ba9f3bba2e6b75fc139159817b2a1802c72d9917
[libav.git] / libavcodec / alsdec.c
1 /*
2 * MPEG-4 ALS decoder
3 * Copyright (c) 2009 Thilo Borgmann <thilo.borgmann _at_ googlemail.com>
4 *
5 * This file is part of Libav.
6 *
7 * Libav is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * Libav is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 /**
23 * @file
24 * MPEG-4 ALS decoder
25 * @author Thilo Borgmann <thilo.borgmann _at_ googlemail.com>
26 */
27
28
29 //#define DEBUG
30
31
32 #include "avcodec.h"
33 #include "get_bits.h"
34 #include "unary.h"
35 #include "mpeg4audio.h"
36 #include "bytestream.h"
37 #include "bgmc.h"
38 #include "dsputil.h"
39 #include "libavutil/samplefmt.h"
40 #include "libavutil/crc.h"
41
42 #include <stdint.h>
43
44 /** Rice parameters and corresponding index offsets for decoding the
45 * indices of scaled PARCOR values. The table chosen is set globally
46 * by the encoder and stored in ALSSpecificConfig.
47 */
48 static const int8_t parcor_rice_table[3][20][2] = {
49 { {-52, 4}, {-29, 5}, {-31, 4}, { 19, 4}, {-16, 4},
50 { 12, 3}, { -7, 3}, { 9, 3}, { -5, 3}, { 6, 3},
51 { -4, 3}, { 3, 3}, { -3, 2}, { 3, 2}, { -2, 2},
52 { 3, 2}, { -1, 2}, { 2, 2}, { -1, 2}, { 2, 2} },
53 { {-58, 3}, {-42, 4}, {-46, 4}, { 37, 5}, {-36, 4},
54 { 29, 4}, {-29, 4}, { 25, 4}, {-23, 4}, { 20, 4},
55 {-17, 4}, { 16, 4}, {-12, 4}, { 12, 3}, {-10, 4},
56 { 7, 3}, { -4, 4}, { 3, 3}, { -1, 3}, { 1, 3} },
57 { {-59, 3}, {-45, 5}, {-50, 4}, { 38, 4}, {-39, 4},
58 { 32, 4}, {-30, 4}, { 25, 3}, {-23, 3}, { 20, 3},
59 {-20, 3}, { 16, 3}, {-13, 3}, { 10, 3}, { -7, 3},
60 { 3, 3}, { 0, 3}, { -1, 3}, { 2, 3}, { -1, 2} }
61 };
62
63
64 /** Scaled PARCOR values used for the first two PARCOR coefficients.
65 * To be indexed by the Rice coded indices.
66 * Generated by: parcor_scaled_values[i] = 32 + ((i * (i+1)) << 7) - (1 << 20)
67 * Actual values are divided by 32 in order to be stored in 16 bits.
68 */
69 static const int16_t parcor_scaled_values[] = {
70 -1048544 / 32, -1048288 / 32, -1047776 / 32, -1047008 / 32,
71 -1045984 / 32, -1044704 / 32, -1043168 / 32, -1041376 / 32,
72 -1039328 / 32, -1037024 / 32, -1034464 / 32, -1031648 / 32,
73 -1028576 / 32, -1025248 / 32, -1021664 / 32, -1017824 / 32,
74 -1013728 / 32, -1009376 / 32, -1004768 / 32, -999904 / 32,
75 -994784 / 32, -989408 / 32, -983776 / 32, -977888 / 32,
76 -971744 / 32, -965344 / 32, -958688 / 32, -951776 / 32,
77 -944608 / 32, -937184 / 32, -929504 / 32, -921568 / 32,
78 -913376 / 32, -904928 / 32, -896224 / 32, -887264 / 32,
79 -878048 / 32, -868576 / 32, -858848 / 32, -848864 / 32,
80 -838624 / 32, -828128 / 32, -817376 / 32, -806368 / 32,
81 -795104 / 32, -783584 / 32, -771808 / 32, -759776 / 32,
82 -747488 / 32, -734944 / 32, -722144 / 32, -709088 / 32,
83 -695776 / 32, -682208 / 32, -668384 / 32, -654304 / 32,
84 -639968 / 32, -625376 / 32, -610528 / 32, -595424 / 32,
85 -580064 / 32, -564448 / 32, -548576 / 32, -532448 / 32,
86 -516064 / 32, -499424 / 32, -482528 / 32, -465376 / 32,
87 -447968 / 32, -430304 / 32, -412384 / 32, -394208 / 32,
88 -375776 / 32, -357088 / 32, -338144 / 32, -318944 / 32,
89 -299488 / 32, -279776 / 32, -259808 / 32, -239584 / 32,
90 -219104 / 32, -198368 / 32, -177376 / 32, -156128 / 32,
91 -134624 / 32, -112864 / 32, -90848 / 32, -68576 / 32,
92 -46048 / 32, -23264 / 32, -224 / 32, 23072 / 32,
93 46624 / 32, 70432 / 32, 94496 / 32, 118816 / 32,
94 143392 / 32, 168224 / 32, 193312 / 32, 218656 / 32,
95 244256 / 32, 270112 / 32, 296224 / 32, 322592 / 32,
96 349216 / 32, 376096 / 32, 403232 / 32, 430624 / 32,
97 458272 / 32, 486176 / 32, 514336 / 32, 542752 / 32,
98 571424 / 32, 600352 / 32, 629536 / 32, 658976 / 32,
99 688672 / 32, 718624 / 32, 748832 / 32, 779296 / 32,
100 810016 / 32, 840992 / 32, 872224 / 32, 903712 / 32,
101 935456 / 32, 967456 / 32, 999712 / 32, 1032224 / 32
102 };
103
104
105 /** Gain values of p(0) for long-term prediction.
106 * To be indexed by the Rice coded indices.
107 */
108 static const uint8_t ltp_gain_values [4][4] = {
109 { 0, 8, 16, 24},
110 {32, 40, 48, 56},
111 {64, 70, 76, 82},
112 {88, 92, 96, 100}
113 };
114
115
116 /** Inter-channel weighting factors for multi-channel correlation.
117 * To be indexed by the Rice coded indices.
118 */
119 static const int16_t mcc_weightings[] = {
120 204, 192, 179, 166, 153, 140, 128, 115,
121 102, 89, 76, 64, 51, 38, 25, 12,
122 0, -12, -25, -38, -51, -64, -76, -89,
123 -102, -115, -128, -140, -153, -166, -179, -192
124 };
125
126
127 /** Tail codes used in arithmetic coding using block Gilbert-Moore codes.
128 */
129 static const uint8_t tail_code[16][6] = {
130 { 74, 44, 25, 13, 7, 3},
131 { 68, 42, 24, 13, 7, 3},
132 { 58, 39, 23, 13, 7, 3},
133 {126, 70, 37, 19, 10, 5},
134 {132, 70, 37, 20, 10, 5},
135 {124, 70, 38, 20, 10, 5},
136 {120, 69, 37, 20, 11, 5},
137 {116, 67, 37, 20, 11, 5},
138 {108, 66, 36, 20, 10, 5},
139 {102, 62, 36, 20, 10, 5},
140 { 88, 58, 34, 19, 10, 5},
141 {162, 89, 49, 25, 13, 7},
142 {156, 87, 49, 26, 14, 7},
143 {150, 86, 47, 26, 14, 7},
144 {142, 84, 47, 26, 14, 7},
145 {131, 79, 46, 26, 14, 7}
146 };
147
148
149 enum RA_Flag {
150 RA_FLAG_NONE,
151 RA_FLAG_FRAMES,
152 RA_FLAG_HEADER
153 };
154
155
156 typedef struct {
157 uint32_t samples; ///< number of samples, 0xFFFFFFFF if unknown
158 int resolution; ///< 000 = 8-bit; 001 = 16-bit; 010 = 24-bit; 011 = 32-bit
159 int floating; ///< 1 = IEEE 32-bit floating-point, 0 = integer
160 int msb_first; ///< 1 = original CRC calculated on big-endian system, 0 = little-endian
161 int frame_length; ///< frame length for each frame (last frame may differ)
162 int ra_distance; ///< distance between RA frames (in frames, 0...255)
163 enum RA_Flag ra_flag; ///< indicates where the size of ra units is stored
164 int adapt_order; ///< adaptive order: 1 = on, 0 = off
165 int coef_table; ///< table index of Rice code parameters
166 int long_term_prediction; ///< long term prediction (LTP): 1 = on, 0 = off
167 int max_order; ///< maximum prediction order (0..1023)
168 int block_switching; ///< number of block switching levels
169 int bgmc; ///< "Block Gilbert-Moore Code": 1 = on, 0 = off (Rice coding only)
170 int sb_part; ///< sub-block partition
171 int joint_stereo; ///< joint stereo: 1 = on, 0 = off
172 int mc_coding; ///< extended inter-channel coding (multi channel coding): 1 = on, 0 = off
173 int chan_config; ///< indicates that a chan_config_info field is present
174 int chan_sort; ///< channel rearrangement: 1 = on, 0 = off
175 int rlslms; ///< use "Recursive Least Square-Least Mean Square" predictor: 1 = on, 0 = off
176 int chan_config_info; ///< mapping of channels to loudspeaker locations. Unused until setting channel configuration is implemented.
177 int *chan_pos; ///< original channel positions
178 int crc_enabled; ///< enable Cyclic Redundancy Checksum
179 } ALSSpecificConfig;
180
181
182 typedef struct {
183 int stop_flag;
184 int master_channel;
185 int time_diff_flag;
186 int time_diff_sign;
187 int time_diff_index;
188 int weighting[6];
189 } ALSChannelData;
190
191
192 typedef struct {
193 AVCodecContext *avctx;
194 AVFrame frame;
195 ALSSpecificConfig sconf;
196 GetBitContext gb;
197 DSPContext dsp;
198 const AVCRC *crc_table;
199 uint32_t crc_org; ///< CRC value of the original input data
200 uint32_t crc; ///< CRC value calculated from decoded data
201 unsigned int cur_frame_length; ///< length of the current frame to decode
202 unsigned int frame_id; ///< the frame ID / number of the current frame
203 unsigned int js_switch; ///< if true, joint-stereo decoding is enforced
204 unsigned int num_blocks; ///< number of blocks used in the current frame
205 unsigned int s_max; ///< maximum Rice parameter allowed in entropy coding
206 uint8_t *bgmc_lut; ///< pointer at lookup tables used for BGMC
207 int *bgmc_lut_status; ///< pointer at lookup table status flags used for BGMC
208 int ltp_lag_length; ///< number of bits used for ltp lag value
209 int *const_block; ///< contains const_block flags for all channels
210 unsigned int *shift_lsbs; ///< contains shift_lsbs flags for all channels
211 unsigned int *opt_order; ///< contains opt_order flags for all channels
212 int *store_prev_samples; ///< contains store_prev_samples flags for all channels
213 int *use_ltp; ///< contains use_ltp flags for all channels
214 int *ltp_lag; ///< contains ltp lag values for all channels
215 int **ltp_gain; ///< gain values for ltp 5-tap filter for a channel
216 int *ltp_gain_buffer; ///< contains all gain values for ltp 5-tap filter
217 int32_t **quant_cof; ///< quantized parcor coefficients for a channel
218 int32_t *quant_cof_buffer; ///< contains all quantized parcor coefficients
219 int32_t **lpc_cof; ///< coefficients of the direct form prediction filter for a channel
220 int32_t *lpc_cof_buffer; ///< contains all coefficients of the direct form prediction filter
221 int32_t *lpc_cof_reversed_buffer; ///< temporary buffer to set up a reversed versio of lpc_cof_buffer
222 ALSChannelData **chan_data; ///< channel data for multi-channel correlation
223 ALSChannelData *chan_data_buffer; ///< contains channel data for all channels
224 int *reverted_channels; ///< stores a flag for each reverted channel
225 int32_t *prev_raw_samples; ///< contains unshifted raw samples from the previous block
226 int32_t **raw_samples; ///< decoded raw samples for each channel
227 int32_t *raw_buffer; ///< contains all decoded raw samples including carryover samples
228 uint8_t *crc_buffer; ///< buffer of byte order corrected samples used for CRC check
229 } ALSDecContext;
230
231
232 typedef struct {
233 unsigned int block_length; ///< number of samples within the block
234 unsigned int ra_block; ///< if true, this is a random access block
235 int *const_block; ///< if true, this is a constant value block
236 int js_blocks; ///< true if this block contains a difference signal
237 unsigned int *shift_lsbs; ///< shift of values for this block
238 unsigned int *opt_order; ///< prediction order of this block
239 int *store_prev_samples;///< if true, carryover samples have to be stored
240 int *use_ltp; ///< if true, long-term prediction is used
241 int *ltp_lag; ///< lag value for long-term prediction
242 int *ltp_gain; ///< gain values for ltp 5-tap filter
243 int32_t *quant_cof; ///< quantized parcor coefficients
244 int32_t *lpc_cof; ///< coefficients of the direct form prediction
245 int32_t *raw_samples; ///< decoded raw samples / residuals for this block
246 int32_t *prev_raw_samples; ///< contains unshifted raw samples from the previous block
247 int32_t *raw_other; ///< decoded raw samples of the other channel of a channel pair
248 } ALSBlockData;
249
250
251 static av_cold void dprint_specific_config(ALSDecContext *ctx)
252 {
253 #ifdef DEBUG
254 AVCodecContext *avctx = ctx->avctx;
255 ALSSpecificConfig *sconf = &ctx->sconf;
256
257 av_dlog(avctx, "resolution = %i\n", sconf->resolution);
258 av_dlog(avctx, "floating = %i\n", sconf->floating);
259 av_dlog(avctx, "frame_length = %i\n", sconf->frame_length);
260 av_dlog(avctx, "ra_distance = %i\n", sconf->ra_distance);
261 av_dlog(avctx, "ra_flag = %i\n", sconf->ra_flag);
262 av_dlog(avctx, "adapt_order = %i\n", sconf->adapt_order);
263 av_dlog(avctx, "coef_table = %i\n", sconf->coef_table);
264 av_dlog(avctx, "long_term_prediction = %i\n", sconf->long_term_prediction);
265 av_dlog(avctx, "max_order = %i\n", sconf->max_order);
266 av_dlog(avctx, "block_switching = %i\n", sconf->block_switching);
267 av_dlog(avctx, "bgmc = %i\n", sconf->bgmc);
268 av_dlog(avctx, "sb_part = %i\n", sconf->sb_part);
269 av_dlog(avctx, "joint_stereo = %i\n", sconf->joint_stereo);
270 av_dlog(avctx, "mc_coding = %i\n", sconf->mc_coding);
271 av_dlog(avctx, "chan_config = %i\n", sconf->chan_config);
272 av_dlog(avctx, "chan_sort = %i\n", sconf->chan_sort);
273 av_dlog(avctx, "RLSLMS = %i\n", sconf->rlslms);
274 av_dlog(avctx, "chan_config_info = %i\n", sconf->chan_config_info);
275 #endif
276 }
277
278
279 /** Read an ALSSpecificConfig from a buffer into the output struct.
280 */
281 static av_cold int read_specific_config(ALSDecContext *ctx)
282 {
283 GetBitContext gb;
284 uint64_t ht_size;
285 int i, config_offset;
286 MPEG4AudioConfig m4ac;
287 ALSSpecificConfig *sconf = &ctx->sconf;
288 AVCodecContext *avctx = ctx->avctx;
289 uint32_t als_id, header_size, trailer_size;
290
291 init_get_bits(&gb, avctx->extradata, avctx->extradata_size * 8);
292
293 config_offset = avpriv_mpeg4audio_get_config(&m4ac, avctx->extradata,
294 avctx->extradata_size * 8, 1);
295
296 if (config_offset < 0)
297 return -1;
298
299 skip_bits_long(&gb, config_offset);
300
301 if (get_bits_left(&gb) < (30 << 3))
302 return -1;
303
304 // read the fixed items
305 als_id = get_bits_long(&gb, 32);
306 avctx->sample_rate = m4ac.sample_rate;
307 skip_bits_long(&gb, 32); // sample rate already known
308 sconf->samples = get_bits_long(&gb, 32);
309 avctx->channels = m4ac.channels;
310 skip_bits(&gb, 16); // number of channels already knwon
311 skip_bits(&gb, 3); // skip file_type
312 sconf->resolution = get_bits(&gb, 3);
313 sconf->floating = get_bits1(&gb);
314 sconf->msb_first = get_bits1(&gb);
315 sconf->frame_length = get_bits(&gb, 16) + 1;
316 sconf->ra_distance = get_bits(&gb, 8);
317 sconf->ra_flag = get_bits(&gb, 2);
318 sconf->adapt_order = get_bits1(&gb);
319 sconf->coef_table = get_bits(&gb, 2);
320 sconf->long_term_prediction = get_bits1(&gb);
321 sconf->max_order = get_bits(&gb, 10);
322 sconf->block_switching = get_bits(&gb, 2);
323 sconf->bgmc = get_bits1(&gb);
324 sconf->sb_part = get_bits1(&gb);
325 sconf->joint_stereo = get_bits1(&gb);
326 sconf->mc_coding = get_bits1(&gb);
327 sconf->chan_config = get_bits1(&gb);
328 sconf->chan_sort = get_bits1(&gb);
329 sconf->crc_enabled = get_bits1(&gb);
330 sconf->rlslms = get_bits1(&gb);
331 skip_bits(&gb, 5); // skip 5 reserved bits
332 skip_bits1(&gb); // skip aux_data_enabled
333
334
335 // check for ALSSpecificConfig struct
336 if (als_id != MKBETAG('A','L','S','\0'))
337 return -1;
338
339 ctx->cur_frame_length = sconf->frame_length;
340
341 // read channel config
342 if (sconf->chan_config)
343 sconf->chan_config_info = get_bits(&gb, 16);
344 // TODO: use this to set avctx->channel_layout
345
346
347 // read channel sorting
348 if (sconf->chan_sort && avctx->channels > 1) {
349 int chan_pos_bits = av_ceil_log2(avctx->channels);
350 int bits_needed = avctx->channels * chan_pos_bits + 7;
351 if (get_bits_left(&gb) < bits_needed)
352 return -1;
353
354 if (!(sconf->chan_pos = av_malloc(avctx->channels * sizeof(*sconf->chan_pos))))
355 return AVERROR(ENOMEM);
356
357 for (i = 0; i < avctx->channels; i++)
358 sconf->chan_pos[i] = get_bits(&gb, chan_pos_bits);
359
360 align_get_bits(&gb);
361 // TODO: use this to actually do channel sorting
362 } else {
363 sconf->chan_sort = 0;
364 }
365
366
367 // read fixed header and trailer sizes,
368 // if size = 0xFFFFFFFF then there is no data field!
369 if (get_bits_left(&gb) < 64)
370 return -1;
371
372 header_size = get_bits_long(&gb, 32);
373 trailer_size = get_bits_long(&gb, 32);
374 if (header_size == 0xFFFFFFFF)
375 header_size = 0;
376 if (trailer_size == 0xFFFFFFFF)
377 trailer_size = 0;
378
379 ht_size = ((int64_t)(header_size) + (int64_t)(trailer_size)) << 3;
380
381
382 // skip the header and trailer data
383 if (get_bits_left(&gb) < ht_size)
384 return -1;
385
386 if (ht_size > INT32_MAX)
387 return -1;
388
389 skip_bits_long(&gb, ht_size);
390
391
392 // initialize CRC calculation
393 if (sconf->crc_enabled) {
394 if (get_bits_left(&gb) < 32)
395 return -1;
396
397 if (avctx->err_recognition & AV_EF_CRCCHECK) {
398 ctx->crc_table = av_crc_get_table(AV_CRC_32_IEEE_LE);
399 ctx->crc = 0xFFFFFFFF;
400 ctx->crc_org = ~get_bits_long(&gb, 32);
401 } else
402 skip_bits_long(&gb, 32);
403 }
404
405
406 // no need to read the rest of ALSSpecificConfig (ra_unit_size & aux data)
407
408 dprint_specific_config(ctx);
409
410 return 0;
411 }
412
413
414 /** Check the ALSSpecificConfig for unsupported features.
415 */
416 static int check_specific_config(ALSDecContext *ctx)
417 {
418 ALSSpecificConfig *sconf = &ctx->sconf;
419 int error = 0;
420
421 // report unsupported feature and set error value
422 #define MISSING_ERR(cond, str, errval) \
423 { \
424 if (cond) { \
425 av_log_missing_feature(ctx->avctx, str, 0); \
426 error = errval; \
427 } \
428 }
429
430 MISSING_ERR(sconf->floating, "Floating point decoding", AVERROR_PATCHWELCOME);
431 MISSING_ERR(sconf->rlslms, "Adaptive RLS-LMS prediction", AVERROR_PATCHWELCOME);
432 MISSING_ERR(sconf->chan_sort, "Channel sorting", 0);
433
434 return error;
435 }
436
437
438 /** Parse the bs_info field to extract the block partitioning used in
439 * block switching mode, refer to ISO/IEC 14496-3, section 11.6.2.
440 */
441 static void parse_bs_info(const uint32_t bs_info, unsigned int n,
442 unsigned int div, unsigned int **div_blocks,
443 unsigned int *num_blocks)
444 {
445 if (n < 31 && ((bs_info << n) & 0x40000000)) {
446 // if the level is valid and the investigated bit n is set
447 // then recursively check both children at bits (2n+1) and (2n+2)
448 n *= 2;
449 div += 1;
450 parse_bs_info(bs_info, n + 1, div, div_blocks, num_blocks);
451 parse_bs_info(bs_info, n + 2, div, div_blocks, num_blocks);
452 } else {
453 // else the bit is not set or the last level has been reached
454 // (bit implicitly not set)
455 **div_blocks = div;
456 (*div_blocks)++;
457 (*num_blocks)++;
458 }
459 }
460
461
462 /** Read and decode a Rice codeword.
463 */
464 static int32_t decode_rice(GetBitContext *gb, unsigned int k)
465 {
466 int max = get_bits_left(gb) - k;
467 int q = get_unary(gb, 0, max);
468 int r = k ? get_bits1(gb) : !(q & 1);
469
470 if (k > 1) {
471 q <<= (k - 1);
472 q += get_bits_long(gb, k - 1);
473 } else if (!k) {
474 q >>= 1;
475 }
476 return r ? q : ~q;
477 }
478
479
480 /** Convert PARCOR coefficient k to direct filter coefficient.
481 */
482 static void parcor_to_lpc(unsigned int k, const int32_t *par, int32_t *cof)
483 {
484 int i, j;
485
486 for (i = 0, j = k - 1; i < j; i++, j--) {
487 int tmp1 = ((MUL64(par[k], cof[j]) + (1 << 19)) >> 20);
488 cof[j] += ((MUL64(par[k], cof[i]) + (1 << 19)) >> 20);
489 cof[i] += tmp1;
490 }
491 if (i == j)
492 cof[i] += ((MUL64(par[k], cof[j]) + (1 << 19)) >> 20);
493
494 cof[k] = par[k];
495 }
496
497
498 /** Read block switching field if necessary and set actual block sizes.
499 * Also assure that the block sizes of the last frame correspond to the
500 * actual number of samples.
501 */
502 static void get_block_sizes(ALSDecContext *ctx, unsigned int *div_blocks,
503 uint32_t *bs_info)
504 {
505 ALSSpecificConfig *sconf = &ctx->sconf;
506 GetBitContext *gb = &ctx->gb;
507 unsigned int *ptr_div_blocks = div_blocks;
508 unsigned int b;
509
510 if (sconf->block_switching) {
511 unsigned int bs_info_len = 1 << (sconf->block_switching + 2);
512 *bs_info = get_bits_long(gb, bs_info_len);
513 *bs_info <<= (32 - bs_info_len);
514 }
515
516 ctx->num_blocks = 0;
517 parse_bs_info(*bs_info, 0, 0, &ptr_div_blocks, &ctx->num_blocks);
518
519 // The last frame may have an overdetermined block structure given in
520 // the bitstream. In that case the defined block structure would need
521 // more samples than available to be consistent.
522 // The block structure is actually used but the block sizes are adapted
523 // to fit the actual number of available samples.
524 // Example: 5 samples, 2nd level block sizes: 2 2 2 2.
525 // This results in the actual block sizes: 2 2 1 0.
526 // This is not specified in 14496-3 but actually done by the reference
527 // codec RM22 revision 2.
528 // This appears to happen in case of an odd number of samples in the last
529 // frame which is actually not allowed by the block length switching part
530 // of 14496-3.
531 // The ALS conformance files feature an odd number of samples in the last
532 // frame.
533
534 for (b = 0; b < ctx->num_blocks; b++)
535 div_blocks[b] = ctx->sconf.frame_length >> div_blocks[b];
536
537 if (ctx->cur_frame_length != ctx->sconf.frame_length) {
538 unsigned int remaining = ctx->cur_frame_length;
539
540 for (b = 0; b < ctx->num_blocks; b++) {
541 if (remaining <= div_blocks[b]) {
542 div_blocks[b] = remaining;
543 ctx->num_blocks = b + 1;
544 break;
545 }
546
547 remaining -= div_blocks[b];
548 }
549 }
550 }
551
552
553 /** Read the block data for a constant block
554 */
555 static void read_const_block_data(ALSDecContext *ctx, ALSBlockData *bd)
556 {
557 ALSSpecificConfig *sconf = &ctx->sconf;
558 AVCodecContext *avctx = ctx->avctx;
559 GetBitContext *gb = &ctx->gb;
560
561 *bd->raw_samples = 0;
562 *bd->const_block = get_bits1(gb); // 1 = constant value, 0 = zero block (silence)
563 bd->js_blocks = get_bits1(gb);
564
565 // skip 5 reserved bits
566 skip_bits(gb, 5);
567
568 if (*bd->const_block) {
569 unsigned int const_val_bits = sconf->floating ? 24 : avctx->bits_per_raw_sample;
570 *bd->raw_samples = get_sbits_long(gb, const_val_bits);
571 }
572
573 // ensure constant block decoding by reusing this field
574 *bd->const_block = 1;
575 }
576
577
578 /** Decode the block data for a constant block
579 */
580 static void decode_const_block_data(ALSDecContext *ctx, ALSBlockData *bd)
581 {
582 int smp = bd->block_length - 1;
583 int32_t val = *bd->raw_samples;
584 int32_t *dst = bd->raw_samples + 1;
585
586 // write raw samples into buffer
587 for (; smp; smp--)
588 *dst++ = val;
589 }
590
591
592 /** Read the block data for a non-constant block
593 */
594 static int read_var_block_data(ALSDecContext *ctx, ALSBlockData *bd)
595 {
596 ALSSpecificConfig *sconf = &ctx->sconf;
597 AVCodecContext *avctx = ctx->avctx;
598 GetBitContext *gb = &ctx->gb;
599 unsigned int k;
600 unsigned int s[8];
601 unsigned int sx[8];
602 unsigned int sub_blocks, log2_sub_blocks, sb_length;
603 unsigned int start = 0;
604 unsigned int opt_order;
605 int sb;
606 int32_t *quant_cof = bd->quant_cof;
607 int32_t *current_res;
608
609
610 // ensure variable block decoding by reusing this field
611 *bd->const_block = 0;
612
613 *bd->opt_order = 1;
614 bd->js_blocks = get_bits1(gb);
615
616 opt_order = *bd->opt_order;
617
618 // determine the number of subblocks for entropy decoding
619 if (!sconf->bgmc && !sconf->sb_part) {
620 log2_sub_blocks = 0;
621 } else {
622 if (sconf->bgmc && sconf->sb_part)
623 log2_sub_blocks = get_bits(gb, 2);
624 else
625 log2_sub_blocks = 2 * get_bits1(gb);
626 }
627
628 sub_blocks = 1 << log2_sub_blocks;
629
630 // do not continue in case of a damaged stream since
631 // block_length must be evenly divisible by sub_blocks
632 if (bd->block_length & (sub_blocks - 1)) {
633 av_log(avctx, AV_LOG_WARNING,
634 "Block length is not evenly divisible by the number of subblocks.\n");
635 return -1;
636 }
637
638 sb_length = bd->block_length >> log2_sub_blocks;
639
640 if (sconf->bgmc) {
641 s[0] = get_bits(gb, 8 + (sconf->resolution > 1));
642 for (k = 1; k < sub_blocks; k++)
643 s[k] = s[k - 1] + decode_rice(gb, 2);
644
645 for (k = 0; k < sub_blocks; k++) {
646 sx[k] = s[k] & 0x0F;
647 s [k] >>= 4;
648 }
649 } else {
650 s[0] = get_bits(gb, 4 + (sconf->resolution > 1));
651 for (k = 1; k < sub_blocks; k++)
652 s[k] = s[k - 1] + decode_rice(gb, 0);
653 }
654 for (k = 1; k < sub_blocks; k++)
655 if (s[k] > 32) {
656 av_log(avctx, AV_LOG_ERROR, "k invalid for rice code.\n");
657 return AVERROR_INVALIDDATA;
658 }
659
660 if (get_bits1(gb))
661 *bd->shift_lsbs = get_bits(gb, 4) + 1;
662
663 *bd->store_prev_samples = (bd->js_blocks && bd->raw_other) || *bd->shift_lsbs;
664
665
666 if (!sconf->rlslms) {
667 if (sconf->adapt_order) {
668 int opt_order_length = av_ceil_log2(av_clip((bd->block_length >> 3) - 1,
669 2, sconf->max_order + 1));
670 *bd->opt_order = get_bits(gb, opt_order_length);
671 if (*bd->opt_order > sconf->max_order) {
672 *bd->opt_order = sconf->max_order;
673 av_log(avctx, AV_LOG_ERROR, "Predictor order too large!\n");
674 return AVERROR_INVALIDDATA;
675 }
676 } else {
677 *bd->opt_order = sconf->max_order;
678 }
679
680 opt_order = *bd->opt_order;
681
682 if (opt_order) {
683 int add_base;
684
685 if (sconf->coef_table == 3) {
686 add_base = 0x7F;
687
688 // read coefficient 0
689 quant_cof[0] = 32 * parcor_scaled_values[get_bits(gb, 7)];
690
691 // read coefficient 1
692 if (opt_order > 1)
693 quant_cof[1] = -32 * parcor_scaled_values[get_bits(gb, 7)];
694
695 // read coefficients 2 to opt_order
696 for (k = 2; k < opt_order; k++)
697 quant_cof[k] = get_bits(gb, 7);
698 } else {
699 int k_max;
700 add_base = 1;
701
702 // read coefficient 0 to 19
703 k_max = FFMIN(opt_order, 20);
704 for (k = 0; k < k_max; k++) {
705 int rice_param = parcor_rice_table[sconf->coef_table][k][1];
706 int offset = parcor_rice_table[sconf->coef_table][k][0];
707 quant_cof[k] = decode_rice(gb, rice_param) + offset;
708 if (quant_cof[k] < -64 || quant_cof[k] > 63) {
709 av_log(avctx, AV_LOG_ERROR, "quant_cof %d is out of range\n", quant_cof[k]);
710 return AVERROR_INVALIDDATA;
711 }
712 }
713
714 // read coefficients 20 to 126
715 k_max = FFMIN(opt_order, 127);
716 for (; k < k_max; k++)
717 quant_cof[k] = decode_rice(gb, 2) + (k & 1);
718
719 // read coefficients 127 to opt_order
720 for (; k < opt_order; k++)
721 quant_cof[k] = decode_rice(gb, 1);
722
723 quant_cof[0] = 32 * parcor_scaled_values[quant_cof[0] + 64];
724
725 if (opt_order > 1)
726 quant_cof[1] = -32 * parcor_scaled_values[quant_cof[1] + 64];
727 }
728
729 for (k = 2; k < opt_order; k++)
730 quant_cof[k] = (quant_cof[k] << 14) + (add_base << 13);
731 }
732 }
733
734 // read LTP gain and lag values
735 if (sconf->long_term_prediction) {
736 *bd->use_ltp = get_bits1(gb);
737
738 if (*bd->use_ltp) {
739 int r, c;
740
741 bd->ltp_gain[0] = decode_rice(gb, 1) << 3;
742 bd->ltp_gain[1] = decode_rice(gb, 2) << 3;
743
744 r = get_unary(gb, 0, 3);
745 c = get_bits(gb, 2);
746 bd->ltp_gain[2] = ltp_gain_values[r][c];
747
748 bd->ltp_gain[3] = decode_rice(gb, 2) << 3;
749 bd->ltp_gain[4] = decode_rice(gb, 1) << 3;
750
751 *bd->ltp_lag = get_bits(gb, ctx->ltp_lag_length);
752 *bd->ltp_lag += FFMAX(4, opt_order + 1);
753 }
754 }
755
756 // read first value and residuals in case of a random access block
757 if (bd->ra_block) {
758 if (opt_order)
759 bd->raw_samples[0] = decode_rice(gb, avctx->bits_per_raw_sample - 4);
760 if (opt_order > 1)
761 bd->raw_samples[1] = decode_rice(gb, FFMIN(s[0] + 3, ctx->s_max));
762 if (opt_order > 2)
763 bd->raw_samples[2] = decode_rice(gb, FFMIN(s[0] + 1, ctx->s_max));
764
765 start = FFMIN(opt_order, 3);
766 }
767
768 // read all residuals
769 if (sconf->bgmc) {
770 int delta[8];
771 unsigned int k [8];
772 unsigned int b = av_clip((av_ceil_log2(bd->block_length) - 3) >> 1, 0, 5);
773
774 // read most significant bits
775 unsigned int high;
776 unsigned int low;
777 unsigned int value;
778
779 ff_bgmc_decode_init(gb, &high, &low, &value);
780
781 current_res = bd->raw_samples + start;
782
783 for (sb = 0; sb < sub_blocks; sb++) {
784 unsigned int sb_len = sb_length - (sb ? 0 : start);
785
786 k [sb] = s[sb] > b ? s[sb] - b : 0;
787 delta[sb] = 5 - s[sb] + k[sb];
788
789 ff_bgmc_decode(gb, sb_len, current_res,
790 delta[sb], sx[sb], &high, &low, &value, ctx->bgmc_lut, ctx->bgmc_lut_status);
791
792 current_res += sb_len;
793 }
794
795 ff_bgmc_decode_end(gb);
796
797
798 // read least significant bits and tails
799 current_res = bd->raw_samples + start;
800
801 for (sb = 0; sb < sub_blocks; sb++, start = 0) {
802 unsigned int cur_tail_code = tail_code[sx[sb]][delta[sb]];
803 unsigned int cur_k = k[sb];
804 unsigned int cur_s = s[sb];
805
806 for (; start < sb_length; start++) {
807 int32_t res = *current_res;
808
809 if (res == cur_tail_code) {
810 unsigned int max_msb = (2 + (sx[sb] > 2) + (sx[sb] > 10))
811 << (5 - delta[sb]);
812
813 res = decode_rice(gb, cur_s);
814
815 if (res >= 0) {
816 res += (max_msb ) << cur_k;
817 } else {
818 res -= (max_msb - 1) << cur_k;
819 }
820 } else {
821 if (res > cur_tail_code)
822 res--;
823
824 if (res & 1)
825 res = -res;
826
827 res >>= 1;
828
829 if (cur_k) {
830 res <<= cur_k;
831 res |= get_bits_long(gb, cur_k);
832 }
833 }
834
835 *current_res++ = res;
836 }
837 }
838 } else {
839 current_res = bd->raw_samples + start;
840
841 for (sb = 0; sb < sub_blocks; sb++, start = 0)
842 for (; start < sb_length; start++)
843 *current_res++ = decode_rice(gb, s[sb]);
844 }
845
846 if (!sconf->mc_coding || ctx->js_switch)
847 align_get_bits(gb);
848
849 return 0;
850 }
851
852
853 /** Decode the block data for a non-constant block
854 */
855 static int decode_var_block_data(ALSDecContext *ctx, ALSBlockData *bd)
856 {
857 ALSSpecificConfig *sconf = &ctx->sconf;
858 unsigned int block_length = bd->block_length;
859 unsigned int smp = 0;
860 unsigned int k;
861 int opt_order = *bd->opt_order;
862 int sb;
863 int64_t y;
864 int32_t *quant_cof = bd->quant_cof;
865 int32_t *lpc_cof = bd->lpc_cof;
866 int32_t *raw_samples = bd->raw_samples;
867 int32_t *raw_samples_end = bd->raw_samples + bd->block_length;
868 int32_t *lpc_cof_reversed = ctx->lpc_cof_reversed_buffer;
869
870 // reverse long-term prediction
871 if (*bd->use_ltp) {
872 int ltp_smp;
873
874 for (ltp_smp = FFMAX(*bd->ltp_lag - 2, 0); ltp_smp < block_length; ltp_smp++) {
875 int center = ltp_smp - *bd->ltp_lag;
876 int begin = FFMAX(0, center - 2);
877 int end = center + 3;
878 int tab = 5 - (end - begin);
879 int base;
880
881 y = 1 << 6;
882
883 for (base = begin; base < end; base++, tab++)
884 y += MUL64(bd->ltp_gain[tab], raw_samples[base]);
885
886 raw_samples[ltp_smp] += y >> 7;
887 }
888 }
889
890 // reconstruct all samples from residuals
891 if (bd->ra_block) {
892 for (smp = 0; smp < opt_order; smp++) {
893 y = 1 << 19;
894
895 for (sb = 0; sb < smp; sb++)
896 y += MUL64(lpc_cof[sb], raw_samples[-(sb + 1)]);
897
898 *raw_samples++ -= y >> 20;
899 parcor_to_lpc(smp, quant_cof, lpc_cof);
900 }
901 } else {
902 for (k = 0; k < opt_order; k++)
903 parcor_to_lpc(k, quant_cof, lpc_cof);
904
905 // store previous samples in case that they have to be altered
906 if (*bd->store_prev_samples)
907 memcpy(bd->prev_raw_samples, raw_samples - sconf->max_order,
908 sizeof(*bd->prev_raw_samples) * sconf->max_order);
909
910 // reconstruct difference signal for prediction (joint-stereo)
911 if (bd->js_blocks && bd->raw_other) {
912 int32_t *left, *right;
913
914 if (bd->raw_other > raw_samples) { // D = R - L
915 left = raw_samples;
916 right = bd->raw_other;
917 } else { // D = R - L
918 left = bd->raw_other;
919 right = raw_samples;
920 }
921
922 for (sb = -1; sb >= -sconf->max_order; sb--)
923 raw_samples[sb] = right[sb] - left[sb];
924 }
925
926 // reconstruct shifted signal
927 if (*bd->shift_lsbs)
928 for (sb = -1; sb >= -sconf->max_order; sb--)
929 raw_samples[sb] >>= *bd->shift_lsbs;
930 }
931
932 // reverse linear prediction coefficients for efficiency
933 lpc_cof = lpc_cof + opt_order;
934
935 for (sb = 0; sb < opt_order; sb++)
936 lpc_cof_reversed[sb] = lpc_cof[-(sb + 1)];
937
938 // reconstruct raw samples
939 raw_samples = bd->raw_samples + smp;
940 lpc_cof = lpc_cof_reversed + opt_order;
941
942 for (; raw_samples < raw_samples_end; raw_samples++) {
943 y = 1 << 19;
944
945 for (sb = -opt_order; sb < 0; sb++)
946 y += MUL64(lpc_cof[sb], raw_samples[sb]);
947
948 *raw_samples -= y >> 20;
949 }
950
951 raw_samples = bd->raw_samples;
952
953 // restore previous samples in case that they have been altered
954 if (*bd->store_prev_samples)
955 memcpy(raw_samples - sconf->max_order, bd->prev_raw_samples,
956 sizeof(*raw_samples) * sconf->max_order);
957
958 return 0;
959 }
960
961
962 /** Read the block data.
963 */
964 static int read_block(ALSDecContext *ctx, ALSBlockData *bd)
965 {
966 GetBitContext *gb = &ctx->gb;
967
968 *bd->shift_lsbs = 0;
969 // read block type flag and read the samples accordingly
970 if (get_bits1(gb)) {
971 if (read_var_block_data(ctx, bd))
972 return -1;
973 } else {
974 read_const_block_data(ctx, bd);
975 }
976
977 return 0;
978 }
979
980
981 /** Decode the block data.
982 */
983 static int decode_block(ALSDecContext *ctx, ALSBlockData *bd)
984 {
985 unsigned int smp;
986
987 // read block type flag and read the samples accordingly
988 if (*bd->const_block)
989 decode_const_block_data(ctx, bd);
990 else if (decode_var_block_data(ctx, bd))
991 return -1;
992
993 // TODO: read RLSLMS extension data
994
995 if (*bd->shift_lsbs)
996 for (smp = 0; smp < bd->block_length; smp++)
997 bd->raw_samples[smp] <<= *bd->shift_lsbs;
998
999 return 0;
1000 }
1001
1002
1003 /** Read and decode block data successively.
1004 */
1005 static int read_decode_block(ALSDecContext *ctx, ALSBlockData *bd)
1006 {
1007 int ret;
1008
1009 ret = read_block(ctx, bd);
1010
1011 if (ret)
1012 return ret;
1013
1014 ret = decode_block(ctx, bd);
1015
1016 return ret;
1017 }
1018
1019
1020 /** Compute the number of samples left to decode for the current frame and
1021 * sets these samples to zero.
1022 */
1023 static void zero_remaining(unsigned int b, unsigned int b_max,
1024 const unsigned int *div_blocks, int32_t *buf)
1025 {
1026 unsigned int count = 0;
1027
1028 for (; b < b_max; b++)
1029 count += div_blocks[b];
1030
1031 if (count)
1032 memset(buf, 0, sizeof(*buf) * count);
1033 }
1034
1035
1036 /** Decode blocks independently.
1037 */
1038 static int decode_blocks_ind(ALSDecContext *ctx, unsigned int ra_frame,
1039 unsigned int c, const unsigned int *div_blocks,
1040 unsigned int *js_blocks)
1041 {
1042 unsigned int b;
1043 ALSBlockData bd = { 0 };
1044
1045 bd.ra_block = ra_frame;
1046 bd.const_block = ctx->const_block;
1047 bd.shift_lsbs = ctx->shift_lsbs;
1048 bd.opt_order = ctx->opt_order;
1049 bd.store_prev_samples = ctx->store_prev_samples;
1050 bd.use_ltp = ctx->use_ltp;
1051 bd.ltp_lag = ctx->ltp_lag;
1052 bd.ltp_gain = ctx->ltp_gain[0];
1053 bd.quant_cof = ctx->quant_cof[0];
1054 bd.lpc_cof = ctx->lpc_cof[0];
1055 bd.prev_raw_samples = ctx->prev_raw_samples;
1056 bd.raw_samples = ctx->raw_samples[c];
1057
1058
1059 for (b = 0; b < ctx->num_blocks; b++) {
1060 bd.block_length = div_blocks[b];
1061
1062 if (read_decode_block(ctx, &bd)) {
1063 // damaged block, write zero for the rest of the frame
1064 zero_remaining(b, ctx->num_blocks, div_blocks, bd.raw_samples);
1065 return -1;
1066 }
1067 bd.raw_samples += div_blocks[b];
1068 bd.ra_block = 0;
1069 }
1070
1071 return 0;
1072 }
1073
1074
1075 /** Decode blocks dependently.
1076 */
1077 static int decode_blocks(ALSDecContext *ctx, unsigned int ra_frame,
1078 unsigned int c, const unsigned int *div_blocks,
1079 unsigned int *js_blocks)
1080 {
1081 ALSSpecificConfig *sconf = &ctx->sconf;
1082 unsigned int offset = 0;
1083 unsigned int b;
1084 ALSBlockData bd[2] = { { 0 } };
1085
1086 bd[0].ra_block = ra_frame;
1087 bd[0].const_block = ctx->const_block;
1088 bd[0].shift_lsbs = ctx->shift_lsbs;
1089 bd[0].opt_order = ctx->opt_order;
1090 bd[0].store_prev_samples = ctx->store_prev_samples;
1091 bd[0].use_ltp = ctx->use_ltp;
1092 bd[0].ltp_lag = ctx->ltp_lag;
1093 bd[0].ltp_gain = ctx->ltp_gain[0];
1094 bd[0].quant_cof = ctx->quant_cof[0];
1095 bd[0].lpc_cof = ctx->lpc_cof[0];
1096 bd[0].prev_raw_samples = ctx->prev_raw_samples;
1097 bd[0].js_blocks = *js_blocks;
1098
1099 bd[1].ra_block = ra_frame;
1100 bd[1].const_block = ctx->const_block;
1101 bd[1].shift_lsbs = ctx->shift_lsbs;
1102 bd[1].opt_order = ctx->opt_order;
1103 bd[1].store_prev_samples = ctx->store_prev_samples;
1104 bd[1].use_ltp = ctx->use_ltp;
1105 bd[1].ltp_lag = ctx->ltp_lag;
1106 bd[1].ltp_gain = ctx->ltp_gain[0];
1107 bd[1].quant_cof = ctx->quant_cof[0];
1108 bd[1].lpc_cof = ctx->lpc_cof[0];
1109 bd[1].prev_raw_samples = ctx->prev_raw_samples;
1110 bd[1].js_blocks = *(js_blocks + 1);
1111
1112 // decode all blocks
1113 for (b = 0; b < ctx->num_blocks; b++) {
1114 unsigned int s;
1115
1116 bd[0].block_length = div_blocks[b];
1117 bd[1].block_length = div_blocks[b];
1118
1119 bd[0].raw_samples = ctx->raw_samples[c ] + offset;
1120 bd[1].raw_samples = ctx->raw_samples[c + 1] + offset;
1121
1122 bd[0].raw_other = bd[1].raw_samples;
1123 bd[1].raw_other = bd[0].raw_samples;
1124
1125 if(read_decode_block(ctx, &bd[0]) || read_decode_block(ctx, &bd[1])) {
1126 // damaged block, write zero for the rest of the frame
1127 zero_remaining(b, ctx->num_blocks, div_blocks, bd[0].raw_samples);
1128 zero_remaining(b, ctx->num_blocks, div_blocks, bd[1].raw_samples);
1129 return -1;
1130 }
1131
1132 // reconstruct joint-stereo blocks
1133 if (bd[0].js_blocks) {
1134 if (bd[1].js_blocks)
1135 av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel pair!\n");
1136
1137 for (s = 0; s < div_blocks[b]; s++)
1138 bd[0].raw_samples[s] = bd[1].raw_samples[s] - bd[0].raw_samples[s];
1139 } else if (bd[1].js_blocks) {
1140 for (s = 0; s < div_blocks[b]; s++)
1141 bd[1].raw_samples[s] = bd[1].raw_samples[s] + bd[0].raw_samples[s];
1142 }
1143
1144 offset += div_blocks[b];
1145 bd[0].ra_block = 0;
1146 bd[1].ra_block = 0;
1147 }
1148
1149 // store carryover raw samples,
1150 // the others channel raw samples are stored by the calling function.
1151 memmove(ctx->raw_samples[c] - sconf->max_order,
1152 ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
1153 sizeof(*ctx->raw_samples[c]) * sconf->max_order);
1154
1155 return 0;
1156 }
1157
1158
1159 /** Read the channel data.
1160 */
1161 static int read_channel_data(ALSDecContext *ctx, ALSChannelData *cd, int c)
1162 {
1163 GetBitContext *gb = &ctx->gb;
1164 ALSChannelData *current = cd;
1165 unsigned int channels = ctx->avctx->channels;
1166 int entries = 0;
1167
1168 while (entries < channels && !(current->stop_flag = get_bits1(gb))) {
1169 current->master_channel = get_bits_long(gb, av_ceil_log2(channels));
1170
1171 if (current->master_channel >= channels) {
1172 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid master channel!\n");
1173 return -1;
1174 }
1175
1176 if (current->master_channel != c) {
1177 current->time_diff_flag = get_bits1(gb);
1178 current->weighting[0] = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];
1179 current->weighting[1] = mcc_weightings[av_clip(decode_rice(gb, 2) + 14, 0, 32)];
1180 current->weighting[2] = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];
1181
1182 if (current->time_diff_flag) {
1183 current->weighting[3] = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];
1184 current->weighting[4] = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];
1185 current->weighting[5] = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];
1186
1187 current->time_diff_sign = get_bits1(gb);
1188 current->time_diff_index = get_bits(gb, ctx->ltp_lag_length - 3) + 3;
1189 }
1190 }
1191
1192 current++;
1193 entries++;
1194 }
1195
1196 if (entries == channels) {
1197 av_log(ctx->avctx, AV_LOG_ERROR, "Damaged channel data!\n");
1198 return -1;
1199 }
1200
1201 align_get_bits(gb);
1202 return 0;
1203 }
1204
1205
1206 /** Recursively reverts the inter-channel correlation for a block.
1207 */
1208 static int revert_channel_correlation(ALSDecContext *ctx, ALSBlockData *bd,
1209 ALSChannelData **cd, int *reverted,
1210 unsigned int offset, int c)
1211 {
1212 ALSChannelData *ch = cd[c];
1213 unsigned int dep = 0;
1214 unsigned int channels = ctx->avctx->channels;
1215
1216 if (reverted[c])
1217 return 0;
1218
1219 reverted[c] = 1;
1220
1221 while (dep < channels && !ch[dep].stop_flag) {
1222 revert_channel_correlation(ctx, bd, cd, reverted, offset,
1223 ch[dep].master_channel);
1224
1225 dep++;
1226 }
1227
1228 if (dep == channels) {
1229 av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel correlation!\n");
1230 return -1;
1231 }
1232
1233 bd->const_block = ctx->const_block + c;
1234 bd->shift_lsbs = ctx->shift_lsbs + c;
1235 bd->opt_order = ctx->opt_order + c;
1236 bd->store_prev_samples = ctx->store_prev_samples + c;
1237 bd->use_ltp = ctx->use_ltp + c;
1238 bd->ltp_lag = ctx->ltp_lag + c;
1239 bd->ltp_gain = ctx->ltp_gain[c];
1240 bd->lpc_cof = ctx->lpc_cof[c];
1241 bd->quant_cof = ctx->quant_cof[c];
1242 bd->raw_samples = ctx->raw_samples[c] + offset;
1243
1244 dep = 0;
1245 while (!ch[dep].stop_flag) {
1246 unsigned int smp;
1247 unsigned int begin = 1;
1248 unsigned int end = bd->block_length - 1;
1249 int64_t y;
1250 int32_t *master = ctx->raw_samples[ch[dep].master_channel] + offset;
1251
1252 if (ch[dep].time_diff_flag) {
1253 int t = ch[dep].time_diff_index;
1254
1255 if (ch[dep].time_diff_sign) {
1256 t = -t;
1257 begin -= t;
1258 } else {
1259 end -= t;
1260 }
1261
1262 for (smp = begin; smp < end; smp++) {
1263 y = (1 << 6) +
1264 MUL64(ch[dep].weighting[0], master[smp - 1 ]) +
1265 MUL64(ch[dep].weighting[1], master[smp ]) +
1266 MUL64(ch[dep].weighting[2], master[smp + 1 ]) +
1267 MUL64(ch[dep].weighting[3], master[smp - 1 + t]) +
1268 MUL64(ch[dep].weighting[4], master[smp + t]) +
1269 MUL64(ch[dep].weighting[5], master[smp + 1 + t]);
1270
1271 bd->raw_samples[smp] += y >> 7;
1272 }
1273 } else {
1274 for (smp = begin; smp < end; smp++) {
1275 y = (1 << 6) +
1276 MUL64(ch[dep].weighting[0], master[smp - 1]) +
1277 MUL64(ch[dep].weighting[1], master[smp ]) +
1278 MUL64(ch[dep].weighting[2], master[smp + 1]);
1279
1280 bd->raw_samples[smp] += y >> 7;
1281 }
1282 }
1283
1284 dep++;
1285 }
1286
1287 return 0;
1288 }
1289
1290
1291 /** Read the frame data.
1292 */
1293 static int read_frame_data(ALSDecContext *ctx, unsigned int ra_frame)
1294 {
1295 ALSSpecificConfig *sconf = &ctx->sconf;
1296 AVCodecContext *avctx = ctx->avctx;
1297 GetBitContext *gb = &ctx->gb;
1298 unsigned int div_blocks[32]; ///< block sizes.
1299 unsigned int c;
1300 unsigned int js_blocks[2];
1301
1302 uint32_t bs_info = 0;
1303
1304 // skip the size of the ra unit if present in the frame
1305 if (sconf->ra_flag == RA_FLAG_FRAMES && ra_frame)
1306 skip_bits_long(gb, 32);
1307
1308 if (sconf->mc_coding && sconf->joint_stereo) {
1309 ctx->js_switch = get_bits1(gb);
1310 align_get_bits(gb);
1311 }
1312
1313 if (!sconf->mc_coding || ctx->js_switch) {
1314 int independent_bs = !sconf->joint_stereo;
1315
1316 for (c = 0; c < avctx->channels; c++) {
1317 js_blocks[0] = 0;
1318 js_blocks[1] = 0;
1319
1320 get_block_sizes(ctx, div_blocks, &bs_info);
1321
1322 // if joint_stereo and block_switching is set, independent decoding
1323 // is signaled via the first bit of bs_info
1324 if (sconf->joint_stereo && sconf->block_switching)
1325 if (bs_info >> 31)
1326 independent_bs = 2;
1327
1328 // if this is the last channel, it has to be decoded independently
1329 if (c == avctx->channels - 1)
1330 independent_bs = 1;
1331
1332 if (independent_bs) {
1333 if (decode_blocks_ind(ctx, ra_frame, c, div_blocks, js_blocks))
1334 return -1;
1335
1336 independent_bs--;
1337 } else {
1338 if (decode_blocks(ctx, ra_frame, c, div_blocks, js_blocks))
1339 return -1;
1340
1341 c++;
1342 }
1343
1344 // store carryover raw samples
1345 memmove(ctx->raw_samples[c] - sconf->max_order,
1346 ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
1347 sizeof(*ctx->raw_samples[c]) * sconf->max_order);
1348 }
1349 } else { // multi-channel coding
1350 ALSBlockData bd = { 0 };
1351 int b, ret;
1352 int *reverted_channels = ctx->reverted_channels;
1353 unsigned int offset = 0;
1354
1355 for (c = 0; c < avctx->channels; c++)
1356 if (ctx->chan_data[c] < ctx->chan_data_buffer) {
1357 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid channel data!\n");
1358 return -1;
1359 }
1360
1361 memset(reverted_channels, 0, sizeof(*reverted_channels) * avctx->channels);
1362
1363 bd.ra_block = ra_frame;
1364 bd.prev_raw_samples = ctx->prev_raw_samples;
1365
1366 get_block_sizes(ctx, div_blocks, &bs_info);
1367
1368 for (b = 0; b < ctx->num_blocks; b++) {
1369 bd.block_length = div_blocks[b];
1370
1371 for (c = 0; c < avctx->channels; c++) {
1372 bd.const_block = ctx->const_block + c;
1373 bd.shift_lsbs = ctx->shift_lsbs + c;
1374 bd.opt_order = ctx->opt_order + c;
1375 bd.store_prev_samples = ctx->store_prev_samples + c;
1376 bd.use_ltp = ctx->use_ltp + c;
1377 bd.ltp_lag = ctx->ltp_lag + c;
1378 bd.ltp_gain = ctx->ltp_gain[c];
1379 bd.lpc_cof = ctx->lpc_cof[c];
1380 bd.quant_cof = ctx->quant_cof[c];
1381 bd.raw_samples = ctx->raw_samples[c] + offset;
1382 bd.raw_other = NULL;
1383
1384 if ((ret = read_block(ctx, &bd)) < 0)
1385 return ret;
1386 if ((ret = read_channel_data(ctx, ctx->chan_data[c], c)) < 0)
1387 return ret;
1388 }
1389
1390 for (c = 0; c < avctx->channels; c++)
1391 if (revert_channel_correlation(ctx, &bd, ctx->chan_data,
1392 reverted_channels, offset, c))
1393 return -1;
1394
1395 for (c = 0; c < avctx->channels; c++) {
1396 bd.const_block = ctx->const_block + c;
1397 bd.shift_lsbs = ctx->shift_lsbs + c;
1398 bd.opt_order = ctx->opt_order + c;
1399 bd.store_prev_samples = ctx->store_prev_samples + c;
1400 bd.use_ltp = ctx->use_ltp + c;
1401 bd.ltp_lag = ctx->ltp_lag + c;
1402 bd.ltp_gain = ctx->ltp_gain[c];
1403 bd.lpc_cof = ctx->lpc_cof[c];
1404 bd.quant_cof = ctx->quant_cof[c];
1405 bd.raw_samples = ctx->raw_samples[c] + offset;
1406 if ((ret = decode_block(ctx, &bd)) < 0)
1407 return ret;
1408 }
1409
1410 memset(reverted_channels, 0, avctx->channels * sizeof(*reverted_channels));
1411 offset += div_blocks[b];
1412 bd.ra_block = 0;
1413 }
1414
1415 // store carryover raw samples
1416 for (c = 0; c < avctx->channels; c++)
1417 memmove(ctx->raw_samples[c] - sconf->max_order,
1418 ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
1419 sizeof(*ctx->raw_samples[c]) * sconf->max_order);
1420 }
1421
1422 // TODO: read_diff_float_data
1423
1424 return 0;
1425 }
1426
1427
1428 /** Decode an ALS frame.
1429 */
1430 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr,
1431 AVPacket *avpkt)
1432 {
1433 ALSDecContext *ctx = avctx->priv_data;
1434 ALSSpecificConfig *sconf = &ctx->sconf;
1435 const uint8_t *buffer = avpkt->data;
1436 int buffer_size = avpkt->size;
1437 int invalid_frame, ret;
1438 unsigned int c, sample, ra_frame, bytes_read, shift;
1439
1440 init_get_bits(&ctx->gb, buffer, buffer_size * 8);
1441
1442 // In the case that the distance between random access frames is set to zero
1443 // (sconf->ra_distance == 0) no frame is treated as a random access frame.
1444 // For the first frame, if prediction is used, all samples used from the
1445 // previous frame are assumed to be zero.
1446 ra_frame = sconf->ra_distance && !(ctx->frame_id % sconf->ra_distance);
1447
1448 // the last frame to decode might have a different length
1449 if (sconf->samples != 0xFFFFFFFF)
1450 ctx->cur_frame_length = FFMIN(sconf->samples - ctx->frame_id * (uint64_t) sconf->frame_length,
1451 sconf->frame_length);
1452 else
1453 ctx->cur_frame_length = sconf->frame_length;
1454
1455 // decode the frame data
1456 if ((invalid_frame = read_frame_data(ctx, ra_frame)) < 0)
1457 av_log(ctx->avctx, AV_LOG_WARNING,
1458 "Reading frame data failed. Skipping RA unit.\n");
1459
1460 ctx->frame_id++;
1461
1462 /* get output buffer */
1463 ctx->frame.nb_samples = ctx->cur_frame_length;
1464 if ((ret = avctx->get_buffer(avctx, &ctx->frame)) < 0) {
1465 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
1466 return ret;
1467 }
1468
1469 // transform decoded frame into output format
1470 #define INTERLEAVE_OUTPUT(bps) \
1471 { \
1472 int##bps##_t *dest = (int##bps##_t*)ctx->frame.data[0]; \
1473 shift = bps - ctx->avctx->bits_per_raw_sample; \
1474 for (sample = 0; sample < ctx->cur_frame_length; sample++) \
1475 for (c = 0; c < avctx->channels; c++) \
1476 *dest++ = ctx->raw_samples[c][sample] << shift; \
1477 }
1478
1479 if (ctx->avctx->bits_per_raw_sample <= 16) {
1480 INTERLEAVE_OUTPUT(16)
1481 } else {
1482 INTERLEAVE_OUTPUT(32)
1483 }
1484
1485 // update CRC
1486 if (sconf->crc_enabled && (avctx->err_recognition & AV_EF_CRCCHECK)) {
1487 int swap = HAVE_BIGENDIAN != sconf->msb_first;
1488
1489 if (ctx->avctx->bits_per_raw_sample == 24) {
1490 int32_t *src = (int32_t *)ctx->frame.data[0];
1491
1492 for (sample = 0;
1493 sample < ctx->cur_frame_length * avctx->channels;
1494 sample++) {
1495 int32_t v;
1496
1497 if (swap)
1498 v = av_bswap32(src[sample]);
1499 else
1500 v = src[sample];
1501 if (!HAVE_BIGENDIAN)
1502 v >>= 8;
1503
1504 ctx->crc = av_crc(ctx->crc_table, ctx->crc, (uint8_t*)(&v), 3);
1505 }
1506 } else {
1507 uint8_t *crc_source;
1508
1509 if (swap) {
1510 if (ctx->avctx->bits_per_raw_sample <= 16) {
1511 int16_t *src = (int16_t*) ctx->frame.data[0];
1512 int16_t *dest = (int16_t*) ctx->crc_buffer;
1513 for (sample = 0;
1514 sample < ctx->cur_frame_length * avctx->channels;
1515 sample++)
1516 *dest++ = av_bswap16(src[sample]);
1517 } else {
1518 ctx->dsp.bswap_buf((uint32_t*)ctx->crc_buffer,
1519 (uint32_t *)ctx->frame.data[0],
1520 ctx->cur_frame_length * avctx->channels);
1521 }
1522 crc_source = ctx->crc_buffer;
1523 } else {
1524 crc_source = ctx->frame.data[0];
1525 }
1526
1527 ctx->crc = av_crc(ctx->crc_table, ctx->crc, crc_source,
1528 ctx->cur_frame_length * avctx->channels *
1529 av_get_bytes_per_sample(avctx->sample_fmt));
1530 }
1531
1532
1533 // check CRC sums if this is the last frame
1534 if (ctx->cur_frame_length != sconf->frame_length &&
1535 ctx->crc_org != ctx->crc) {
1536 av_log(avctx, AV_LOG_ERROR, "CRC error.\n");
1537 }
1538 }
1539
1540 *got_frame_ptr = 1;
1541 *(AVFrame *)data = ctx->frame;
1542
1543
1544 bytes_read = invalid_frame ? buffer_size :
1545 (get_bits_count(&ctx->gb) + 7) >> 3;
1546
1547 return bytes_read;
1548 }
1549
1550
1551 /** Uninitialize the ALS decoder.
1552 */
1553 static av_cold int decode_end(AVCodecContext *avctx)
1554 {
1555 ALSDecContext *ctx = avctx->priv_data;
1556
1557 av_freep(&ctx->sconf.chan_pos);
1558
1559 ff_bgmc_end(&ctx->bgmc_lut, &ctx->bgmc_lut_status);
1560
1561 av_freep(&ctx->const_block);
1562 av_freep(&ctx->shift_lsbs);
1563 av_freep(&ctx->opt_order);
1564 av_freep(&ctx->store_prev_samples);
1565 av_freep(&ctx->use_ltp);
1566 av_freep(&ctx->ltp_lag);
1567 av_freep(&ctx->ltp_gain);
1568 av_freep(&ctx->ltp_gain_buffer);
1569 av_freep(&ctx->quant_cof);
1570 av_freep(&ctx->lpc_cof);
1571 av_freep(&ctx->quant_cof_buffer);
1572 av_freep(&ctx->lpc_cof_buffer);
1573 av_freep(&ctx->lpc_cof_reversed_buffer);
1574 av_freep(&ctx->prev_raw_samples);
1575 av_freep(&ctx->raw_samples);
1576 av_freep(&ctx->raw_buffer);
1577 av_freep(&ctx->chan_data);
1578 av_freep(&ctx->chan_data_buffer);
1579 av_freep(&ctx->reverted_channels);
1580 av_freep(&ctx->crc_buffer);
1581
1582 return 0;
1583 }
1584
1585
1586 /** Initialize the ALS decoder.
1587 */
1588 static av_cold int decode_init(AVCodecContext *avctx)
1589 {
1590 unsigned int c;
1591 unsigned int channel_size;
1592 int num_buffers;
1593 ALSDecContext *ctx = avctx->priv_data;
1594 ALSSpecificConfig *sconf = &ctx->sconf;
1595 ctx->avctx = avctx;
1596
1597 if (!avctx->extradata) {
1598 av_log(avctx, AV_LOG_ERROR, "Missing required ALS extradata.\n");
1599 return -1;
1600 }
1601
1602 if (read_specific_config(ctx)) {
1603 av_log(avctx, AV_LOG_ERROR, "Reading ALSSpecificConfig failed.\n");
1604 decode_end(avctx);
1605 return -1;
1606 }
1607
1608 if (check_specific_config(ctx)) {
1609 decode_end(avctx);
1610 return -1;
1611 }
1612
1613 if (sconf->bgmc)
1614 ff_bgmc_init(avctx, &ctx->bgmc_lut, &ctx->bgmc_lut_status);
1615
1616 if (sconf->floating) {
1617 avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
1618 avctx->bits_per_raw_sample = 32;
1619 } else {
1620 avctx->sample_fmt = sconf->resolution > 1
1621 ? AV_SAMPLE_FMT_S32 : AV_SAMPLE_FMT_S16;
1622 avctx->bits_per_raw_sample = (sconf->resolution + 1) * 8;
1623 }
1624
1625 // set maximum Rice parameter for progressive decoding based on resolution
1626 // This is not specified in 14496-3 but actually done by the reference
1627 // codec RM22 revision 2.
1628 ctx->s_max = sconf->resolution > 1 ? 31 : 15;
1629
1630 // set lag value for long-term prediction
1631 ctx->ltp_lag_length = 8 + (avctx->sample_rate >= 96000) +
1632 (avctx->sample_rate >= 192000);
1633
1634 // allocate quantized parcor coefficient buffer
1635 num_buffers = sconf->mc_coding ? avctx->channels : 1;
1636
1637 ctx->quant_cof = av_malloc(sizeof(*ctx->quant_cof) * num_buffers);
1638 ctx->lpc_cof = av_malloc(sizeof(*ctx->lpc_cof) * num_buffers);
1639 ctx->quant_cof_buffer = av_malloc(sizeof(*ctx->quant_cof_buffer) *
1640 num_buffers * sconf->max_order);
1641 ctx->lpc_cof_buffer = av_malloc(sizeof(*ctx->lpc_cof_buffer) *
1642 num_buffers * sconf->max_order);
1643 ctx->lpc_cof_reversed_buffer = av_malloc(sizeof(*ctx->lpc_cof_buffer) *
1644 sconf->max_order);
1645
1646 if (!ctx->quant_cof || !ctx->lpc_cof ||
1647 !ctx->quant_cof_buffer || !ctx->lpc_cof_buffer ||
1648 !ctx->lpc_cof_reversed_buffer) {
1649 av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
1650 return AVERROR(ENOMEM);
1651 }
1652
1653 // assign quantized parcor coefficient buffers
1654 for (c = 0; c < num_buffers; c++) {
1655 ctx->quant_cof[c] = ctx->quant_cof_buffer + c * sconf->max_order;
1656 ctx->lpc_cof[c] = ctx->lpc_cof_buffer + c * sconf->max_order;
1657 }
1658
1659 // allocate and assign lag and gain data buffer for ltp mode
1660 ctx->const_block = av_malloc (sizeof(*ctx->const_block) * num_buffers);
1661 ctx->shift_lsbs = av_malloc (sizeof(*ctx->shift_lsbs) * num_buffers);
1662 ctx->opt_order = av_malloc (sizeof(*ctx->opt_order) * num_buffers);
1663 ctx->store_prev_samples = av_malloc(sizeof(*ctx->store_prev_samples) * num_buffers);
1664 ctx->use_ltp = av_mallocz(sizeof(*ctx->use_ltp) * num_buffers);
1665 ctx->ltp_lag = av_malloc (sizeof(*ctx->ltp_lag) * num_buffers);
1666 ctx->ltp_gain = av_malloc (sizeof(*ctx->ltp_gain) * num_buffers);
1667 ctx->ltp_gain_buffer = av_malloc (sizeof(*ctx->ltp_gain_buffer) *
1668 num_buffers * 5);
1669
1670 if (!ctx->const_block || !ctx->shift_lsbs ||
1671 !ctx->opt_order || !ctx->store_prev_samples ||
1672 !ctx->use_ltp || !ctx->ltp_lag ||
1673 !ctx->ltp_gain || !ctx->ltp_gain_buffer) {
1674 av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
1675 decode_end(avctx);
1676 return AVERROR(ENOMEM);
1677 }
1678
1679 for (c = 0; c < num_buffers; c++)
1680 ctx->ltp_gain[c] = ctx->ltp_gain_buffer + c * 5;
1681
1682 // allocate and assign channel data buffer for mcc mode
1683 if (sconf->mc_coding) {
1684 ctx->chan_data_buffer = av_malloc(sizeof(*ctx->chan_data_buffer) *
1685 num_buffers * num_buffers);
1686 ctx->chan_data = av_malloc(sizeof(*ctx->chan_data) *
1687 num_buffers);
1688 ctx->reverted_channels = av_malloc(sizeof(*ctx->reverted_channels) *
1689 num_buffers);
1690
1691 if (!ctx->chan_data_buffer || !ctx->chan_data || !ctx->reverted_channels) {
1692 av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
1693 decode_end(avctx);
1694 return AVERROR(ENOMEM);
1695 }
1696
1697 for (c = 0; c < num_buffers; c++)
1698 ctx->chan_data[c] = ctx->chan_data_buffer + c * num_buffers;
1699 } else {
1700 ctx->chan_data = NULL;
1701 ctx->chan_data_buffer = NULL;
1702 ctx->reverted_channels = NULL;
1703 }
1704
1705 channel_size = sconf->frame_length + sconf->max_order;
1706
1707 ctx->prev_raw_samples = av_malloc (sizeof(*ctx->prev_raw_samples) * sconf->max_order);
1708 ctx->raw_buffer = av_mallocz(sizeof(*ctx-> raw_buffer) * avctx->channels * channel_size);
1709 ctx->raw_samples = av_malloc (sizeof(*ctx-> raw_samples) * avctx->channels);
1710
1711 // allocate previous raw sample buffer
1712 if (!ctx->prev_raw_samples || !ctx->raw_buffer|| !ctx->raw_samples) {
1713 av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
1714 decode_end(avctx);
1715 return AVERROR(ENOMEM);
1716 }
1717
1718 // assign raw samples buffers
1719 ctx->raw_samples[0] = ctx->raw_buffer + sconf->max_order;
1720 for (c = 1; c < avctx->channels; c++)
1721 ctx->raw_samples[c] = ctx->raw_samples[c - 1] + channel_size;
1722
1723 // allocate crc buffer
1724 if (HAVE_BIGENDIAN != sconf->msb_first && sconf->crc_enabled &&
1725 (avctx->err_recognition & AV_EF_CRCCHECK)) {
1726 ctx->crc_buffer = av_malloc(sizeof(*ctx->crc_buffer) *
1727 ctx->cur_frame_length *
1728 avctx->channels *
1729 av_get_bytes_per_sample(avctx->sample_fmt));
1730 if (!ctx->crc_buffer) {
1731 av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
1732 decode_end(avctx);
1733 return AVERROR(ENOMEM);
1734 }
1735 }
1736
1737 ff_dsputil_init(&ctx->dsp, avctx);
1738
1739 avcodec_get_frame_defaults(&ctx->frame);
1740 avctx->coded_frame = &ctx->frame;
1741
1742 return 0;
1743 }
1744
1745
1746 /** Flush (reset) the frame ID after seeking.
1747 */
1748 static av_cold void flush(AVCodecContext *avctx)
1749 {
1750 ALSDecContext *ctx = avctx->priv_data;
1751
1752 ctx->frame_id = 0;
1753 }
1754
1755
1756 AVCodec ff_als_decoder = {
1757 .name = "als",
1758 .type = AVMEDIA_TYPE_AUDIO,
1759 .id = AV_CODEC_ID_MP4ALS,
1760 .priv_data_size = sizeof(ALSDecContext),
1761 .init = decode_init,
1762 .close = decode_end,
1763 .decode = decode_frame,
1764 .flush = flush,
1765 .capabilities = CODEC_CAP_SUBFRAMES | CODEC_CAP_DR1,
1766 .long_name = NULL_IF_CONFIG_SMALL("MPEG-4 Audio Lossless Coding (ALS)"),
1767 };