lavc: add a wrapper for AVCodecContext.get_buffer().
[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 "internal.h"
40 #include "libavutil/samplefmt.h"
41 #include "libavutil/crc.h"
42
43 #include <stdint.h>
44
45 /** Rice parameters and corresponding index offsets for decoding the
46 * indices of scaled PARCOR values. The table chosen is set globally
47 * by the encoder and stored in ALSSpecificConfig.
48 */
49 static const int8_t parcor_rice_table[3][20][2] = {
50 { {-52, 4}, {-29, 5}, {-31, 4}, { 19, 4}, {-16, 4},
51 { 12, 3}, { -7, 3}, { 9, 3}, { -5, 3}, { 6, 3},
52 { -4, 3}, { 3, 3}, { -3, 2}, { 3, 2}, { -2, 2},
53 { 3, 2}, { -1, 2}, { 2, 2}, { -1, 2}, { 2, 2} },
54 { {-58, 3}, {-42, 4}, {-46, 4}, { 37, 5}, {-36, 4},
55 { 29, 4}, {-29, 4}, { 25, 4}, {-23, 4}, { 20, 4},
56 {-17, 4}, { 16, 4}, {-12, 4}, { 12, 3}, {-10, 4},
57 { 7, 3}, { -4, 4}, { 3, 3}, { -1, 3}, { 1, 3} },
58 { {-59, 3}, {-45, 5}, {-50, 4}, { 38, 4}, {-39, 4},
59 { 32, 4}, {-30, 4}, { 25, 3}, {-23, 3}, { 20, 3},
60 {-20, 3}, { 16, 3}, {-13, 3}, { 10, 3}, { -7, 3},
61 { 3, 3}, { 0, 3}, { -1, 3}, { 2, 3}, { -1, 2} }
62 };
63
64
65 /** Scaled PARCOR values used for the first two PARCOR coefficients.
66 * To be indexed by the Rice coded indices.
67 * Generated by: parcor_scaled_values[i] = 32 + ((i * (i+1)) << 7) - (1 << 20)
68 * Actual values are divided by 32 in order to be stored in 16 bits.
69 */
70 static const int16_t parcor_scaled_values[] = {
71 -1048544 / 32, -1048288 / 32, -1047776 / 32, -1047008 / 32,
72 -1045984 / 32, -1044704 / 32, -1043168 / 32, -1041376 / 32,
73 -1039328 / 32, -1037024 / 32, -1034464 / 32, -1031648 / 32,
74 -1028576 / 32, -1025248 / 32, -1021664 / 32, -1017824 / 32,
75 -1013728 / 32, -1009376 / 32, -1004768 / 32, -999904 / 32,
76 -994784 / 32, -989408 / 32, -983776 / 32, -977888 / 32,
77 -971744 / 32, -965344 / 32, -958688 / 32, -951776 / 32,
78 -944608 / 32, -937184 / 32, -929504 / 32, -921568 / 32,
79 -913376 / 32, -904928 / 32, -896224 / 32, -887264 / 32,
80 -878048 / 32, -868576 / 32, -858848 / 32, -848864 / 32,
81 -838624 / 32, -828128 / 32, -817376 / 32, -806368 / 32,
82 -795104 / 32, -783584 / 32, -771808 / 32, -759776 / 32,
83 -747488 / 32, -734944 / 32, -722144 / 32, -709088 / 32,
84 -695776 / 32, -682208 / 32, -668384 / 32, -654304 / 32,
85 -639968 / 32, -625376 / 32, -610528 / 32, -595424 / 32,
86 -580064 / 32, -564448 / 32, -548576 / 32, -532448 / 32,
87 -516064 / 32, -499424 / 32, -482528 / 32, -465376 / 32,
88 -447968 / 32, -430304 / 32, -412384 / 32, -394208 / 32,
89 -375776 / 32, -357088 / 32, -338144 / 32, -318944 / 32,
90 -299488 / 32, -279776 / 32, -259808 / 32, -239584 / 32,
91 -219104 / 32, -198368 / 32, -177376 / 32, -156128 / 32,
92 -134624 / 32, -112864 / 32, -90848 / 32, -68576 / 32,
93 -46048 / 32, -23264 / 32, -224 / 32, 23072 / 32,
94 46624 / 32, 70432 / 32, 94496 / 32, 118816 / 32,
95 143392 / 32, 168224 / 32, 193312 / 32, 218656 / 32,
96 244256 / 32, 270112 / 32, 296224 / 32, 322592 / 32,
97 349216 / 32, 376096 / 32, 403232 / 32, 430624 / 32,
98 458272 / 32, 486176 / 32, 514336 / 32, 542752 / 32,
99 571424 / 32, 600352 / 32, 629536 / 32, 658976 / 32,
100 688672 / 32, 718624 / 32, 748832 / 32, 779296 / 32,
101 810016 / 32, 840992 / 32, 872224 / 32, 903712 / 32,
102 935456 / 32, 967456 / 32, 999712 / 32, 1032224 / 32
103 };
104
105
106 /** Gain values of p(0) for long-term prediction.
107 * To be indexed by the Rice coded indices.
108 */
109 static const uint8_t ltp_gain_values [4][4] = {
110 { 0, 8, 16, 24},
111 {32, 40, 48, 56},
112 {64, 70, 76, 82},
113 {88, 92, 96, 100}
114 };
115
116
117 /** Inter-channel weighting factors for multi-channel correlation.
118 * To be indexed by the Rice coded indices.
119 */
120 static const int16_t mcc_weightings[] = {
121 204, 192, 179, 166, 153, 140, 128, 115,
122 102, 89, 76, 64, 51, 38, 25, 12,
123 0, -12, -25, -38, -51, -64, -76, -89,
124 -102, -115, -128, -140, -153, -166, -179, -192
125 };
126
127
128 /** Tail codes used in arithmetic coding using block Gilbert-Moore codes.
129 */
130 static const uint8_t tail_code[16][6] = {
131 { 74, 44, 25, 13, 7, 3},
132 { 68, 42, 24, 13, 7, 3},
133 { 58, 39, 23, 13, 7, 3},
134 {126, 70, 37, 19, 10, 5},
135 {132, 70, 37, 20, 10, 5},
136 {124, 70, 38, 20, 10, 5},
137 {120, 69, 37, 20, 11, 5},
138 {116, 67, 37, 20, 11, 5},
139 {108, 66, 36, 20, 10, 5},
140 {102, 62, 36, 20, 10, 5},
141 { 88, 58, 34, 19, 10, 5},
142 {162, 89, 49, 25, 13, 7},
143 {156, 87, 49, 26, 14, 7},
144 {150, 86, 47, 26, 14, 7},
145 {142, 84, 47, 26, 14, 7},
146 {131, 79, 46, 26, 14, 7}
147 };
148
149
150 enum RA_Flag {
151 RA_FLAG_NONE,
152 RA_FLAG_FRAMES,
153 RA_FLAG_HEADER
154 };
155
156
157 typedef struct {
158 uint32_t samples; ///< number of samples, 0xFFFFFFFF if unknown
159 int resolution; ///< 000 = 8-bit; 001 = 16-bit; 010 = 24-bit; 011 = 32-bit
160 int floating; ///< 1 = IEEE 32-bit floating-point, 0 = integer
161 int msb_first; ///< 1 = original CRC calculated on big-endian system, 0 = little-endian
162 int frame_length; ///< frame length for each frame (last frame may differ)
163 int ra_distance; ///< distance between RA frames (in frames, 0...255)
164 enum RA_Flag ra_flag; ///< indicates where the size of ra units is stored
165 int adapt_order; ///< adaptive order: 1 = on, 0 = off
166 int coef_table; ///< table index of Rice code parameters
167 int long_term_prediction; ///< long term prediction (LTP): 1 = on, 0 = off
168 int max_order; ///< maximum prediction order (0..1023)
169 int block_switching; ///< number of block switching levels
170 int bgmc; ///< "Block Gilbert-Moore Code": 1 = on, 0 = off (Rice coding only)
171 int sb_part; ///< sub-block partition
172 int joint_stereo; ///< joint stereo: 1 = on, 0 = off
173 int mc_coding; ///< extended inter-channel coding (multi channel coding): 1 = on, 0 = off
174 int chan_config; ///< indicates that a chan_config_info field is present
175 int chan_sort; ///< channel rearrangement: 1 = on, 0 = off
176 int rlslms; ///< use "Recursive Least Square-Least Mean Square" predictor: 1 = on, 0 = off
177 int chan_config_info; ///< mapping of channels to loudspeaker locations. Unused until setting channel configuration is implemented.
178 int *chan_pos; ///< original channel positions
179 int crc_enabled; ///< enable Cyclic Redundancy Checksum
180 } ALSSpecificConfig;
181
182
183 typedef struct {
184 int stop_flag;
185 int master_channel;
186 int time_diff_flag;
187 int time_diff_sign;
188 int time_diff_index;
189 int weighting[6];
190 } ALSChannelData;
191
192
193 typedef struct {
194 AVCodecContext *avctx;
195 AVFrame frame;
196 ALSSpecificConfig sconf;
197 GetBitContext gb;
198 DSPContext dsp;
199 const AVCRC *crc_table;
200 uint32_t crc_org; ///< CRC value of the original input data
201 uint32_t crc; ///< CRC value calculated from decoded data
202 unsigned int cur_frame_length; ///< length of the current frame to decode
203 unsigned int frame_id; ///< the frame ID / number of the current frame
204 unsigned int js_switch; ///< if true, joint-stereo decoding is enforced
205 unsigned int num_blocks; ///< number of blocks used in the current frame
206 unsigned int s_max; ///< maximum Rice parameter allowed in entropy coding
207 uint8_t *bgmc_lut; ///< pointer at lookup tables used for BGMC
208 int *bgmc_lut_status; ///< pointer at lookup table status flags used for BGMC
209 int ltp_lag_length; ///< number of bits used for ltp lag value
210 int *const_block; ///< contains const_block flags for all channels
211 unsigned int *shift_lsbs; ///< contains shift_lsbs flags for all channels
212 unsigned int *opt_order; ///< contains opt_order flags for all channels
213 int *store_prev_samples; ///< contains store_prev_samples flags for all channels
214 int *use_ltp; ///< contains use_ltp flags for all channels
215 int *ltp_lag; ///< contains ltp lag values for all channels
216 int **ltp_gain; ///< gain values for ltp 5-tap filter for a channel
217 int *ltp_gain_buffer; ///< contains all gain values for ltp 5-tap filter
218 int32_t **quant_cof; ///< quantized parcor coefficients for a channel
219 int32_t *quant_cof_buffer; ///< contains all quantized parcor coefficients
220 int32_t **lpc_cof; ///< coefficients of the direct form prediction filter for a channel
221 int32_t *lpc_cof_buffer; ///< contains all coefficients of the direct form prediction filter
222 int32_t *lpc_cof_reversed_buffer; ///< temporary buffer to set up a reversed versio of lpc_cof_buffer
223 ALSChannelData **chan_data; ///< channel data for multi-channel correlation
224 ALSChannelData *chan_data_buffer; ///< contains channel data for all channels
225 int *reverted_channels; ///< stores a flag for each reverted channel
226 int32_t *prev_raw_samples; ///< contains unshifted raw samples from the previous block
227 int32_t **raw_samples; ///< decoded raw samples for each channel
228 int32_t *raw_buffer; ///< contains all decoded raw samples including carryover samples
229 uint8_t *crc_buffer; ///< buffer of byte order corrected samples used for CRC check
230 } ALSDecContext;
231
232
233 typedef struct {
234 unsigned int block_length; ///< number of samples within the block
235 unsigned int ra_block; ///< if true, this is a random access block
236 int *const_block; ///< if true, this is a constant value block
237 int js_blocks; ///< true if this block contains a difference signal
238 unsigned int *shift_lsbs; ///< shift of values for this block
239 unsigned int *opt_order; ///< prediction order of this block
240 int *store_prev_samples;///< if true, carryover samples have to be stored
241 int *use_ltp; ///< if true, long-term prediction is used
242 int *ltp_lag; ///< lag value for long-term prediction
243 int *ltp_gain; ///< gain values for ltp 5-tap filter
244 int32_t *quant_cof; ///< quantized parcor coefficients
245 int32_t *lpc_cof; ///< coefficients of the direct form prediction
246 int32_t *raw_samples; ///< decoded raw samples / residuals for this block
247 int32_t *prev_raw_samples; ///< contains unshifted raw samples from the previous block
248 int32_t *raw_other; ///< decoded raw samples of the other channel of a channel pair
249 } ALSBlockData;
250
251
252 static av_cold void dprint_specific_config(ALSDecContext *ctx)
253 {
254 #ifdef DEBUG
255 AVCodecContext *avctx = ctx->avctx;
256 ALSSpecificConfig *sconf = &ctx->sconf;
257
258 av_dlog(avctx, "resolution = %i\n", sconf->resolution);
259 av_dlog(avctx, "floating = %i\n", sconf->floating);
260 av_dlog(avctx, "frame_length = %i\n", sconf->frame_length);
261 av_dlog(avctx, "ra_distance = %i\n", sconf->ra_distance);
262 av_dlog(avctx, "ra_flag = %i\n", sconf->ra_flag);
263 av_dlog(avctx, "adapt_order = %i\n", sconf->adapt_order);
264 av_dlog(avctx, "coef_table = %i\n", sconf->coef_table);
265 av_dlog(avctx, "long_term_prediction = %i\n", sconf->long_term_prediction);
266 av_dlog(avctx, "max_order = %i\n", sconf->max_order);
267 av_dlog(avctx, "block_switching = %i\n", sconf->block_switching);
268 av_dlog(avctx, "bgmc = %i\n", sconf->bgmc);
269 av_dlog(avctx, "sb_part = %i\n", sconf->sb_part);
270 av_dlog(avctx, "joint_stereo = %i\n", sconf->joint_stereo);
271 av_dlog(avctx, "mc_coding = %i\n", sconf->mc_coding);
272 av_dlog(avctx, "chan_config = %i\n", sconf->chan_config);
273 av_dlog(avctx, "chan_sort = %i\n", sconf->chan_sort);
274 av_dlog(avctx, "RLSLMS = %i\n", sconf->rlslms);
275 av_dlog(avctx, "chan_config_info = %i\n", sconf->chan_config_info);
276 #endif
277 }
278
279
280 /** Read an ALSSpecificConfig from a buffer into the output struct.
281 */
282 static av_cold int read_specific_config(ALSDecContext *ctx)
283 {
284 GetBitContext gb;
285 uint64_t ht_size;
286 int i, config_offset;
287 MPEG4AudioConfig m4ac;
288 ALSSpecificConfig *sconf = &ctx->sconf;
289 AVCodecContext *avctx = ctx->avctx;
290 uint32_t als_id, header_size, trailer_size;
291
292 init_get_bits(&gb, avctx->extradata, avctx->extradata_size * 8);
293
294 config_offset = avpriv_mpeg4audio_get_config(&m4ac, avctx->extradata,
295 avctx->extradata_size * 8, 1);
296
297 if (config_offset < 0)
298 return -1;
299
300 skip_bits_long(&gb, config_offset);
301
302 if (get_bits_left(&gb) < (30 << 3))
303 return -1;
304
305 // read the fixed items
306 als_id = get_bits_long(&gb, 32);
307 avctx->sample_rate = m4ac.sample_rate;
308 skip_bits_long(&gb, 32); // sample rate already known
309 sconf->samples = get_bits_long(&gb, 32);
310 avctx->channels = m4ac.channels;
311 skip_bits(&gb, 16); // number of channels already knwon
312 skip_bits(&gb, 3); // skip file_type
313 sconf->resolution = get_bits(&gb, 3);
314 sconf->floating = get_bits1(&gb);
315 sconf->msb_first = get_bits1(&gb);
316 sconf->frame_length = get_bits(&gb, 16) + 1;
317 sconf->ra_distance = get_bits(&gb, 8);
318 sconf->ra_flag = get_bits(&gb, 2);
319 sconf->adapt_order = get_bits1(&gb);
320 sconf->coef_table = get_bits(&gb, 2);
321 sconf->long_term_prediction = get_bits1(&gb);
322 sconf->max_order = get_bits(&gb, 10);
323 sconf->block_switching = get_bits(&gb, 2);
324 sconf->bgmc = get_bits1(&gb);
325 sconf->sb_part = get_bits1(&gb);
326 sconf->joint_stereo = get_bits1(&gb);
327 sconf->mc_coding = get_bits1(&gb);
328 sconf->chan_config = get_bits1(&gb);
329 sconf->chan_sort = get_bits1(&gb);
330 sconf->crc_enabled = get_bits1(&gb);
331 sconf->rlslms = get_bits1(&gb);
332 skip_bits(&gb, 5); // skip 5 reserved bits
333 skip_bits1(&gb); // skip aux_data_enabled
334
335
336 // check for ALSSpecificConfig struct
337 if (als_id != MKBETAG('A','L','S','\0'))
338 return -1;
339
340 ctx->cur_frame_length = sconf->frame_length;
341
342 // read channel config
343 if (sconf->chan_config)
344 sconf->chan_config_info = get_bits(&gb, 16);
345 // TODO: use this to set avctx->channel_layout
346
347
348 // read channel sorting
349 if (sconf->chan_sort && avctx->channels > 1) {
350 int chan_pos_bits = av_ceil_log2(avctx->channels);
351 int bits_needed = avctx->channels * chan_pos_bits + 7;
352 if (get_bits_left(&gb) < bits_needed)
353 return -1;
354
355 if (!(sconf->chan_pos = av_malloc(avctx->channels * sizeof(*sconf->chan_pos))))
356 return AVERROR(ENOMEM);
357
358 for (i = 0; i < avctx->channels; i++)
359 sconf->chan_pos[i] = get_bits(&gb, chan_pos_bits);
360
361 align_get_bits(&gb);
362 // TODO: use this to actually do channel sorting
363 } else {
364 sconf->chan_sort = 0;
365 }
366
367
368 // read fixed header and trailer sizes,
369 // if size = 0xFFFFFFFF then there is no data field!
370 if (get_bits_left(&gb) < 64)
371 return -1;
372
373 header_size = get_bits_long(&gb, 32);
374 trailer_size = get_bits_long(&gb, 32);
375 if (header_size == 0xFFFFFFFF)
376 header_size = 0;
377 if (trailer_size == 0xFFFFFFFF)
378 trailer_size = 0;
379
380 ht_size = ((int64_t)(header_size) + (int64_t)(trailer_size)) << 3;
381
382
383 // skip the header and trailer data
384 if (get_bits_left(&gb) < ht_size)
385 return -1;
386
387 if (ht_size > INT32_MAX)
388 return -1;
389
390 skip_bits_long(&gb, ht_size);
391
392
393 // initialize CRC calculation
394 if (sconf->crc_enabled) {
395 if (get_bits_left(&gb) < 32)
396 return -1;
397
398 if (avctx->err_recognition & AV_EF_CRCCHECK) {
399 ctx->crc_table = av_crc_get_table(AV_CRC_32_IEEE_LE);
400 ctx->crc = 0xFFFFFFFF;
401 ctx->crc_org = ~get_bits_long(&gb, 32);
402 } else
403 skip_bits_long(&gb, 32);
404 }
405
406
407 // no need to read the rest of ALSSpecificConfig (ra_unit_size & aux data)
408
409 dprint_specific_config(ctx);
410
411 return 0;
412 }
413
414
415 /** Check the ALSSpecificConfig for unsupported features.
416 */
417 static int check_specific_config(ALSDecContext *ctx)
418 {
419 ALSSpecificConfig *sconf = &ctx->sconf;
420 int error = 0;
421
422 // report unsupported feature and set error value
423 #define MISSING_ERR(cond, str, errval) \
424 { \
425 if (cond) { \
426 av_log_missing_feature(ctx->avctx, str, 0); \
427 error = errval; \
428 } \
429 }
430
431 MISSING_ERR(sconf->floating, "Floating point decoding", AVERROR_PATCHWELCOME);
432 MISSING_ERR(sconf->rlslms, "Adaptive RLS-LMS prediction", AVERROR_PATCHWELCOME);
433 MISSING_ERR(sconf->chan_sort, "Channel sorting", 0);
434
435 return error;
436 }
437
438
439 /** Parse the bs_info field to extract the block partitioning used in
440 * block switching mode, refer to ISO/IEC 14496-3, section 11.6.2.
441 */
442 static void parse_bs_info(const uint32_t bs_info, unsigned int n,
443 unsigned int div, unsigned int **div_blocks,
444 unsigned int *num_blocks)
445 {
446 if (n < 31 && ((bs_info << n) & 0x40000000)) {
447 // if the level is valid and the investigated bit n is set
448 // then recursively check both children at bits (2n+1) and (2n+2)
449 n *= 2;
450 div += 1;
451 parse_bs_info(bs_info, n + 1, div, div_blocks, num_blocks);
452 parse_bs_info(bs_info, n + 2, div, div_blocks, num_blocks);
453 } else {
454 // else the bit is not set or the last level has been reached
455 // (bit implicitly not set)
456 **div_blocks = div;
457 (*div_blocks)++;
458 (*num_blocks)++;
459 }
460 }
461
462
463 /** Read and decode a Rice codeword.
464 */
465 static int32_t decode_rice(GetBitContext *gb, unsigned int k)
466 {
467 int max = get_bits_left(gb) - k;
468 int q = get_unary(gb, 0, max);
469 int r = k ? get_bits1(gb) : !(q & 1);
470
471 if (k > 1) {
472 q <<= (k - 1);
473 q += get_bits_long(gb, k - 1);
474 } else if (!k) {
475 q >>= 1;
476 }
477 return r ? q : ~q;
478 }
479
480
481 /** Convert PARCOR coefficient k to direct filter coefficient.
482 */
483 static void parcor_to_lpc(unsigned int k, const int32_t *par, int32_t *cof)
484 {
485 int i, j;
486
487 for (i = 0, j = k - 1; i < j; i++, j--) {
488 int tmp1 = ((MUL64(par[k], cof[j]) + (1 << 19)) >> 20);
489 cof[j] += ((MUL64(par[k], cof[i]) + (1 << 19)) >> 20);
490 cof[i] += tmp1;
491 }
492 if (i == j)
493 cof[i] += ((MUL64(par[k], cof[j]) + (1 << 19)) >> 20);
494
495 cof[k] = par[k];
496 }
497
498
499 /** Read block switching field if necessary and set actual block sizes.
500 * Also assure that the block sizes of the last frame correspond to the
501 * actual number of samples.
502 */
503 static void get_block_sizes(ALSDecContext *ctx, unsigned int *div_blocks,
504 uint32_t *bs_info)
505 {
506 ALSSpecificConfig *sconf = &ctx->sconf;
507 GetBitContext *gb = &ctx->gb;
508 unsigned int *ptr_div_blocks = div_blocks;
509 unsigned int b;
510
511 if (sconf->block_switching) {
512 unsigned int bs_info_len = 1 << (sconf->block_switching + 2);
513 *bs_info = get_bits_long(gb, bs_info_len);
514 *bs_info <<= (32 - bs_info_len);
515 }
516
517 ctx->num_blocks = 0;
518 parse_bs_info(*bs_info, 0, 0, &ptr_div_blocks, &ctx->num_blocks);
519
520 // The last frame may have an overdetermined block structure given in
521 // the bitstream. In that case the defined block structure would need
522 // more samples than available to be consistent.
523 // The block structure is actually used but the block sizes are adapted
524 // to fit the actual number of available samples.
525 // Example: 5 samples, 2nd level block sizes: 2 2 2 2.
526 // This results in the actual block sizes: 2 2 1 0.
527 // This is not specified in 14496-3 but actually done by the reference
528 // codec RM22 revision 2.
529 // This appears to happen in case of an odd number of samples in the last
530 // frame which is actually not allowed by the block length switching part
531 // of 14496-3.
532 // The ALS conformance files feature an odd number of samples in the last
533 // frame.
534
535 for (b = 0; b < ctx->num_blocks; b++)
536 div_blocks[b] = ctx->sconf.frame_length >> div_blocks[b];
537
538 if (ctx->cur_frame_length != ctx->sconf.frame_length) {
539 unsigned int remaining = ctx->cur_frame_length;
540
541 for (b = 0; b < ctx->num_blocks; b++) {
542 if (remaining <= div_blocks[b]) {
543 div_blocks[b] = remaining;
544 ctx->num_blocks = b + 1;
545 break;
546 }
547
548 remaining -= div_blocks[b];
549 }
550 }
551 }
552
553
554 /** Read the block data for a constant block
555 */
556 static void read_const_block_data(ALSDecContext *ctx, ALSBlockData *bd)
557 {
558 ALSSpecificConfig *sconf = &ctx->sconf;
559 AVCodecContext *avctx = ctx->avctx;
560 GetBitContext *gb = &ctx->gb;
561
562 *bd->raw_samples = 0;
563 *bd->const_block = get_bits1(gb); // 1 = constant value, 0 = zero block (silence)
564 bd->js_blocks = get_bits1(gb);
565
566 // skip 5 reserved bits
567 skip_bits(gb, 5);
568
569 if (*bd->const_block) {
570 unsigned int const_val_bits = sconf->floating ? 24 : avctx->bits_per_raw_sample;
571 *bd->raw_samples = get_sbits_long(gb, const_val_bits);
572 }
573
574 // ensure constant block decoding by reusing this field
575 *bd->const_block = 1;
576 }
577
578
579 /** Decode the block data for a constant block
580 */
581 static void decode_const_block_data(ALSDecContext *ctx, ALSBlockData *bd)
582 {
583 int smp = bd->block_length - 1;
584 int32_t val = *bd->raw_samples;
585 int32_t *dst = bd->raw_samples + 1;
586
587 // write raw samples into buffer
588 for (; smp; smp--)
589 *dst++ = val;
590 }
591
592
593 /** Read the block data for a non-constant block
594 */
595 static int read_var_block_data(ALSDecContext *ctx, ALSBlockData *bd)
596 {
597 ALSSpecificConfig *sconf = &ctx->sconf;
598 AVCodecContext *avctx = ctx->avctx;
599 GetBitContext *gb = &ctx->gb;
600 unsigned int k;
601 unsigned int s[8];
602 unsigned int sx[8];
603 unsigned int sub_blocks, log2_sub_blocks, sb_length;
604 unsigned int start = 0;
605 unsigned int opt_order;
606 int sb;
607 int32_t *quant_cof = bd->quant_cof;
608 int32_t *current_res;
609
610
611 // ensure variable block decoding by reusing this field
612 *bd->const_block = 0;
613
614 *bd->opt_order = 1;
615 bd->js_blocks = get_bits1(gb);
616
617 opt_order = *bd->opt_order;
618
619 // determine the number of subblocks for entropy decoding
620 if (!sconf->bgmc && !sconf->sb_part) {
621 log2_sub_blocks = 0;
622 } else {
623 if (sconf->bgmc && sconf->sb_part)
624 log2_sub_blocks = get_bits(gb, 2);
625 else
626 log2_sub_blocks = 2 * get_bits1(gb);
627 }
628
629 sub_blocks = 1 << log2_sub_blocks;
630
631 // do not continue in case of a damaged stream since
632 // block_length must be evenly divisible by sub_blocks
633 if (bd->block_length & (sub_blocks - 1)) {
634 av_log(avctx, AV_LOG_WARNING,
635 "Block length is not evenly divisible by the number of subblocks.\n");
636 return -1;
637 }
638
639 sb_length = bd->block_length >> log2_sub_blocks;
640
641 if (sconf->bgmc) {
642 s[0] = get_bits(gb, 8 + (sconf->resolution > 1));
643 for (k = 1; k < sub_blocks; k++)
644 s[k] = s[k - 1] + decode_rice(gb, 2);
645
646 for (k = 0; k < sub_blocks; k++) {
647 sx[k] = s[k] & 0x0F;
648 s [k] >>= 4;
649 }
650 } else {
651 s[0] = get_bits(gb, 4 + (sconf->resolution > 1));
652 for (k = 1; k < sub_blocks; k++)
653 s[k] = s[k - 1] + decode_rice(gb, 0);
654 }
655 for (k = 1; k < sub_blocks; k++)
656 if (s[k] > 32) {
657 av_log(avctx, AV_LOG_ERROR, "k invalid for rice code.\n");
658 return AVERROR_INVALIDDATA;
659 }
660
661 if (get_bits1(gb))
662 *bd->shift_lsbs = get_bits(gb, 4) + 1;
663
664 *bd->store_prev_samples = (bd->js_blocks && bd->raw_other) || *bd->shift_lsbs;
665
666
667 if (!sconf->rlslms) {
668 if (sconf->adapt_order) {
669 int opt_order_length = av_ceil_log2(av_clip((bd->block_length >> 3) - 1,
670 2, sconf->max_order + 1));
671 *bd->opt_order = get_bits(gb, opt_order_length);
672 if (*bd->opt_order > sconf->max_order) {
673 *bd->opt_order = sconf->max_order;
674 av_log(avctx, AV_LOG_ERROR, "Predictor order too large!\n");
675 return AVERROR_INVALIDDATA;
676 }
677 } else {
678 *bd->opt_order = sconf->max_order;
679 }
680
681 opt_order = *bd->opt_order;
682
683 if (opt_order) {
684 int add_base;
685
686 if (sconf->coef_table == 3) {
687 add_base = 0x7F;
688
689 // read coefficient 0
690 quant_cof[0] = 32 * parcor_scaled_values[get_bits(gb, 7)];
691
692 // read coefficient 1
693 if (opt_order > 1)
694 quant_cof[1] = -32 * parcor_scaled_values[get_bits(gb, 7)];
695
696 // read coefficients 2 to opt_order
697 for (k = 2; k < opt_order; k++)
698 quant_cof[k] = get_bits(gb, 7);
699 } else {
700 int k_max;
701 add_base = 1;
702
703 // read coefficient 0 to 19
704 k_max = FFMIN(opt_order, 20);
705 for (k = 0; k < k_max; k++) {
706 int rice_param = parcor_rice_table[sconf->coef_table][k][1];
707 int offset = parcor_rice_table[sconf->coef_table][k][0];
708 quant_cof[k] = decode_rice(gb, rice_param) + offset;
709 if (quant_cof[k] < -64 || quant_cof[k] > 63) {
710 av_log(avctx, AV_LOG_ERROR, "quant_cof %d is out of range\n", quant_cof[k]);
711 return AVERROR_INVALIDDATA;
712 }
713 }
714
715 // read coefficients 20 to 126
716 k_max = FFMIN(opt_order, 127);
717 for (; k < k_max; k++)
718 quant_cof[k] = decode_rice(gb, 2) + (k & 1);
719
720 // read coefficients 127 to opt_order
721 for (; k < opt_order; k++)
722 quant_cof[k] = decode_rice(gb, 1);
723
724 quant_cof[0] = 32 * parcor_scaled_values[quant_cof[0] + 64];
725
726 if (opt_order > 1)
727 quant_cof[1] = -32 * parcor_scaled_values[quant_cof[1] + 64];
728 }
729
730 for (k = 2; k < opt_order; k++)
731 quant_cof[k] = (quant_cof[k] << 14) + (add_base << 13);
732 }
733 }
734
735 // read LTP gain and lag values
736 if (sconf->long_term_prediction) {
737 *bd->use_ltp = get_bits1(gb);
738
739 if (*bd->use_ltp) {
740 int r, c;
741
742 bd->ltp_gain[0] = decode_rice(gb, 1) << 3;
743 bd->ltp_gain[1] = decode_rice(gb, 2) << 3;
744
745 r = get_unary(gb, 0, 3);
746 c = get_bits(gb, 2);
747 bd->ltp_gain[2] = ltp_gain_values[r][c];
748
749 bd->ltp_gain[3] = decode_rice(gb, 2) << 3;
750 bd->ltp_gain[4] = decode_rice(gb, 1) << 3;
751
752 *bd->ltp_lag = get_bits(gb, ctx->ltp_lag_length);
753 *bd->ltp_lag += FFMAX(4, opt_order + 1);
754 }
755 }
756
757 // read first value and residuals in case of a random access block
758 if (bd->ra_block) {
759 if (opt_order)
760 bd->raw_samples[0] = decode_rice(gb, avctx->bits_per_raw_sample - 4);
761 if (opt_order > 1)
762 bd->raw_samples[1] = decode_rice(gb, FFMIN(s[0] + 3, ctx->s_max));
763 if (opt_order > 2)
764 bd->raw_samples[2] = decode_rice(gb, FFMIN(s[0] + 1, ctx->s_max));
765
766 start = FFMIN(opt_order, 3);
767 }
768
769 // read all residuals
770 if (sconf->bgmc) {
771 int delta[8];
772 unsigned int k [8];
773 unsigned int b = av_clip((av_ceil_log2(bd->block_length) - 3) >> 1, 0, 5);
774
775 // read most significant bits
776 unsigned int high;
777 unsigned int low;
778 unsigned int value;
779
780 ff_bgmc_decode_init(gb, &high, &low, &value);
781
782 current_res = bd->raw_samples + start;
783
784 for (sb = 0; sb < sub_blocks; sb++) {
785 unsigned int sb_len = sb_length - (sb ? 0 : start);
786
787 k [sb] = s[sb] > b ? s[sb] - b : 0;
788 delta[sb] = 5 - s[sb] + k[sb];
789
790 ff_bgmc_decode(gb, sb_len, current_res,
791 delta[sb], sx[sb], &high, &low, &value, ctx->bgmc_lut, ctx->bgmc_lut_status);
792
793 current_res += sb_len;
794 }
795
796 ff_bgmc_decode_end(gb);
797
798
799 // read least significant bits and tails
800 current_res = bd->raw_samples + start;
801
802 for (sb = 0; sb < sub_blocks; sb++, start = 0) {
803 unsigned int cur_tail_code = tail_code[sx[sb]][delta[sb]];
804 unsigned int cur_k = k[sb];
805 unsigned int cur_s = s[sb];
806
807 for (; start < sb_length; start++) {
808 int32_t res = *current_res;
809
810 if (res == cur_tail_code) {
811 unsigned int max_msb = (2 + (sx[sb] > 2) + (sx[sb] > 10))
812 << (5 - delta[sb]);
813
814 res = decode_rice(gb, cur_s);
815
816 if (res >= 0) {
817 res += (max_msb ) << cur_k;
818 } else {
819 res -= (max_msb - 1) << cur_k;
820 }
821 } else {
822 if (res > cur_tail_code)
823 res--;
824
825 if (res & 1)
826 res = -res;
827
828 res >>= 1;
829
830 if (cur_k) {
831 res <<= cur_k;
832 res |= get_bits_long(gb, cur_k);
833 }
834 }
835
836 *current_res++ = res;
837 }
838 }
839 } else {
840 current_res = bd->raw_samples + start;
841
842 for (sb = 0; sb < sub_blocks; sb++, start = 0)
843 for (; start < sb_length; start++)
844 *current_res++ = decode_rice(gb, s[sb]);
845 }
846
847 if (!sconf->mc_coding || ctx->js_switch)
848 align_get_bits(gb);
849
850 return 0;
851 }
852
853
854 /** Decode the block data for a non-constant block
855 */
856 static int decode_var_block_data(ALSDecContext *ctx, ALSBlockData *bd)
857 {
858 ALSSpecificConfig *sconf = &ctx->sconf;
859 unsigned int block_length = bd->block_length;
860 unsigned int smp = 0;
861 unsigned int k;
862 int opt_order = *bd->opt_order;
863 int sb;
864 int64_t y;
865 int32_t *quant_cof = bd->quant_cof;
866 int32_t *lpc_cof = bd->lpc_cof;
867 int32_t *raw_samples = bd->raw_samples;
868 int32_t *raw_samples_end = bd->raw_samples + bd->block_length;
869 int32_t *lpc_cof_reversed = ctx->lpc_cof_reversed_buffer;
870
871 // reverse long-term prediction
872 if (*bd->use_ltp) {
873 int ltp_smp;
874
875 for (ltp_smp = FFMAX(*bd->ltp_lag - 2, 0); ltp_smp < block_length; ltp_smp++) {
876 int center = ltp_smp - *bd->ltp_lag;
877 int begin = FFMAX(0, center - 2);
878 int end = center + 3;
879 int tab = 5 - (end - begin);
880 int base;
881
882 y = 1 << 6;
883
884 for (base = begin; base < end; base++, tab++)
885 y += MUL64(bd->ltp_gain[tab], raw_samples[base]);
886
887 raw_samples[ltp_smp] += y >> 7;
888 }
889 }
890
891 // reconstruct all samples from residuals
892 if (bd->ra_block) {
893 for (smp = 0; smp < opt_order; smp++) {
894 y = 1 << 19;
895
896 for (sb = 0; sb < smp; sb++)
897 y += MUL64(lpc_cof[sb], raw_samples[-(sb + 1)]);
898
899 *raw_samples++ -= y >> 20;
900 parcor_to_lpc(smp, quant_cof, lpc_cof);
901 }
902 } else {
903 for (k = 0; k < opt_order; k++)
904 parcor_to_lpc(k, quant_cof, lpc_cof);
905
906 // store previous samples in case that they have to be altered
907 if (*bd->store_prev_samples)
908 memcpy(bd->prev_raw_samples, raw_samples - sconf->max_order,
909 sizeof(*bd->prev_raw_samples) * sconf->max_order);
910
911 // reconstruct difference signal for prediction (joint-stereo)
912 if (bd->js_blocks && bd->raw_other) {
913 int32_t *left, *right;
914
915 if (bd->raw_other > raw_samples) { // D = R - L
916 left = raw_samples;
917 right = bd->raw_other;
918 } else { // D = R - L
919 left = bd->raw_other;
920 right = raw_samples;
921 }
922
923 for (sb = -1; sb >= -sconf->max_order; sb--)
924 raw_samples[sb] = right[sb] - left[sb];
925 }
926
927 // reconstruct shifted signal
928 if (*bd->shift_lsbs)
929 for (sb = -1; sb >= -sconf->max_order; sb--)
930 raw_samples[sb] >>= *bd->shift_lsbs;
931 }
932
933 // reverse linear prediction coefficients for efficiency
934 lpc_cof = lpc_cof + opt_order;
935
936 for (sb = 0; sb < opt_order; sb++)
937 lpc_cof_reversed[sb] = lpc_cof[-(sb + 1)];
938
939 // reconstruct raw samples
940 raw_samples = bd->raw_samples + smp;
941 lpc_cof = lpc_cof_reversed + opt_order;
942
943 for (; raw_samples < raw_samples_end; raw_samples++) {
944 y = 1 << 19;
945
946 for (sb = -opt_order; sb < 0; sb++)
947 y += MUL64(lpc_cof[sb], raw_samples[sb]);
948
949 *raw_samples -= y >> 20;
950 }
951
952 raw_samples = bd->raw_samples;
953
954 // restore previous samples in case that they have been altered
955 if (*bd->store_prev_samples)
956 memcpy(raw_samples - sconf->max_order, bd->prev_raw_samples,
957 sizeof(*raw_samples) * sconf->max_order);
958
959 return 0;
960 }
961
962
963 /** Read the block data.
964 */
965 static int read_block(ALSDecContext *ctx, ALSBlockData *bd)
966 {
967 GetBitContext *gb = &ctx->gb;
968
969 *bd->shift_lsbs = 0;
970 // read block type flag and read the samples accordingly
971 if (get_bits1(gb)) {
972 if (read_var_block_data(ctx, bd))
973 return -1;
974 } else {
975 read_const_block_data(ctx, bd);
976 }
977
978 return 0;
979 }
980
981
982 /** Decode the block data.
983 */
984 static int decode_block(ALSDecContext *ctx, ALSBlockData *bd)
985 {
986 unsigned int smp;
987
988 // read block type flag and read the samples accordingly
989 if (*bd->const_block)
990 decode_const_block_data(ctx, bd);
991 else if (decode_var_block_data(ctx, bd))
992 return -1;
993
994 // TODO: read RLSLMS extension data
995
996 if (*bd->shift_lsbs)
997 for (smp = 0; smp < bd->block_length; smp++)
998 bd->raw_samples[smp] <<= *bd->shift_lsbs;
999
1000 return 0;
1001 }
1002
1003
1004 /** Read and decode block data successively.
1005 */
1006 static int read_decode_block(ALSDecContext *ctx, ALSBlockData *bd)
1007 {
1008 int ret;
1009
1010 ret = read_block(ctx, bd);
1011
1012 if (ret)
1013 return ret;
1014
1015 ret = decode_block(ctx, bd);
1016
1017 return ret;
1018 }
1019
1020
1021 /** Compute the number of samples left to decode for the current frame and
1022 * sets these samples to zero.
1023 */
1024 static void zero_remaining(unsigned int b, unsigned int b_max,
1025 const unsigned int *div_blocks, int32_t *buf)
1026 {
1027 unsigned int count = 0;
1028
1029 for (; b < b_max; b++)
1030 count += div_blocks[b];
1031
1032 if (count)
1033 memset(buf, 0, sizeof(*buf) * count);
1034 }
1035
1036
1037 /** Decode blocks independently.
1038 */
1039 static int decode_blocks_ind(ALSDecContext *ctx, unsigned int ra_frame,
1040 unsigned int c, const unsigned int *div_blocks,
1041 unsigned int *js_blocks)
1042 {
1043 unsigned int b;
1044 ALSBlockData bd = { 0 };
1045
1046 bd.ra_block = ra_frame;
1047 bd.const_block = ctx->const_block;
1048 bd.shift_lsbs = ctx->shift_lsbs;
1049 bd.opt_order = ctx->opt_order;
1050 bd.store_prev_samples = ctx->store_prev_samples;
1051 bd.use_ltp = ctx->use_ltp;
1052 bd.ltp_lag = ctx->ltp_lag;
1053 bd.ltp_gain = ctx->ltp_gain[0];
1054 bd.quant_cof = ctx->quant_cof[0];
1055 bd.lpc_cof = ctx->lpc_cof[0];
1056 bd.prev_raw_samples = ctx->prev_raw_samples;
1057 bd.raw_samples = ctx->raw_samples[c];
1058
1059
1060 for (b = 0; b < ctx->num_blocks; b++) {
1061 bd.block_length = div_blocks[b];
1062
1063 if (read_decode_block(ctx, &bd)) {
1064 // damaged block, write zero for the rest of the frame
1065 zero_remaining(b, ctx->num_blocks, div_blocks, bd.raw_samples);
1066 return -1;
1067 }
1068 bd.raw_samples += div_blocks[b];
1069 bd.ra_block = 0;
1070 }
1071
1072 return 0;
1073 }
1074
1075
1076 /** Decode blocks dependently.
1077 */
1078 static int decode_blocks(ALSDecContext *ctx, unsigned int ra_frame,
1079 unsigned int c, const unsigned int *div_blocks,
1080 unsigned int *js_blocks)
1081 {
1082 ALSSpecificConfig *sconf = &ctx->sconf;
1083 unsigned int offset = 0;
1084 unsigned int b;
1085 ALSBlockData bd[2] = { { 0 } };
1086
1087 bd[0].ra_block = ra_frame;
1088 bd[0].const_block = ctx->const_block;
1089 bd[0].shift_lsbs = ctx->shift_lsbs;
1090 bd[0].opt_order = ctx->opt_order;
1091 bd[0].store_prev_samples = ctx->store_prev_samples;
1092 bd[0].use_ltp = ctx->use_ltp;
1093 bd[0].ltp_lag = ctx->ltp_lag;
1094 bd[0].ltp_gain = ctx->ltp_gain[0];
1095 bd[0].quant_cof = ctx->quant_cof[0];
1096 bd[0].lpc_cof = ctx->lpc_cof[0];
1097 bd[0].prev_raw_samples = ctx->prev_raw_samples;
1098 bd[0].js_blocks = *js_blocks;
1099
1100 bd[1].ra_block = ra_frame;
1101 bd[1].const_block = ctx->const_block;
1102 bd[1].shift_lsbs = ctx->shift_lsbs;
1103 bd[1].opt_order = ctx->opt_order;
1104 bd[1].store_prev_samples = ctx->store_prev_samples;
1105 bd[1].use_ltp = ctx->use_ltp;
1106 bd[1].ltp_lag = ctx->ltp_lag;
1107 bd[1].ltp_gain = ctx->ltp_gain[0];
1108 bd[1].quant_cof = ctx->quant_cof[0];
1109 bd[1].lpc_cof = ctx->lpc_cof[0];
1110 bd[1].prev_raw_samples = ctx->prev_raw_samples;
1111 bd[1].js_blocks = *(js_blocks + 1);
1112
1113 // decode all blocks
1114 for (b = 0; b < ctx->num_blocks; b++) {
1115 unsigned int s;
1116
1117 bd[0].block_length = div_blocks[b];
1118 bd[1].block_length = div_blocks[b];
1119
1120 bd[0].raw_samples = ctx->raw_samples[c ] + offset;
1121 bd[1].raw_samples = ctx->raw_samples[c + 1] + offset;
1122
1123 bd[0].raw_other = bd[1].raw_samples;
1124 bd[1].raw_other = bd[0].raw_samples;
1125
1126 if(read_decode_block(ctx, &bd[0]) || read_decode_block(ctx, &bd[1])) {
1127 // damaged block, write zero for the rest of the frame
1128 zero_remaining(b, ctx->num_blocks, div_blocks, bd[0].raw_samples);
1129 zero_remaining(b, ctx->num_blocks, div_blocks, bd[1].raw_samples);
1130 return -1;
1131 }
1132
1133 // reconstruct joint-stereo blocks
1134 if (bd[0].js_blocks) {
1135 if (bd[1].js_blocks)
1136 av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel pair!\n");
1137
1138 for (s = 0; s < div_blocks[b]; s++)
1139 bd[0].raw_samples[s] = bd[1].raw_samples[s] - bd[0].raw_samples[s];
1140 } else if (bd[1].js_blocks) {
1141 for (s = 0; s < div_blocks[b]; s++)
1142 bd[1].raw_samples[s] = bd[1].raw_samples[s] + bd[0].raw_samples[s];
1143 }
1144
1145 offset += div_blocks[b];
1146 bd[0].ra_block = 0;
1147 bd[1].ra_block = 0;
1148 }
1149
1150 // store carryover raw samples,
1151 // the others channel raw samples are stored by the calling function.
1152 memmove(ctx->raw_samples[c] - sconf->max_order,
1153 ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
1154 sizeof(*ctx->raw_samples[c]) * sconf->max_order);
1155
1156 return 0;
1157 }
1158
1159
1160 /** Read the channel data.
1161 */
1162 static int read_channel_data(ALSDecContext *ctx, ALSChannelData *cd, int c)
1163 {
1164 GetBitContext *gb = &ctx->gb;
1165 ALSChannelData *current = cd;
1166 unsigned int channels = ctx->avctx->channels;
1167 int entries = 0;
1168
1169 while (entries < channels && !(current->stop_flag = get_bits1(gb))) {
1170 current->master_channel = get_bits_long(gb, av_ceil_log2(channels));
1171
1172 if (current->master_channel >= channels) {
1173 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid master channel!\n");
1174 return -1;
1175 }
1176
1177 if (current->master_channel != c) {
1178 current->time_diff_flag = get_bits1(gb);
1179 current->weighting[0] = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];
1180 current->weighting[1] = mcc_weightings[av_clip(decode_rice(gb, 2) + 14, 0, 32)];
1181 current->weighting[2] = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];
1182
1183 if (current->time_diff_flag) {
1184 current->weighting[3] = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];
1185 current->weighting[4] = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];
1186 current->weighting[5] = mcc_weightings[av_clip(decode_rice(gb, 1) + 16, 0, 32)];
1187
1188 current->time_diff_sign = get_bits1(gb);
1189 current->time_diff_index = get_bits(gb, ctx->ltp_lag_length - 3) + 3;
1190 }
1191 }
1192
1193 current++;
1194 entries++;
1195 }
1196
1197 if (entries == channels) {
1198 av_log(ctx->avctx, AV_LOG_ERROR, "Damaged channel data!\n");
1199 return -1;
1200 }
1201
1202 align_get_bits(gb);
1203 return 0;
1204 }
1205
1206
1207 /** Recursively reverts the inter-channel correlation for a block.
1208 */
1209 static int revert_channel_correlation(ALSDecContext *ctx, ALSBlockData *bd,
1210 ALSChannelData **cd, int *reverted,
1211 unsigned int offset, int c)
1212 {
1213 ALSChannelData *ch = cd[c];
1214 unsigned int dep = 0;
1215 unsigned int channels = ctx->avctx->channels;
1216
1217 if (reverted[c])
1218 return 0;
1219
1220 reverted[c] = 1;
1221
1222 while (dep < channels && !ch[dep].stop_flag) {
1223 revert_channel_correlation(ctx, bd, cd, reverted, offset,
1224 ch[dep].master_channel);
1225
1226 dep++;
1227 }
1228
1229 if (dep == channels) {
1230 av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel correlation!\n");
1231 return -1;
1232 }
1233
1234 bd->const_block = ctx->const_block + c;
1235 bd->shift_lsbs = ctx->shift_lsbs + c;
1236 bd->opt_order = ctx->opt_order + c;
1237 bd->store_prev_samples = ctx->store_prev_samples + c;
1238 bd->use_ltp = ctx->use_ltp + c;
1239 bd->ltp_lag = ctx->ltp_lag + c;
1240 bd->ltp_gain = ctx->ltp_gain[c];
1241 bd->lpc_cof = ctx->lpc_cof[c];
1242 bd->quant_cof = ctx->quant_cof[c];
1243 bd->raw_samples = ctx->raw_samples[c] + offset;
1244
1245 dep = 0;
1246 while (!ch[dep].stop_flag) {
1247 unsigned int smp;
1248 unsigned int begin = 1;
1249 unsigned int end = bd->block_length - 1;
1250 int64_t y;
1251 int32_t *master = ctx->raw_samples[ch[dep].master_channel] + offset;
1252
1253 if (ch[dep].time_diff_flag) {
1254 int t = ch[dep].time_diff_index;
1255
1256 if (ch[dep].time_diff_sign) {
1257 t = -t;
1258 begin -= t;
1259 } else {
1260 end -= t;
1261 }
1262
1263 for (smp = begin; smp < end; smp++) {
1264 y = (1 << 6) +
1265 MUL64(ch[dep].weighting[0], master[smp - 1 ]) +
1266 MUL64(ch[dep].weighting[1], master[smp ]) +
1267 MUL64(ch[dep].weighting[2], master[smp + 1 ]) +
1268 MUL64(ch[dep].weighting[3], master[smp - 1 + t]) +
1269 MUL64(ch[dep].weighting[4], master[smp + t]) +
1270 MUL64(ch[dep].weighting[5], master[smp + 1 + t]);
1271
1272 bd->raw_samples[smp] += y >> 7;
1273 }
1274 } else {
1275 for (smp = begin; smp < end; smp++) {
1276 y = (1 << 6) +
1277 MUL64(ch[dep].weighting[0], master[smp - 1]) +
1278 MUL64(ch[dep].weighting[1], master[smp ]) +
1279 MUL64(ch[dep].weighting[2], master[smp + 1]);
1280
1281 bd->raw_samples[smp] += y >> 7;
1282 }
1283 }
1284
1285 dep++;
1286 }
1287
1288 return 0;
1289 }
1290
1291
1292 /** Read the frame data.
1293 */
1294 static int read_frame_data(ALSDecContext *ctx, unsigned int ra_frame)
1295 {
1296 ALSSpecificConfig *sconf = &ctx->sconf;
1297 AVCodecContext *avctx = ctx->avctx;
1298 GetBitContext *gb = &ctx->gb;
1299 unsigned int div_blocks[32]; ///< block sizes.
1300 unsigned int c;
1301 unsigned int js_blocks[2];
1302
1303 uint32_t bs_info = 0;
1304
1305 // skip the size of the ra unit if present in the frame
1306 if (sconf->ra_flag == RA_FLAG_FRAMES && ra_frame)
1307 skip_bits_long(gb, 32);
1308
1309 if (sconf->mc_coding && sconf->joint_stereo) {
1310 ctx->js_switch = get_bits1(gb);
1311 align_get_bits(gb);
1312 }
1313
1314 if (!sconf->mc_coding || ctx->js_switch) {
1315 int independent_bs = !sconf->joint_stereo;
1316
1317 for (c = 0; c < avctx->channels; c++) {
1318 js_blocks[0] = 0;
1319 js_blocks[1] = 0;
1320
1321 get_block_sizes(ctx, div_blocks, &bs_info);
1322
1323 // if joint_stereo and block_switching is set, independent decoding
1324 // is signaled via the first bit of bs_info
1325 if (sconf->joint_stereo && sconf->block_switching)
1326 if (bs_info >> 31)
1327 independent_bs = 2;
1328
1329 // if this is the last channel, it has to be decoded independently
1330 if (c == avctx->channels - 1)
1331 independent_bs = 1;
1332
1333 if (independent_bs) {
1334 if (decode_blocks_ind(ctx, ra_frame, c, div_blocks, js_blocks))
1335 return -1;
1336
1337 independent_bs--;
1338 } else {
1339 if (decode_blocks(ctx, ra_frame, c, div_blocks, js_blocks))
1340 return -1;
1341
1342 c++;
1343 }
1344
1345 // store carryover raw samples
1346 memmove(ctx->raw_samples[c] - sconf->max_order,
1347 ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
1348 sizeof(*ctx->raw_samples[c]) * sconf->max_order);
1349 }
1350 } else { // multi-channel coding
1351 ALSBlockData bd = { 0 };
1352 int b, ret;
1353 int *reverted_channels = ctx->reverted_channels;
1354 unsigned int offset = 0;
1355
1356 for (c = 0; c < avctx->channels; c++)
1357 if (ctx->chan_data[c] < ctx->chan_data_buffer) {
1358 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid channel data!\n");
1359 return -1;
1360 }
1361
1362 memset(reverted_channels, 0, sizeof(*reverted_channels) * avctx->channels);
1363
1364 bd.ra_block = ra_frame;
1365 bd.prev_raw_samples = ctx->prev_raw_samples;
1366
1367 get_block_sizes(ctx, div_blocks, &bs_info);
1368
1369 for (b = 0; b < ctx->num_blocks; b++) {
1370 bd.block_length = div_blocks[b];
1371
1372 for (c = 0; c < avctx->channels; c++) {
1373 bd.const_block = ctx->const_block + c;
1374 bd.shift_lsbs = ctx->shift_lsbs + c;
1375 bd.opt_order = ctx->opt_order + c;
1376 bd.store_prev_samples = ctx->store_prev_samples + c;
1377 bd.use_ltp = ctx->use_ltp + c;
1378 bd.ltp_lag = ctx->ltp_lag + c;
1379 bd.ltp_gain = ctx->ltp_gain[c];
1380 bd.lpc_cof = ctx->lpc_cof[c];
1381 bd.quant_cof = ctx->quant_cof[c];
1382 bd.raw_samples = ctx->raw_samples[c] + offset;
1383 bd.raw_other = NULL;
1384
1385 if ((ret = read_block(ctx, &bd)) < 0)
1386 return ret;
1387 if ((ret = read_channel_data(ctx, ctx->chan_data[c], c)) < 0)
1388 return ret;
1389 }
1390
1391 for (c = 0; c < avctx->channels; c++)
1392 if (revert_channel_correlation(ctx, &bd, ctx->chan_data,
1393 reverted_channels, offset, c))
1394 return -1;
1395
1396 for (c = 0; c < avctx->channels; c++) {
1397 bd.const_block = ctx->const_block + c;
1398 bd.shift_lsbs = ctx->shift_lsbs + c;
1399 bd.opt_order = ctx->opt_order + c;
1400 bd.store_prev_samples = ctx->store_prev_samples + c;
1401 bd.use_ltp = ctx->use_ltp + c;
1402 bd.ltp_lag = ctx->ltp_lag + c;
1403 bd.ltp_gain = ctx->ltp_gain[c];
1404 bd.lpc_cof = ctx->lpc_cof[c];
1405 bd.quant_cof = ctx->quant_cof[c];
1406 bd.raw_samples = ctx->raw_samples[c] + offset;
1407 if ((ret = decode_block(ctx, &bd)) < 0)
1408 return ret;
1409 }
1410
1411 memset(reverted_channels, 0, avctx->channels * sizeof(*reverted_channels));
1412 offset += div_blocks[b];
1413 bd.ra_block = 0;
1414 }
1415
1416 // store carryover raw samples
1417 for (c = 0; c < avctx->channels; c++)
1418 memmove(ctx->raw_samples[c] - sconf->max_order,
1419 ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
1420 sizeof(*ctx->raw_samples[c]) * sconf->max_order);
1421 }
1422
1423 // TODO: read_diff_float_data
1424
1425 return 0;
1426 }
1427
1428
1429 /** Decode an ALS frame.
1430 */
1431 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr,
1432 AVPacket *avpkt)
1433 {
1434 ALSDecContext *ctx = avctx->priv_data;
1435 ALSSpecificConfig *sconf = &ctx->sconf;
1436 const uint8_t *buffer = avpkt->data;
1437 int buffer_size = avpkt->size;
1438 int invalid_frame, ret;
1439 unsigned int c, sample, ra_frame, bytes_read, shift;
1440
1441 init_get_bits(&ctx->gb, buffer, buffer_size * 8);
1442
1443 // In the case that the distance between random access frames is set to zero
1444 // (sconf->ra_distance == 0) no frame is treated as a random access frame.
1445 // For the first frame, if prediction is used, all samples used from the
1446 // previous frame are assumed to be zero.
1447 ra_frame = sconf->ra_distance && !(ctx->frame_id % sconf->ra_distance);
1448
1449 // the last frame to decode might have a different length
1450 if (sconf->samples != 0xFFFFFFFF)
1451 ctx->cur_frame_length = FFMIN(sconf->samples - ctx->frame_id * (uint64_t) sconf->frame_length,
1452 sconf->frame_length);
1453 else
1454 ctx->cur_frame_length = sconf->frame_length;
1455
1456 // decode the frame data
1457 if ((invalid_frame = read_frame_data(ctx, ra_frame)) < 0)
1458 av_log(ctx->avctx, AV_LOG_WARNING,
1459 "Reading frame data failed. Skipping RA unit.\n");
1460
1461 ctx->frame_id++;
1462
1463 /* get output buffer */
1464 ctx->frame.nb_samples = ctx->cur_frame_length;
1465 if ((ret = ff_get_buffer(avctx, &ctx->frame)) < 0) {
1466 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
1467 return ret;
1468 }
1469
1470 // transform decoded frame into output format
1471 #define INTERLEAVE_OUTPUT(bps) \
1472 { \
1473 int##bps##_t *dest = (int##bps##_t*)ctx->frame.data[0]; \
1474 shift = bps - ctx->avctx->bits_per_raw_sample; \
1475 for (sample = 0; sample < ctx->cur_frame_length; sample++) \
1476 for (c = 0; c < avctx->channels; c++) \
1477 *dest++ = ctx->raw_samples[c][sample] << shift; \
1478 }
1479
1480 if (ctx->avctx->bits_per_raw_sample <= 16) {
1481 INTERLEAVE_OUTPUT(16)
1482 } else {
1483 INTERLEAVE_OUTPUT(32)
1484 }
1485
1486 // update CRC
1487 if (sconf->crc_enabled && (avctx->err_recognition & AV_EF_CRCCHECK)) {
1488 int swap = HAVE_BIGENDIAN != sconf->msb_first;
1489
1490 if (ctx->avctx->bits_per_raw_sample == 24) {
1491 int32_t *src = (int32_t *)ctx->frame.data[0];
1492
1493 for (sample = 0;
1494 sample < ctx->cur_frame_length * avctx->channels;
1495 sample++) {
1496 int32_t v;
1497
1498 if (swap)
1499 v = av_bswap32(src[sample]);
1500 else
1501 v = src[sample];
1502 if (!HAVE_BIGENDIAN)
1503 v >>= 8;
1504
1505 ctx->crc = av_crc(ctx->crc_table, ctx->crc, (uint8_t*)(&v), 3);
1506 }
1507 } else {
1508 uint8_t *crc_source;
1509
1510 if (swap) {
1511 if (ctx->avctx->bits_per_raw_sample <= 16) {
1512 int16_t *src = (int16_t*) ctx->frame.data[0];
1513 int16_t *dest = (int16_t*) ctx->crc_buffer;
1514 for (sample = 0;
1515 sample < ctx->cur_frame_length * avctx->channels;
1516 sample++)
1517 *dest++ = av_bswap16(src[sample]);
1518 } else {
1519 ctx->dsp.bswap_buf((uint32_t*)ctx->crc_buffer,
1520 (uint32_t *)ctx->frame.data[0],
1521 ctx->cur_frame_length * avctx->channels);
1522 }
1523 crc_source = ctx->crc_buffer;
1524 } else {
1525 crc_source = ctx->frame.data[0];
1526 }
1527
1528 ctx->crc = av_crc(ctx->crc_table, ctx->crc, crc_source,
1529 ctx->cur_frame_length * avctx->channels *
1530 av_get_bytes_per_sample(avctx->sample_fmt));
1531 }
1532
1533
1534 // check CRC sums if this is the last frame
1535 if (ctx->cur_frame_length != sconf->frame_length &&
1536 ctx->crc_org != ctx->crc) {
1537 av_log(avctx, AV_LOG_ERROR, "CRC error.\n");
1538 }
1539 }
1540
1541 *got_frame_ptr = 1;
1542 *(AVFrame *)data = ctx->frame;
1543
1544
1545 bytes_read = invalid_frame ? buffer_size :
1546 (get_bits_count(&ctx->gb) + 7) >> 3;
1547
1548 return bytes_read;
1549 }
1550
1551
1552 /** Uninitialize the ALS decoder.
1553 */
1554 static av_cold int decode_end(AVCodecContext *avctx)
1555 {
1556 ALSDecContext *ctx = avctx->priv_data;
1557
1558 av_freep(&ctx->sconf.chan_pos);
1559
1560 ff_bgmc_end(&ctx->bgmc_lut, &ctx->bgmc_lut_status);
1561
1562 av_freep(&ctx->const_block);
1563 av_freep(&ctx->shift_lsbs);
1564 av_freep(&ctx->opt_order);
1565 av_freep(&ctx->store_prev_samples);
1566 av_freep(&ctx->use_ltp);
1567 av_freep(&ctx->ltp_lag);
1568 av_freep(&ctx->ltp_gain);
1569 av_freep(&ctx->ltp_gain_buffer);
1570 av_freep(&ctx->quant_cof);
1571 av_freep(&ctx->lpc_cof);
1572 av_freep(&ctx->quant_cof_buffer);
1573 av_freep(&ctx->lpc_cof_buffer);
1574 av_freep(&ctx->lpc_cof_reversed_buffer);
1575 av_freep(&ctx->prev_raw_samples);
1576 av_freep(&ctx->raw_samples);
1577 av_freep(&ctx->raw_buffer);
1578 av_freep(&ctx->chan_data);
1579 av_freep(&ctx->chan_data_buffer);
1580 av_freep(&ctx->reverted_channels);
1581 av_freep(&ctx->crc_buffer);
1582
1583 return 0;
1584 }
1585
1586
1587 /** Initialize the ALS decoder.
1588 */
1589 static av_cold int decode_init(AVCodecContext *avctx)
1590 {
1591 unsigned int c;
1592 unsigned int channel_size;
1593 int num_buffers;
1594 ALSDecContext *ctx = avctx->priv_data;
1595 ALSSpecificConfig *sconf = &ctx->sconf;
1596 ctx->avctx = avctx;
1597
1598 if (!avctx->extradata) {
1599 av_log(avctx, AV_LOG_ERROR, "Missing required ALS extradata.\n");
1600 return -1;
1601 }
1602
1603 if (read_specific_config(ctx)) {
1604 av_log(avctx, AV_LOG_ERROR, "Reading ALSSpecificConfig failed.\n");
1605 decode_end(avctx);
1606 return -1;
1607 }
1608
1609 if (check_specific_config(ctx)) {
1610 decode_end(avctx);
1611 return -1;
1612 }
1613
1614 if (sconf->bgmc)
1615 ff_bgmc_init(avctx, &ctx->bgmc_lut, &ctx->bgmc_lut_status);
1616
1617 if (sconf->floating) {
1618 avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
1619 avctx->bits_per_raw_sample = 32;
1620 } else {
1621 avctx->sample_fmt = sconf->resolution > 1
1622 ? AV_SAMPLE_FMT_S32 : AV_SAMPLE_FMT_S16;
1623 avctx->bits_per_raw_sample = (sconf->resolution + 1) * 8;
1624 }
1625
1626 // set maximum Rice parameter for progressive decoding based on resolution
1627 // This is not specified in 14496-3 but actually done by the reference
1628 // codec RM22 revision 2.
1629 ctx->s_max = sconf->resolution > 1 ? 31 : 15;
1630
1631 // set lag value for long-term prediction
1632 ctx->ltp_lag_length = 8 + (avctx->sample_rate >= 96000) +
1633 (avctx->sample_rate >= 192000);
1634
1635 // allocate quantized parcor coefficient buffer
1636 num_buffers = sconf->mc_coding ? avctx->channels : 1;
1637
1638 ctx->quant_cof = av_malloc(sizeof(*ctx->quant_cof) * num_buffers);
1639 ctx->lpc_cof = av_malloc(sizeof(*ctx->lpc_cof) * num_buffers);
1640 ctx->quant_cof_buffer = av_malloc(sizeof(*ctx->quant_cof_buffer) *
1641 num_buffers * sconf->max_order);
1642 ctx->lpc_cof_buffer = av_malloc(sizeof(*ctx->lpc_cof_buffer) *
1643 num_buffers * sconf->max_order);
1644 ctx->lpc_cof_reversed_buffer = av_malloc(sizeof(*ctx->lpc_cof_buffer) *
1645 sconf->max_order);
1646
1647 if (!ctx->quant_cof || !ctx->lpc_cof ||
1648 !ctx->quant_cof_buffer || !ctx->lpc_cof_buffer ||
1649 !ctx->lpc_cof_reversed_buffer) {
1650 av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
1651 return AVERROR(ENOMEM);
1652 }
1653
1654 // assign quantized parcor coefficient buffers
1655 for (c = 0; c < num_buffers; c++) {
1656 ctx->quant_cof[c] = ctx->quant_cof_buffer + c * sconf->max_order;
1657 ctx->lpc_cof[c] = ctx->lpc_cof_buffer + c * sconf->max_order;
1658 }
1659
1660 // allocate and assign lag and gain data buffer for ltp mode
1661 ctx->const_block = av_malloc (sizeof(*ctx->const_block) * num_buffers);
1662 ctx->shift_lsbs = av_malloc (sizeof(*ctx->shift_lsbs) * num_buffers);
1663 ctx->opt_order = av_malloc (sizeof(*ctx->opt_order) * num_buffers);
1664 ctx->store_prev_samples = av_malloc(sizeof(*ctx->store_prev_samples) * num_buffers);
1665 ctx->use_ltp = av_mallocz(sizeof(*ctx->use_ltp) * num_buffers);
1666 ctx->ltp_lag = av_malloc (sizeof(*ctx->ltp_lag) * num_buffers);
1667 ctx->ltp_gain = av_malloc (sizeof(*ctx->ltp_gain) * num_buffers);
1668 ctx->ltp_gain_buffer = av_malloc (sizeof(*ctx->ltp_gain_buffer) *
1669 num_buffers * 5);
1670
1671 if (!ctx->const_block || !ctx->shift_lsbs ||
1672 !ctx->opt_order || !ctx->store_prev_samples ||
1673 !ctx->use_ltp || !ctx->ltp_lag ||
1674 !ctx->ltp_gain || !ctx->ltp_gain_buffer) {
1675 av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
1676 decode_end(avctx);
1677 return AVERROR(ENOMEM);
1678 }
1679
1680 for (c = 0; c < num_buffers; c++)
1681 ctx->ltp_gain[c] = ctx->ltp_gain_buffer + c * 5;
1682
1683 // allocate and assign channel data buffer for mcc mode
1684 if (sconf->mc_coding) {
1685 ctx->chan_data_buffer = av_malloc(sizeof(*ctx->chan_data_buffer) *
1686 num_buffers * num_buffers);
1687 ctx->chan_data = av_malloc(sizeof(*ctx->chan_data) *
1688 num_buffers);
1689 ctx->reverted_channels = av_malloc(sizeof(*ctx->reverted_channels) *
1690 num_buffers);
1691
1692 if (!ctx->chan_data_buffer || !ctx->chan_data || !ctx->reverted_channels) {
1693 av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
1694 decode_end(avctx);
1695 return AVERROR(ENOMEM);
1696 }
1697
1698 for (c = 0; c < num_buffers; c++)
1699 ctx->chan_data[c] = ctx->chan_data_buffer + c * num_buffers;
1700 } else {
1701 ctx->chan_data = NULL;
1702 ctx->chan_data_buffer = NULL;
1703 ctx->reverted_channels = NULL;
1704 }
1705
1706 channel_size = sconf->frame_length + sconf->max_order;
1707
1708 ctx->prev_raw_samples = av_malloc (sizeof(*ctx->prev_raw_samples) * sconf->max_order);
1709 ctx->raw_buffer = av_mallocz(sizeof(*ctx-> raw_buffer) * avctx->channels * channel_size);
1710 ctx->raw_samples = av_malloc (sizeof(*ctx-> raw_samples) * avctx->channels);
1711
1712 // allocate previous raw sample buffer
1713 if (!ctx->prev_raw_samples || !ctx->raw_buffer|| !ctx->raw_samples) {
1714 av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
1715 decode_end(avctx);
1716 return AVERROR(ENOMEM);
1717 }
1718
1719 // assign raw samples buffers
1720 ctx->raw_samples[0] = ctx->raw_buffer + sconf->max_order;
1721 for (c = 1; c < avctx->channels; c++)
1722 ctx->raw_samples[c] = ctx->raw_samples[c - 1] + channel_size;
1723
1724 // allocate crc buffer
1725 if (HAVE_BIGENDIAN != sconf->msb_first && sconf->crc_enabled &&
1726 (avctx->err_recognition & AV_EF_CRCCHECK)) {
1727 ctx->crc_buffer = av_malloc(sizeof(*ctx->crc_buffer) *
1728 ctx->cur_frame_length *
1729 avctx->channels *
1730 av_get_bytes_per_sample(avctx->sample_fmt));
1731 if (!ctx->crc_buffer) {
1732 av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
1733 decode_end(avctx);
1734 return AVERROR(ENOMEM);
1735 }
1736 }
1737
1738 ff_dsputil_init(&ctx->dsp, avctx);
1739
1740 avcodec_get_frame_defaults(&ctx->frame);
1741 avctx->coded_frame = &ctx->frame;
1742
1743 return 0;
1744 }
1745
1746
1747 /** Flush (reset) the frame ID after seeking.
1748 */
1749 static av_cold void flush(AVCodecContext *avctx)
1750 {
1751 ALSDecContext *ctx = avctx->priv_data;
1752
1753 ctx->frame_id = 0;
1754 }
1755
1756
1757 AVCodec ff_als_decoder = {
1758 .name = "als",
1759 .type = AVMEDIA_TYPE_AUDIO,
1760 .id = AV_CODEC_ID_MP4ALS,
1761 .priv_data_size = sizeof(ALSDecContext),
1762 .init = decode_init,
1763 .close = decode_end,
1764 .decode = decode_frame,
1765 .flush = flush,
1766 .capabilities = CODEC_CAP_SUBFRAMES | CODEC_CAP_DR1,
1767 .long_name = NULL_IF_CONFIG_SMALL("MPEG-4 Audio Lossless Coding (ALS)"),
1768 };