16 or 30
64#define QDM2_SB_USED(sub_sampling) (((sub_sampling) >= 2) ? 30 : 8 << (sub_sampling))
65
66#define FIX_NOISE_IDX(noise_idx) \
67  if ((noise_idx) >= 3840) \
68    (noise_idx) -= 3840; \
69
70#define SB_DITHERING_NOISE(sb,noise_idx) (noise_table[(noise_idx)++] * sb_noise_attenuation[(sb)])
71
72#define BITS_LEFT(length,gb) ((length) - get_bits_count ((gb)))
73
74#define SAMPLES_NEEDED \
75     av_log (NULL,AV_LOG_INFO,"This file triggers some untested code. Please contact the developers.\n");
76
77#define SAMPLES_NEEDED_2(why) \
78     av_log (NULL,AV_LOG_INFO,"This file triggers some missing code. Please contact the developers.\nPosition: %s\n",why);
79
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_16(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 fft_frame_size;      ///< size of fft frame, in components (1 comples = re + im)
143    int frame_size;          ///< size of data frame
144    int frequency_range;
145    int sub_sampling;        ///< subsampling: 0=25%, 1=50%, 2=100% */
146    int coeff_per_sb_select; ///< selector for "num. of coeffs. per subband" tables. Can be 0, 1, 2
147    int cm_table_select;     ///< selector for "coding method" tables. Can be 0, 1 (from init: 0-4)
148
149    /// Packets and packet lists
150    QDM2SubPacket sub_packets[16];      ///< the packets themselves
151    QDM2SubPNode sub_packet_list_A[16]; ///< list of all packets
152    QDM2SubPNode sub_packet_list_B[16]; ///< FFT packets B are on list
153    int sub_packets_B;                  ///< number of packets on 'B' list
154    QDM2SubPNode sub_packet_list_C[16]; ///< packets with errors?
155    QDM2SubPNode sub_packet_list_D[16]; ///< DCT packets
156
157    /// FFT and tones
158    FFTTone fft_tones[1000];
159    int fft_tone_start;
160    int fft_tone_end;
161    FFTCoefficient fft_coefs[1000];
162    int fft_coefs_index;
163    int fft_coefs_min_index[5];
164    int fft_coefs_max_index[5];
165    int fft_level_exp[6];
166    RDFTContext rdft_ctx;
167    QDM2FFT fft;
168
169    /// I/O data
170    const uint8_t *compressed_data;
171    int compressed_size;
172    float output_buffer[1024];
173
174    /// Synthesis filter
175    DECLARE_ALIGNED_16(MPA_INT, synth_buf[MPA_MAX_CHANNELS][512*2]);
176    int synth_buf_offset[MPA_MAX_CHANNELS];
177    DECLARE_ALIGNED_16(int32_t, sb_samples[MPA_MAX_CHANNELS][128][SBLIMIT]);
178
179    /// Mixed temporary data used in decoding
180    float tone_level[MPA_MAX_CHANNELS][30][64];
181    int8_t coding_method[MPA_MAX_CHANNELS][30][64];
182    int8_t quantized_coeffs[MPA_MAX_CHANNELS][10][8];
183    int8_t tone_level_idx_base[MPA_MAX_CHANNELS][30][8];
184    int8_t tone_level_idx_hi1[MPA_MAX_CHANNELS][3][8][8];
185    int8_t tone_level_idx_mid[MPA_MAX_CHANNELS][26][8];
186    int8_t tone_level_idx_hi2[MPA_MAX_CHANNELS][26];
187    int8_t tone_level_idx[MPA_MAX_CHANNELS][30][64];
188    int8_t tone_level_idx_temp[MPA_MAX_CHANNELS][30][64];
189
190    // Flags
191    int has_errors;         ///< packet has errors
192    int superblocktype_2_3; ///< select fft tables and some algorithm based on superblock type
193    int do_synth_filter;    ///< used to perform or skip synthesis filter
194
195    int sub_packet;
196    int noise_idx; ///< index for dithering noise table
197} QDM2Context;
198
199
200static uint8_t empty_buffer[FF_INPUT_BUFFER_PADDING_SIZE];
201
202static VLC vlc_tab_level;
203static VLC vlc_tab_diff;
204static VLC vlc_tab_run;
205static VLC fft_level_exp_alt_vlc;
206static VLC fft_level_exp_vlc;
207static VLC fft_stereo_exp_vlc;
208static VLC fft_stereo_phase_vlc;
209static VLC vlc_tab_tone_level_idx_hi1;
210static VLC vlc_tab_tone_level_idx_mid;
211static VLC vlc_tab_tone_level_idx_hi2;
212static VLC vlc_tab_type30;
213static VLC vlc_tab_type34;
214static VLC vlc_tab_fft_tone_offset[5];
215
216static uint16_t softclip_table[HARDCLIP_THRESHOLD - SOFTCLIP_THRESHOLD + 1];
217static float noise_table[4096];
218static uint8_t random_dequant_index[256][5];
219static uint8_t random_dequant_type24[128][3];
220static float noise_samples[128];
221
222static DECLARE_ALIGNED_16(MPA_INT, mpa_window[512]);
223
224
225static av_cold void softclip_table_init(void) {
226    int i;
227    double dfl = SOFTCLIP_THRESHOLD - 32767;
228    float delta = 1.0 / -dfl;
229    for (i = 0; i < HARDCLIP_THRESHOLD - SOFTCLIP_THRESHOLD + 1; i++)
230        softclip_table[i] = SOFTCLIP_THRESHOLD - ((int)(sin((float)i * delta) * dfl) & 0x0000FFFF);
231}
232
233
234// random generated table
235static av_cold void rnd_table_init(void) {
236    int i,j;
237    uint32_t ldw,hdw;
238    uint64_t tmp64_1;
239    uint64_t random_seed = 0;
240    float delta = 1.0 / 16384.0;
241    for(i = 0; i < 4096 ;i++) {
242        random_seed = random_seed * 214013 + 2531011;
243        noise_table[i] = (delta * (float)(((int32_t)random_seed >> 16) & 0x00007FFF)- 1.0) * 1.3;
244    }
245
246    for (i = 0; i < 256 ;i++) {
247        random_seed = 81;
248        ldw = i;
249        for (j = 0; j < 5 ;j++) {
250            random_dequant_index[i][j] = (uint8_t)((ldw / random_seed) & 0xFF);
251            ldw = (uint32_t)ldw % (uint32_t)random_seed;
252            tmp64_1 = (random_seed * 0x55555556);
253            hdw = (uint32_t)(tmp64_1 >> 32);
254            random_seed = (uint64_t)(hdw + (ldw >> 31));
255        }
256    }
257    for (i = 0; i < 128 ;i++) {
258        random_seed = 25;
259        ldw = i;
260        for (j = 0; j < 3 ;j++) {
261            random_dequant_type24[i][j] = (uint8_t)((ldw / random_seed) & 0xFF);
262            ldw = (uint32_t)ldw % (uint32_t)random_seed;
263            tmp64_1 = (random_seed * 0x66666667);
264            hdw = (uint32_t)(tmp64_1 >> 33);
265            random_seed = hdw + (ldw >> 31);
266        }
267    }
268}
269
270
271static av_cold void init_noise_samples(void) {
272    int i;
273    int random_seed = 0;
274    float delta = 1.0 / 16384.0;
275    for (i = 0; i < 128;i++) {
276        random_seed = random_seed * 214013 + 2531011;
277        noise_samples[i] = (delta * (float)((random_seed >> 16) & 0x00007fff) - 1.0);
278    }
279}
280
281
282static av_cold void qdm2_init_vlc(void)
283{
284    init_vlc (&vlc_tab_level, 8, 24,
285        vlc_tab_level_huffbits, 1, 1,
286        vlc_tab_level_huffcodes, 2, 2, INIT_VLC_USE_STATIC | INIT_VLC_LE);
287
288    init_vlc (&vlc_tab_diff, 8, 37,
289        vlc_tab_diff_huffbits, 1, 1,
290        vlc_tab_diff_huffcodes, 2, 2, INIT_VLC_USE_STATIC | INIT_VLC_LE);
291
292    init_vlc (&vlc_tab_run, 5, 6,
293        vlc_tab_run_huffbits, 1, 1,
294        vlc_tab_run_huffcodes, 1, 1, INIT_VLC_USE_STATIC | INIT_VLC_LE);
295
296    init_vlc (&fft_level_exp_alt_vlc, 8, 28,
297        fft_level_exp_alt_huffbits, 1, 1,
298        fft_level_exp_alt_huffcodes, 2, 2, INIT_VLC_USE_STATIC | INIT_VLC_LE);
299
300    init_vlc (&fft_level_exp_vlc, 8, 20,
301        fft_level_exp_huffbits, 1, 1,
302        fft_level_exp_huffcodes, 2, 2, INIT_VLC_USE_STATIC | INIT_VLC_LE);
303
304    init_vlc (&fft_stereo_exp_vlc, 6, 7,
305        fft_stereo_exp_huffbits, 1, 1,
306        fft_stereo_exp_huffcodes, 1, 1, INIT_VLC_USE_STATIC | INIT_VLC_LE);
307
308    init_vlc (&fft_stereo_phase_vlc, 6, 9,
309        fft_stereo_phase_huffbits, 1, 1,
310        fft_stereo_phase_huffcodes, 1, 1, INIT_VLC_USE_STATIC | INIT_VLC_LE);
311
312    init_vlc (&vlc_tab_tone_level_idx_hi1, 8, 20,
313        vlc_tab_tone_level_idx_hi1_huffbits, 1, 1,
314        vlc_tab_tone_level_idx_hi1_huffcodes, 2, 2, INIT_VLC_USE_STATIC | INIT_VLC_LE);
315
316    init_vlc (&vlc_tab_tone_level_idx_mid, 8, 24,
317        vlc_tab_tone_level_idx_mid_huffbits, 1, 1,
318        vlc_tab_tone_level_idx_mid_huffcodes, 2, 2, INIT_VLC_USE_STATIC | INIT_VLC_LE);
319
320    init_vlc (&vlc_tab_tone_level_idx_hi2, 8, 24,
321        vlc_tab_tone_level_idx_hi2_huffbits, 1, 1,
322        vlc_tab_tone_level_idx_hi2_huffcodes, 2, 2, INIT_VLC_USE_STATIC | INIT_VLC_LE);
323
324    init_vlc (&vlc_tab_type30, 6, 9,
325        vlc_tab_type30_huffbits, 1, 1,
326        vlc_tab_type30_huffcodes, 1, 1, INIT_VLC_USE_STATIC | INIT_VLC_LE);
327
328    init_vlc (&vlc_tab_type34, 5, 10,
329        vlc_tab_type34_huffbits, 1, 1,
330        vlc_tab_type34_huffcodes, 1, 1, INIT_VLC_USE_STATIC | INIT_VLC_LE);
331
332    init_vlc (&vlc_tab_fft_tone_offset[0], 8, 23,
333        vlc_tab_fft_tone_offset_0_huffbits, 1, 1,
334        vlc_tab_fft_tone_offset_0_huffcodes, 2, 2, INIT_VLC_USE_STATIC | INIT_VLC_LE);
335
336    init_vlc (&vlc_tab_fft_tone_offset[1], 8, 28,
337        vlc_tab_fft_tone_offset_1_huffbits, 1, 1,
338        vlc_tab_fft_tone_offset_1_huffcodes, 2, 2, INIT_VLC_USE_STATIC | INIT_VLC_LE);
339
340    init_vlc (&vlc_tab_fft_tone_offset[2], 8, 32,
341        vlc_tab_fft_tone_offset_2_huffbits, 1, 1,
342        vlc_tab_fft_tone_offset_2_huffcodes, 2, 2, INIT_VLC_USE_STATIC | INIT_VLC_LE);
343
344    init_vlc (&vlc_tab_fft_tone_offset[3], 8, 35,
345        vlc_tab_fft_tone_offset_3_huffbits, 1, 1,
346        vlc_tab_fft_tone_offset_3_huffcodes, 2, 2, INIT_VLC_USE_STATIC | INIT_VLC_LE);
347
348    init_vlc (&vlc_tab_fft_tone_offset[4], 8, 38,
349        vlc_tab_fft_tone_offset_4_huffbits, 1, 1,
350        vlc_tab_fft_tone_offset_4_huffcodes, 2, 2, INIT_VLC_USE_STATIC | INIT_VLC_LE);
351}
352
353
354/* for floating point to fixed point conversion */
355static const float f2i_scale = (float) (1 << (FRAC_BITS - 15));
356
357
358static int qdm2_get_vlc (GetBitContext *gb, VLC *vlc, int flag, int depth)
359{
360    int value;
361
362    value = get_vlc2(gb, vlc->table, vlc->bits, depth);
363
364    /* stage-2, 3 bits exponent escape sequence */
365    if (value-- == 0)
366        value = get_bits (gb, get_bits (gb, 3) + 1);
367
368    /* stage-3, optional */
369    if (flag) {
370        int tmp = vlc_stage3_values[value];
371
372        if ((value & ~3) > 0)
373            tmp += get_bits (gb, (value >> 2));
374        value = tmp;
375    }
376
377    return value;
378}
379
380
381static int qdm2_get_se_vlc (VLC *vlc, GetBitContext *gb, int depth)
382{
383    int value = qdm2_get_vlc (gb, vlc, 0, depth);
384
385    return (value & 1) ? ((value + 1) >> 1) : -(value >> 1);
386}
387
388
389/**
390 * QDM2 checksum
391 *
392 * @param data      pointer to data to be checksum'ed
393 * @param length    data length
394 * @param value     checksum value
395 *
396 * @return          0 if checksum is OK
397 */
398static uint16_t qdm2_packet_checksum (const uint8_t *data, int length, int value) {
399    int i;
400
401    for (i=0; i < length; i++)
402        value -= data[i];
403
404    return (uint16_t)(value & 0xffff);
405}
406
407
408/**
409 * Fills a QDM2SubPacket structure with packet type, size, and data pointer.
410 *
411 * @param gb            bitreader context
412 * @param sub_packet    packet under analysis
413 */
414static void qdm2_decode_sub_packet_header (GetBitContext *gb, QDM2SubPacket *sub_packet)
415{
416    sub_packet->type = get_bits (gb, 8);
417
418    if (sub_packet->type == 0) {
419        sub_packet->size = 0;
420        sub_packet->data = NULL;
421    } else {
422        sub_packet->size = get_bits (gb, 8);
423
424      if (sub_packet->type & 0x80) {
425          sub_packet->size <<= 8;
426          sub_packet->size  |= get_bits (gb, 8);
427          sub_packet->type  &= 0x7f;
428      }
429
430      if (sub_packet->type == 0x7f)
431          sub_packet->type |= (get_bits (gb, 8) << 8);
432
433      sub_packet->data = &gb->buffer[get_bits_count(gb) / 8]; // FIXME: this depends on bitreader internal data
434    }
435
436    av_log(NULL,AV_LOG_DEBUG,"Subpacket: type=%d size=%d start_offs=%x\n",
437        sub_packet->type, sub_packet->size, get_bits_count(gb) / 8);
438}
439
440
441/**
442 * Return node pointer to first packet of requested type in list.
443 *
444 * @param list    list of subpackets to be scanned
445 * @param type    type of searched subpacket
446 * @return        node pointer for subpacket if found, else NULL
447 */
448static QDM2SubPNode* qdm2_search_subpacket_type_in_list (QDM2SubPNode *list, int type)
449{
450    while (list != NULL && list->packet != NULL) {
451        if (list->packet->type == type)
452            return list;
453        list = list->next;
454    }
455    return NULL;
456}
457
458
459/**
460 * Replaces 8 elements with their average value.
461 * Called by qdm2_decode_superblock before starting subblock decoding.
462 *
463 * @param q       context
464 */
465static void average_quantized_coeffs (QDM2Context *q)
466{
467    int i, j, n, ch, sum;
468
469    n = coeff_per_sb_for_avg[q->coeff_per_sb_select][QDM2_SB_USED(q->sub_sampling) - 1] + 1;
470
471    for (ch = 0; ch < q->nb_channels; ch++)
472        for (i = 0; i < n; i++) {
473            sum = 0;
474
475            for (j = 0; j < 8; j++)
476                sum += q->quantized_coeffs[ch][i][j];
477
478            sum /= 8;
479            if (sum > 0)
480                sum--;
481
482            for (j=0; j < 8; j++)
483                q->quantized_coeffs[ch][i][j] = sum;
484        }
485}
486
487
488/**
489 * Build subband samples with noise weighted by q->tone_level.
490 * Called by synthfilt_build_sb_samples.
491 *
492 * @param q     context
493 * @param sb    subband index
494 */
495static void build_sb_samples_from_noise (QDM2Context *q, int sb)
496{
497    int ch, j;
498
499    FIX_NOISE_IDX(q->noise_idx);
500
501    if (!q->nb_channels)
502        return;
503
504    for (ch = 0; ch < q->nb_channels; ch++)
505        for (j = 0; j < 64; j++) {
506            q->sb_samples[ch][j * 2][sb] = (int32_t)(f2i_scale * SB_DITHERING_NOISE(sb,q->noise_idx) * q->tone_level[ch][sb][j] + .5);
507            q->sb_samples[ch][j * 2 + 1][sb] = (int32_t)(f2i_scale * SB_DITHERING_NOISE(sb,q->noise_idx) * q->tone_level[ch][sb][j] + .5);
508        }
509}
510
511
512/**
513 * Called while processing data from subpackets 11 and 12.
514 * Used after making changes to coding_method array.
515 *
516 * @param sb               subband index
517 * @param channels         number of channels
518 * @param coding_method    q->coding_method[0][0][0]
519 */
520static void fix_coding_method_array (int sb, int channels, sb_int8_array coding_method)
521{
522    int j,k;
523    int ch;
524    int run, case_val;
525    int switchtable[23] = {0,5,1,5,5,5,5,5,2,5,5,5,5,5,5,5,3,5,5,5,5,5,4};
526
527    for (ch = 0; ch < channels; ch++) {
528        for (j = 0; j < 64; ) {
529            if((coding_method[ch][sb][j] - 8) > 22) {
530                run = 1;
531                case_val = 8;
532            } else {
533                switch (switchtable[coding_method[ch][sb][j]-8]) {
534                    case 0: run = 10; case_val = 10; break;
535                    case 1: run = 1; case_val = 16; break;
536                    case 2: run = 5; case_val = 24; break;
537                    case 3: run = 3; case_val = 30; break;
538                    case 4: run = 1; case_val = 30; break;
539                    case 5: run = 1; case_val = 8; break;
540                    default: run = 1; case_val = 8; break;
541                }
542            }
543            for (k = 0; k < run; k++)
544                if (j + k < 128)
545                    if (coding_method[ch][sb + (j + k) / 64][(j + k) % 64] > coding_method[ch][sb][j])
546                        if (k > 0) {
547                           SAMPLES_NEEDED
548                            //not debugged, almost never used
549                            memset(&coding_method[ch][sb][j + k], case_val, k * sizeof(int8_t));
550                            memset(&coding_method[ch][sb][j + k], case_val, 3 * sizeof(int8_t));
551                        }
552            j += run;
553        }
554    }
555}
556
557
558/**
559 * Related to synthesis filter
560 * Called by process_subpacket_10
561 *
562 * @param q       context
563 * @param flag    1 if called after getting data from subpacket 10, 0 if no subpacket 10
564 */
565static void fill_tone_level_array (QDM2Context *q, int flag)
566{
567    int i, sb, ch, sb_used;
568    int tmp, tab;
569
570    // This should never happen
571    if (q->nb_channels <= 0)
572        return;
573
574    for (ch = 0; ch < q->nb_channels; ch++)
575        for (sb = 0; sb < 30; sb++)
576            for (i = 0; i < 8; i++) {
577                if ((tab=coeff_per_sb_for_dequant[q->coeff_per_sb_select][sb]) < (last_coeff[q->coeff_per_sb_select] - 1))
578                    tmp = q->quantized_coeffs[ch][tab + 1][i] * dequant_table[q->coeff_per_sb_select][tab + 1][sb]+
579                          q->quantized_coeffs[ch][tab][i] * dequant_table[q->coeff_per_sb_select][tab][sb];
580                else
581                    tmp = q->quantized_coeffs[ch][tab][i] * dequant_table[q->coeff_per_sb_select][tab][sb];
582                if(tmp < 0)
583                    tmp += 0xff;
584                q->tone_level_idx_base[ch][sb][i] = (tmp / 256) & 0xff;
585            }
586
587    sb_used = QDM2_SB_USED(q->sub_sampling);
588
589    if ((q->superblocktype_2_3 != 0) && !flag) {
590        for (sb = 0; sb < sb_used; sb++)
591            for (ch = 0; ch < q->nb_channels; ch++)
592                for (i = 0; i < 64; i++) {
593                    q->tone_level_idx[ch][sb][i] = q->tone_level_idx_base[ch][sb][i / 8];
594                    if (q->tone_level_idx[ch][sb][i] < 0)
595                        q->tone_level[ch][sb][i] = 0;
596                    else
597                        q->tone_level[ch][sb][i] = fft_tone_level_table[0][q->tone_level_idx[ch][sb][i] & 0x3f];
598                }
599    } else {
600        tab = q->superblocktype_2_3 ? 0 : 1;
601        for (sb = 0; sb < sb_used; sb++) {
602            if ((sb >= 4) && (sb <= 23)) {
603                for (ch = 0; ch < q->nb_channels; ch++)
604                    for (i = 0; i < 64; i++) {
605                        tmp = q->tone_level_idx_base[ch][sb][i / 8] -
606                              q->tone_level_idx_hi1[ch][sb / 8][i / 8][i % 8] -
607                              q->tone_level_idx_mid[ch][sb - 4][i / 8] -
608                              q->tone_level_idx_hi2[ch][sb - 4];
609                        q->tone_level_idx[ch][sb][i] = tmp & 0xff;
610                        if ((tmp < 0) || (!q->superblocktype_2_3 && !tmp))
611                            q->tone_level[ch][sb][i] = 0;
612                        else
613                            q->tone_level[ch][sb][i] = fft_tone_level_table[tab][tmp & 0x3f];
614                }
615            } else {
616                if (sb > 4) {
617                    for (ch = 0; ch < q->nb_channels; ch++)
618                        for (i = 0; i < 64; i++) {
619                            tmp = q->tone_level_idx_base[ch][sb][i / 8] -
620                                  q->tone_level_idx_hi1[ch][2][i / 8][i % 8] -
621                                  q->tone_level_idx_hi2[ch][sb - 4];
622                            q->tone_level_idx[ch][sb][i] = tmp & 0xff;
623                            if ((tmp < 0) || (!q->superblocktype_2_3 && !tmp))
624                                q->tone_level[ch][sb][i] = 0;
625                            else
626                                q->tone_level[ch][sb][i] = fft_tone_level_table[tab][tmp & 0x3f];
627                    }
628                } else {
629                    for (ch = 0; ch < q->nb_channels; ch++)
630                        for (i = 0; i < 64; i++) {
631                            tmp = q->tone_level_idx[ch][sb][i] = q->tone_level_idx_base[ch][sb][i / 8];
632                            if ((tmp < 0) || (!q->superblocktype_2_3 && !tmp))
633                                q->tone_level[ch][sb][i] = 0;
634                            else
635                                q->tone_level[ch][sb][i] = fft_tone_level_table[tab][tmp & 0x3f];
636                        }
637                }
638            }
639        }
640    }
641
642    return;
643}
644
645
646/**
647 * Related to synthesis filter
648 * Called by process_subpacket_11
649 * c is built with data from subpacket 11
650 * Most of this function is used only if superblock_type_2_3 == 0, never seen it in samples
651 *
652 * @param tone_level_idx
653 * @param tone_level_idx_temp
654 * @param coding_method        q->coding_method[0][0][0]
655 * @param nb_channels          number of channels
656 * @param c                    coming from subpacket 11, passed as 8*c
657 * @param superblocktype_2_3   flag based on superblock packet type
658 * @param cm_table_select      q->cm_table_select
659 */
660static void fill_coding_method_array (sb_int8_array tone_level_idx, sb_int8_array tone_level_idx_temp,
661                sb_int8_array coding_method, int nb_channels,
662                int c, int superblocktype_2_3, int cm_table_select)
663{
664    int ch, sb, j;
665    int tmp, acc, esp_40, comp;
666    int add1, add2, add3, add4;
667    int64_t multres;
668
669    // This should never happen
670    if (nb_channels <= 0)
671        return;
672
673    if (!superblocktype_2_3) {
674        /* This case is untested, no samples available */
675        SAMPLES_NEEDED
676        for (ch = 0; ch < nb_channels; ch++)
677            for (sb = 0; sb < 30; sb++) {
678                for (j = 1; j < 63; j++) {  // The loop only iterates to 63 so the code doesn't overflow the buffer
679                    add1 = tone_level_idx[ch][sb][j] - 10;
680                    if (add1 < 0)
681                        add1 = 0;
682                    add2 = add3 = add4 = 0;
683                    if (sb > 1) {
684                        add2 = tone_level_idx[ch][sb - 2][j] + tone_level_idx_offset_table[sb][0] - 6;
685                        if (add2 < 0)
686                            add2 = 0;
687                    }
688                    if (sb > 0) {
689                        add3 = tone_level_idx[ch][sb - 1][j] + tone_level_idx_offset_table[sb][1] - 6;
690                        if (add3 < 0)
691                            add3 = 0;
692                    }
693                    if (sb < 29) {
694                        add4 = tone_level_idx[ch][sb + 1][j] + tone_level_idx_offset_table[sb][3] - 6;
695                        if (add4 < 0)
696                            add4 = 0;
697                    }
698                    tmp = tone_level_idx[ch][sb][j + 1] * 2 - add4 - add3 - add2 - add1;
699                    if (tmp < 0)
700                        tmp = 0;
701                    tone_level_idx_temp[ch][sb][j + 1] = tmp & 0xff;
702                }
703                tone_level_idx_temp[ch][sb][0] = tone_level_idx_temp[ch][sb][1];
704            }
705            acc = 0;
706            for (ch = 0; ch < nb_channels; ch++)
707                for (sb = 0; sb < 30; sb++)
708                    for (j = 0; j < 64; j++)
709                        acc += tone_level_idx_temp[ch][sb][j];
710            if (acc)
711                tmp = c * 256 / (acc & 0xffff);
712            multres = 0x66666667 * (acc * 10);
713            esp_40 = (multres >> 32) / 8 + ((multres & 0xffffffff) >> 31);
714            for (ch = 0;  ch < nb_channels; ch++)
715                for (sb = 0; sb < 30; sb++)
716                    for (j = 0; j < 64; j++) {
717                        comp = tone_level_idx_temp[ch][sb][j]* esp_40 * 10;
718                        if (comp < 0)
719                            comp += 0xff;
720                        comp /= 256; // signed shift
721                        switch(sb) {
722                            case 0:
723                                if (comp < 30)
724                                    comp = 30;
725                                comp += 15;
726                                break;
727                            case 1:
728                                if (comp < 24)
729                                    comp = 24;
730                                comp += 10;
731                                break;
732                            case 2:
733                            case 3:
734                            case 4:
735                                if (comp < 16)
736                                    comp = 16;
737                        }
738                        if (comp <= 5)
739                            tmp = 0;
740                        else if (comp <= 10)
741                            tmp = 10;
742                        else if (comp <= 16)
743                            tmp = 16;
744                        else if (comp <= 24)
745                            tmp = -1;
746                        else
747                            tmp = 0;
748                        coding_method[ch][sb][j] = ((tmp & 0xfffa) + 30 )& 0xff;
749                    }
750            for (sb = 0; sb < 30; sb++)
751                fix_coding_method_array(sb, nb_channels, coding_method);
752            for (ch = 0; ch < nb_channels; ch++)
753                for (sb = 0; sb < 30; sb++)
754                    for (j = 0; j < 64; j++)
755                        if (sb >= 10) {
756                            if (coding_method[ch][sb][j] < 10)
757                                coding_method[ch][sb][j] = 10;
758                        } else {
759                            if (sb >= 2) {
760                                if (coding_method[ch][sb][j] < 16)
761                                    coding_method[ch][sb][j] = 16;
762                            } else {
763                                if (coding_method[ch][sb][j] < 30)
764                                    coding_method[ch][sb][j] = 30;
765                            }
766                        }
767    } else { // superblocktype_2_3 != 0
768        for (ch = 0; ch < nb_channels; ch++)
769            for (sb = 0; sb < 30; sb++)
770                for (j = 0; j < 64; j++)
771                    coding_method[ch][sb][j] = coding_method_table[cm_table_select][sb];
772    }
773
774    return;
775}
776
777
778/**
779 *
780 * Called by process_subpacket_11 to process more data from subpacket 11 with sb 0-8
781 * Called by process_subpacket_12 to process data from subpacket 12 with sb 8-sb_used
782 *
783 * @param q         context
784 * @param gb        bitreader context
785 * @param length    packet length in bits
786 * @param sb_min    lower subband processed (sb_min included)
787 * @param sb_max    higher subband processed (sb_max excluded)
788 */
789static void synthfilt_build_sb_samples (QDM2Context *q, GetBitContext *gb, int length, int sb_min, int sb_max)
790{
791    int sb, j, k, n, ch, run, channels;
792    int joined_stereo, zero_encoding, chs;
793    int type34_first;
794    float type34_div = 0;
795    float type34_predictor;
796    float samples[10], sign_bits[16];
797
798    if (length == 0) {
799        // If no data use noise
800        for (sb=sb_min; sb < sb_max; sb++)
801            build_sb_samples_from_noise (q, sb);
802
803        return;
804    }
805
806    for (sb = sb_min; sb < sb_max; sb++) {
807        FIX_NOISE_IDX(q->noise_idx);
808
809        channels = q->nb_channels;
810
811        if (q->nb_channels <= 1 || sb < 12)
812            joined_stereo = 0;
813        else if (sb >= 24)
814            joined_stereo = 1;
815        else
816            joined_stereo = (BITS_LEFT(length,gb) >= 1) ? get_bits1 (gb) : 0;
817
818        if (joined_stereo) {
819            if (BITS_LEFT(length,gb) >= 16)
820                for (j = 0; j < 16; j++)
821                    sign_bits[j] = get_bits1 (gb);
822
823            for (j = 0; j < 64; j++)
824                if (q->coding_method[1][sb][j] > q->coding_method[0][sb][j])
825                    q->coding_method[0][sb][j] = q->coding_method[1][sb][j];
826
827            fix_coding_method_array(sb, q->nb_channels, q->coding_method);
828            channels = 1;
829        }
830
831        for (ch = 0; ch < channels; ch++) {
832            zero_encoding = (BITS_LEFT(length,gb) >= 1) ? get_bits1(gb) : 0;
833            type34_predictor = 0.0;
834            type34_first = 1;
835
836            for (j = 0; j < 128; ) {
837                switch (q->coding_method[ch][sb][j / 2]) {
838                    case 8:
839                        if (BITS_LEFT(length,gb) >= 10) {
840                            if (zero_encoding) {
841                                for (k = 0; k < 5; k++) {
842                                    if ((j + 2 * k) >= 128)
843                                        break;
844                                    samples[2 * k] = get_bits1(gb) ? dequant_1bit[joined_stereo][2 * get_bits1(gb)] : 0;
845                                }
846                            } else {
847                                n = get_bits(gb, 8);
848                                for (k = 0; k < 5; k++)
849                                    samples[2 * k] = dequant_1bit[joined_stereo][random_dequant_index[n][k]];
850                            }
851                            for (k = 0; k < 5; k++)
852                                samples[2 * k + 1] = SB_DITHERING_NOISE(sb,q->noise_idx);
853                        } else {
854                            for (k = 0; k < 10; k++)
855                                samples[k] = SB_DITHERING_NOISE(sb,q->noise_idx);
856                        }
857                        run = 10;
858                        break;
859
860                    case 10:
861                        if (BITS_LEFT(length,gb) >= 1) {
862                            float f = 0.81;
863
864                            if (get_bits1(gb))
865                                f = -f;
866                            f -= noise_samples[((sb + 1) * (j +5 * ch + 1)) & 127] * 9.0 / 40.0;
867                            samples[0] = f;
868                        } else {
869                            samples[0] = SB_DITHERING_NOISE(sb,q->noise_idx);
870                        }
871                        run = 1;
872                        break;
873
874                    case 16:
875                        if (BITS_LEFT(length,gb) >= 10) {
876                            if (zero_encoding) {
877                                for (k = 0; k < 5; k++) {
878                                    if ((j + k) >= 128)
879                                        break;
880                                    samples[k] = (get_bits1(gb) == 0) ? 0 : dequant_1bit[joined_stereo][2 * get_bits1(gb)];
881                                }
882                            } else {
883                                n = get_bits (gb, 8);
884                                for (k = 0; k < 5; k++)
885                                    samples[k] = dequant_1bit[joined_stereo][random_dequant_index[n][k]];
886                            }
887                        } else {
888                            for (k = 0; k < 5; k++)
889                                samples[k] = SB_DITHERING_NOISE(sb,q->noise_idx);
890                        }
891                        run = 5;
892                        break;
893
894                    case 24:
895                        if (BITS_LEFT(length,gb) >= 7) {
896                            n = get_bits(gb, 7);
897                            for (k = 0; k < 3; k++)
898                                samples[k] = (random_dequant_type24[n][k] - 2.0) * 0.5;
899                        } else {
900                            for (k = 0; k < 3; k++)
901                                samples[k] = SB_DITHERING_NOISE(sb,q->noise_idx);
902                        }
903                        run = 3;
904                        break;
905
906                    case 30:
907                        if (BITS_LEFT(length,gb) >= 4)
908                            samples[0] = type30_dequant[qdm2_get_vlc(gb, &vlc_tab_type30, 0, 1)];
909                        else
910                            samples[0] = SB_DITHERING_NOISE(sb,q->noise_idx);
911
912                        run = 1;
913                        break;
914
915                    case 34:
916                        if (BITS_LEFT(length,gb) >= 7) {
917                            if (type34_first) {
918                                type34_div = (float)(1 << get_bits(gb, 2));
919                                samples[0] = ((float)get_bits(gb, 5) - 16.0) / 15.0;
920                                type34_predictor = samples[0];
921                                type34_first = 0;
922                            } else {
923                                samples[0] = type34_delta[qdm2_get_vlc(gb, &vlc_tab_type34, 0, 1)] / type34_div + type34_predictor;
924                                type34_predictor = samples[0];
925                            }
926                        } else {
927                            samples[0] = SB_DITHERING_NOISE(sb,q->noise_idx);
928                        }
929                        run = 1;
930                        break;
931
932                    default:
933                        samples[0] = SB_DITHERING_NOISE(sb,q->noise_idx);
934                        run = 1;
935                        break;
936                }
937
938                if (joined_stereo) {
939                    float tmp[10][MPA_MAX_CHANNELS];
940
941                    for (k = 0; k < run; k++) {
942                        tmp[k][0] = samples[k];
943                        tmp[k][1] = (sign_bits[(j + k) / 8]) ? -samples[k] : samples[k];
944                    }
945                    for (chs = 0; chs < q->nb_channels; chs++)
946                        for (k = 0; k < run; k++)
947                            if ((j + k) < 128)
948                                q->sb_samples[chs][j + k][sb] = (int32_t)(f2i_scale * q->tone_level[chs][sb][((j + k)/2)] * tmp[k][chs] + .5);
949                } else {
950                    for (k = 0; k < run; k++)
951                        if ((j + k) < 128)
952                            q->sb_samples[ch][j + k][sb] = (int32_t)(f2i_scale * q->tone_level[ch][sb][(j + k)/2] * samples[k] + .5);
953                }
954
955                j += run;
956            } // j loop
957        } // channel loop
958    } // subband loop
959}
960
961
962/**
963 * Init the first element of a channel in quantized_coeffs with data from packet 10 (quantized_coeffs[ch][0]).
964 * This is similar to process_subpacket_9, but for a single channel and for element [0]
965 * same VLC tables as process_subpacket_9 are used.
966 *
967 * @param q         context
968 * @param quantized_coeffs    pointer to quantized_coeffs[ch][0]
969 * @param gb        bitreader context
970 * @param length    packet length in bits
971 */
972static void init_quantized_coeffs_elem0 (int8_t *quantized_coeffs, GetBitContext *gb, int length)
973{
974    int i, k, run, level, diff;
975
976    if (BITS_LEFT(length,gb) < 16)
977        return;
978    level = qdm2_get_vlc(gb, &vlc_tab_level, 0, 2);
979
980    quantized_coeffs[0] = level;
981
982    for (i = 0; i < 7; ) {
983        if (BITS_LEFT(length,gb) < 16)
984            break;
985        run = qdm2_get_vlc(gb, &vlc_tab_run, 0, 1) + 1;
986
987        if (BITS_LEFT(length,gb) < 16)
988            break;
989        diff = qdm2_get_se_vlc(&vlc_tab_diff, gb, 2);
990
991        for (k = 1; k <= run; k++)
992            quantized_coeffs[i + k] = (level + ((k * diff) / run));
993
994        level += diff;
995        i += run;
996    }
997}
998
999
1000/**
1001 * Related to synthesis filter, process data from packet 10
1002 * Init part of quantized_coeffs via function init_quantized_coeffs_elem0
1003 * Init tone_level_idx_hi1, tone_level_idx_hi2, tone_level_idx_mid with data from packet 10
1004 *
1005 * @param q         context
1006 * @param gb        bitreader context
1007 * @param length    packet length in bits
1008 */
1009static void init_tone_level_dequantization (QDM2Context *q, GetBitContext *gb, int length)
1010{
1011    int sb, j, k, n, ch;
1012
1013    for (ch = 0; ch < q->nb_channels; ch++) {
1014        init_quantized_coeffs_elem0(q->quantized_coeffs[ch][0], gb, length);
1015
1016        if (BITS_LEFT(length,gb) < 16) {
1017            memset(q->quantized_coeffs[ch][0], 0, 8);
1018            break;
1019        }
1020    }
1021
1022    n = q->sub_sampling + 1;
1023
1024    for (sb = 0; sb < n; sb++)
1025        for (ch = 0; ch < q->nb_channels; ch++)
1026            for (j = 0; j < 8; j++) {
1027                if (BITS_LEFT(length,gb) < 1)
1028                    break;
1029                if (get_bits1(gb)) {
1030                    for (k=0; k < 8; k++) {
1031                        if (BITS_LEFT(length,gb) < 16)
1032                            break;
1033                        q->tone_level_idx_hi1[ch][sb][j][k] = qdm2_get_vlc(gb, &vlc_tab_tone_level_idx_hi1, 0, 2);
1034                    }
1035                } else {
1036                    for (k=0; k < 8; k++)
1037                        q->tone_level_idx_hi1[ch][sb][j][k] = 0;
1038                }
1039            }
1040
1041    n = QDM2_SB_USED(q->sub_sampling) - 4;
1042
1043    for (sb = 0; sb < n; sb++)
1044        for (ch = 0; ch < q->nb_channels; ch++) {
1045            if (BITS_LEFT(length,gb) < 16)
1046                break;
1047            q->tone_level_idx_hi2[ch][sb] = qdm2_get_vlc(gb, &vlc_tab_tone_level_idx_hi2, 0, 2);
1048            if (sb > 19)
1049                q->tone_level_idx_hi2[ch][sb] -= 16;
1050            else
1051                for (j = 0; j < 8; j++)
1052                    q->tone_level_idx_mid[ch][sb][j] = -16;
1053        }
1054
1055    n = QDM2_SB_USED(q->sub_sampling) - 5;
1056
1057    for (sb = 0; sb < n; sb++)
1058        for (ch = 0; ch < q->nb_channels; ch++)
1059            for (j = 0; j < 8; j++) {
1060                if (BITS_LEFT(length,gb) < 16)
1061                    break;
1062                q->tone_level_idx_mid[ch][sb][j] = qdm2_get_vlc(gb, &vlc_tab_tone_level_idx_mid, 0, 2) - 32;
1063            }
1064}
1065
1066/**
1067 * Process subpacket 9, init quantized_coeffs with data from it
1068 *
1069 * @param q       context
1070 * @param node    pointer to node with packet
1071 */
1072static void process_subpacket_9 (QDM2Context *q, QDM2SubPNode *node)
1073{
1074    GetBitContext gb;
1075    int i, j, k, n, ch, run, level, diff;
1076
1077    init_get_bits(&gb, node->packet->data, node->packet->size*8);
1078
1079    n = coeff_per_sb_for_avg[q->coeff_per_sb_select][QDM2_SB_USED(q->sub_sampling) - 1] + 1; // same as averagesomething function
1080
1081    for (i = 1; i < n; i++)
1082        for (ch=0; ch < q->nb_channels; ch++) {
1083            level = qdm2_get_vlc(&gb, &vlc_tab_level, 0, 2);
1084            q->quantized_coeffs[ch][i][0] = level;
1085
1086            for (j = 0; j < (8 - 1); ) {
1087                run = qdm2_get_vlc(&gb, &vlc_tab_run, 0, 1) + 1;
1088                diff = qdm2_get_se_vlc(&vlc_tab_diff, &gb, 2);
1089
1090                for (k = 1; k <= run; k++)
1091                    q->quantized_coeffs[ch][i][j + k] = (level + ((k*diff) / run));
1092
1093                level += diff;
1094                j += run;
1095            }
1096        }
1097
1098    for (ch = 0; ch < q->nb_channels; ch++)
1099        for (i = 0; i < 8; i++)
1100            q->quantized_coeffs[ch][0][i] = 0;
1101}
1102
1103
1104/**
1105 * Process subpacket 10 if not null, else
1106 *
1107 * @param q         context
1108 * @param node      pointer to node with packet
1109 * @param length    packet length in bits
1110 */
1111static void process_subpacket_10 (QDM2Context *q, QDM2SubPNode *node, int length)
1112{
1113    GetBitContext gb;
1114
1115    init_get_bits(&gb, ((node == NULL) ? empty_buffer : node->packet->data), ((node == NULL) ? 0 : node->packet->size*8));
1116
1117    if (length != 0) {
1118        init_tone_level_dequantization(q, &gb, length);
1119        fill_tone_level_array(q, 1);
1120    } else {
1121        fill_tone_level_array(q, 0);
1122    }
1123}
1124
1125
1126/**
1127 * Process subpacket 11
1128 *
1129 * @param q         context
1130 * @param node      pointer to node with packet
1131 * @param length    packet length in bit
1132 */
1133static void process_subpacket_11 (QDM2Context *q, QDM2SubPNode *node, int length)
1134{
1135    GetBitContext gb;
1136
1137    init_get_bits(&gb, ((node == NULL) ? empty_buffer : node->packet->data), ((node == NULL) ? 0 : node->packet->size*8));
1138    if (length >= 32) {
1139        int c = get_bits (&gb, 13);
1140
1141        if (c > 3)
1142            fill_coding_method_array (q->tone_level_idx, q->tone_level_idx_temp, q->coding_method,
1143                                      q->nb_channels, 8*c, q->superblocktype_2_3, q->cm_table_select);
1144    }
1145
1146    synthfilt_build_sb_samples(q, &gb, length, 0, 8);
1147}
1148
1149
1150/**
1151 * Process subpacket 12
1152 *
1153 * @param q         context
1154 * @param node      pointer to node with packet
1155 * @param length    packet length in bits
1156 */
1157static void process_subpacket_12 (QDM2Context *q, QDM2SubPNode *node, int length)
1158{
1159    GetBitContext gb;
1160
1161    init_get_bits(&gb, ((node == NULL) ? empty_buffer : node->packet->data), ((node == NULL) ? 0 : node->packet->size*8));
1162    synthfilt_build_sb_samples(q, &gb, length, 8, QDM2_SB_USED(q->sub_sampling));
1163}
1164
1165/*
1166 * Process new subpackets for synthesis filter
1167 *
1168 * @param q       context
1169 * @param list    list with synthesis filter packets (list D)
1170 */
1171static void process_synthesis_subpackets (QDM2Context *q, QDM2SubPNode *list)
1172{
1173    QDM2SubPNode *nodes[4];
1174
1175    nodes[0] = qdm2_search_subpacket_type_in_list(list, 9);
1176    if (nodes[0] != NULL)
1177        process_subpacket_9(q, nodes[0]);
1178
1179    nodes[1] = qdm2_search_subpacket_type_in_list(list, 10);
1180    if (nodes[1] != NULL)
1181        process_subpacket_10(q, nodes[1], nodes[1]->packet->size << 3);
1182    else
1183        process_subpacket_10(q, NULL, 0);
1184
1185    nodes[2] = qdm2_search_subpacket_type_in_list(list, 11);
1186    if (nodes[0] != NULL && nodes[1] != NULL && nodes[2] != NULL)
1187        process_subpacket_11(q, nodes[2], (nodes[2]->packet->size << 3));
1188    else
1189        process_subpacket_11(q, NULL, 0);
1190
1191    nodes[3] = qdm2_search_subpacket_type_in_list(list, 12);
1192    if (nodes[0] != NULL && nodes[1] != NULL && nodes[3] != NULL)
1193        process_subpacket_12(q, nodes[3], (nodes[3]->packet->size << 3));
1194    else
1195        process_subpacket_12(q, NULL, 0);
1196}
1197
1198
1199/*
1200 * Decode superblock, fill packet lists.
1201 *
1202 * @param q    context
1203 */
1204static void qdm2_decode_super_block (QDM2Context *q)
1205{
1206    GetBitContext gb;
1207    QDM2SubPacket header, *packet;
1208    int i, packet_bytes, sub_packet_size, sub_packets_D;
1209    unsigned int next_index = 0;
1210
1211    memset(q->tone_level_idx_hi1, 0, sizeof(q->tone_level_idx_hi1));
1212    memset(q->tone_level_idx_mid, 0, sizeof(q->tone_level_idx_mid));
1213    memset(q->tone_level_idx_hi2, 0, sizeof(q->tone_level_idx_hi2));
1214
1215    q->sub_packets_B = 0;
1216    sub_packets_D = 0;
1217
1218    average_quantized_coeffs(q); // average elements in quantized_coeffs[max_ch][10][8]
1219
1220    init_get_bits(&gb, q->compressed_data, q->compressed_size*8);
1221    qdm2_decode_sub_packet_header(&gb, &header);
1222
1223    if (header.type < 2 || header.type >= 8) {
1224        q->has_errors = 1;
1225        av_log(NULL,AV_LOG_ERROR,"bad superblock type\n");
1226        return;
1227    }
1228
1229    q->superblocktype_2_3 = (header.type == 2 || header.type == 3);
1230    packet_bytes = (q->compressed_size - get_bits_count(&gb) / 8);
1231
1232    init_get_bits(&gb, header.data, header.size*8);
1233
1234    if (header.type == 2 || header.type == 4 || header.type == 5) {
1235        int csum = 257 * get_bits(&gb, 8) + 2 * get_bits(&gb, 8);
1236
1237        csum = qdm2_packet_checksum(q->compressed_data, q->checksum_size, csum);
1238
1239        if (csum != 0) {
1240            q->has_errors = 1;
1241            av_log(NULL,AV_LOG_ERROR,"bad packet checksum\n");
1242            return;
1243        }
1244    }
1245
1246    q->sub_packet_list_B[0].packet = NULL;
1247    q->sub_packet_list_D[0].packet = NULL;
1248
1249    for (i = 0; i < 6; i++)
1250        if (--q->fft_level_exp[i] < 0)
1251            q->fft_level_exp[i] = 0;
1252
1253    for (i = 0; packet_bytes > 0; i++) {
1254        int j;
1255
1256        q->sub_packet_list_A[i].next = NULL;
1257
1258        if (i > 0) {
1259            q->sub_packet_list_A[i - 1].next = &q->sub_packet_list_A[i];
1260
1261            /* seek to next block */
1262            init_get_bits(&gb, header.data, header.size*8);
1263            skip_bits(&gb, next_index*8);
1264
1265            if (next_index >= header.size)
1266                break;
1267        }
1268
1269        /* decode subpacket */
1270        packet = &q->sub_packets[i];
1271        qdm2_decode_sub_packet_header(&gb, packet);
1272        next_index = packet->size + get_bits_count(&gb) / 8;
1273        sub_packet_size = ((packet->size > 0xff) ? 1 : 0) + packet->size + 2;
1274
1275        if (packet->type == 0)
1276            break;
1277
1278        if (sub_packet_size > packet_bytes) {
1279            if (packet->type != 10 && packet->type != 11 && packet->type != 12)
1280                break;
1281            packet->size += packet_bytes - sub_packet_size;
1282        }
1283
1284        packet_bytes -= sub_packet_size;
1285
1286        /* add subpacket to 'all subpackets' list */
1287        q->sub_packet_list_A[i].packet = packet;
1288
1289        /* add subpacket to related list */
1290        if (packet->type == 8) {
1291            SAMPLES_NEEDED_2("packet type 8");
1292            return;
1293        } else if (packet->type >= 9 && packet->type <= 12) {
1294            /* packets for MPEG Audio like Synthesis Filter */
1295            QDM2_LIST_ADD(q->sub_packet_list_D, sub_packets_D, packet);
1296        } else if (packet->type == 13) {
1297            for (j = 0; j < 6; j++)
1298                q->fft_level_exp[j] = get_bits(&gb, 6);
1299        } else if (packet->type == 14) {
1300            for (j = 0; j < 6; j++)
1301                q->fft_level_exp[j] = qdm2_get_vlc(&gb, &fft_level_exp_vlc, 0, 2);
1302        } else if (packet->type == 15) {
1303            SAMPLES_NEEDED_2("packet type 15")
1304            return;
1305        } else if (packet->type >= 16 && packet->type < 48 && !fft_subpackets[packet->type - 16]) {
1306            /* packets for FFT */
1307            QDM2_LIST_ADD(q->sub_packet_list_B, q->sub_packets_B, packet);
1308        }
1309    } // Packet bytes loop
1310
1311/* **************************************************************** */
1312    if (q->sub_packet_list_D[0].packet != NULL) {
1313        process_synthesis_subpackets(q, q->sub_packet_list_D);
1314        q->do_synth_filter = 1;
1315    } else if (q->do_synth_filter) {
1316        process_subpacket_10(q, NULL, 0);
1317        process_subpacket_11(q, NULL, 0);
1318        process_subpacket_12(q, NULL, 0);
1319    }
1320/* **************************************************************** */
1321}
1322
1323
1324static void qdm2_fft_init_coefficient (QDM2Context *q, int sub_packet,
1325                       int offset, int duration, int channel,
1326                       int exp, int phase)
1327{
1328    if (q->fft_coefs_min_index[duration] < 0)
1329        q->fft_coefs_min_index[duration] = q->fft_coefs_index;
1330
1331    q->fft_coefs[q->fft_coefs_index].sub_packet = ((sub_packet >= 16) ? (sub_packet - 16) : sub_packet);
1332    q->fft_coefs[q->fft_coefs_index].channel = channel;
1333    q->fft_coefs[q->fft_coefs_index].offset = offset;
1334    q->fft_coefs[q->fft_coefs_index].exp = exp;
1335    q->fft_coefs[q->fft_coefs_index].phase = phase;
1336    q->fft_coefs_index++;
1337}
1338
1339
1340static void qdm2_fft_decode_tones (QDM2Context *q, int duration, GetBitContext *gb, int b)
1341{
1342    int channel, stereo, phase, exp;
1343    int local_int_4,  local_int_8,  stereo_phase,  local_int_10;
1344    int local_int_14, stereo_exp, local_int_20, local_int_28;
1345    int n, offset;
1346
1347    local_int_4 = 0;
1348    local_int_28 = 0;
1349    local_int_20 = 2;
1350    local_int_8 = (4 - duration);
1351    local_int_10 = 1 << (q->group_order - duration - 1);
1352    offset = 1;
1353
1354    while (1) {
1355        if (q->superblocktype_2_3) {
1356            while ((n = qdm2_get_vlc(gb, &vlc_tab_fft_tone_offset[local_int_8], 1, 2)) < 2) {
1357                offset = 1;
1358                if (n == 0) {
1359                    local_int_4 += local_int_10;
1360                    local_int_28 += (1 << local_int_8);
1361                } else {
1362                    local_int_4 += 8*local_int_10;
1363                    local_int_28 += (8 << local_int_8);
1364                }
1365            }
1366            offset += (n - 2);
1367        } else {
1368            offset += qdm2_get_vlc(gb, &vlc_tab_fft_tone_offset[local_int_8], 1, 2);
1369            while (offset >= (local_int_10 - 1)) {
1370                offset += (1 - (local_int_10 - 1));
1371                local_int_4  += local_int_10;
1372                local_int_28 += (1 << local_int_8);
1373            }
1374        }
1375
1376        if (local_int_4 >= q->group_size)
1377            return;
1378
1379        local_int_14 = (offset >> local_int_8);
1380
1381        if (q->nb_channels > 1) {
1382            channel = get_bits1(gb);
1383            stereo = get_bits1(gb);
1384        } else {
1385            channel = 0;
1386            stereo = 0;
1387        }
1388
1389        exp = qdm2_get_vlc(gb, (b ? &fft_level_exp_vlc : &fft_level_exp_alt_vlc), 0, 2);
1390        exp += q->fft_level_exp[fft_level_index_table[local_int_14]];
1391        exp = (exp < 0) ? 0 : exp;
1392
1393        phase = get_bits(gb, 3);
1394        stereo_exp = 0;
1395        stereo_phase = 0;
1396
1397        if (stereo) {
1398            stereo_exp = (exp - qdm2_get_vlc(gb, &fft_stereo_exp_vlc, 0, 1));
1399            stereo_phase = (phase - qdm2_get_vlc(gb, &fft_stereo_phase_vlc, 0, 1));
1400            if (stereo_phase < 0)
1401                stereo_phase += 8;
1402        }
1403
1404        if (q->frequency_range > (local_int_14 + 1)) {
1405            int sub_packet = (local_int_20 + local_int_28);
1406
1407            qdm2_fft_init_coefficient(q, sub_packet, offset, duration, channel, exp, phase);
1408            if (stereo)
1409                qdm2_fft_init_coefficient(q, sub_packet, offset, duration, (1 - channel), stereo_exp, stereo_phase);
1410        }
1411
1412        offset++;
1413    }
1414}
1415
1416
1417static void qdm2_decode_fft_packets (QDM2Context *q)
1418{
1419    int i, j, min, max, value, type, unknown_flag;
1420    GetBitContext gb;
1421
1422    if (q->sub_packet_list_B[0].packet == NULL)
1423        return;
1424
1425    /* reset minimum indexes for FFT coefficients */
1426    q->fft_coefs_index = 0;
1427    for (i=0; i < 5; i++)
1428        q->fft_coefs_min_index[i] = -1;
1429
1430    /* process subpackets ordered by type, largest type first */
1431    for (i = 0, max = 256; i < q->sub_packets_B; i++) {
1432        QDM2SubPacket *packet= NULL;
1433
1434        /* find subpacket with largest type less than max */
1435        for (j = 0, min = 0; j < q->sub_packets_B; j++) {
1436            value = q->sub_packet_list_B[j].packet->type;
1437            if (value > min && value < max) {
1438                min = value;
1439                packet = q->sub_packet_list_B[j].packet;
1440            }
1441        }
1442
1443        max = min;
1444
1445        /* check for errors (?) */
1446        if (!packet)
1447            return;
1448
1449        if (i == 0 && (packet->type < 16 || packet->type >= 48 || fft_subpackets[packet->type - 16]))
1450            return;
1451
1452        /* decode FFT tones */
1453        init_get_bits (&gb, packet->data, packet->size*8);
1454
1455        if (packet->type >= 32 && packet->type < 48 && !fft_subpackets[packet->type - 16])
1456            unknown_flag = 1;
1457        else
1458            unknown_flag = 0;
1459
1460        type = packet->type;
1461
1462        if ((type >= 17 && type < 24) || (type >= 33 && type < 40)) {
1463            int duration = q->sub_sampling + 5 - (type & 15);
1464
1465            if (duration >= 0 && duration < 4)
1466                qdm2_fft_decode_tones(q, duration, &gb, unknown_flag);
1467        } else if (type == 31) {
1468            for (j=0; j < 4; j++)
1469                qdm2_fft_decode_tones(q, j, &gb, unknown_flag);
1470        } else if (type == 46) {
1471            for (j=0; j < 6; j++)
1472                q->fft_level_exp[j] = get_bits(&gb, 6);
1473            for (j=0; j < 4; j++)
1474            qdm2_fft_decode_tones(q, j, &gb, unknown_flag);
1475        }
1476    } // Loop on B packets
1477
1478    /* calculate maximum indexes for FFT coefficients */
1479    for (i = 0, j = -1; i < 5; i++)
1480        if (q->fft_coefs_min_index[i] >= 0) {
1481            if (j >= 0)
1482                q->fft_coefs_max_index[j] = q->fft_coefs_min_index[i];
1483            j = i;
1484        }
1485    if (j >= 0)
1486        q->fft_coefs_max_index[j] = q->fft_coefs_index;
1487}
1488
1489
1490static void qdm2_fft_generate_tone (QDM2Context *q, FFTTone *tone)
1491{
1492   float level, f[6];
1493   int i;
1494   QDM2Complex c;
1495   const double iscale = 2.0*M_PI / 512.0;
1496
1497    tone->phase += tone->phase_shift;
1498
1499    /* calculate current level (maximum amplitude) of tone */
1500    level = fft_tone_envelope_table[tone->duration][tone->time_index] * tone->level;
1501    c.im = level * sin(tone->phase*iscale);
1502    c.re = level * cos(tone->phase*iscale);
1503
1504    /* generate FFT coefficients for tone */
1505    if (tone->duration >= 3 || tone->cutoff >= 3) {
1506        tone->complex[0].im += c.im;
1507        tone->complex[0].re += c.re;
1508        tone->complex[1].im -= c.im;
1509        tone->complex[1].re -= c.re;
1510    } else {
1511        f[1] = -tone->table[4];
1512        f[0] =  tone->table[3] - tone->table[0];
1513        f[2] =  1.0 - tone->table[2] - tone->table[3];
1514        f[3] =  tone->table[1] + tone->table[4] - 1.0;
1515        f[4] =  tone->table[0] - tone->table[1];
1516        f[5] =  tone->table[2];
1517        for (i = 0; i < 2; i++) {
1518            tone->complex[fft_cutoff_index_table[tone->cutoff][i]].re += c.re * f[i];
1519            tone->complex[fft_cutoff_index_table[tone->cutoff][i]].im += c.im *((tone->cutoff <= i) ? -f[i] : f[i]);
1520        }
1521        for (i = 0; i < 4; i++) {
1522            tone->complex[i].re += c.re * f[i+2];
1523            tone->complex[i].im += c.im * f[i+2];
1524        }
1525    }
1526
1527    /* copy the tone if it has not yet died out */
1528    if (++tone->time_index < ((1 << (5 - tone->duration)) - 1)) {
1529      memcpy(&q->fft_tones[q->fft_tone_end], tone, sizeof(FFTTone));
1530      q->fft_tone_end = (q->fft_tone_end + 1) % 1000;
1531    }
1532}
1533
1534
1535static void qdm2_fft_tone_synthesizer (QDM2Context *q, int sub_packet)
1536{
1537    int i, j, ch;
1538    const double iscale = 0.25 * M_PI;
1539
1540    for (ch = 0; ch < q->channels; ch++) {
1541        memset(q->fft.complex[ch], 0, q->fft_size * sizeof(QDM2Complex));
1542    }
1543
1544
1545    /* apply FFT tones with duration 4 (1 FFT period) */
1546    if (q->fft_coefs_min_index[4] >= 0)
1547        for (i = q->fft_coefs_min_index[4]; i < q->fft_coefs_max_index[4]; i++) {
1548            float level;
1549            QDM2Complex c;
1550
1551            if (q->fft_coefs[i].sub_packet != sub_packet)
1552                break;
1553
1554            ch = (q->channels == 1) ? 0 : q->fft_coefs[i].channel;
1555            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];
1556
1557            c.re = level * cos(q->fft_coefs[i].phase * iscale);
1558            c.im = level * sin(q->fft_coefs[i].phase * iscale);
1559            q->fft.complex[ch][q->fft_coefs[i].offset + 0].re += c.re;
1560            q->fft.complex[ch][q->fft_coefs[i].offset + 0].im += c.im;
1561            q->fft.complex[ch][q->fft_coefs[i].offset + 1].re -= c.re;
1562            q->fft.complex[ch][q->fft_coefs[i].offset + 1].im -= c.im;
1563        }
1564
1565    /* generate existing FFT tones */
1566    for (i = q->fft_tone_end; i != q->fft_tone_start; ) {
1567        qdm2_fft_generate_tone(q, &q->fft_tones[q->fft_tone_start]);
1568        q->fft_tone_start = (q->fft_tone_start + 1) % 1000;
1569    }
1570
1571    /* create and generate new FFT tones with duration 0 (long) to 3 (short) */
1572    for (i = 0; i < 4; i++)
1573        if (q->fft_coefs_min_index[i] >= 0) {
1574            for (j = q->fft_coefs_min_index[i]; j < q->fft_coefs_max_index[i]; j++) {
1575                int offset, four_i;
1576                FFTTone tone;
1577
1578                if (q->fft_coefs[j].sub_packet != sub_packet)
1579                    break;
1580
1581                four_i = (4 - i);
1582                offset = q->fft_coefs[j].offset >> four_i;
1583                ch = (q->channels == 1) ? 0 : q->fft_coefs[j].channel;
1584
1585                if (offset < q->frequency_range) {
1586                    if (offset < 2)
1587                        tone.cutoff = offset;
1588                    else
1589                        tone.cutoff = (offset >= 60) ? 3 : 2;
1590
1591                    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];
1592                    tone.complex = &q->fft.complex[ch][offset];
1593                    tone.table = fft_tone_sample_table[i][q->fft_coefs[j].offset - (offset << four_i)];
1594                    tone.phase = 64 * q->fft_coefs[j].phase - (offset << 8) - 128;
1595                    tone.phase_shift = (2 * q->fft_coefs[j].offset + 1) << (7 - four_i);
1596                    tone.duration = i;
1597                    tone.time_index = 0;
1598
1599                    qdm2_fft_generate_tone(q, &tone);
1600                }
1601            }
1602            q->fft_coefs_min_index[i] = j;
1603        }
1604}
1605
1606
1607static void qdm2_calculate_fft (QDM2Context *q, int channel, int sub_packet)
1608{
1609    const float gain = (q->channels == 1 && q->nb_channels == 2) ? 0.5f : 1.0f;
1610    int i;
1611    q->fft.complex[channel][0].re *= 2.0f;
1612    q->fft.complex[channel][0].im = 0.0f;
1613    ff_rdft_calc(&q->rdft_ctx, (FFTSample *)q->fft.complex[channel]);
1614    /* add samples to output buffer */
1615    for (i = 0; i < ((q->fft_frame_size + 15) & ~15); i++)
1616        q->output_buffer[q->channels * i + channel] += ((float *) q->fft.complex[channel])[i] * gain;
1617}
1618
1619
1620/**
1621 * @param q        context
1622 * @param index    subpacket number
1623 */
1624static void qdm2_synthesis_filter (QDM2Context *q, int index)
1625{
1626    OUT_INT samples[MPA_MAX_CHANNELS * MPA_FRAME_SIZE];
1627    int i, k, ch, sb_used, sub_sampling, dither_state = 0;
1628
1629    /* copy sb_samples */
1630    sb_used = QDM2_SB_USED(q->sub_sampling);
1631
1632    for (ch = 0; ch < q->channels; ch++)
1633        for (i = 0; i < 8; i++)
1634            for (k=sb_used; k < SBLIMIT; k++)
1635                q->sb_samples[ch][(8 * index) + i][k] = 0;
1636
1637    for (ch = 0; ch < q->nb_channels; ch++) {
1638        OUT_INT *samples_ptr = samples + ch;
1639
1640        for (i = 0; i < 8; i++) {
1641            ff_mpa_synth_filter(q->synth_buf[ch], &(q->synth_buf_offset[ch]),
1642                mpa_window, &dither_state,
1643                samples_ptr, q->nb_channels,
1644                q->sb_samples[ch][(8 * index) + i]);
1645            samples_ptr += 32 * q->nb_channels;
1646        }
1647    }
1648
1649    /* add samples to output buffer */
1650    sub_sampling = (4 >> q->sub_sampling);
1651
1652    for (ch = 0; ch < q->channels; ch++)
1653        for (i = 0; i < q->frame_size; i++)
1654            q->output_buffer[q->channels * i + ch] += (float)(samples[q->nb_channels * sub_sampling * i + ch] >> (sizeof(OUT_INT)*8-16));
1655}
1656
1657
1658/**
1659 * Init static data (does not depend on specific file)
1660 *
1661 * @param q    context
1662 */
1663static av_cold void qdm2_init(QDM2Context *q) {
1664    static int initialized = 0;
1665
1666    if (initialized != 0)
1667        return;
1668    initialized = 1;
1669
1670    qdm2_init_vlc();
1671    ff_mpa_synth_init(mpa_window);
1672    softclip_table_init();
1673    rnd_table_init();
1674    init_noise_samples();
1675
1676    av_log(NULL, AV_LOG_DEBUG, "init done\n");
1677}
1678
1679
1680#if 0
1681static void dump_context(QDM2Context *q)
1682{
1683    int i;
1684#define PRINT(a,b) av_log(NULL,AV_LOG_DEBUG," %s = %d\n", a, b);
1685    PRINT("compressed_data",q->compressed_data);
1686    PRINT("compressed_size",q->compressed_size);
1687    PRINT("frame_size",q->frame_size);
1688    PRINT("checksum_size",q->checksum_size);
1689    PRINT("channels",q->channels);
1690    PRINT("nb_channels",q->nb_channels);
1691    PRINT("fft_frame_size",q->fft_frame_size);
1692    PRINT("fft_size",q->fft_size);
1693    PRINT("sub_sampling",q->sub_sampling);
1694    PRINT("fft_order",q->fft_order);
1695    PRINT("group_order",q->group_order);
1696    PRINT("group_size",q->group_size);
1697    PRINT("sub_packet",q->sub_packet);
1698    PRINT("frequency_range",q->frequency_range);
1699    PRINT("has_errors",q->has_errors);
1700    PRINT("fft_tone_end",q->fft_tone_end);
1701    PRINT("fft_tone_start",q->fft_tone_start);
1702    PRINT("fft_coefs_index",q->fft_coefs_index);
1703    PRINT("coeff_per_sb_select",q->coeff_per_sb_select);
1704    PRINT("cm_table_select",q->cm_table_select);
1705    PRINT("noise_idx",q->noise_idx);
1706
1707    for (i = q->fft_tone_start; i < q->fft_tone_end; i++)
1708    {
1709    FFTTone *t = &q->fft_tones[i];
1710
1711    av_log(NULL,AV_LOG_DEBUG,"Tone (%d) dump:\n", i);
1712    av_log(NULL,AV_LOG_DEBUG,"  level = %f\n", t->level);
1713//  PRINT(" level", t->level);
1714    PRINT(" phase", t->phase);
1715    PRINT(" phase_shift", t->phase_shift);
1716    PRINT(" duration", t->duration);
1717    PRINT(" samples_im", t->samples_im);
1718    PRINT(" samples_re", t->samples_re);
1719    PRINT(" table", t->table);
1720    }
1721
1722}
1723#endif
1724
1725
1726/**
1727 * Init parameters from codec extradata
1728 */
1729static av_cold int qdm2_decode_init(AVCodecContext *avctx)
1730{
1731    QDM2Context *s = avctx->priv_data;
1732    uint8_t *extradata;
1733    int extradata_size;
1734    int tmp_val, tmp, size;
1735
1736    /* extradata parsing
1737
1738    Structure:
1739    wave {
1740        frma (QDM2)
1741        QDCA
1742        QDCP
1743    }
1744
1745    32  size (including this field)
1746    32  tag (=frma)
1747    32  type (=QDM2 or QDMC)
1748
1749    32  size (including this field, in bytes)
1750    32  tag (=QDCA) // maybe mandatory parameters
1751    32  unknown (=1)
1752    32  channels (=2)
1753    32  samplerate (=44100)
1754    32  bitrate (=96000)
1755    32  block size (=4096)
1756    32  frame size (=256) (for one channel)
1757    32  packet size (=1300)
1758
1759    32  size (including this field, in bytes)
1760    32  tag (=QDCP) // maybe some tuneable parameters
1761    32  float1 (=1.0)
1762    32  zero ?
1763    32  float2 (=1.0)
1764    32  float3 (=1.0)
1765    32  unknown (27)
1766    32  unknown (8)
1767    32  zero ?
1768    */
1769
1770    if (!avctx->extradata || (avctx->extradata_size < 48)) {
1771        av_log(avctx, AV_LOG_ERROR, "extradata missing or truncated\n");
1772        return -1;
1773    }
1774
1775    extradata = avctx->extradata;
1776    extradata_size = avctx->extradata_size;
1777
1778    while (extradata_size > 7) {
1779        if (!memcmp(extradata, "frmaQDM", 7))
1780            break;
1781        extradata++;
1782        extradata_size--;
1783    }
1784
1785    if (extradata_size < 12) {
1786        av_log(avctx, AV_LOG_ERROR, "not enough extradata (%i)\n",
1787               extradata_size);
1788        return -1;
1789    }
1790
1791    if (memcmp(extradata, "frmaQDM", 7)) {
1792        av_log(avctx, AV_LOG_ERROR, "invalid headers, QDM? not found\n");
1793        return -1;
1794    }
1795
1796    if (extradata[7] == 'C') {
1797//        s->is_qdmc = 1;
1798        av_log(avctx, AV_LOG_ERROR, "stream is QDMC version 1, which is not supported\n");
1799        return -1;
1800    }
1801
1802    extradata += 8;
1803    extradata_size -= 8;
1804
1805    size = AV_RB32(extradata);
1806
1807    if(size > extradata_size){
1808        av_log(avctx, AV_LOG_ERROR, "extradata size too small, %i < %i\n",
1809               extradata_size, size);
1810        return -1;
1811    }
1812
1813    extradata += 4;
1814    av_log(avctx, AV_LOG_DEBUG, "size: %d\n", size);
1815    if (AV_RB32(extradata) != MKBETAG('Q','D','C','A')) {
1816        av_log(avctx, AV_LOG_ERROR, "invalid extradata, expecting QDCA\n");
1817        return -1;
1818    }
1819
1820    extradata += 8;
1821
1822    avctx->channels = s->nb_channels = s->channels = AV_RB32(extradata);
1823    extradata += 4;
1824
1825    avctx->sample_rate = AV_RB32(extradata);
1826    extradata += 4;
1827
1828    avctx->bit_rate = AV_RB32(extradata);
1829    extradata += 4;
1830
1831    s->group_size = AV_RB32(extradata);
1832    extradata += 4;
1833
1834    s->fft_size = AV_RB32(extradata);
1835    extradata += 4;
1836
1837    s->checksum_size = AV_RB32(extradata);
1838    extradata += 4;
1839
1840    s->fft_order = av_log2(s->fft_size) + 1;
1841    s->fft_frame_size = 2 * s->fft_size; // complex has two floats
1842
1843    // something like max decodable tones
1844    s->group_order = av_log2(s->group_size) + 1;
1845    s->frame_size = s->group_size / 16; // 16 iterations per super block
1846
1847    s->sub_sampling = s->fft_order - 7;
1848    s->frequency_range = 255 / (1 << (2 - s->sub_sampling));
1849
1850    switch ((s->sub_sampling * 2 + s->channels - 1)) {
1851        case 0: tmp = 40; break;
1852        case 1: tmp = 48; break;
1853        case 2: tmp = 56; break;
1854        case 3: tmp = 72; break;
1855        case 4: tmp = 80; break;
1856        case 5: tmp = 100;break;
1857        default: tmp=s->sub_sampling; break;
1858    }
1859    tmp_val = 0;
1860    if ((tmp * 1000) < avctx->bit_rate)  tmp_val = 1;
1861    if ((tmp * 1440) < avctx->bit_rate)  tmp_val = 2;
1862    if ((tmp * 1760) < avctx->bit_rate)  tmp_val = 3;
1863    if ((tmp * 2240) < avctx->bit_rate)  tmp_val = 4;
1864    s->cm_table_select = tmp_val;
1865
1866    if (s->sub_sampling == 0)
1867        tmp = 7999;
1868    else
1869        tmp = ((-(s->sub_sampling -1)) & 8000) + 20000;
1870    /*
1871    0: 7999 -> 0
1872    1: 20000 -> 2
1873    2: 28000 -> 2
1874    */
1875    if (tmp < 8000)
1876        s->coeff_per_sb_select = 0;
1877    else if (tmp <= 16000)
1878        s->coeff_per_sb_select = 1;
1879    else
1880        s->coeff_per_sb_select = 2;
1881
1882    // Fail on unknown fft order
1883    if ((s->fft_order < 7) || (s->fft_order > 9)) {
1884        av_log(avctx, AV_LOG_ERROR, "Unknown FFT order (%d), contact the developers!\n", s->fft_order);
1885        return -1;
1886    }
1887
1888    ff_rdft_init(&s->rdft_ctx, s->fft_order, IRDFT);
1889
1890    qdm2_init(s);
1891
1892    avctx->sample_fmt = SAMPLE_FMT_S16;
1893
1894//    dump_context(s);
1895    return 0;
1896}
1897
1898
1899static av_cold int qdm2_decode_close(AVCodecContext *avctx)
1900{
1901    QDM2Context *s = avctx->priv_data;
1902
1903    ff_rdft_end(&s->rdft_ctx);
1904
1905    return 0;
1906}
1907
1908
1909static void qdm2_decode (QDM2Context *q, const uint8_t *in, int16_t *out)
1910{
1911    int ch, i;
1912    const int frame_size = (q->frame_size * q->channels);
1913
1914    /* select input buffer */
1915    q->compressed_data = in;
1916    q->compressed_size = q->checksum_size;
1917
1918//  dump_context(q);
1919
1920    /* copy old block, clear new block of output samples */
1921    memmove(q->output_buffer, &q->output_buffer[frame_size], frame_size * sizeof(float));
1922    memset(&q->output_buffer[frame_size], 0, frame_size * sizeof(float));
1923
1924    /* decode block of QDM2 compressed data */
1925    if (q->sub_packet == 0) {
1926        q->has_errors = 0; // zero it for a new super block
1927        av_log(NULL,AV_LOG_DEBUG,"Superblock follows\n");
1928        qdm2_decode_super_block(q);
1929    }
1930
1931    /* parse subpackets */
1932    if (!q->has_errors) {
1933        if (q->sub_packet == 2)
1934            qdm2_decode_fft_packets(q);
1935
1936        qdm2_fft_tone_synthesizer(q, q->sub_packet);
1937    }
1938
1939    /* sound synthesis stage 1 (FFT) */
1940    for (ch = 0; ch < q->channels; ch++) {
1941        qdm2_calculate_fft(q, ch, q->sub_packet);
1942
1943        if (!q->has_errors && q->sub_packet_list_C[0].packet != NULL) {
1944            SAMPLES_NEEDED_2("has errors, and C list is not empty")
1945            return;
1946        }
1947    }
1948
1949    /* sound synthesis stage 2 (MPEG audio like synthesis filter) */
1950    if (!q->has_errors && q->do_synth_filter)
1951        qdm2_synthesis_filter(q, q->sub_packet);
1952
1953    q->sub_packet = (q->sub_packet + 1) % 16;
1954
1955    /* clip and convert output float[] to 16bit signed samples */
1956    for (i = 0; i < frame_size; i++) {
1957        int value = (int)q->output_buffer[i];
1958
1959        if (value > SOFTCLIP_THRESHOLD)
1960            value = (value >  HARDCLIP_THRESHOLD) ?  32767 :  softclip_table[ value - SOFTCLIP_THRESHOLD];
1961        else if (value < -SOFTCLIP_THRESHOLD)
1962            value = (value < -HARDCLIP_THRESHOLD) ? -32767 : -softclip_table[-value - SOFTCLIP_THRESHOLD];
1963
1964        out[i] = value;
1965    }
1966}
1967
1968
1969static int qdm2_decode_frame(AVCodecContext *avctx,
1970            void *data, int *data_size,
1971            const uint8_t *buf, int buf_size)
1972{
1973    QDM2Context *s = avctx->priv_data;
1974
1975    if(!buf)
1976        return 0;
1977    if(buf_size < s->checksum_size)
1978        return -1;
1979
1980    *data_size = s->channels * s->frame_size * sizeof(int16_t);
1981
1982    av_log(avctx, AV_LOG_DEBUG, "decode(%d): %p[%d] -> %p[%d]\n",
1983       buf_size, buf, s->checksum_size, data, *data_size);
1984
1985    qdm2_decode(s, buf, data);
1986
1987    // reading only when next superblock found
1988    if (s->sub_packet == 0) {
1989        return s->checksum_size;
1990    }
1991
1992    return 0;
1993}
1994
1995AVCodec qdm2_decoder =
1996{
1997    .name = "qdm2",
1998    .type = CODEC_TYPE_AUDIO,
1999    .id = CODEC_ID_QDM2,
2000    .priv_data_size = sizeof(QDM2Context),
2001    .init = qdm2_decode_init,
2002    .close = qdm2_decode_close,
2003    .decode = qdm2_decode_frame,
2004    .long_name = NULL_IF_CONFIG_SMALL("QDesign Music Codec 2"),
2005};
2006