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 #include "libavutil/channel_layout.h"
39 #include "libavutil/mem_internal.h"
40 #include "libavutil/thread.h"
41 
42 #define BITSTREAM_READER_LE
43 #include "avcodec.h"
44 #include "get_bits.h"
45 #include "bytestream.h"
46 #include "codec_internal.h"
47 #include "internal.h"
48 #include "mpegaudio.h"
49 #include "mpegaudiodsp.h"
50 #include "rdft.h"
51 
52 #include "qdm2_tablegen.h"
53 
54 #define QDM2_LIST_ADD(list, size, packet) \
55 do { \
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 
81 typedef int8_t sb_int8_array[2][30][64];
82 
83 /**
84  * Subpacket
85  */
86 typedef struct QDM2SubPacket {
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  */
95 typedef struct QDM2SubPNode {
96     QDM2SubPacket *packet;      ///< packet
97     struct QDM2SubPNode *next; ///< pointer to next packet in the list, NULL if leaf node
98 } QDM2SubPNode;
99 
100 typedef struct QDM2Complex {
101     float re;
102     float im;
103 } QDM2Complex;
104 
105 typedef struct FFTTone {
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 
116 typedef struct FFTCoefficient {
117     int16_t sub_packet;
118     uint8_t channel;
119     int16_t offset;
120     int16_t exp;
121     uint8_t phase;
122 } FFTCoefficient;
123 
124 typedef struct QDM2FFT {
125     DECLARE_ALIGNED(32, QDM2Complex, complex)[MPA_MAX_CHANNELS][256];
126 } QDM2FFT;
127 
128 /**
129  * QDM2 decoder context
130  */
131 typedef struct QDM2Context {
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 static const int switchtable[23] = {
201     0, 5, 1, 5, 5, 5, 5, 5, 2, 5, 5, 5, 5, 5, 5, 5, 3, 5, 5, 5, 5, 5, 4
202 };
203 
qdm2_get_vlc(GetBitContext *gb, const VLC *vlc, int flag, int depth)204 static int qdm2_get_vlc(GetBitContext *gb, const VLC *vlc, int flag, int depth)
205 {
206     int value;
207 
208     value = get_vlc2(gb, vlc->table, vlc->bits, depth);
209 
210     /* stage-2, 3 bits exponent escape sequence */
211     if (value < 0)
212         value = get_bits(gb, get_bits(gb, 3) + 1);
213 
214     /* stage-3, optional */
215     if (flag) {
216         int tmp;
217 
218         if (value >= 60) {
219             av_log(NULL, AV_LOG_ERROR, "value %d in qdm2_get_vlc too large\n", value);
220             return 0;
221         }
222 
223         tmp= vlc_stage3_values[value];
224 
225         if ((value & ~3) > 0)
226             tmp += get_bits(gb, (value >> 2));
227         value = tmp;
228     }
229 
230     return value;
231 }
232 
qdm2_get_se_vlc(const VLC *vlc, GetBitContext *gb, int depth)233 static int qdm2_get_se_vlc(const VLC *vlc, GetBitContext *gb, int depth)
234 {
235     int value = qdm2_get_vlc(gb, vlc, 0, depth);
236 
237     return (value & 1) ? ((value + 1) >> 1) : -(value >> 1);
238 }
239 
240 /**
241  * QDM2 checksum
242  *
243  * @param data      pointer to data to be checksummed
244  * @param length    data length
245  * @param value     checksum value
246  *
247  * @return          0 if checksum is OK
248  */
qdm2_packet_checksum(const uint8_t *data, int length, int value)249 static uint16_t qdm2_packet_checksum(const uint8_t *data, int length, int value)
250 {
251     int i;
252 
253     for (i = 0; i < length; i++)
254         value -= data[i];
255 
256     return (uint16_t)(value & 0xffff);
257 }
258 
259 /**
260  * Fill a QDM2SubPacket structure with packet type, size, and data pointer.
261  *
262  * @param gb            bitreader context
263  * @param sub_packet    packet under analysis
264  */
qdm2_decode_sub_packet_header(GetBitContext *gb, QDM2SubPacket *sub_packet)265 static void qdm2_decode_sub_packet_header(GetBitContext *gb,
266                                           QDM2SubPacket *sub_packet)
267 {
268     sub_packet->type = get_bits(gb, 8);
269 
270     if (sub_packet->type == 0) {
271         sub_packet->size = 0;
272         sub_packet->data = NULL;
273     } else {
274         sub_packet->size = get_bits(gb, 8);
275 
276         if (sub_packet->type & 0x80) {
277             sub_packet->size <<= 8;
278             sub_packet->size  |= get_bits(gb, 8);
279             sub_packet->type  &= 0x7f;
280         }
281 
282         if (sub_packet->type == 0x7f)
283             sub_packet->type |= (get_bits(gb, 8) << 8);
284 
285         // FIXME: this depends on bitreader-internal data
286         sub_packet->data = &gb->buffer[get_bits_count(gb) / 8];
287     }
288 
289     av_log(NULL, AV_LOG_DEBUG, "Subpacket: type=%d size=%d start_offs=%x\n",
290            sub_packet->type, sub_packet->size, get_bits_count(gb) / 8);
291 }
292 
293 /**
294  * Return node pointer to first packet of requested type in list.
295  *
296  * @param list    list of subpackets to be scanned
297  * @param type    type of searched subpacket
298  * @return        node pointer for subpacket if found, else NULL
299  */
qdm2_search_subpacket_type_in_list(QDM2SubPNode *list, int type)300 static QDM2SubPNode *qdm2_search_subpacket_type_in_list(QDM2SubPNode *list,
301                                                         int type)
302 {
303     while (list && list->packet) {
304         if (list->packet->type == type)
305             return list;
306         list = list->next;
307     }
308     return NULL;
309 }
310 
311 /**
312  * Replace 8 elements with their average value.
313  * Called by qdm2_decode_superblock before starting subblock decoding.
314  *
315  * @param q       context
316  */
average_quantized_coeffs(QDM2Context *q)317 static void average_quantized_coeffs(QDM2Context *q)
318 {
319     int i, j, n, ch, sum;
320 
321     n = coeff_per_sb_for_avg[q->coeff_per_sb_select][QDM2_SB_USED(q->sub_sampling) - 1] + 1;
322 
323     for (ch = 0; ch < q->nb_channels; ch++)
324         for (i = 0; i < n; i++) {
325             sum = 0;
326 
327             for (j = 0; j < 8; j++)
328                 sum += q->quantized_coeffs[ch][i][j];
329 
330             sum /= 8;
331             if (sum > 0)
332                 sum--;
333 
334             for (j = 0; j < 8; j++)
335                 q->quantized_coeffs[ch][i][j] = sum;
336         }
337 }
338 
339 /**
340  * Build subband samples with noise weighted by q->tone_level.
341  * Called by synthfilt_build_sb_samples.
342  *
343  * @param q     context
344  * @param sb    subband index
345  */
build_sb_samples_from_noise(QDM2Context *q, int sb)346 static void build_sb_samples_from_noise(QDM2Context *q, int sb)
347 {
348     int ch, j;
349 
350     FIX_NOISE_IDX(q->noise_idx);
351 
352     if (!q->nb_channels)
353         return;
354 
355     for (ch = 0; ch < q->nb_channels; ch++) {
356         for (j = 0; j < 64; j++) {
357             q->sb_samples[ch][j * 2][sb] =
358                 SB_DITHERING_NOISE(sb, q->noise_idx) * q->tone_level[ch][sb][j];
359             q->sb_samples[ch][j * 2 + 1][sb] =
360                 SB_DITHERING_NOISE(sb, q->noise_idx) * q->tone_level[ch][sb][j];
361         }
362     }
363 }
364 
365 /**
366  * Called while processing data from subpackets 11 and 12.
367  * Used after making changes to coding_method array.
368  *
369  * @param sb               subband index
370  * @param channels         number of channels
371  * @param coding_method    q->coding_method[0][0][0]
372  */
fix_coding_method_array(int sb, int channels, sb_int8_array coding_method)373 static int fix_coding_method_array(int sb, int channels,
374                                    sb_int8_array coding_method)
375 {
376     int j, k;
377     int ch;
378     int run, case_val;
379 
380     for (ch = 0; ch < channels; ch++) {
381         for (j = 0; j < 64; ) {
382             if (coding_method[ch][sb][j] < 8)
383                 return -1;
384             if ((coding_method[ch][sb][j] - 8) > 22) {
385                 run      = 1;
386                 case_val = 8;
387             } else {
388                 switch (switchtable[coding_method[ch][sb][j] - 8]) {
389                 case 0: run  = 10;
390                     case_val = 10;
391                     break;
392                 case 1: run  = 1;
393                     case_val = 16;
394                     break;
395                 case 2: run  = 5;
396                     case_val = 24;
397                     break;
398                 case 3: run  = 3;
399                     case_val = 30;
400                     break;
401                 case 4: run  = 1;
402                     case_val = 30;
403                     break;
404                 case 5: run  = 1;
405                     case_val = 8;
406                     break;
407                 default: run = 1;
408                     case_val = 8;
409                     break;
410                 }
411             }
412             for (k = 0; k < run; k++) {
413                 if (j + k < 128) {
414                     int sbjk = sb + (j + k) / 64;
415                     if (sbjk > 29) {
416                         SAMPLES_NEEDED
417                         continue;
418                     }
419                     if (coding_method[ch][sbjk][(j + k) % 64] > coding_method[ch][sb][j]) {
420                         if (k > 0) {
421                             SAMPLES_NEEDED
422                             //not debugged, almost never used
423                             memset(&coding_method[ch][sb][j + k], case_val,
424                                    k *sizeof(int8_t));
425                             memset(&coding_method[ch][sb][j + k], case_val,
426                                    3 * sizeof(int8_t));
427                         }
428                     }
429                 }
430             }
431             j += run;
432         }
433     }
434     return 0;
435 }
436 
437 /**
438  * Related to synthesis filter
439  * Called by process_subpacket_10
440  *
441  * @param q       context
442  * @param flag    1 if called after getting data from subpacket 10, 0 if no subpacket 10
443  */
fill_tone_level_array(QDM2Context *q, int flag)444 static void fill_tone_level_array(QDM2Context *q, int flag)
445 {
446     int i, sb, ch, sb_used;
447     int tmp, tab;
448 
449     for (ch = 0; ch < q->nb_channels; ch++)
450         for (sb = 0; sb < 30; sb++)
451             for (i = 0; i < 8; i++) {
452                 if ((tab=coeff_per_sb_for_dequant[q->coeff_per_sb_select][sb]) < (last_coeff[q->coeff_per_sb_select] - 1))
453                     tmp = q->quantized_coeffs[ch][tab + 1][i] * dequant_table[q->coeff_per_sb_select][tab + 1][sb]+
454                           q->quantized_coeffs[ch][tab][i] * dequant_table[q->coeff_per_sb_select][tab][sb];
455                 else
456                     tmp = q->quantized_coeffs[ch][tab][i] * dequant_table[q->coeff_per_sb_select][tab][sb];
457                 if(tmp < 0)
458                     tmp += 0xff;
459                 q->tone_level_idx_base[ch][sb][i] = (tmp / 256) & 0xff;
460             }
461 
462     sb_used = QDM2_SB_USED(q->sub_sampling);
463 
464     if ((q->superblocktype_2_3 != 0) && !flag) {
465         for (sb = 0; sb < sb_used; sb++)
466             for (ch = 0; ch < q->nb_channels; ch++)
467                 for (i = 0; i < 64; i++) {
468                     q->tone_level_idx[ch][sb][i] = q->tone_level_idx_base[ch][sb][i / 8];
469                     if (q->tone_level_idx[ch][sb][i] < 0)
470                         q->tone_level[ch][sb][i] = 0;
471                     else
472                         q->tone_level[ch][sb][i] = fft_tone_level_table[0][q->tone_level_idx[ch][sb][i] & 0x3f];
473                 }
474     } else {
475         tab = q->superblocktype_2_3 ? 0 : 1;
476         for (sb = 0; sb < sb_used; sb++) {
477             if ((sb >= 4) && (sb <= 23)) {
478                 for (ch = 0; ch < q->nb_channels; ch++)
479                     for (i = 0; i < 64; i++) {
480                         tmp = q->tone_level_idx_base[ch][sb][i / 8] -
481                               q->tone_level_idx_hi1[ch][sb / 8][i / 8][i % 8] -
482                               q->tone_level_idx_mid[ch][sb - 4][i / 8] -
483                               q->tone_level_idx_hi2[ch][sb - 4];
484                         q->tone_level_idx[ch][sb][i] = tmp & 0xff;
485                         if ((tmp < 0) || (!q->superblocktype_2_3 && !tmp))
486                             q->tone_level[ch][sb][i] = 0;
487                         else
488                             q->tone_level[ch][sb][i] = fft_tone_level_table[tab][tmp & 0x3f];
489                 }
490             } else {
491                 if (sb > 4) {
492                     for (ch = 0; ch < q->nb_channels; ch++)
493                         for (i = 0; i < 64; i++) {
494                             tmp = q->tone_level_idx_base[ch][sb][i / 8] -
495                                   q->tone_level_idx_hi1[ch][2][i / 8][i % 8] -
496                                   q->tone_level_idx_hi2[ch][sb - 4];
497                             q->tone_level_idx[ch][sb][i] = tmp & 0xff;
498                             if ((tmp < 0) || (!q->superblocktype_2_3 && !tmp))
499                                 q->tone_level[ch][sb][i] = 0;
500                             else
501                                 q->tone_level[ch][sb][i] = fft_tone_level_table[tab][tmp & 0x3f];
502                     }
503                 } else {
504                     for (ch = 0; ch < q->nb_channels; ch++)
505                         for (i = 0; i < 64; i++) {
506                             tmp = q->tone_level_idx[ch][sb][i] = q->tone_level_idx_base[ch][sb][i / 8];
507                             if ((tmp < 0) || (!q->superblocktype_2_3 && !tmp))
508                                 q->tone_level[ch][sb][i] = 0;
509                             else
510                                 q->tone_level[ch][sb][i] = fft_tone_level_table[tab][tmp & 0x3f];
511                         }
512                 }
513             }
514         }
515     }
516 }
517 
518 /**
519  * Related to synthesis filter
520  * Called by process_subpacket_11
521  * c is built with data from subpacket 11
522  * Most of this function is used only if superblock_type_2_3 == 0,
523  * never seen it in samples.
524  *
525  * @param tone_level_idx
526  * @param tone_level_idx_temp
527  * @param coding_method        q->coding_method[0][0][0]
528  * @param nb_channels          number of channels
529  * @param c                    coming from subpacket 11, passed as 8*c
530  * @param superblocktype_2_3   flag based on superblock packet type
531  * @param cm_table_select      q->cm_table_select
532  */
fill_coding_method_array(sb_int8_array tone_level_idx, sb_int8_array tone_level_idx_temp, sb_int8_array coding_method, int nb_channels, int c, int superblocktype_2_3, int cm_table_select)533 static void fill_coding_method_array(sb_int8_array tone_level_idx,
534                                      sb_int8_array tone_level_idx_temp,
535                                      sb_int8_array coding_method,
536                                      int nb_channels,
537                                      int c, int superblocktype_2_3,
538                                      int cm_table_select)
539 {
540     int ch, sb, j;
541     int tmp, acc, esp_40, comp;
542     int add1, add2, add3, add4;
543     int64_t multres;
544 
545     if (!superblocktype_2_3) {
546         /* This case is untested, no samples available */
547         avpriv_request_sample(NULL, "!superblocktype_2_3");
548         return;
549         for (ch = 0; ch < nb_channels; ch++) {
550             for (sb = 0; sb < 30; sb++) {
551                 for (j = 1; j < 63; j++) {  // The loop only iterates to 63 so the code doesn't overflow the buffer
552                     add1 = tone_level_idx[ch][sb][j] - 10;
553                     if (add1 < 0)
554                         add1 = 0;
555                     add2 = add3 = add4 = 0;
556                     if (sb > 1) {
557                         add2 = tone_level_idx[ch][sb - 2][j] + tone_level_idx_offset_table[sb][0] - 6;
558                         if (add2 < 0)
559                             add2 = 0;
560                     }
561                     if (sb > 0) {
562                         add3 = tone_level_idx[ch][sb - 1][j] + tone_level_idx_offset_table[sb][1] - 6;
563                         if (add3 < 0)
564                             add3 = 0;
565                     }
566                     if (sb < 29) {
567                         add4 = tone_level_idx[ch][sb + 1][j] + tone_level_idx_offset_table[sb][3] - 6;
568                         if (add4 < 0)
569                             add4 = 0;
570                     }
571                     tmp = tone_level_idx[ch][sb][j + 1] * 2 - add4 - add3 - add2 - add1;
572                     if (tmp < 0)
573                         tmp = 0;
574                     tone_level_idx_temp[ch][sb][j + 1] = tmp & 0xff;
575                 }
576                 tone_level_idx_temp[ch][sb][0] = tone_level_idx_temp[ch][sb][1];
577             }
578         }
579         acc = 0;
580         for (ch = 0; ch < nb_channels; ch++)
581             for (sb = 0; sb < 30; sb++)
582                 for (j = 0; j < 64; j++)
583                     acc += tone_level_idx_temp[ch][sb][j];
584 
585         multres = 0x66666667LL * (acc * 10);
586         esp_40 = (multres >> 32) / 8 + ((multres & 0xffffffff) >> 31);
587         for (ch = 0;  ch < nb_channels; ch++)
588             for (sb = 0; sb < 30; sb++)
589                 for (j = 0; j < 64; j++) {
590                     comp = tone_level_idx_temp[ch][sb][j]* esp_40 * 10;
591                     if (comp < 0)
592                         comp += 0xff;
593                     comp /= 256; // signed shift
594                     switch(sb) {
595                         case 0:
596                             if (comp < 30)
597                                 comp = 30;
598                             comp += 15;
599                             break;
600                         case 1:
601                             if (comp < 24)
602                                 comp = 24;
603                             comp += 10;
604                             break;
605                         case 2:
606                         case 3:
607                         case 4:
608                             if (comp < 16)
609                                 comp = 16;
610                     }
611                     if (comp <= 5)
612                         tmp = 0;
613                     else if (comp <= 10)
614                         tmp = 10;
615                     else if (comp <= 16)
616                         tmp = 16;
617                     else if (comp <= 24)
618                         tmp = -1;
619                     else
620                         tmp = 0;
621                     coding_method[ch][sb][j] = ((tmp & 0xfffa) + 30 )& 0xff;
622                 }
623         for (sb = 0; sb < 30; sb++)
624             fix_coding_method_array(sb, nb_channels, coding_method);
625         for (ch = 0; ch < nb_channels; ch++)
626             for (sb = 0; sb < 30; sb++)
627                 for (j = 0; j < 64; j++)
628                     if (sb >= 10) {
629                         if (coding_method[ch][sb][j] < 10)
630                             coding_method[ch][sb][j] = 10;
631                     } else {
632                         if (sb >= 2) {
633                             if (coding_method[ch][sb][j] < 16)
634                                 coding_method[ch][sb][j] = 16;
635                         } else {
636                             if (coding_method[ch][sb][j] < 30)
637                                 coding_method[ch][sb][j] = 30;
638                         }
639                     }
640     } else { // superblocktype_2_3 != 0
641         for (ch = 0; ch < nb_channels; ch++)
642             for (sb = 0; sb < 30; sb++)
643                 for (j = 0; j < 64; j++)
644                     coding_method[ch][sb][j] = coding_method_table[cm_table_select][sb];
645     }
646 }
647 
648 /**
649  * Called by process_subpacket_11 to process more data from subpacket 11
650  * with sb 0-8.
651  * Called by process_subpacket_12 to process data from subpacket 12 with
652  * sb 8-sb_used.
653  *
654  * @param q         context
655  * @param gb        bitreader context
656  * @param length    packet length in bits
657  * @param sb_min    lower subband processed (sb_min included)
658  * @param sb_max    higher subband processed (sb_max excluded)
659  */
synthfilt_build_sb_samples(QDM2Context *q, GetBitContext *gb, int length, int sb_min, int sb_max)660 static int synthfilt_build_sb_samples(QDM2Context *q, GetBitContext *gb,
661                                        int length, int sb_min, int sb_max)
662 {
663     int sb, j, k, n, ch, run, channels;
664     int joined_stereo, zero_encoding;
665     int type34_first;
666     float type34_div = 0;
667     float type34_predictor;
668     float samples[10];
669     int sign_bits[16] = {0};
670 
671     if (length == 0) {
672         // If no data use noise
673         for (sb=sb_min; sb < sb_max; sb++)
674             build_sb_samples_from_noise(q, sb);
675 
676         return 0;
677     }
678 
679     for (sb = sb_min; sb < sb_max; sb++) {
680         channels = q->nb_channels;
681 
682         if (q->nb_channels <= 1 || sb < 12)
683             joined_stereo = 0;
684         else if (sb >= 24)
685             joined_stereo = 1;
686         else
687             joined_stereo = (get_bits_left(gb) >= 1) ? get_bits1(gb) : 0;
688 
689         if (joined_stereo) {
690             if (get_bits_left(gb) >= 16)
691                 for (j = 0; j < 16; j++)
692                     sign_bits[j] = get_bits1(gb);
693 
694             for (j = 0; j < 64; j++)
695                 if (q->coding_method[1][sb][j] > q->coding_method[0][sb][j])
696                     q->coding_method[0][sb][j] = q->coding_method[1][sb][j];
697 
698             if (fix_coding_method_array(sb, q->nb_channels,
699                                             q->coding_method)) {
700                 av_log(NULL, AV_LOG_ERROR, "coding method invalid\n");
701                 build_sb_samples_from_noise(q, sb);
702                 continue;
703             }
704             channels = 1;
705         }
706 
707         for (ch = 0; ch < channels; ch++) {
708             FIX_NOISE_IDX(q->noise_idx);
709             zero_encoding = (get_bits_left(gb) >= 1) ? get_bits1(gb) : 0;
710             type34_predictor = 0.0;
711             type34_first = 1;
712 
713             for (j = 0; j < 128; ) {
714                 switch (q->coding_method[ch][sb][j / 2]) {
715                     case 8:
716                         if (get_bits_left(gb) >= 10) {
717                             if (zero_encoding) {
718                                 for (k = 0; k < 5; k++) {
719                                     if ((j + 2 * k) >= 128)
720                                         break;
721                                     samples[2 * k] = get_bits1(gb) ? dequant_1bit[joined_stereo][2 * get_bits1(gb)] : 0;
722                                 }
723                             } else {
724                                 n = get_bits(gb, 8);
725                                 if (n >= 243) {
726                                     av_log(NULL, AV_LOG_ERROR, "Invalid 8bit codeword\n");
727                                     return AVERROR_INVALIDDATA;
728                                 }
729 
730                                 for (k = 0; k < 5; k++)
731                                     samples[2 * k] = dequant_1bit[joined_stereo][random_dequant_index[n][k]];
732                             }
733                             for (k = 0; k < 5; k++)
734                                 samples[2 * k + 1] = SB_DITHERING_NOISE(sb,q->noise_idx);
735                         } else {
736                             for (k = 0; k < 10; k++)
737                                 samples[k] = SB_DITHERING_NOISE(sb,q->noise_idx);
738                         }
739                         run = 10;
740                         break;
741 
742                     case 10:
743                         if (get_bits_left(gb) >= 1) {
744                             float f = 0.81;
745 
746                             if (get_bits1(gb))
747                                 f = -f;
748                             f -= noise_samples[((sb + 1) * (j +5 * ch + 1)) & 127] * 9.0 / 40.0;
749                             samples[0] = f;
750                         } else {
751                             samples[0] = SB_DITHERING_NOISE(sb,q->noise_idx);
752                         }
753                         run = 1;
754                         break;
755 
756                     case 16:
757                         if (get_bits_left(gb) >= 10) {
758                             if (zero_encoding) {
759                                 for (k = 0; k < 5; k++) {
760                                     if ((j + k) >= 128)
761                                         break;
762                                     samples[k] = (get_bits1(gb) == 0) ? 0 : dequant_1bit[joined_stereo][2 * get_bits1(gb)];
763                                 }
764                             } else {
765                                 n = get_bits (gb, 8);
766                                 if (n >= 243) {
767                                     av_log(NULL, AV_LOG_ERROR, "Invalid 8bit codeword\n");
768                                     return AVERROR_INVALIDDATA;
769                                 }
770 
771                                 for (k = 0; k < 5; k++)
772                                     samples[k] = dequant_1bit[joined_stereo][random_dequant_index[n][k]];
773                             }
774                         } else {
775                             for (k = 0; k < 5; k++)
776                                 samples[k] = SB_DITHERING_NOISE(sb,q->noise_idx);
777                         }
778                         run = 5;
779                         break;
780 
781                     case 24:
782                         if (get_bits_left(gb) >= 7) {
783                             n = get_bits(gb, 7);
784                             if (n >= 125) {
785                                 av_log(NULL, AV_LOG_ERROR, "Invalid 7bit codeword\n");
786                                 return AVERROR_INVALIDDATA;
787                             }
788 
789                             for (k = 0; k < 3; k++)
790                                 samples[k] = (random_dequant_type24[n][k] - 2.0) * 0.5;
791                         } else {
792                             for (k = 0; k < 3; k++)
793                                 samples[k] = SB_DITHERING_NOISE(sb,q->noise_idx);
794                         }
795                         run = 3;
796                         break;
797 
798                     case 30:
799                         if (get_bits_left(gb) >= 4) {
800                             unsigned index = qdm2_get_vlc(gb, &vlc_tab_type30, 0, 1);
801                             if (index >= FF_ARRAY_ELEMS(type30_dequant)) {
802                                 av_log(NULL, AV_LOG_ERROR, "index %d out of type30_dequant array\n", index);
803                                 return AVERROR_INVALIDDATA;
804                             }
805                             samples[0] = type30_dequant[index];
806                         } else
807                             samples[0] = SB_DITHERING_NOISE(sb,q->noise_idx);
808 
809                         run = 1;
810                         break;
811 
812                     case 34:
813                         if (get_bits_left(gb) >= 7) {
814                             if (type34_first) {
815                                 type34_div = (float)(1 << get_bits(gb, 2));
816                                 samples[0] = ((float)get_bits(gb, 5) - 16.0) / 15.0;
817                                 type34_predictor = samples[0];
818                                 type34_first = 0;
819                             } else {
820                                 unsigned index = qdm2_get_vlc(gb, &vlc_tab_type34, 0, 1);
821                                 if (index >= FF_ARRAY_ELEMS(type34_delta)) {
822                                     av_log(NULL, AV_LOG_ERROR, "index %d out of type34_delta array\n", index);
823                                     return AVERROR_INVALIDDATA;
824                                 }
825                                 samples[0] = type34_delta[index] / type34_div + type34_predictor;
826                                 type34_predictor = samples[0];
827                             }
828                         } else {
829                             samples[0] = SB_DITHERING_NOISE(sb,q->noise_idx);
830                         }
831                         run = 1;
832                         break;
833 
834                     default:
835                         samples[0] = SB_DITHERING_NOISE(sb,q->noise_idx);
836                         run = 1;
837                         break;
838                 }
839 
840                 if (joined_stereo) {
841                     for (k = 0; k < run && j + k < 128; k++) {
842                         q->sb_samples[0][j + k][sb] =
843                             q->tone_level[0][sb][(j + k) / 2] * samples[k];
844                         if (q->nb_channels == 2) {
845                             if (sign_bits[(j + k) / 8])
846                                 q->sb_samples[1][j + k][sb] =
847                                     q->tone_level[1][sb][(j + k) / 2] * -samples[k];
848                             else
849                                 q->sb_samples[1][j + k][sb] =
850                                     q->tone_level[1][sb][(j + k) / 2] * samples[k];
851                         }
852                     }
853                 } else {
854                     for (k = 0; k < run; k++)
855                         if ((j + k) < 128)
856                             q->sb_samples[ch][j + k][sb] = q->tone_level[ch][sb][(j + k)/2] * samples[k];
857                 }
858 
859                 j += run;
860             } // j loop
861         } // channel loop
862     } // subband loop
863     return 0;
864 }
865 
866 /**
867  * Init the first element of a channel in quantized_coeffs with data
868  * from packet 10 (quantized_coeffs[ch][0]).
869  * This is similar to process_subpacket_9, but for a single channel
870  * and for element [0]
871  * same VLC tables as process_subpacket_9 are used.
872  *
873  * @param quantized_coeffs    pointer to quantized_coeffs[ch][0]
874  * @param gb        bitreader context
875  */
init_quantized_coeffs_elem0(int8_t *quantized_coeffs, GetBitContext *gb)876 static int init_quantized_coeffs_elem0(int8_t *quantized_coeffs,
877                                         GetBitContext *gb)
878 {
879     int i, k, run, level, diff;
880 
881     if (get_bits_left(gb) < 16)
882         return -1;
883     level = qdm2_get_vlc(gb, &vlc_tab_level, 0, 2);
884 
885     quantized_coeffs[0] = level;
886 
887     for (i = 0; i < 7; ) {
888         if (get_bits_left(gb) < 16)
889             return -1;
890         run = qdm2_get_vlc(gb, &vlc_tab_run, 0, 1) + 1;
891 
892         if (i + run >= 8)
893             return -1;
894 
895         if (get_bits_left(gb) < 16)
896             return -1;
897         diff = qdm2_get_se_vlc(&vlc_tab_diff, gb, 2);
898 
899         for (k = 1; k <= run; k++)
900             quantized_coeffs[i + k] = (level + ((k * diff) / run));
901 
902         level += diff;
903         i += run;
904     }
905     return 0;
906 }
907 
908 /**
909  * Related to synthesis filter, process data from packet 10
910  * Init part of quantized_coeffs via function init_quantized_coeffs_elem0
911  * Init tone_level_idx_hi1, tone_level_idx_hi2, tone_level_idx_mid with
912  * data from packet 10
913  *
914  * @param q         context
915  * @param gb        bitreader context
916  */
init_tone_level_dequantization(QDM2Context *q, GetBitContext *gb)917 static void init_tone_level_dequantization(QDM2Context *q, GetBitContext *gb)
918 {
919     int sb, j, k, n, ch;
920 
921     for (ch = 0; ch < q->nb_channels; ch++) {
922         init_quantized_coeffs_elem0(q->quantized_coeffs[ch][0], gb);
923 
924         if (get_bits_left(gb) < 16) {
925             memset(q->quantized_coeffs[ch][0], 0, 8);
926             break;
927         }
928     }
929 
930     n = q->sub_sampling + 1;
931 
932     for (sb = 0; sb < n; sb++)
933         for (ch = 0; ch < q->nb_channels; ch++)
934             for (j = 0; j < 8; j++) {
935                 if (get_bits_left(gb) < 1)
936                     break;
937                 if (get_bits1(gb)) {
938                     for (k=0; k < 8; k++) {
939                         if (get_bits_left(gb) < 16)
940                             break;
941                         q->tone_level_idx_hi1[ch][sb][j][k] = qdm2_get_vlc(gb, &vlc_tab_tone_level_idx_hi1, 0, 2);
942                     }
943                 } else {
944                     for (k=0; k < 8; k++)
945                         q->tone_level_idx_hi1[ch][sb][j][k] = 0;
946                 }
947             }
948 
949     n = QDM2_SB_USED(q->sub_sampling) - 4;
950 
951     for (sb = 0; sb < n; sb++)
952         for (ch = 0; ch < q->nb_channels; ch++) {
953             if (get_bits_left(gb) < 16)
954                 break;
955             q->tone_level_idx_hi2[ch][sb] = qdm2_get_vlc(gb, &vlc_tab_tone_level_idx_hi2, 0, 2);
956             if (sb > 19)
957                 q->tone_level_idx_hi2[ch][sb] -= 16;
958             else
959                 for (j = 0; j < 8; j++)
960                     q->tone_level_idx_mid[ch][sb][j] = -16;
961         }
962 
963     n = QDM2_SB_USED(q->sub_sampling) - 5;
964 
965     for (sb = 0; sb < n; sb++)
966         for (ch = 0; ch < q->nb_channels; ch++)
967             for (j = 0; j < 8; j++) {
968                 if (get_bits_left(gb) < 16)
969                     break;
970                 q->tone_level_idx_mid[ch][sb][j] = qdm2_get_vlc(gb, &vlc_tab_tone_level_idx_mid, 0, 2) - 32;
971             }
972 }
973 
974 /**
975  * Process subpacket 9, init quantized_coeffs with data from it
976  *
977  * @param q       context
978  * @param node    pointer to node with packet
979  */
process_subpacket_9(QDM2Context *q, QDM2SubPNode *node)980 static int process_subpacket_9(QDM2Context *q, QDM2SubPNode *node)
981 {
982     GetBitContext gb;
983     int i, j, k, n, ch, run, level, diff;
984 
985     init_get_bits(&gb, node->packet->data, node->packet->size * 8);
986 
987     n = coeff_per_sb_for_avg[q->coeff_per_sb_select][QDM2_SB_USED(q->sub_sampling) - 1] + 1;
988 
989     for (i = 1; i < n; i++)
990         for (ch = 0; ch < q->nb_channels; ch++) {
991             level = qdm2_get_vlc(&gb, &vlc_tab_level, 0, 2);
992             q->quantized_coeffs[ch][i][0] = level;
993 
994             for (j = 0; j < (8 - 1); ) {
995                 run  = qdm2_get_vlc(&gb, &vlc_tab_run, 0, 1) + 1;
996                 diff = qdm2_get_se_vlc(&vlc_tab_diff, &gb, 2);
997 
998                 if (j + run >= 8)
999                     return -1;
1000 
1001                 for (k = 1; k <= run; k++)
1002                     q->quantized_coeffs[ch][i][j + k] = (level + ((k * diff) / run));
1003 
1004                 level += diff;
1005                 j     += run;
1006             }
1007         }
1008 
1009     for (ch = 0; ch < q->nb_channels; ch++)
1010         for (i = 0; i < 8; i++)
1011             q->quantized_coeffs[ch][0][i] = 0;
1012 
1013     return 0;
1014 }
1015 
1016 /**
1017  * Process subpacket 10 if not null, else
1018  *
1019  * @param q         context
1020  * @param node      pointer to node with packet
1021  */
process_subpacket_10(QDM2Context *q, QDM2SubPNode *node)1022 static void process_subpacket_10(QDM2Context *q, QDM2SubPNode *node)
1023 {
1024     GetBitContext gb;
1025 
1026     if (node) {
1027         init_get_bits(&gb, node->packet->data, node->packet->size * 8);
1028         init_tone_level_dequantization(q, &gb);
1029         fill_tone_level_array(q, 1);
1030     } else {
1031         fill_tone_level_array(q, 0);
1032     }
1033 }
1034 
1035 /**
1036  * Process subpacket 11
1037  *
1038  * @param q         context
1039  * @param node      pointer to node with packet
1040  */
process_subpacket_11(QDM2Context *q, QDM2SubPNode *node)1041 static void process_subpacket_11(QDM2Context *q, QDM2SubPNode *node)
1042 {
1043     GetBitContext gb;
1044     int length = 0;
1045 
1046     if (node) {
1047         length = node->packet->size * 8;
1048         init_get_bits(&gb, node->packet->data, length);
1049     }
1050 
1051     if (length >= 32) {
1052         int c = get_bits(&gb, 13);
1053 
1054         if (c > 3)
1055             fill_coding_method_array(q->tone_level_idx,
1056                                      q->tone_level_idx_temp, q->coding_method,
1057                                      q->nb_channels, 8 * c,
1058                                      q->superblocktype_2_3, q->cm_table_select);
1059     }
1060 
1061     synthfilt_build_sb_samples(q, &gb, length, 0, 8);
1062 }
1063 
1064 /**
1065  * Process subpacket 12
1066  *
1067  * @param q         context
1068  * @param node      pointer to node with packet
1069  */
process_subpacket_12(QDM2Context *q, QDM2SubPNode *node)1070 static void process_subpacket_12(QDM2Context *q, QDM2SubPNode *node)
1071 {
1072     GetBitContext gb;
1073     int length = 0;
1074 
1075     if (node) {
1076         length = node->packet->size * 8;
1077         init_get_bits(&gb, node->packet->data, length);
1078     }
1079 
1080     synthfilt_build_sb_samples(q, &gb, length, 8, QDM2_SB_USED(q->sub_sampling));
1081 }
1082 
1083 /**
1084  * Process new subpackets for synthesis filter
1085  *
1086  * @param q       context
1087  * @param list    list with synthesis filter packets (list D)
1088  */
process_synthesis_subpackets(QDM2Context *q, QDM2SubPNode *list)1089 static void process_synthesis_subpackets(QDM2Context *q, QDM2SubPNode *list)
1090 {
1091     QDM2SubPNode *nodes[4];
1092 
1093     nodes[0] = qdm2_search_subpacket_type_in_list(list, 9);
1094     if (nodes[0])
1095         process_subpacket_9(q, nodes[0]);
1096 
1097     nodes[1] = qdm2_search_subpacket_type_in_list(list, 10);
1098     if (nodes[1])
1099         process_subpacket_10(q, nodes[1]);
1100     else
1101         process_subpacket_10(q, NULL);
1102 
1103     nodes[2] = qdm2_search_subpacket_type_in_list(list, 11);
1104     if (nodes[0] && nodes[1] && nodes[2])
1105         process_subpacket_11(q, nodes[2]);
1106     else
1107         process_subpacket_11(q, NULL);
1108 
1109     nodes[3] = qdm2_search_subpacket_type_in_list(list, 12);
1110     if (nodes[0] && nodes[1] && nodes[3])
1111         process_subpacket_12(q, nodes[3]);
1112     else
1113         process_subpacket_12(q, NULL);
1114 }
1115 
1116 /**
1117  * Decode superblock, fill packet lists.
1118  *
1119  * @param q    context
1120  */
qdm2_decode_super_block(QDM2Context *q)1121 static void qdm2_decode_super_block(QDM2Context *q)
1122 {
1123     GetBitContext gb;
1124     QDM2SubPacket header, *packet;
1125     int i, packet_bytes, sub_packet_size, sub_packets_D;
1126     unsigned int next_index = 0;
1127 
1128     memset(q->tone_level_idx_hi1, 0, sizeof(q->tone_level_idx_hi1));
1129     memset(q->tone_level_idx_mid, 0, sizeof(q->tone_level_idx_mid));
1130     memset(q->tone_level_idx_hi2, 0, sizeof(q->tone_level_idx_hi2));
1131 
1132     q->sub_packets_B = 0;
1133     sub_packets_D    = 0;
1134 
1135     average_quantized_coeffs(q); // average elements in quantized_coeffs[max_ch][10][8]
1136 
1137     init_get_bits(&gb, q->compressed_data, q->compressed_size * 8);
1138     qdm2_decode_sub_packet_header(&gb, &header);
1139 
1140     if (header.type < 2 || header.type >= 8) {
1141         q->has_errors = 1;
1142         av_log(NULL, AV_LOG_ERROR, "bad superblock type\n");
1143         return;
1144     }
1145 
1146     q->superblocktype_2_3 = (header.type == 2 || header.type == 3);
1147     packet_bytes          = (q->compressed_size - get_bits_count(&gb) / 8);
1148 
1149     init_get_bits(&gb, header.data, header.size * 8);
1150 
1151     if (header.type == 2 || header.type == 4 || header.type == 5) {
1152         int csum = 257 * get_bits(&gb, 8);
1153         csum += 2 * get_bits(&gb, 8);
1154 
1155         csum = qdm2_packet_checksum(q->compressed_data, q->checksum_size, csum);
1156 
1157         if (csum != 0) {
1158             q->has_errors = 1;
1159             av_log(NULL, AV_LOG_ERROR, "bad packet checksum\n");
1160             return;
1161         }
1162     }
1163 
1164     q->sub_packet_list_B[0].packet = NULL;
1165     q->sub_packet_list_D[0].packet = NULL;
1166 
1167     for (i = 0; i < 6; i++)
1168         if (--q->fft_level_exp[i] < 0)
1169             q->fft_level_exp[i] = 0;
1170 
1171     for (i = 0; packet_bytes > 0; i++) {
1172         int j;
1173 
1174         if (i >= FF_ARRAY_ELEMS(q->sub_packet_list_A)) {
1175             SAMPLES_NEEDED_2("too many packet bytes");
1176             return;
1177         }
1178 
1179         q->sub_packet_list_A[i].next = NULL;
1180 
1181         if (i > 0) {
1182             q->sub_packet_list_A[i - 1].next = &q->sub_packet_list_A[i];
1183 
1184             /* seek to next block */
1185             init_get_bits(&gb, header.data, header.size * 8);
1186             skip_bits(&gb, next_index * 8);
1187 
1188             if (next_index >= header.size)
1189                 break;
1190         }
1191 
1192         /* decode subpacket */
1193         packet = &q->sub_packets[i];
1194         qdm2_decode_sub_packet_header(&gb, packet);
1195         next_index      = packet->size + get_bits_count(&gb) / 8;
1196         sub_packet_size = ((packet->size > 0xff) ? 1 : 0) + packet->size + 2;
1197 
1198         if (packet->type == 0)
1199             break;
1200 
1201         if (sub_packet_size > packet_bytes) {
1202             if (packet->type != 10 && packet->type != 11 && packet->type != 12)
1203                 break;
1204             packet->size += packet_bytes - sub_packet_size;
1205         }
1206 
1207         packet_bytes -= sub_packet_size;
1208 
1209         /* add subpacket to 'all subpackets' list */
1210         q->sub_packet_list_A[i].packet = packet;
1211 
1212         /* add subpacket to related list */
1213         if (packet->type == 8) {
1214             SAMPLES_NEEDED_2("packet type 8");
1215             return;
1216         } else if (packet->type >= 9 && packet->type <= 12) {
1217             /* packets for MPEG Audio like Synthesis Filter */
1218             QDM2_LIST_ADD(q->sub_packet_list_D, sub_packets_D, packet);
1219         } else if (packet->type == 13) {
1220             for (j = 0; j < 6; j++)
1221                 q->fft_level_exp[j] = get_bits(&gb, 6);
1222         } else if (packet->type == 14) {
1223             for (j = 0; j < 6; j++)
1224                 q->fft_level_exp[j] = qdm2_get_vlc(&gb, &fft_level_exp_vlc, 0, 2);
1225         } else if (packet->type == 15) {
1226             SAMPLES_NEEDED_2("packet type 15")
1227             return;
1228         } else if (packet->type >= 16 && packet->type < 48 &&
1229                    !fft_subpackets[packet->type - 16]) {
1230             /* packets for FFT */
1231             QDM2_LIST_ADD(q->sub_packet_list_B, q->sub_packets_B, packet);
1232         }
1233     } // Packet bytes loop
1234 
1235     if (q->sub_packet_list_D[0].packet) {
1236         process_synthesis_subpackets(q, q->sub_packet_list_D);
1237         q->do_synth_filter = 1;
1238     } else if (q->do_synth_filter) {
1239         process_subpacket_10(q, NULL);
1240         process_subpacket_11(q, NULL);
1241         process_subpacket_12(q, NULL);
1242     }
1243 }
1244 
qdm2_fft_init_coefficient(QDM2Context *q, int sub_packet, int offset, int duration, int channel, int exp, int phase)1245 static void qdm2_fft_init_coefficient(QDM2Context *q, int sub_packet,
1246                                       int offset, int duration, int channel,
1247                                       int exp, int phase)
1248 {
1249     if (q->fft_coefs_min_index[duration] < 0)
1250         q->fft_coefs_min_index[duration] = q->fft_coefs_index;
1251 
1252     q->fft_coefs[q->fft_coefs_index].sub_packet =
1253         ((sub_packet >= 16) ? (sub_packet - 16) : sub_packet);
1254     q->fft_coefs[q->fft_coefs_index].channel = channel;
1255     q->fft_coefs[q->fft_coefs_index].offset  = offset;
1256     q->fft_coefs[q->fft_coefs_index].exp     = exp;
1257     q->fft_coefs[q->fft_coefs_index].phase   = phase;
1258     q->fft_coefs_index++;
1259 }
1260 
qdm2_fft_decode_tones(QDM2Context *q, int duration, GetBitContext *gb, int b)1261 static void qdm2_fft_decode_tones(QDM2Context *q, int duration,
1262                                   GetBitContext *gb, int b)
1263 {
1264     int channel, stereo, phase, exp;
1265     int local_int_4, local_int_8, stereo_phase, local_int_10;
1266     int local_int_14, stereo_exp, local_int_20, local_int_28;
1267     int n, offset;
1268 
1269     local_int_4  = 0;
1270     local_int_28 = 0;
1271     local_int_20 = 2;
1272     local_int_8  = (4 - duration);
1273     local_int_10 = 1 << (q->group_order - duration - 1);
1274     offset       = 1;
1275 
1276     while (get_bits_left(gb)>0) {
1277         if (q->superblocktype_2_3) {
1278             while ((n = qdm2_get_vlc(gb, &vlc_tab_fft_tone_offset[local_int_8], 1, 2)) < 2) {
1279                 if (get_bits_left(gb)<0) {
1280                     if(local_int_4 < q->group_size)
1281                         av_log(NULL, AV_LOG_ERROR, "overread in qdm2_fft_decode_tones()\n");
1282                     return;
1283                 }
1284                 offset = 1;
1285                 if (n == 0) {
1286                     local_int_4  += local_int_10;
1287                     local_int_28 += (1 << local_int_8);
1288                 } else {
1289                     local_int_4  += 8 * local_int_10;
1290                     local_int_28 += (8 << local_int_8);
1291                 }
1292             }
1293             offset += (n - 2);
1294         } else {
1295             if (local_int_10 <= 2) {
1296                 av_log(NULL, AV_LOG_ERROR, "qdm2_fft_decode_tones() stuck\n");
1297                 return;
1298             }
1299             offset += qdm2_get_vlc(gb, &vlc_tab_fft_tone_offset[local_int_8], 1, 2);
1300             while (offset >= (local_int_10 - 1)) {
1301                 offset       += (1 - (local_int_10 - 1));
1302                 local_int_4  += local_int_10;
1303                 local_int_28 += (1 << local_int_8);
1304             }
1305         }
1306 
1307         if (local_int_4 >= q->group_size)
1308             return;
1309 
1310         local_int_14 = (offset >> local_int_8);
1311         if (local_int_14 >= FF_ARRAY_ELEMS(fft_level_index_table))
1312             return;
1313 
1314         if (q->nb_channels > 1) {
1315             channel = get_bits1(gb);
1316             stereo  = get_bits1(gb);
1317         } else {
1318             channel = 0;
1319             stereo  = 0;
1320         }
1321 
1322         exp  = qdm2_get_vlc(gb, (b ? &fft_level_exp_vlc : &fft_level_exp_alt_vlc), 0, 2);
1323         exp += q->fft_level_exp[fft_level_index_table[local_int_14]];
1324         exp  = (exp < 0) ? 0 : exp;
1325 
1326         phase        = get_bits(gb, 3);
1327         stereo_exp   = 0;
1328         stereo_phase = 0;
1329 
1330         if (stereo) {
1331             stereo_exp   = (exp - qdm2_get_vlc(gb, &fft_stereo_exp_vlc, 0, 1));
1332             stereo_phase = (phase - qdm2_get_vlc(gb, &fft_stereo_phase_vlc, 0, 1));
1333             if (stereo_phase < 0)
1334                 stereo_phase += 8;
1335         }
1336 
1337         if (q->frequency_range > (local_int_14 + 1)) {
1338             int sub_packet = (local_int_20 + local_int_28);
1339 
1340             if (q->fft_coefs_index + stereo >= FF_ARRAY_ELEMS(q->fft_coefs))
1341                 return;
1342 
1343             qdm2_fft_init_coefficient(q, sub_packet, offset, duration,
1344                                       channel, exp, phase);
1345             if (stereo)
1346                 qdm2_fft_init_coefficient(q, sub_packet, offset, duration,
1347                                           1 - channel,
1348                                           stereo_exp, stereo_phase);
1349         }
1350         offset++;
1351     }
1352 }
1353 
qdm2_decode_fft_packets(QDM2Context *q)1354 static void qdm2_decode_fft_packets(QDM2Context *q)
1355 {
1356     int i, j, min, max, value, type, unknown_flag;
1357     GetBitContext gb;
1358 
1359     if (!q->sub_packet_list_B[0].packet)
1360         return;
1361 
1362     /* reset minimum indexes for FFT coefficients */
1363     q->fft_coefs_index = 0;
1364     for (i = 0; i < 5; i++)
1365         q->fft_coefs_min_index[i] = -1;
1366 
1367     /* process subpackets ordered by type, largest type first */
1368     for (i = 0, max = 256; i < q->sub_packets_B; i++) {
1369         QDM2SubPacket *packet = NULL;
1370 
1371         /* find subpacket with largest type less than max */
1372         for (j = 0, min = 0; j < q->sub_packets_B; j++) {
1373             value = q->sub_packet_list_B[j].packet->type;
1374             if (value > min && value < max) {
1375                 min    = value;
1376                 packet = q->sub_packet_list_B[j].packet;
1377             }
1378         }
1379 
1380         max = min;
1381 
1382         /* check for errors (?) */
1383         if (!packet)
1384             return;
1385 
1386         if (i == 0 &&
1387             (packet->type < 16 || packet->type >= 48 ||
1388              fft_subpackets[packet->type - 16]))
1389             return;
1390 
1391         /* decode FFT tones */
1392         init_get_bits(&gb, packet->data, packet->size * 8);
1393 
1394         if (packet->type >= 32 && packet->type < 48 && !fft_subpackets[packet->type - 16])
1395             unknown_flag = 1;
1396         else
1397             unknown_flag = 0;
1398 
1399         type = packet->type;
1400 
1401         if ((type >= 17 && type < 24) || (type >= 33 && type < 40)) {
1402             int duration = q->sub_sampling + 5 - (type & 15);
1403 
1404             if (duration >= 0 && duration < 4)
1405                 qdm2_fft_decode_tones(q, duration, &gb, unknown_flag);
1406         } else if (type == 31) {
1407             for (j = 0; j < 4; j++)
1408                 qdm2_fft_decode_tones(q, j, &gb, unknown_flag);
1409         } else if (type == 46) {
1410             for (j = 0; j < 6; j++)
1411                 q->fft_level_exp[j] = get_bits(&gb, 6);
1412             for (j = 0; j < 4; j++)
1413                 qdm2_fft_decode_tones(q, j, &gb, unknown_flag);
1414         }
1415     } // Loop on B packets
1416 
1417     /* calculate maximum indexes for FFT coefficients */
1418     for (i = 0, j = -1; i < 5; i++)
1419         if (q->fft_coefs_min_index[i] >= 0) {
1420             if (j >= 0)
1421                 q->fft_coefs_max_index[j] = q->fft_coefs_min_index[i];
1422             j = i;
1423         }
1424     if (j >= 0)
1425         q->fft_coefs_max_index[j] = q->fft_coefs_index;
1426 }
1427 
qdm2_fft_generate_tone(QDM2Context *q, FFTTone *tone)1428 static void qdm2_fft_generate_tone(QDM2Context *q, FFTTone *tone)
1429 {
1430     float level, f[6];
1431     int i;
1432     QDM2Complex c;
1433     const double iscale = 2.0 * M_PI / 512.0;
1434 
1435     tone->phase += tone->phase_shift;
1436 
1437     /* calculate current level (maximum amplitude) of tone */
1438     level = fft_tone_envelope_table[tone->duration][tone->time_index] * tone->level;
1439     c.im  = level * sin(tone->phase * iscale);
1440     c.re  = level * cos(tone->phase * iscale);
1441 
1442     /* generate FFT coefficients for tone */
1443     if (tone->duration >= 3 || tone->cutoff >= 3) {
1444         tone->complex[0].im += c.im;
1445         tone->complex[0].re += c.re;
1446         tone->complex[1].im -= c.im;
1447         tone->complex[1].re -= c.re;
1448     } else {
1449         f[1] = -tone->table[4];
1450         f[0] = tone->table[3] - tone->table[0];
1451         f[2] = 1.0 - tone->table[2] - tone->table[3];
1452         f[3] = tone->table[1] + tone->table[4] - 1.0;
1453         f[4] = tone->table[0] - tone->table[1];
1454         f[5] = tone->table[2];
1455         for (i = 0; i < 2; i++) {
1456             tone->complex[fft_cutoff_index_table[tone->cutoff][i]].re +=
1457                 c.re * f[i];
1458             tone->complex[fft_cutoff_index_table[tone->cutoff][i]].im +=
1459                 c.im * ((tone->cutoff <= i) ? -f[i] : f[i]);
1460         }
1461         for (i = 0; i < 4; i++) {
1462             tone->complex[i].re += c.re * f[i + 2];
1463             tone->complex[i].im += c.im * f[i + 2];
1464         }
1465     }
1466 
1467     /* copy the tone if it has not yet died out */
1468     if (++tone->time_index < ((1 << (5 - tone->duration)) - 1)) {
1469         memcpy(&q->fft_tones[q->fft_tone_end], tone, sizeof(FFTTone));
1470         q->fft_tone_end = (q->fft_tone_end + 1) % 1000;
1471     }
1472 }
1473 
qdm2_fft_tone_synthesizer(QDM2Context *q, int sub_packet)1474 static void qdm2_fft_tone_synthesizer(QDM2Context *q, int sub_packet)
1475 {
1476     int i, j, ch;
1477     const double iscale = 0.25 * M_PI;
1478 
1479     for (ch = 0; ch < q->channels; ch++) {
1480         memset(q->fft.complex[ch], 0, q->fft_size * sizeof(QDM2Complex));
1481     }
1482 
1483 
1484     /* apply FFT tones with duration 4 (1 FFT period) */
1485     if (q->fft_coefs_min_index[4] >= 0)
1486         for (i = q->fft_coefs_min_index[4]; i < q->fft_coefs_max_index[4]; i++) {
1487             float level;
1488             QDM2Complex c;
1489 
1490             if (q->fft_coefs[i].sub_packet != sub_packet)
1491                 break;
1492 
1493             ch = (q->channels == 1) ? 0 : q->fft_coefs[i].channel;
1494             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];
1495 
1496             c.re = level * cos(q->fft_coefs[i].phase * iscale);
1497             c.im = level * sin(q->fft_coefs[i].phase * iscale);
1498             q->fft.complex[ch][q->fft_coefs[i].offset + 0].re += c.re;
1499             q->fft.complex[ch][q->fft_coefs[i].offset + 0].im += c.im;
1500             q->fft.complex[ch][q->fft_coefs[i].offset + 1].re -= c.re;
1501             q->fft.complex[ch][q->fft_coefs[i].offset + 1].im -= c.im;
1502         }
1503 
1504     /* generate existing FFT tones */
1505     for (i = q->fft_tone_end; i != q->fft_tone_start; ) {
1506         qdm2_fft_generate_tone(q, &q->fft_tones[q->fft_tone_start]);
1507         q->fft_tone_start = (q->fft_tone_start + 1) % 1000;
1508     }
1509 
1510     /* create and generate new FFT tones with duration 0 (long) to 3 (short) */
1511     for (i = 0; i < 4; i++)
1512         if (q->fft_coefs_min_index[i] >= 0) {
1513             for (j = q->fft_coefs_min_index[i]; j < q->fft_coefs_max_index[i]; j++) {
1514                 int offset, four_i;
1515                 FFTTone tone;
1516 
1517                 if (q->fft_coefs[j].sub_packet != sub_packet)
1518                     break;
1519 
1520                 four_i = (4 - i);
1521                 offset = q->fft_coefs[j].offset >> four_i;
1522                 ch = (q->channels == 1) ? 0 : q->fft_coefs[j].channel;
1523 
1524                 if (offset < q->frequency_range) {
1525                     if (offset < 2)
1526                         tone.cutoff = offset;
1527                     else
1528                         tone.cutoff = (offset >= 60) ? 3 : 2;
1529 
1530                     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];
1531                     tone.complex = &q->fft.complex[ch][offset];
1532                     tone.table = fft_tone_sample_table[i][q->fft_coefs[j].offset - (offset << four_i)];
1533                     tone.phase = 64 * q->fft_coefs[j].phase - (offset << 8) - 128;
1534                     tone.phase_shift = (2 * q->fft_coefs[j].offset + 1) << (7 - four_i);
1535                     tone.duration = i;
1536                     tone.time_index = 0;
1537 
1538                     qdm2_fft_generate_tone(q, &tone);
1539                 }
1540             }
1541             q->fft_coefs_min_index[i] = j;
1542         }
1543 }
1544 
qdm2_calculate_fft(QDM2Context *q, int channel, int sub_packet)1545 static void qdm2_calculate_fft(QDM2Context *q, int channel, int sub_packet)
1546 {
1547     const float gain = (q->channels == 1 && q->nb_channels == 2) ? 0.5f : 1.0f;
1548     float *out       = q->output_buffer + channel;
1549     int i;
1550     q->fft.complex[channel][0].re *= 2.0f;
1551     q->fft.complex[channel][0].im  = 0.0f;
1552     q->rdft_ctx.rdft_calc(&q->rdft_ctx, (FFTSample *)q->fft.complex[channel]);
1553     /* add samples to output buffer */
1554     for (i = 0; i < FFALIGN(q->fft_size, 8); i++) {
1555         out[0]           += q->fft.complex[channel][i].re * gain;
1556         out[q->channels] += q->fft.complex[channel][i].im * gain;
1557         out              += 2 * q->channels;
1558     }
1559 }
1560 
1561 /**
1562  * @param q        context
1563  * @param index    subpacket number
1564  */
qdm2_synthesis_filter(QDM2Context *q, int index)1565 static void qdm2_synthesis_filter(QDM2Context *q, int index)
1566 {
1567     int i, k, ch, sb_used, sub_sampling, dither_state = 0;
1568 
1569     /* copy sb_samples */
1570     sb_used = QDM2_SB_USED(q->sub_sampling);
1571 
1572     for (ch = 0; ch < q->channels; ch++)
1573         for (i = 0; i < 8; i++)
1574             for (k = sb_used; k < SBLIMIT; k++)
1575                 q->sb_samples[ch][(8 * index) + i][k] = 0;
1576 
1577     for (ch = 0; ch < q->nb_channels; ch++) {
1578         float *samples_ptr = q->samples + ch;
1579 
1580         for (i = 0; i < 8; i++) {
1581             ff_mpa_synth_filter_float(&q->mpadsp,
1582                                       q->synth_buf[ch], &(q->synth_buf_offset[ch]),
1583                                       ff_mpa_synth_window_float, &dither_state,
1584                                       samples_ptr, q->nb_channels,
1585                                       q->sb_samples[ch][(8 * index) + i]);
1586             samples_ptr += 32 * q->nb_channels;
1587         }
1588     }
1589 
1590     /* add samples to output buffer */
1591     sub_sampling = (4 >> q->sub_sampling);
1592 
1593     for (ch = 0; ch < q->channels; ch++)
1594         for (i = 0; i < q->frame_size; i++)
1595             q->output_buffer[q->channels * i + ch] += (1 << 23) * q->samples[q->nb_channels * sub_sampling * i + ch];
1596 }
1597 
1598 /**
1599  * Init static data (does not depend on specific file)
1600  */
qdm2_init_static_data(void)1601 static av_cold void qdm2_init_static_data(void) {
1602     qdm2_init_vlc();
1603     softclip_table_init();
1604     rnd_table_init();
1605     init_noise_samples();
1606 
1607     ff_mpa_synth_init_float();
1608 }
1609 
1610 /**
1611  * Init parameters from codec extradata
1612  */
qdm2_decode_init(AVCodecContext *avctx)1613 static av_cold int qdm2_decode_init(AVCodecContext *avctx)
1614 {
1615     static AVOnce init_static_once = AV_ONCE_INIT;
1616     QDM2Context *s = avctx->priv_data;
1617     int tmp_val, tmp, size;
1618     GetByteContext gb;
1619 
1620     /* extradata parsing
1621 
1622     Structure:
1623     wave {
1624         frma (QDM2)
1625         QDCA
1626         QDCP
1627     }
1628 
1629     32  size (including this field)
1630     32  tag (=frma)
1631     32  type (=QDM2 or QDMC)
1632 
1633     32  size (including this field, in bytes)
1634     32  tag (=QDCA) // maybe mandatory parameters
1635     32  unknown (=1)
1636     32  channels (=2)
1637     32  samplerate (=44100)
1638     32  bitrate (=96000)
1639     32  block size (=4096)
1640     32  frame size (=256) (for one channel)
1641     32  packet size (=1300)
1642 
1643     32  size (including this field, in bytes)
1644     32  tag (=QDCP) // maybe some tuneable parameters
1645     32  float1 (=1.0)
1646     32  zero ?
1647     32  float2 (=1.0)
1648     32  float3 (=1.0)
1649     32  unknown (27)
1650     32  unknown (8)
1651     32  zero ?
1652     */
1653 
1654     if (!avctx->extradata || (avctx->extradata_size < 48)) {
1655         av_log(avctx, AV_LOG_ERROR, "extradata missing or truncated\n");
1656         return AVERROR_INVALIDDATA;
1657     }
1658 
1659     bytestream2_init(&gb, avctx->extradata, avctx->extradata_size);
1660 
1661     while (bytestream2_get_bytes_left(&gb) > 8) {
1662         if (bytestream2_peek_be64(&gb) == (((uint64_t)MKBETAG('f','r','m','a') << 32) |
1663                                             (uint64_t)MKBETAG('Q','D','M','2')))
1664             break;
1665         bytestream2_skip(&gb, 1);
1666     }
1667 
1668     if (bytestream2_get_bytes_left(&gb) < 12) {
1669         av_log(avctx, AV_LOG_ERROR, "not enough extradata (%i)\n",
1670                bytestream2_get_bytes_left(&gb));
1671         return AVERROR_INVALIDDATA;
1672     }
1673 
1674     bytestream2_skip(&gb, 8);
1675     size = bytestream2_get_be32(&gb);
1676 
1677     if (size > bytestream2_get_bytes_left(&gb)) {
1678         av_log(avctx, AV_LOG_ERROR, "extradata size too small, %i < %i\n",
1679                bytestream2_get_bytes_left(&gb), size);
1680         return AVERROR_INVALIDDATA;
1681     }
1682 
1683     av_log(avctx, AV_LOG_DEBUG, "size: %d\n", size);
1684     if (bytestream2_get_be32(&gb) != MKBETAG('Q','D','C','A')) {
1685         av_log(avctx, AV_LOG_ERROR, "invalid extradata, expecting QDCA\n");
1686         return AVERROR_INVALIDDATA;
1687     }
1688 
1689     bytestream2_skip(&gb, 4);
1690 
1691     s->nb_channels = s->channels = bytestream2_get_be32(&gb);
1692     if (s->channels <= 0 || s->channels > MPA_MAX_CHANNELS) {
1693         av_log(avctx, AV_LOG_ERROR, "Invalid number of channels\n");
1694         return AVERROR_INVALIDDATA;
1695     }
1696     av_channel_layout_uninit(&avctx->ch_layout);
1697     av_channel_layout_default(&avctx->ch_layout, s->channels);
1698 
1699     avctx->sample_rate = bytestream2_get_be32(&gb);
1700     avctx->bit_rate = bytestream2_get_be32(&gb);
1701     s->group_size = bytestream2_get_be32(&gb);
1702     s->fft_size = bytestream2_get_be32(&gb);
1703     s->checksum_size = bytestream2_get_be32(&gb);
1704     if (s->checksum_size >= 1U << 28 || s->checksum_size <= 1) {
1705         av_log(avctx, AV_LOG_ERROR, "data block size invalid (%u)\n", s->checksum_size);
1706         return AVERROR_INVALIDDATA;
1707     }
1708 
1709     s->fft_order = av_log2(s->fft_size) + 1;
1710 
1711     // Fail on unknown fft order
1712     if ((s->fft_order < 7) || (s->fft_order > 9)) {
1713         avpriv_request_sample(avctx, "Unknown FFT order %d", s->fft_order);
1714         return AVERROR_PATCHWELCOME;
1715     }
1716 
1717     // something like max decodable tones
1718     s->group_order = av_log2(s->group_size) + 1;
1719     s->frame_size = s->group_size / 16; // 16 iterations per super block
1720 
1721     if (s->frame_size > QDM2_MAX_FRAME_SIZE)
1722         return AVERROR_INVALIDDATA;
1723 
1724     s->sub_sampling = s->fft_order - 7;
1725     s->frequency_range = 255 / (1 << (2 - s->sub_sampling));
1726 
1727     if (s->frame_size * 4 >> s->sub_sampling > MPA_FRAME_SIZE) {
1728         avpriv_request_sample(avctx, "large frames");
1729         return AVERROR_PATCHWELCOME;
1730     }
1731 
1732     switch ((s->sub_sampling * 2 + s->channels - 1)) {
1733         case 0: tmp = 40; break;
1734         case 1: tmp = 48; break;
1735         case 2: tmp = 56; break;
1736         case 3: tmp = 72; break;
1737         case 4: tmp = 80; break;
1738         case 5: tmp = 100;break;
1739         default: tmp=s->sub_sampling; break;
1740     }
1741     tmp_val = 0;
1742     if ((tmp * 1000) < avctx->bit_rate)  tmp_val = 1;
1743     if ((tmp * 1440) < avctx->bit_rate)  tmp_val = 2;
1744     if ((tmp * 1760) < avctx->bit_rate)  tmp_val = 3;
1745     if ((tmp * 2240) < avctx->bit_rate)  tmp_val = 4;
1746     s->cm_table_select = tmp_val;
1747 
1748     if (avctx->bit_rate <= 8000)
1749         s->coeff_per_sb_select = 0;
1750     else if (avctx->bit_rate < 16000)
1751         s->coeff_per_sb_select = 1;
1752     else
1753         s->coeff_per_sb_select = 2;
1754 
1755     if (s->fft_size != (1 << (s->fft_order - 1))) {
1756         av_log(avctx, AV_LOG_ERROR, "FFT size %d not power of 2.\n", s->fft_size);
1757         return AVERROR_INVALIDDATA;
1758     }
1759 
1760     ff_rdft_init(&s->rdft_ctx, s->fft_order, IDFT_C2R);
1761     ff_mpadsp_init(&s->mpadsp);
1762 
1763     avctx->sample_fmt = AV_SAMPLE_FMT_S16;
1764 
1765     ff_thread_once(&init_static_once, qdm2_init_static_data);
1766 
1767     return 0;
1768 }
1769 
qdm2_decode_close(AVCodecContext *avctx)1770 static av_cold int qdm2_decode_close(AVCodecContext *avctx)
1771 {
1772     QDM2Context *s = avctx->priv_data;
1773 
1774     ff_rdft_end(&s->rdft_ctx);
1775 
1776     return 0;
1777 }
1778 
qdm2_decode(QDM2Context *q, const uint8_t *in, int16_t *out)1779 static int qdm2_decode(QDM2Context *q, const uint8_t *in, int16_t *out)
1780 {
1781     int ch, i;
1782     const int frame_size = (q->frame_size * q->channels);
1783 
1784     if((unsigned)frame_size > FF_ARRAY_ELEMS(q->output_buffer)/2)
1785         return -1;
1786 
1787     /* select input buffer */
1788     q->compressed_data = in;
1789     q->compressed_size = q->checksum_size;
1790 
1791     /* copy old block, clear new block of output samples */
1792     memmove(q->output_buffer, &q->output_buffer[frame_size], frame_size * sizeof(float));
1793     memset(&q->output_buffer[frame_size], 0, frame_size * sizeof(float));
1794 
1795     /* decode block of QDM2 compressed data */
1796     if (q->sub_packet == 0) {
1797         q->has_errors = 0; // zero it for a new super block
1798         av_log(NULL,AV_LOG_DEBUG,"Superblock follows\n");
1799         qdm2_decode_super_block(q);
1800     }
1801 
1802     /* parse subpackets */
1803     if (!q->has_errors) {
1804         if (q->sub_packet == 2)
1805             qdm2_decode_fft_packets(q);
1806 
1807         qdm2_fft_tone_synthesizer(q, q->sub_packet);
1808     }
1809 
1810     /* sound synthesis stage 1 (FFT) */
1811     for (ch = 0; ch < q->channels; ch++) {
1812         qdm2_calculate_fft(q, ch, q->sub_packet);
1813 
1814         if (!q->has_errors && q->sub_packet_list_C[0].packet) {
1815             SAMPLES_NEEDED_2("has errors, and C list is not empty")
1816             return -1;
1817         }
1818     }
1819 
1820     /* sound synthesis stage 2 (MPEG audio like synthesis filter) */
1821     if (!q->has_errors && q->do_synth_filter)
1822         qdm2_synthesis_filter(q, q->sub_packet);
1823 
1824     q->sub_packet = (q->sub_packet + 1) % 16;
1825 
1826     /* clip and convert output float[] to 16-bit signed samples */
1827     for (i = 0; i < frame_size; i++) {
1828         int value = (int)q->output_buffer[i];
1829 
1830         if (value > SOFTCLIP_THRESHOLD)
1831             value = (value >  HARDCLIP_THRESHOLD) ?  32767 :  softclip_table[ value - SOFTCLIP_THRESHOLD];
1832         else if (value < -SOFTCLIP_THRESHOLD)
1833             value = (value < -HARDCLIP_THRESHOLD) ? -32767 : -softclip_table[-value - SOFTCLIP_THRESHOLD];
1834 
1835         out[i] = value;
1836     }
1837 
1838     return 0;
1839 }
1840 
qdm2_decode_frame(AVCodecContext *avctx, AVFrame *frame, int *got_frame_ptr, AVPacket *avpkt)1841 static int qdm2_decode_frame(AVCodecContext *avctx, AVFrame *frame,
1842                              int *got_frame_ptr, AVPacket *avpkt)
1843 {
1844     const uint8_t *buf = avpkt->data;
1845     int buf_size = avpkt->size;
1846     QDM2Context *s = avctx->priv_data;
1847     int16_t *out;
1848     int i, ret;
1849 
1850     if(!buf)
1851         return 0;
1852     if(buf_size < s->checksum_size)
1853         return -1;
1854 
1855     /* get output buffer */
1856     frame->nb_samples = 16 * s->frame_size;
1857     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
1858         return ret;
1859     out = (int16_t *)frame->data[0];
1860 
1861     for (i = 0; i < 16; i++) {
1862         if ((ret = qdm2_decode(s, buf, out)) < 0)
1863             return ret;
1864         out += s->channels * s->frame_size;
1865     }
1866 
1867     *got_frame_ptr = 1;
1868 
1869     return s->checksum_size;
1870 }
1871 
1872 const FFCodec ff_qdm2_decoder = {
1873     .p.name           = "qdm2",
1874     .p.long_name      = NULL_IF_CONFIG_SMALL("QDesign Music Codec 2"),
1875     .p.type           = AVMEDIA_TYPE_AUDIO,
1876     .p.id             = AV_CODEC_ID_QDM2,
1877     .priv_data_size   = sizeof(QDM2Context),
1878     .init             = qdm2_decode_init,
1879     .close            = qdm2_decode_close,
1880     FF_CODEC_DECODE_CB(qdm2_decode_frame),
1881     .p.capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
1882     .caps_internal    = FF_CODEC_CAP_INIT_THREADSAFE,
1883 };
1884