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Imported Debian version 2.4.3~trusty1
[deb_ffmpeg.git] / ffmpeg / libavcodec / alsdec.c
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2ba45a60
DM		 1/*
2 * MPEG-4 ALS decoder
3 * Copyright (c) 2009 Thilo Borgmann <thilo.borgmann _at_ mail.de>
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg 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 * FFmpeg 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 FFmpeg; 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_ mail.de>
26 */
27
28#include <inttypes.h>
29
30#include "avcodec.h"
31#include "get_bits.h"
32#include "unary.h"
33#include "mpeg4audio.h"
34#include "bytestream.h"
35#include "bgmc.h"
36#include "bswapdsp.h"
37#include "internal.h"
38#include "libavutil/samplefmt.h"
39#include "libavutil/crc.h"
40
41#include <stdint.h>
42
43/** Rice parameters and corresponding index offsets for decoding the
44 * indices of scaled PARCOR values. The table chosen is set globally
45 * by the encoder and stored in ALSSpecificConfig.
46 */
47static const int8_t parcor_rice_table[3][20][2] = {
48 { {-52, 4}, {-29, 5}, {-31, 4}, { 19, 4}, {-16, 4},
49 { 12, 3}, { -7, 3}, { 9, 3}, { -5, 3}, { 6, 3},
50 { -4, 3}, { 3, 3}, { -3, 2}, { 3, 2}, { -2, 2},
51 { 3, 2}, { -1, 2}, { 2, 2}, { -1, 2}, { 2, 2} },
52 { {-58, 3}, {-42, 4}, {-46, 4}, { 37, 5}, {-36, 4},
53 { 29, 4}, {-29, 4}, { 25, 4}, {-23, 4}, { 20, 4},
54 {-17, 4}, { 16, 4}, {-12, 4}, { 12, 3}, {-10, 4},
55 { 7, 3}, { -4, 4}, { 3, 3}, { -1, 3}, { 1, 3} },
56 { {-59, 3}, {-45, 5}, {-50, 4}, { 38, 4}, {-39, 4},
57 { 32, 4}, {-30, 4}, { 25, 3}, {-23, 3}, { 20, 3},
58 {-20, 3}, { 16, 3}, {-13, 3}, { 10, 3}, { -7, 3},
59 { 3, 3}, { 0, 3}, { -1, 3}, { 2, 3}, { -1, 2} }
60};
61
62
63/** Scaled PARCOR values used for the first two PARCOR coefficients.
64 * To be indexed by the Rice coded indices.
65 * Generated by: parcor_scaled_values[i] = 32 + ((i * (i+1)) << 7) - (1 << 20)
66 * Actual values are divided by 32 in order to be stored in 16 bits.
67 */
68static const int16_t parcor_scaled_values[] = {
69 -1048544 / 32, -1048288 / 32, -1047776 / 32, -1047008 / 32,
70 -1045984 / 32, -1044704 / 32, -1043168 / 32, -1041376 / 32,
71 -1039328 / 32, -1037024 / 32, -1034464 / 32, -1031648 / 32,
72 -1028576 / 32, -1025248 / 32, -1021664 / 32, -1017824 / 32,
73 -1013728 / 32, -1009376 / 32, -1004768 / 32, -999904 / 32,
74 -994784 / 32, -989408 / 32, -983776 / 32, -977888 / 32,
75 -971744 / 32, -965344 / 32, -958688 / 32, -951776 / 32,
76 -944608 / 32, -937184 / 32, -929504 / 32, -921568 / 32,
77 -913376 / 32, -904928 / 32, -896224 / 32, -887264 / 32,
78 -878048 / 32, -868576 / 32, -858848 / 32, -848864 / 32,
79 -838624 / 32, -828128 / 32, -817376 / 32, -806368 / 32,
80 -795104 / 32, -783584 / 32, -771808 / 32, -759776 / 32,
81 -747488 / 32, -734944 / 32, -722144 / 32, -709088 / 32,
82 -695776 / 32, -682208 / 32, -668384 / 32, -654304 / 32,
83 -639968 / 32, -625376 / 32, -610528 / 32, -595424 / 32,
84 -580064 / 32, -564448 / 32, -548576 / 32, -532448 / 32,
85 -516064 / 32, -499424 / 32, -482528 / 32, -465376 / 32,
86 -447968 / 32, -430304 / 32, -412384 / 32, -394208 / 32,
87 -375776 / 32, -357088 / 32, -338144 / 32, -318944 / 32,
88 -299488 / 32, -279776 / 32, -259808 / 32, -239584 / 32,
89 -219104 / 32, -198368 / 32, -177376 / 32, -156128 / 32,
90 -134624 / 32, -112864 / 32, -90848 / 32, -68576 / 32,
91 -46048 / 32, -23264 / 32, -224 / 32, 23072 / 32,
92 46624 / 32, 70432 / 32, 94496 / 32, 118816 / 32,
93 143392 / 32, 168224 / 32, 193312 / 32, 218656 / 32,
94 244256 / 32, 270112 / 32, 296224 / 32, 322592 / 32,
95 349216 / 32, 376096 / 32, 403232 / 32, 430624 / 32,
96 458272 / 32, 486176 / 32, 514336 / 32, 542752 / 32,
97 571424 / 32, 600352 / 32, 629536 / 32, 658976 / 32,
98 688672 / 32, 718624 / 32, 748832 / 32, 779296 / 32,
99 810016 / 32, 840992 / 32, 872224 / 32, 903712 / 32,
100 935456 / 32, 967456 / 32, 999712 / 32, 1032224 / 32
101};
102
103
104/** Gain values of p(0) for long-term prediction.
105 * To be indexed by the Rice coded indices.
106 */
107static const uint8_t ltp_gain_values [4][4] = {
108 { 0, 8, 16, 24},
109 {32, 40, 48, 56},
110 {64, 70, 76, 82},
111 {88, 92, 96, 100}
112};
113
114
115/** Inter-channel weighting factors for multi-channel correlation.
116 * To be indexed by the Rice coded indices.
117 */
118static const int16_t mcc_weightings[] = {
119 204, 192, 179, 166, 153, 140, 128, 115,
120 102, 89, 76, 64, 51, 38, 25, 12,
121 0, -12, -25, -38, -51, -64, -76, -89,
122 -102, -115, -128, -140, -153, -166, -179, -192
123};
124
125
126/** Tail codes used in arithmetic coding using block Gilbert-Moore codes.
127 */
128static const uint8_t tail_code[16][6] = {
129 { 74, 44, 25, 13, 7, 3},
130 { 68, 42, 24, 13, 7, 3},
131 { 58, 39, 23, 13, 7, 3},
132 {126, 70, 37, 19, 10, 5},
133 {132, 70, 37, 20, 10, 5},
134 {124, 70, 38, 20, 10, 5},
135 {120, 69, 37, 20, 11, 5},
136 {116, 67, 37, 20, 11, 5},
137 {108, 66, 36, 20, 10, 5},
138 {102, 62, 36, 20, 10, 5},
139 { 88, 58, 34, 19, 10, 5},
140 {162, 89, 49, 25, 13, 7},
141 {156, 87, 49, 26, 14, 7},
142 {150, 86, 47, 26, 14, 7},
143 {142, 84, 47, 26, 14, 7},
144 {131, 79, 46, 26, 14, 7}
145};
146
147
148enum RA_Flag {
149 RA_FLAG_NONE,
150 RA_FLAG_FRAMES,
151 RA_FLAG_HEADER
152};
153
154
155typedef struct {
156 uint32_t samples; ///< number of samples, 0xFFFFFFFF if unknown
157 int resolution; ///< 000 = 8-bit; 001 = 16-bit; 010 = 24-bit; 011 = 32-bit
158 int floating; ///< 1 = IEEE 32-bit floating-point, 0 = integer
159 int msb_first; ///< 1 = original CRC calculated on big-endian system, 0 = little-endian
160 int frame_length; ///< frame length for each frame (last frame may differ)
161 int ra_distance; ///< distance between RA frames (in frames, 0...255)
162 enum RA_Flag ra_flag; ///< indicates where the size of ra units is stored
163 int adapt_order; ///< adaptive order: 1 = on, 0 = off
164 int coef_table; ///< table index of Rice code parameters
165 int long_term_prediction; ///< long term prediction (LTP): 1 = on, 0 = off
166 int max_order; ///< maximum prediction order (0..1023)
167 int block_switching; ///< number of block switching levels
168 int bgmc; ///< "Block Gilbert-Moore Code": 1 = on, 0 = off (Rice coding only)
169 int sb_part; ///< sub-block partition
170 int joint_stereo; ///< joint stereo: 1 = on, 0 = off
171 int mc_coding; ///< extended inter-channel coding (multi channel coding): 1 = on, 0 = off
172 int chan_config; ///< indicates that a chan_config_info field is present
173 int chan_sort; ///< channel rearrangement: 1 = on, 0 = off
174 int rlslms; ///< use "Recursive Least Square-Least Mean Square" predictor: 1 = on, 0 = off
175 int chan_config_info; ///< mapping of channels to loudspeaker locations. Unused until setting channel configuration is implemented.
176 int *chan_pos; ///< original channel positions
177 int crc_enabled; ///< enable Cyclic Redundancy Checksum
178} ALSSpecificConfig;
179
180
181typedef struct {
182 int stop_flag;
183 int master_channel;
184 int time_diff_flag;
185 int time_diff_sign;
186 int time_diff_index;
187 int weighting[6];
188} ALSChannelData;
189
190
191typedef struct {
192 AVCodecContext *avctx;
193 ALSSpecificConfig sconf;
194 GetBitContext gb;
195 BswapDSPContext bdsp;
196 const AVCRC *crc_table;
197 uint32_t crc_org; ///< CRC value of the original input data
198 uint32_t crc; ///< CRC value calculated from decoded data
199 unsigned int cur_frame_length; ///< length of the current frame to decode
200 unsigned int frame_id; ///< the frame ID / number of the current frame
201 unsigned int js_switch; ///< if true, joint-stereo decoding is enforced
202 unsigned int cs_switch; ///< if true, channel rearrangement is done
203 unsigned int num_blocks; ///< number of blocks used in the current frame
204 unsigned int s_max; ///< maximum Rice parameter allowed in entropy coding
205 uint8_t *bgmc_lut; ///< pointer at lookup tables used for BGMC
206 int *bgmc_lut_status; ///< pointer at lookup table status flags used for BGMC
207 int ltp_lag_length; ///< number of bits used for ltp lag value
208 int *const_block; ///< contains const_block flags for all channels
209 unsigned int *shift_lsbs; ///< contains shift_lsbs flags for all channels
210 unsigned int *opt_order; ///< contains opt_order flags for all channels
211 int *store_prev_samples; ///< contains store_prev_samples flags for all channels
212 int *use_ltp; ///< contains use_ltp flags for all channels
213 int *ltp_lag; ///< contains ltp lag values for all channels
214 int **ltp_gain; ///< gain values for ltp 5-tap filter for a channel
215 int *ltp_gain_buffer; ///< contains all gain values for ltp 5-tap filter
216 int32_t **quant_cof; ///< quantized parcor coefficients for a channel
217 int32_t *quant_cof_buffer; ///< contains all quantized parcor coefficients
218 int32_t **lpc_cof; ///< coefficients of the direct form prediction filter for a channel
219 int32_t *lpc_cof_buffer; ///< contains all coefficients of the direct form prediction filter
220 int32_t *lpc_cof_reversed_buffer; ///< temporary buffer to set up a reversed versio of lpc_cof_buffer
221 ALSChannelData **chan_data; ///< channel data for multi-channel correlation
222 ALSChannelData *chan_data_buffer; ///< contains channel data for all channels
223 int *reverted_channels; ///< stores a flag for each reverted channel
224 int32_t *prev_raw_samples; ///< contains unshifted raw samples from the previous block
225 int32_t **raw_samples; ///< decoded raw samples for each channel
226 int32_t *raw_buffer; ///< contains all decoded raw samples including carryover samples
227 uint8_t *crc_buffer; ///< buffer of byte order corrected samples used for CRC check
228} ALSDecContext;
229
230
231typedef struct {
232 unsigned int block_length; ///< number of samples within the block
233 unsigned int ra_block; ///< if true, this is a random access block
234 int *const_block; ///< if true, this is a constant value block
235 int js_blocks; ///< true if this block contains a difference signal
236 unsigned int *shift_lsbs; ///< shift of values for this block
237 unsigned int *opt_order; ///< prediction order of this block
238 int *store_prev_samples;///< if true, carryover samples have to be stored
239 int *use_ltp; ///< if true, long-term prediction is used
240 int *ltp_lag; ///< lag value for long-term prediction
241 int *ltp_gain; ///< gain values for ltp 5-tap filter
242 int32_t *quant_cof; ///< quantized parcor coefficients
243 int32_t *lpc_cof; ///< coefficients of the direct form prediction
244 int32_t *raw_samples; ///< decoded raw samples / residuals for this block
245 int32_t *prev_raw_samples; ///< contains unshifted raw samples from the previous block
246 int32_t *raw_other; ///< decoded raw samples of the other channel of a channel pair
247} ALSBlockData;
248
249
250static av_cold void dprint_specific_config(ALSDecContext *ctx)
251{
252#ifdef DEBUG
253 AVCodecContext *avctx = ctx->avctx;
254 ALSSpecificConfig *sconf = &ctx->sconf;
255
256 av_dlog(avctx, "resolution = %i\n", sconf->resolution);
257 av_dlog(avctx, "floating = %i\n", sconf->floating);
258 av_dlog(avctx, "frame_length = %i\n", sconf->frame_length);
259 av_dlog(avctx, "ra_distance = %i\n", sconf->ra_distance);
260 av_dlog(avctx, "ra_flag = %i\n", sconf->ra_flag);
261 av_dlog(avctx, "adapt_order = %i\n", sconf->adapt_order);
262 av_dlog(avctx, "coef_table = %i\n", sconf->coef_table);
263 av_dlog(avctx, "long_term_prediction = %i\n", sconf->long_term_prediction);
264 av_dlog(avctx, "max_order = %i\n", sconf->max_order);
265 av_dlog(avctx, "block_switching = %i\n", sconf->block_switching);
266 av_dlog(avctx, "bgmc = %i\n", sconf->bgmc);
267 av_dlog(avctx, "sb_part = %i\n", sconf->sb_part);
268 av_dlog(avctx, "joint_stereo = %i\n", sconf->joint_stereo);
269 av_dlog(avctx, "mc_coding = %i\n", sconf->mc_coding);
270 av_dlog(avctx, "chan_config = %i\n", sconf->chan_config);
271 av_dlog(avctx, "chan_sort = %i\n", sconf->chan_sort);
272 av_dlog(avctx, "RLSLMS = %i\n", sconf->rlslms);
273 av_dlog(avctx, "chan_config_info = %i\n", sconf->chan_config_info);
274#endif
275}
276
277
278/** Read an ALSSpecificConfig from a buffer into the output struct.
279 */
280static av_cold int read_specific_config(ALSDecContext *ctx)
281{
282 GetBitContext gb;
283 uint64_t ht_size;
284 int i, config_offset;
285 MPEG4AudioConfig m4ac = {0};
286 ALSSpecificConfig *sconf = &ctx->sconf;
287 AVCodecContext *avctx = ctx->avctx;
288 uint32_t als_id, header_size, trailer_size;
289 int ret;
290
291 if ((ret = init_get_bits8(&gb, avctx->extradata, avctx->extradata_size)) < 0)
292 return ret;
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 AVERROR_INVALIDDATA;
299
300 skip_bits_long(&gb, config_offset);
301
302 if (get_bits_left(&gb) < (30 << 3))
303 return AVERROR_INVALIDDATA;
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 known
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 AVERROR_INVALIDDATA;
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 AVERROR_INVALIDDATA;
354
355 if (!(sconf->chan_pos = av_malloc(avctx->channels * sizeof(*sconf->chan_pos))))
356 return AVERROR(ENOMEM);
357
358 ctx->cs_switch = 1;
359
360 for (i = 0; i < avctx->channels; i++) {
361 int idx;
362
363 idx = get_bits(&gb, chan_pos_bits);
364 if (idx >= avctx->channels) {
365 av_log(avctx, AV_LOG_WARNING, "Invalid channel reordering.\n");
366 ctx->cs_switch = 0;
367 break;
368 }
369 sconf->chan_pos[idx] = i;
370 }
371
372 align_get_bits(&gb);
373 }
374
375
376 // read fixed header and trailer sizes,
377 // if size = 0xFFFFFFFF then there is no data field!
378 if (get_bits_left(&gb) < 64)
379 return AVERROR_INVALIDDATA;
380
381 header_size = get_bits_long(&gb, 32);
382 trailer_size = get_bits_long(&gb, 32);
383 if (header_size == 0xFFFFFFFF)
384 header_size = 0;
385 if (trailer_size == 0xFFFFFFFF)
386 trailer_size = 0;
387
388 ht_size = ((int64_t)(header_size) + (int64_t)(trailer_size)) << 3;
389
390
391 // skip the header and trailer data
392 if (get_bits_left(&gb) < ht_size)
393 return AVERROR_INVALIDDATA;
394
395 if (ht_size > INT32_MAX)
396 return AVERROR_PATCHWELCOME;
397
398 skip_bits_long(&gb, ht_size);
399
400
401 // initialize CRC calculation
402 if (sconf->crc_enabled) {
403 if (get_bits_left(&gb) < 32)
404 return AVERROR_INVALIDDATA;
405
406 if (avctx->err_recognition & (AV_EF_CRCCHECK|AV_EF_CAREFUL)) {
407 ctx->crc_table = av_crc_get_table(AV_CRC_32_IEEE_LE);
408 ctx->crc = 0xFFFFFFFF;
409 ctx->crc_org = ~get_bits_long(&gb, 32);
410 } else
411 skip_bits_long(&gb, 32);
412 }
413
414
415 // no need to read the rest of ALSSpecificConfig (ra_unit_size & aux data)
416
417 dprint_specific_config(ctx);
418
419 return 0;
420}
421
422
423/** Check the ALSSpecificConfig for unsupported features.
424 */
425static int check_specific_config(ALSDecContext *ctx)
426{
427 ALSSpecificConfig *sconf = &ctx->sconf;
428 int error = 0;
429
430 // report unsupported feature and set error value
431 #define MISSING_ERR(cond, str, errval) \
432 { \
433 if (cond) { \
434 avpriv_report_missing_feature(ctx->avctx, \
435 str); \
436 error = errval; \
437 } \
438 }
439
440 MISSING_ERR(sconf->floating, "Floating point decoding", AVERROR_PATCHWELCOME);
441 MISSING_ERR(sconf->rlslms, "Adaptive RLS-LMS prediction", AVERROR_PATCHWELCOME);
442
443 return error;
444}
445
446
447/** Parse the bs_info field to extract the block partitioning used in
448 * block switching mode, refer to ISO/IEC 14496-3, section 11.6.2.
449 */
450static void parse_bs_info(const uint32_t bs_info, unsigned int n,
451 unsigned int div, unsigned int **div_blocks,
452 unsigned int *num_blocks)
453{
454 if (n < 31 && ((bs_info << n) & 0x40000000)) {
455 // if the level is valid and the investigated bit n is set
456 // then recursively check both children at bits (2n+1) and (2n+2)
457 n *= 2;
458 div += 1;
459 parse_bs_info(bs_info, n + 1, div, div_blocks, num_blocks);
460 parse_bs_info(bs_info, n + 2, div, div_blocks, num_blocks);
461 } else {
462 // else the bit is not set or the last level has been reached
463 // (bit implicitly not set)
464 **div_blocks = div;
465 (*div_blocks)++;
466 (*num_blocks)++;
467 }
468}
469
470
471/** Read and decode a Rice codeword.
472 */
473static int32_t decode_rice(GetBitContext *gb, unsigned int k)
474{
475 int max = get_bits_left(gb) - k;
476 int q = get_unary(gb, 0, max);
477 int r = k ? get_bits1(gb) : !(q & 1);
478
479 if (k > 1) {
480 q <<= (k - 1);
481 q += get_bits_long(gb, k - 1);
482 } else if (!k) {
483 q >>= 1;
484 }
485 return r ? q : ~q;
486}
487
488
489/** Convert PARCOR coefficient k to direct filter coefficient.
490 */
491static void parcor_to_lpc(unsigned int k, const int32_t *par, int32_t *cof)
492{
493 int i, j;
494
495 for (i = 0, j = k - 1; i < j; i++, j--) {
496 int tmp1 = ((MUL64(par[k], cof[j]) + (1 << 19)) >> 20);
497 cof[j] += ((MUL64(par[k], cof[i]) + (1 << 19)) >> 20);
498 cof[i] += tmp1;
499 }
500 if (i == j)
501 cof[i] += ((MUL64(par[k], cof[j]) + (1 << 19)) >> 20);
502
503 cof[k] = par[k];
504}
505
506
507/** Read block switching field if necessary and set actual block sizes.
508 * Also assure that the block sizes of the last frame correspond to the
509 * actual number of samples.
510 */
511static void get_block_sizes(ALSDecContext *ctx, unsigned int *div_blocks,
512 uint32_t *bs_info)
513{
514 ALSSpecificConfig *sconf = &ctx->sconf;
515 GetBitContext *gb = &ctx->gb;
516 unsigned int *ptr_div_blocks = div_blocks;
517 unsigned int b;
518
519 if (sconf->block_switching) {
520 unsigned int bs_info_len = 1 << (sconf->block_switching + 2);
521 *bs_info = get_bits_long(gb, bs_info_len);
522 *bs_info <<= (32 - bs_info_len);
523 }
524
525 ctx->num_blocks = 0;
526 parse_bs_info(*bs_info, 0, 0, &ptr_div_blocks, &ctx->num_blocks);
527
528 // The last frame may have an overdetermined block structure given in
529 // the bitstream. In that case the defined block structure would need
530 // more samples than available to be consistent.
531 // The block structure is actually used but the block sizes are adapted
532 // to fit the actual number of available samples.
533 // Example: 5 samples, 2nd level block sizes: 2 2 2 2.
534 // This results in the actual block sizes: 2 2 1 0.
535 // This is not specified in 14496-3 but actually done by the reference
536 // codec RM22 revision 2.
537 // This appears to happen in case of an odd number of samples in the last
538 // frame which is actually not allowed by the block length switching part
539 // of 14496-3.
540 // The ALS conformance files feature an odd number of samples in the last
541 // frame.
542
543 for (b = 0; b < ctx->num_blocks; b++)
544 div_blocks[b] = ctx->sconf.frame_length >> div_blocks[b];
545
546 if (ctx->cur_frame_length != ctx->sconf.frame_length) {
547 unsigned int remaining = ctx->cur_frame_length;
548
549 for (b = 0; b < ctx->num_blocks; b++) {
550 if (remaining <= div_blocks[b]) {
551 div_blocks[b] = remaining;
552 ctx->num_blocks = b + 1;
553 break;
554 }
555
556 remaining -= div_blocks[b];
557 }
558 }
559}
560
561
562/** Read the block data for a constant block
563 */
564static int read_const_block_data(ALSDecContext *ctx, ALSBlockData *bd)
565{
566 ALSSpecificConfig *sconf = &ctx->sconf;
567 AVCodecContext *avctx = ctx->avctx;
568 GetBitContext *gb = &ctx->gb;
569
570 if (bd->block_length <= 0)
571 return AVERROR_INVALIDDATA;
572
573 *bd->raw_samples = 0;
574 *bd->const_block = get_bits1(gb); // 1 = constant value, 0 = zero block (silence)
575 bd->js_blocks = get_bits1(gb);
576
577 // skip 5 reserved bits
578 skip_bits(gb, 5);
579
580 if (*bd->const_block) {
581 unsigned int const_val_bits = sconf->floating ? 24 : avctx->bits_per_raw_sample;
582 *bd->raw_samples = get_sbits_long(gb, const_val_bits);
583 }
584
585 // ensure constant block decoding by reusing this field
586 *bd->const_block = 1;
587
588 return 0;
589}
590
591
592/** Decode the block data for a constant block
593 */
594static void decode_const_block_data(ALSDecContext *ctx, ALSBlockData *bd)
595{
596 int smp = bd->block_length - 1;
597 int32_t val = *bd->raw_samples;
598 int32_t *dst = bd->raw_samples + 1;
599
600 // write raw samples into buffer
601 for (; smp; smp--)
602 *dst++ = val;
603}
604
605
606/** Read the block data for a non-constant block
607 */
608static int read_var_block_data(ALSDecContext *ctx, ALSBlockData *bd)
609{
610 ALSSpecificConfig *sconf = &ctx->sconf;
611 AVCodecContext *avctx = ctx->avctx;
612 GetBitContext *gb = &ctx->gb;
613 unsigned int k;
614 unsigned int s[8];
615 unsigned int sx[8];
616 unsigned int sub_blocks, log2_sub_blocks, sb_length;
617 unsigned int start = 0;
618 unsigned int opt_order;
619 int sb;
620 int32_t *quant_cof = bd->quant_cof;
621 int32_t *current_res;
622
623
624 // ensure variable block decoding by reusing this field
625 *bd->const_block = 0;
626
627 *bd->opt_order = 1;
628 bd->js_blocks = get_bits1(gb);
629
630 opt_order = *bd->opt_order;
631
632 // determine the number of subblocks for entropy decoding
633 if (!sconf->bgmc && !sconf->sb_part) {
634 log2_sub_blocks = 0;
635 } else {
636 if (sconf->bgmc && sconf->sb_part)
637 log2_sub_blocks = get_bits(gb, 2);
638 else
639 log2_sub_blocks = 2 * get_bits1(gb);
640 }
641
642 sub_blocks = 1 << log2_sub_blocks;
643
644 // do not continue in case of a damaged stream since
645 // block_length must be evenly divisible by sub_blocks
646 if (bd->block_length & (sub_blocks - 1)) {
647 av_log(avctx, AV_LOG_WARNING,
648 "Block length is not evenly divisible by the number of subblocks.\n");
649 return AVERROR_INVALIDDATA;
650 }
651
652 sb_length = bd->block_length >> log2_sub_blocks;
653
654 if (sconf->bgmc) {
655 s[0] = get_bits(gb, 8 + (sconf->resolution > 1));
656 for (k = 1; k < sub_blocks; k++)
657 s[k] = s[k - 1] + decode_rice(gb, 2);
658
659 for (k = 0; k < sub_blocks; k++) {
660 sx[k] = s[k] & 0x0F;
661 s [k] >>= 4;
662 }
663 } else {
664 s[0] = get_bits(gb, 4 + (sconf->resolution > 1));
665 for (k = 1; k < sub_blocks; k++)
666 s[k] = s[k - 1] + decode_rice(gb, 0);
667 }
668 for (k = 1; k < sub_blocks; k++)
669 if (s[k] > 32) {
670 av_log(avctx, AV_LOG_ERROR, "k invalid for rice code.\n");
671 return AVERROR_INVALIDDATA;
672 }
673
674 if (get_bits1(gb))
675 *bd->shift_lsbs = get_bits(gb, 4) + 1;
676
677 *bd->store_prev_samples = (bd->js_blocks && bd->raw_other) || *bd->shift_lsbs;
678
679
680 if (!sconf->rlslms) {
681 if (sconf->adapt_order) {
682 int opt_order_length = av_ceil_log2(av_clip((bd->block_length >> 3) - 1,
683 2, sconf->max_order + 1));
684 *bd->opt_order = get_bits(gb, opt_order_length);
685 if (*bd->opt_order > sconf->max_order) {
686 *bd->opt_order = sconf->max_order;
687 av_log(avctx, AV_LOG_ERROR, "Predictor order too large.\n");
688 return AVERROR_INVALIDDATA;
689 }
690 } else {
691 *bd->opt_order = sconf->max_order;
692 }
693 if (*bd->opt_order > bd->block_length) {
694 *bd->opt_order = bd->block_length;
695 av_log(avctx, AV_LOG_ERROR, "Predictor order too large.\n");
696 return AVERROR_INVALIDDATA;
697 }
698 opt_order = *bd->opt_order;
699
700 if (opt_order) {
701 int add_base;
702
703 if (sconf->coef_table == 3) {
704 add_base = 0x7F;
705
706 // read coefficient 0
707 quant_cof[0] = 32 * parcor_scaled_values[get_bits(gb, 7)];
708
709 // read coefficient 1
710 if (opt_order > 1)
711 quant_cof[1] = -32 * parcor_scaled_values[get_bits(gb, 7)];
712
713 // read coefficients 2 to opt_order
714 for (k = 2; k < opt_order; k++)
715 quant_cof[k] = get_bits(gb, 7);
716 } else {
717 int k_max;
718 add_base = 1;
719
720 // read coefficient 0 to 19
721 k_max = FFMIN(opt_order, 20);
722 for (k = 0; k < k_max; k++) {
723 int rice_param = parcor_rice_table[sconf->coef_table][k][1];
724 int offset = parcor_rice_table[sconf->coef_table][k][0];
725 quant_cof[k] = decode_rice(gb, rice_param) + offset;
726 if (quant_cof[k] < -64 || quant_cof[k] > 63) {
727 av_log(avctx, AV_LOG_ERROR,
728 "quant_cof %"PRIu32" is out of range.\n",
729 quant_cof[k]);
730 return AVERROR_INVALIDDATA;
731 }
732 }
733
734 // read coefficients 20 to 126
735 k_max = FFMIN(opt_order, 127);
736 for (; k < k_max; k++)
737 quant_cof[k] = decode_rice(gb, 2) + (k & 1);
738
739 // read coefficients 127 to opt_order
740 for (; k < opt_order; k++)
741 quant_cof[k] = decode_rice(gb, 1);
742
743 quant_cof[0] = 32 * parcor_scaled_values[quant_cof[0] + 64];
744
745 if (opt_order > 1)
746 quant_cof[1] = -32 * parcor_scaled_values[quant_cof[1] + 64];
747 }
748
749 for (k = 2; k < opt_order; k++)
750 quant_cof[k] = (quant_cof[k] << 14) + (add_base << 13);
751 }
752 }
753
754 // read LTP gain and lag values
755 if (sconf->long_term_prediction) {
756 *bd->use_ltp = get_bits1(gb);
757
758 if (*bd->use_ltp) {
759 int r, c;
760
761 bd->ltp_gain[0] = decode_rice(gb, 1) << 3;
762 bd->ltp_gain[1] = decode_rice(gb, 2) << 3;
763
764 r = get_unary(gb, 0, 3);
765 c = get_bits(gb, 2);
766 bd->ltp_gain[2] = ltp_gain_values[r][c];
767
768 bd->ltp_gain[3] = decode_rice(gb, 2) << 3;
769 bd->ltp_gain[4] = decode_rice(gb, 1) << 3;
770
771 *bd->ltp_lag = get_bits(gb, ctx->ltp_lag_length);
772 *bd->ltp_lag += FFMAX(4, opt_order + 1);
773 }
774 }
775
776 // read first value and residuals in case of a random access block
777 if (bd->ra_block) {
778 if (opt_order)
779 bd->raw_samples[0] = decode_rice(gb, avctx->bits_per_raw_sample - 4);
780 if (opt_order > 1)
781 bd->raw_samples[1] = decode_rice(gb, FFMIN(s[0] + 3, ctx->s_max));
782 if (opt_order > 2)
783 bd->raw_samples[2] = decode_rice(gb, FFMIN(s[0] + 1, ctx->s_max));
784
785 start = FFMIN(opt_order, 3);
786 }
787
788 // read all residuals
789 if (sconf->bgmc) {
790 int delta[8];
791 unsigned int k [8];
792 unsigned int b = av_clip((av_ceil_log2(bd->block_length) - 3) >> 1, 0, 5);
793
794 // read most significant bits
795 unsigned int high;
796 unsigned int low;
797 unsigned int value;
798
799 ff_bgmc_decode_init(gb, &high, &low, &value);
800
801 current_res = bd->raw_samples + start;
802
803 for (sb = 0; sb < sub_blocks; sb++) {
804 unsigned int sb_len = sb_length - (sb ? 0 : start);
805
806 k [sb] = s[sb] > b ? s[sb] - b : 0;
807 delta[sb] = 5 - s[sb] + k[sb];
808
809 ff_bgmc_decode(gb, sb_len, current_res,
810 delta[sb], sx[sb], &high, &low, &value, ctx->bgmc_lut, ctx->bgmc_lut_status);
811
812 current_res += sb_len;
813 }
814
815 ff_bgmc_decode_end(gb);
816
817
818 // read least significant bits and tails
819 current_res = bd->raw_samples + start;
820
821 for (sb = 0; sb < sub_blocks; sb++, start = 0) {
822 unsigned int cur_tail_code = tail_code[sx[sb]][delta[sb]];
823 unsigned int cur_k = k[sb];
824 unsigned int cur_s = s[sb];
825
826 for (; start < sb_length; start++) {
827 int32_t res = *current_res;
828
829 if (res == cur_tail_code) {
830 unsigned int max_msb = (2 + (sx[sb] > 2) + (sx[sb] > 10))
831 << (5 - delta[sb]);
832
833 res = decode_rice(gb, cur_s);
834
835 if (res >= 0) {
836 res += (max_msb ) << cur_k;
837 } else {
838 res -= (max_msb - 1) << cur_k;
839 }
840 } else {
841 if (res > cur_tail_code)
842 res--;
843
844 if (res & 1)
845 res = -res;
846
847 res >>= 1;
848
849 if (cur_k) {
850 res <<= cur_k;
851 res |= get_bits_long(gb, cur_k);
852 }
853 }
854
855 *current_res++ = res;
856 }
857 }
858 } else {
859 current_res = bd->raw_samples + start;
860
861 for (sb = 0; sb < sub_blocks; sb++, start = 0)
862 for (; start < sb_length; start++)
863 *current_res++ = decode_rice(gb, s[sb]);
864 }
865
866 if (!sconf->mc_coding || ctx->js_switch)
867 align_get_bits(gb);
868
869 return 0;
870}
871
872
873/** Decode the block data for a non-constant block
874 */
875static int decode_var_block_data(ALSDecContext *ctx, ALSBlockData *bd)
876{
877 ALSSpecificConfig *sconf = &ctx->sconf;
878 unsigned int block_length = bd->block_length;
879 unsigned int smp = 0;
880 unsigned int k;
881 int opt_order = *bd->opt_order;
882 int sb;
883 int64_t y;
884 int32_t *quant_cof = bd->quant_cof;
885 int32_t *lpc_cof = bd->lpc_cof;
886 int32_t *raw_samples = bd->raw_samples;
887 int32_t *raw_samples_end = bd->raw_samples + bd->block_length;
888 int32_t *lpc_cof_reversed = ctx->lpc_cof_reversed_buffer;
889
890 // reverse long-term prediction
891 if (*bd->use_ltp) {
892 int ltp_smp;
893
894 for (ltp_smp = FFMAX(*bd->ltp_lag - 2, 0); ltp_smp < block_length; ltp_smp++) {
895 int center = ltp_smp - *bd->ltp_lag;
896 int begin = FFMAX(0, center - 2);
897 int end = center + 3;
898 int tab = 5 - (end - begin);
899 int base;
900
901 y = 1 << 6;
902
903 for (base = begin; base < end; base++, tab++)
904 y += MUL64(bd->ltp_gain[tab], raw_samples[base]);
905
906 raw_samples[ltp_smp] += y >> 7;
907 }
908 }
909
910 // reconstruct all samples from residuals
911 if (bd->ra_block) {
912 for (smp = 0; smp < opt_order; smp++) {
913 y = 1 << 19;
914
915 for (sb = 0; sb < smp; sb++)
916 y += MUL64(lpc_cof[sb], raw_samples[-(sb + 1)]);
917
918 *raw_samples++ -= y >> 20;
919 parcor_to_lpc(smp, quant_cof, lpc_cof);
920 }
921 } else {
922 for (k = 0; k < opt_order; k++)
923 parcor_to_lpc(k, quant_cof, lpc_cof);
924
925 // store previous samples in case that they have to be altered
926 if (*bd->store_prev_samples)
927 memcpy(bd->prev_raw_samples, raw_samples - sconf->max_order,
928 sizeof(*bd->prev_raw_samples) * sconf->max_order);
929
930 // reconstruct difference signal for prediction (joint-stereo)
931 if (bd->js_blocks && bd->raw_other) {
932 int32_t *left, *right;
933
934 if (bd->raw_other > raw_samples) { // D = R - L
935 left = raw_samples;
936 right = bd->raw_other;
937 } else { // D = R - L
938 left = bd->raw_other;
939 right = raw_samples;
940 }
941
942 for (sb = -1; sb >= -sconf->max_order; sb--)
943 raw_samples[sb] = right[sb] - left[sb];
944 }
945
946 // reconstruct shifted signal
947 if (*bd->shift_lsbs)
948 for (sb = -1; sb >= -sconf->max_order; sb--)
949 raw_samples[sb] >>= *bd->shift_lsbs;
950 }
951
952 // reverse linear prediction coefficients for efficiency
953 lpc_cof = lpc_cof + opt_order;
954
955 for (sb = 0; sb < opt_order; sb++)
956 lpc_cof_reversed[sb] = lpc_cof[-(sb + 1)];
957
958 // reconstruct raw samples
959 raw_samples = bd->raw_samples + smp;
960 lpc_cof = lpc_cof_reversed + opt_order;
961
962 for (; raw_samples < raw_samples_end; raw_samples++) {
963 y = 1 << 19;
964
965 for (sb = -opt_order; sb < 0; sb++)
966 y += MUL64(lpc_cof[sb], raw_samples[sb]);
967
968 *raw_samples -= y >> 20;
969 }
970
971 raw_samples = bd->raw_samples;
972
973 // restore previous samples in case that they have been altered
974 if (*bd->store_prev_samples)
975 memcpy(raw_samples - sconf->max_order, bd->prev_raw_samples,
976 sizeof(*raw_samples) * sconf->max_order);
977
978 return 0;
979}
980
981
982/** Read the block data.
983 */
984static int read_block(ALSDecContext *ctx, ALSBlockData *bd)
985{
986 int ret;
987 GetBitContext *gb = &ctx->gb;
988
989 *bd->shift_lsbs = 0;
990 // read block type flag and read the samples accordingly
991 if (get_bits1(gb)) {
992 ret = read_var_block_data(ctx, bd);
993 } else {
994 ret = read_const_block_data(ctx, bd);
995 }
996
997 return ret;
998}
999
1000
1001/** Decode the block data.
1002 */
1003static int decode_block(ALSDecContext *ctx, ALSBlockData *bd)
1004{
1005 unsigned int smp;
1006 int ret = 0;
1007
1008 // read block type flag and read the samples accordingly
1009 if (*bd->const_block)
1010 decode_const_block_data(ctx, bd);
1011 else
1012 ret = decode_var_block_data(ctx, bd); // always return 0
1013
1014 if (ret < 0)
1015 return ret;
1016
1017 // TODO: read RLSLMS extension data
1018
1019 if (*bd->shift_lsbs)
1020 for (smp = 0; smp < bd->block_length; smp++)
1021 bd->raw_samples[smp] <<= *bd->shift_lsbs;
1022
1023 return 0;
1024}
1025
1026
1027/** Read and decode block data successively.
1028 */
1029static int read_decode_block(ALSDecContext *ctx, ALSBlockData *bd)
1030{
1031 int ret;
1032
1033 if ((ret = read_block(ctx, bd)) < 0)
1034 return ret;
1035
1036 return decode_block(ctx, bd);
1037}
1038
1039
1040/** Compute the number of samples left to decode for the current frame and
1041 * sets these samples to zero.
1042 */
1043static void zero_remaining(unsigned int b, unsigned int b_max,
1044 const unsigned int *div_blocks, int32_t *buf)
1045{
1046 unsigned int count = 0;
1047
1048 while (b < b_max)
1049 count += div_blocks[b++];
1050
1051 if (count)
1052 memset(buf, 0, sizeof(*buf) * count);
1053}
1054
1055
1056/** Decode blocks independently.
1057 */
1058static int decode_blocks_ind(ALSDecContext *ctx, unsigned int ra_frame,
1059 unsigned int c, const unsigned int *div_blocks,
1060 unsigned int *js_blocks)
1061{
1062 int ret;
1063 unsigned int b;
1064 ALSBlockData bd = { 0 };
1065
1066 bd.ra_block = ra_frame;
1067 bd.const_block = ctx->const_block;
1068 bd.shift_lsbs = ctx->shift_lsbs;
1069 bd.opt_order = ctx->opt_order;
1070 bd.store_prev_samples = ctx->store_prev_samples;
1071 bd.use_ltp = ctx->use_ltp;
1072 bd.ltp_lag = ctx->ltp_lag;
1073 bd.ltp_gain = ctx->ltp_gain[0];
1074 bd.quant_cof = ctx->quant_cof[0];
1075 bd.lpc_cof = ctx->lpc_cof[0];
1076 bd.prev_raw_samples = ctx->prev_raw_samples;
1077 bd.raw_samples = ctx->raw_samples[c];
1078
1079
1080 for (b = 0; b < ctx->num_blocks; b++) {
1081 bd.block_length = div_blocks[b];
1082
1083 if ((ret = read_decode_block(ctx, &bd)) < 0) {
1084 // damaged block, write zero for the rest of the frame
1085 zero_remaining(b, ctx->num_blocks, div_blocks, bd.raw_samples);
1086 return ret;
1087 }
1088 bd.raw_samples += div_blocks[b];
1089 bd.ra_block = 0;
1090 }
1091
1092 return 0;
1093}
1094
1095
1096/** Decode blocks dependently.
1097 */
1098static int decode_blocks(ALSDecContext *ctx, unsigned int ra_frame,
1099 unsigned int c, const unsigned int *div_blocks,
1100 unsigned int *js_blocks)
1101{
1102 ALSSpecificConfig *sconf = &ctx->sconf;
1103 unsigned int offset = 0;
1104 unsigned int b;
1105 int ret;
1106 ALSBlockData bd[2] = { { 0 } };
1107
1108 bd[0].ra_block = ra_frame;
1109 bd[0].const_block = ctx->const_block;
1110 bd[0].shift_lsbs = ctx->shift_lsbs;
1111 bd[0].opt_order = ctx->opt_order;
1112 bd[0].store_prev_samples = ctx->store_prev_samples;
1113 bd[0].use_ltp = ctx->use_ltp;
1114 bd[0].ltp_lag = ctx->ltp_lag;
1115 bd[0].ltp_gain = ctx->ltp_gain[0];
1116 bd[0].quant_cof = ctx->quant_cof[0];
1117 bd[0].lpc_cof = ctx->lpc_cof[0];
1118 bd[0].prev_raw_samples = ctx->prev_raw_samples;
1119 bd[0].js_blocks = *js_blocks;
1120
1121 bd[1].ra_block = ra_frame;
1122 bd[1].const_block = ctx->const_block;
1123 bd[1].shift_lsbs = ctx->shift_lsbs;
1124 bd[1].opt_order = ctx->opt_order;
1125 bd[1].store_prev_samples = ctx->store_prev_samples;
1126 bd[1].use_ltp = ctx->use_ltp;
1127 bd[1].ltp_lag = ctx->ltp_lag;
1128 bd[1].ltp_gain = ctx->ltp_gain[0];
1129 bd[1].quant_cof = ctx->quant_cof[0];
1130 bd[1].lpc_cof = ctx->lpc_cof[0];
1131 bd[1].prev_raw_samples = ctx->prev_raw_samples;
1132 bd[1].js_blocks = *(js_blocks + 1);
1133
1134 // decode all blocks
1135 for (b = 0; b < ctx->num_blocks; b++) {
1136 unsigned int s;
1137
1138 bd[0].block_length = div_blocks[b];
1139 bd[1].block_length = div_blocks[b];
1140
1141 bd[0].raw_samples = ctx->raw_samples[c ] + offset;
1142 bd[1].raw_samples = ctx->raw_samples[c + 1] + offset;
1143
1144 bd[0].raw_other = bd[1].raw_samples;
1145 bd[1].raw_other = bd[0].raw_samples;
1146
1147 if ((ret = read_decode_block(ctx, &bd[0])) < 0 ||
1148 (ret = read_decode_block(ctx, &bd[1])) < 0)
1149 goto fail;
1150
1151 // reconstruct joint-stereo blocks
1152 if (bd[0].js_blocks) {
1153 if (bd[1].js_blocks)
1154 av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel pair.\n");
1155
1156 for (s = 0; s < div_blocks[b]; s++)
1157 bd[0].raw_samples[s] = bd[1].raw_samples[s] - bd[0].raw_samples[s];
1158 } else if (bd[1].js_blocks) {
1159 for (s = 0; s < div_blocks[b]; s++)
1160 bd[1].raw_samples[s] = bd[1].raw_samples[s] + bd[0].raw_samples[s];
1161 }
1162
1163 offset += div_blocks[b];
1164 bd[0].ra_block = 0;
1165 bd[1].ra_block = 0;
1166 }
1167
1168 // store carryover raw samples,
1169 // the others channel raw samples are stored by the calling function.
1170 memmove(ctx->raw_samples[c] - sconf->max_order,
1171 ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
1172 sizeof(*ctx->raw_samples[c]) * sconf->max_order);
1173
1174 return 0;
1175fail:
1176 // damaged block, write zero for the rest of the frame
1177 zero_remaining(b, ctx->num_blocks, div_blocks, bd[0].raw_samples);
1178 zero_remaining(b, ctx->num_blocks, div_blocks, bd[1].raw_samples);
1179 return ret;
1180}
1181
1182static inline int als_weighting(GetBitContext *gb, int k, int off)
1183{
1184 int idx = av_clip(decode_rice(gb, k) + off,
1185 0, FF_ARRAY_ELEMS(mcc_weightings) - 1);
1186 return mcc_weightings[idx];
1187}
1188
1189/** Read the channel data.
1190 */
1191static int read_channel_data(ALSDecContext *ctx, ALSChannelData *cd, int c)
1192{
1193 GetBitContext *gb = &ctx->gb;
1194 ALSChannelData *current = cd;
1195 unsigned int channels = ctx->avctx->channels;
1196 int entries = 0;
1197
1198 while (entries < channels && !(current->stop_flag = get_bits1(gb))) {
1199 current->master_channel = get_bits_long(gb, av_ceil_log2(channels));
1200
1201 if (current->master_channel >= channels) {
1202 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid master channel.\n");
1203 return AVERROR_INVALIDDATA;
1204 }
1205
1206 if (current->master_channel != c) {
1207 current->time_diff_flag = get_bits1(gb);
1208 current->weighting[0] = als_weighting(gb, 1, 16);
1209 current->weighting[1] = als_weighting(gb, 2, 14);
1210 current->weighting[2] = als_weighting(gb, 1, 16);
1211
1212 if (current->time_diff_flag) {
1213 current->weighting[3] = als_weighting(gb, 1, 16);
1214 current->weighting[4] = als_weighting(gb, 1, 16);
1215 current->weighting[5] = als_weighting(gb, 1, 16);
1216
1217 current->time_diff_sign = get_bits1(gb);
1218 current->time_diff_index = get_bits(gb, ctx->ltp_lag_length - 3) + 3;
1219 }
1220 }
1221
1222 current++;
1223 entries++;
1224 }
1225
1226 if (entries == channels) {
1227 av_log(ctx->avctx, AV_LOG_ERROR, "Damaged channel data.\n");
1228 return AVERROR_INVALIDDATA;
1229 }
1230
1231 align_get_bits(gb);
1232 return 0;
1233}
1234
1235
1236/** Recursively reverts the inter-channel correlation for a block.
1237 */
1238static int revert_channel_correlation(ALSDecContext *ctx, ALSBlockData *bd,
1239 ALSChannelData **cd, int *reverted,
1240 unsigned int offset, int c)
1241{
1242 ALSChannelData *ch = cd[c];
1243 unsigned int dep = 0;
1244 unsigned int channels = ctx->avctx->channels;
1245
1246 if (reverted[c])
1247 return 0;
1248
1249 reverted[c] = 1;
1250
1251 while (dep < channels && !ch[dep].stop_flag) {
1252 revert_channel_correlation(ctx, bd, cd, reverted, offset,
1253 ch[dep].master_channel);
1254
1255 dep++;
1256 }
1257
1258 if (dep == channels) {
1259 av_log(ctx->avctx, AV_LOG_WARNING, "Invalid channel correlation.\n");
1260 return AVERROR_INVALIDDATA;
1261 }
1262
1263 bd->const_block = ctx->const_block + c;
1264 bd->shift_lsbs = ctx->shift_lsbs + c;
1265 bd->opt_order = ctx->opt_order + c;
1266 bd->store_prev_samples = ctx->store_prev_samples + c;
1267 bd->use_ltp = ctx->use_ltp + c;
1268 bd->ltp_lag = ctx->ltp_lag + c;
1269 bd->ltp_gain = ctx->ltp_gain[c];
1270 bd->lpc_cof = ctx->lpc_cof[c];
1271 bd->quant_cof = ctx->quant_cof[c];
1272 bd->raw_samples = ctx->raw_samples[c] + offset;
1273
1274 for (dep = 0; !ch[dep].stop_flag; dep++) {
1275 unsigned int smp;
1276 unsigned int begin = 1;
1277 unsigned int end = bd->block_length - 1;
1278 int64_t y;
1279 int32_t *master = ctx->raw_samples[ch[dep].master_channel] + offset;
1280
1281 if (ch[dep].master_channel == c)
1282 continue;
1283
1284 if (ch[dep].time_diff_flag) {
1285 int t = ch[dep].time_diff_index;
1286
1287 if (ch[dep].time_diff_sign) {
1288 t = -t;
1289 begin -= t;
1290 } else {
1291 end -= t;
1292 }
1293
1294 for (smp = begin; smp < end; smp++) {
1295 y = (1 << 6) +
1296 MUL64(ch[dep].weighting[0], master[smp - 1 ]) +
1297 MUL64(ch[dep].weighting[1], master[smp ]) +
1298 MUL64(ch[dep].weighting[2], master[smp + 1 ]) +
1299 MUL64(ch[dep].weighting[3], master[smp - 1 + t]) +
1300 MUL64(ch[dep].weighting[4], master[smp + t]) +
1301 MUL64(ch[dep].weighting[5], master[smp + 1 + t]);
1302
1303 bd->raw_samples[smp] += y >> 7;
1304 }
1305 } else {
1306 for (smp = begin; smp < end; smp++) {
1307 y = (1 << 6) +
1308 MUL64(ch[dep].weighting[0], master[smp - 1]) +
1309 MUL64(ch[dep].weighting[1], master[smp ]) +
1310 MUL64(ch[dep].weighting[2], master[smp + 1]);
1311
1312 bd->raw_samples[smp] += y >> 7;
1313 }
1314 }
1315 }
1316
1317 return 0;
1318}
1319
1320
1321/** Read the frame data.
1322 */
1323static int read_frame_data(ALSDecContext *ctx, unsigned int ra_frame)
1324{
1325 ALSSpecificConfig *sconf = &ctx->sconf;
1326 AVCodecContext *avctx = ctx->avctx;
1327 GetBitContext *gb = &ctx->gb;
1328 unsigned int div_blocks[32]; ///< block sizes.
1329 unsigned int c;
1330 unsigned int js_blocks[2];
1331 uint32_t bs_info = 0;
1332 int ret;
1333
1334 // skip the size of the ra unit if present in the frame
1335 if (sconf->ra_flag == RA_FLAG_FRAMES && ra_frame)
1336 skip_bits_long(gb, 32);
1337
1338 if (sconf->mc_coding && sconf->joint_stereo) {
1339 ctx->js_switch = get_bits1(gb);
1340 align_get_bits(gb);
1341 }
1342
1343 if (!sconf->mc_coding || ctx->js_switch) {
1344 int independent_bs = !sconf->joint_stereo;
1345
1346 for (c = 0; c < avctx->channels; c++) {
1347 js_blocks[0] = 0;
1348 js_blocks[1] = 0;
1349
1350 get_block_sizes(ctx, div_blocks, &bs_info);
1351
1352 // if joint_stereo and block_switching is set, independent decoding
1353 // is signaled via the first bit of bs_info
1354 if (sconf->joint_stereo && sconf->block_switching)
1355 if (bs_info >> 31)
1356 independent_bs = 2;
1357
1358 // if this is the last channel, it has to be decoded independently
1359 if (c == avctx->channels - 1)
1360 independent_bs = 1;
1361
1362 if (independent_bs) {
1363 ret = decode_blocks_ind(ctx, ra_frame, c,
1364 div_blocks, js_blocks);
1365 if (ret < 0)
1366 return ret;
1367 independent_bs--;
1368 } else {
1369 ret = decode_blocks(ctx, ra_frame, c, div_blocks, js_blocks);
1370 if (ret < 0)
1371 return ret;
1372
1373 c++;
1374 }
1375
1376 // store carryover raw samples
1377 memmove(ctx->raw_samples[c] - sconf->max_order,
1378 ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
1379 sizeof(*ctx->raw_samples[c]) * sconf->max_order);
1380 }
1381 } else { // multi-channel coding
1382 ALSBlockData bd = { 0 };
1383 int b, ret;
1384 int *reverted_channels = ctx->reverted_channels;
1385 unsigned int offset = 0;
1386
1387 for (c = 0; c < avctx->channels; c++)
1388 if (ctx->chan_data[c] < ctx->chan_data_buffer) {
1389 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid channel data.\n");
1390 return AVERROR_INVALIDDATA;
1391 }
1392
1393 memset(reverted_channels, 0, sizeof(*reverted_channels) * avctx->channels);
1394
1395 bd.ra_block = ra_frame;
1396 bd.prev_raw_samples = ctx->prev_raw_samples;
1397
1398 get_block_sizes(ctx, div_blocks, &bs_info);
1399
1400 for (b = 0; b < ctx->num_blocks; b++) {
1401 bd.block_length = div_blocks[b];
1402 if (bd.block_length <= 0) {
1403 av_log(ctx->avctx, AV_LOG_WARNING,
1404 "Invalid block length %u in channel data!\n",
1405 bd.block_length);
1406 continue;
1407 }
1408
1409 for (c = 0; c < avctx->channels; c++) {
1410 bd.const_block = ctx->const_block + c;
1411 bd.shift_lsbs = ctx->shift_lsbs + c;
1412 bd.opt_order = ctx->opt_order + c;
1413 bd.store_prev_samples = ctx->store_prev_samples + c;
1414 bd.use_ltp = ctx->use_ltp + c;
1415 bd.ltp_lag = ctx->ltp_lag + c;
1416 bd.ltp_gain = ctx->ltp_gain[c];
1417 bd.lpc_cof = ctx->lpc_cof[c];
1418 bd.quant_cof = ctx->quant_cof[c];
1419 bd.raw_samples = ctx->raw_samples[c] + offset;
1420 bd.raw_other = NULL;
1421
1422 if ((ret = read_block(ctx, &bd)) < 0)
1423 return ret;
1424 if ((ret = read_channel_data(ctx, ctx->chan_data[c], c)) < 0)
1425 return ret;
1426 }
1427
1428 for (c = 0; c < avctx->channels; c++) {
1429 ret = revert_channel_correlation(ctx, &bd, ctx->chan_data,
1430 reverted_channels, offset, c);
1431 if (ret < 0)
1432 return ret;
1433 }
1434 for (c = 0; c < avctx->channels; c++) {
1435 bd.const_block = ctx->const_block + c;
1436 bd.shift_lsbs = ctx->shift_lsbs + c;
1437 bd.opt_order = ctx->opt_order + c;
1438 bd.store_prev_samples = ctx->store_prev_samples + c;
1439 bd.use_ltp = ctx->use_ltp + c;
1440 bd.ltp_lag = ctx->ltp_lag + c;
1441 bd.ltp_gain = ctx->ltp_gain[c];
1442 bd.lpc_cof = ctx->lpc_cof[c];
1443 bd.quant_cof = ctx->quant_cof[c];
1444 bd.raw_samples = ctx->raw_samples[c] + offset;
1445
1446 if ((ret = decode_block(ctx, &bd)) < 0)
1447 return ret;
1448 }
1449
1450 memset(reverted_channels, 0, avctx->channels * sizeof(*reverted_channels));
1451 offset += div_blocks[b];
1452 bd.ra_block = 0;
1453 }
1454
1455 // store carryover raw samples
1456 for (c = 0; c < avctx->channels; c++)
1457 memmove(ctx->raw_samples[c] - sconf->max_order,
1458 ctx->raw_samples[c] - sconf->max_order + sconf->frame_length,
1459 sizeof(*ctx->raw_samples[c]) * sconf->max_order);
1460 }
1461
1462 // TODO: read_diff_float_data
1463
1464 return 0;
1465}
1466
1467
1468/** Decode an ALS frame.
1469 */
1470static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr,
1471 AVPacket *avpkt)
1472{
1473 ALSDecContext *ctx = avctx->priv_data;
1474 AVFrame *frame = data;
1475 ALSSpecificConfig *sconf = &ctx->sconf;
1476 const uint8_t *buffer = avpkt->data;
1477 int buffer_size = avpkt->size;
1478 int invalid_frame, ret;
1479 unsigned int c, sample, ra_frame, bytes_read, shift;
1480
1481 init_get_bits(&ctx->gb, buffer, buffer_size * 8);
1482
1483 // In the case that the distance between random access frames is set to zero
1484 // (sconf->ra_distance == 0) no frame is treated as a random access frame.
1485 // For the first frame, if prediction is used, all samples used from the
1486 // previous frame are assumed to be zero.
1487 ra_frame = sconf->ra_distance && !(ctx->frame_id % sconf->ra_distance);
1488
1489 // the last frame to decode might have a different length
1490 if (sconf->samples != 0xFFFFFFFF)
1491 ctx->cur_frame_length = FFMIN(sconf->samples - ctx->frame_id * (uint64_t) sconf->frame_length,
1492 sconf->frame_length);
1493 else
1494 ctx->cur_frame_length = sconf->frame_length;
1495
1496 // decode the frame data
1497 if ((invalid_frame = read_frame_data(ctx, ra_frame)) < 0)
1498 av_log(ctx->avctx, AV_LOG_WARNING,
1499 "Reading frame data failed. Skipping RA unit.\n");
1500
1501 ctx->frame_id++;
1502
1503 /* get output buffer */
1504 frame->nb_samples = ctx->cur_frame_length;
1505 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
1506 return ret;
1507
1508 // transform decoded frame into output format
1509 #define INTERLEAVE_OUTPUT(bps) \
1510 { \
1511 int##bps##_t *dest = (int##bps##_t*)frame->data[0]; \
1512 shift = bps - ctx->avctx->bits_per_raw_sample; \
1513 if (!ctx->cs_switch) { \
1514 for (sample = 0; sample < ctx->cur_frame_length; sample++) \
1515 for (c = 0; c < avctx->channels; c++) \
1516 *dest++ = ctx->raw_samples[c][sample] << shift; \
1517 } else { \
1518 for (sample = 0; sample < ctx->cur_frame_length; sample++) \
1519 for (c = 0; c < avctx->channels; c++) \
1520 *dest++ = ctx->raw_samples[sconf->chan_pos[c]][sample] << shift; \
1521 } \
1522 }
1523
1524 if (ctx->avctx->bits_per_raw_sample <= 16) {
1525 INTERLEAVE_OUTPUT(16)
1526 } else {
1527 INTERLEAVE_OUTPUT(32)
1528 }
1529
1530 // update CRC
1531 if (sconf->crc_enabled && (avctx->err_recognition & (AV_EF_CRCCHECK|AV_EF_CAREFUL))) {
1532 int swap = HAVE_BIGENDIAN != sconf->msb_first;
1533
1534 if (ctx->avctx->bits_per_raw_sample == 24) {
1535 int32_t *src = (int32_t *)frame->data[0];
1536
1537 for (sample = 0;
1538 sample < ctx->cur_frame_length * avctx->channels;
1539 sample++) {
1540 int32_t v;
1541
1542 if (swap)
1543 v = av_bswap32(src[sample]);
1544 else
1545 v = src[sample];
1546 if (!HAVE_BIGENDIAN)
1547 v >>= 8;
1548
1549 ctx->crc = av_crc(ctx->crc_table, ctx->crc, (uint8_t*)(&v), 3);
1550 }
1551 } else {
1552 uint8_t *crc_source;
1553
1554 if (swap) {
1555 if (ctx->avctx->bits_per_raw_sample <= 16) {
1556 int16_t *src = (int16_t*) frame->data[0];
1557 int16_t *dest = (int16_t*) ctx->crc_buffer;
1558 for (sample = 0;
1559 sample < ctx->cur_frame_length * avctx->channels;
1560 sample++)
1561 *dest++ = av_bswap16(src[sample]);
1562 } else {
1563 ctx->bdsp.bswap_buf((uint32_t *) ctx->crc_buffer,
1564 (uint32_t *) frame->data[0],
1565 ctx->cur_frame_length * avctx->channels);
1566 }
1567 crc_source = ctx->crc_buffer;
1568 } else {
1569 crc_source = frame->data[0];
1570 }
1571
1572 ctx->crc = av_crc(ctx->crc_table, ctx->crc, crc_source,
1573 ctx->cur_frame_length * avctx->channels *
1574 av_get_bytes_per_sample(avctx->sample_fmt));
1575 }
1576
1577
1578 // check CRC sums if this is the last frame
1579 if (ctx->cur_frame_length != sconf->frame_length &&
1580 ctx->crc_org != ctx->crc) {
1581 av_log(avctx, AV_LOG_ERROR, "CRC error.\n");
1582 if (avctx->err_recognition & AV_EF_EXPLODE)
1583 return AVERROR_INVALIDDATA;
1584 }
1585 }
1586
1587 *got_frame_ptr = 1;
1588
1589 bytes_read = invalid_frame ? buffer_size :
1590 (get_bits_count(&ctx->gb) + 7) >> 3;
1591
1592 return bytes_read;
1593}
1594
1595
1596/** Uninitialize the ALS decoder.
1597 */
1598static av_cold int decode_end(AVCodecContext *avctx)
1599{
1600 ALSDecContext *ctx = avctx->priv_data;
1601
1602 av_freep(&ctx->sconf.chan_pos);
1603
1604 ff_bgmc_end(&ctx->bgmc_lut, &ctx->bgmc_lut_status);
1605
1606 av_freep(&ctx->const_block);
1607 av_freep(&ctx->shift_lsbs);
1608 av_freep(&ctx->opt_order);
1609 av_freep(&ctx->store_prev_samples);
1610 av_freep(&ctx->use_ltp);
1611 av_freep(&ctx->ltp_lag);
1612 av_freep(&ctx->ltp_gain);
1613 av_freep(&ctx->ltp_gain_buffer);
1614 av_freep(&ctx->quant_cof);
1615 av_freep(&ctx->lpc_cof);
1616 av_freep(&ctx->quant_cof_buffer);
1617 av_freep(&ctx->lpc_cof_buffer);
1618 av_freep(&ctx->lpc_cof_reversed_buffer);
1619 av_freep(&ctx->prev_raw_samples);
1620 av_freep(&ctx->raw_samples);
1621 av_freep(&ctx->raw_buffer);
1622 av_freep(&ctx->chan_data);
1623 av_freep(&ctx->chan_data_buffer);
1624 av_freep(&ctx->reverted_channels);
1625 av_freep(&ctx->crc_buffer);
1626
1627 return 0;
1628}
1629
1630
1631/** Initialize the ALS decoder.
1632 */
1633static av_cold int decode_init(AVCodecContext *avctx)
1634{
1635 unsigned int c;
1636 unsigned int channel_size;
1637 int num_buffers, ret;
1638 ALSDecContext *ctx = avctx->priv_data;
1639 ALSSpecificConfig *sconf = &ctx->sconf;
1640 ctx->avctx = avctx;
1641
1642 if (!avctx->extradata) {
1643 av_log(avctx, AV_LOG_ERROR, "Missing required ALS extradata.\n");
1644 return AVERROR_INVALIDDATA;
1645 }
1646
1647 if ((ret = read_specific_config(ctx)) < 0) {
1648 av_log(avctx, AV_LOG_ERROR, "Reading ALSSpecificConfig failed.\n");
1649 goto fail;
1650 }
1651
1652 if ((ret = check_specific_config(ctx)) < 0) {
1653 goto fail;
1654 }
1655
1656 if (sconf->bgmc) {
1657 ret = ff_bgmc_init(avctx, &ctx->bgmc_lut, &ctx->bgmc_lut_status);
1658 if (ret < 0)
1659 goto fail;
1660 }
1661 if (sconf->floating) {
1662 avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
1663 avctx->bits_per_raw_sample = 32;
1664 } else {
1665 avctx->sample_fmt = sconf->resolution > 1
1666 ? AV_SAMPLE_FMT_S32 : AV_SAMPLE_FMT_S16;
1667 avctx->bits_per_raw_sample = (sconf->resolution + 1) * 8;
1668 }
1669
1670 // set maximum Rice parameter for progressive decoding based on resolution
1671 // This is not specified in 14496-3 but actually done by the reference
1672 // codec RM22 revision 2.
1673 ctx->s_max = sconf->resolution > 1 ? 31 : 15;
1674
1675 // set lag value for long-term prediction
1676 ctx->ltp_lag_length = 8 + (avctx->sample_rate >= 96000) +
1677 (avctx->sample_rate >= 192000);
1678
1679 // allocate quantized parcor coefficient buffer
1680 num_buffers = sconf->mc_coding ? avctx->channels : 1;
1681
1682 ctx->quant_cof = av_malloc(sizeof(*ctx->quant_cof) * num_buffers);
1683 ctx->lpc_cof = av_malloc(sizeof(*ctx->lpc_cof) * num_buffers);
1684 ctx->quant_cof_buffer = av_malloc(sizeof(*ctx->quant_cof_buffer) *
1685 num_buffers * sconf->max_order);
1686 ctx->lpc_cof_buffer = av_malloc(sizeof(*ctx->lpc_cof_buffer) *
1687 num_buffers * sconf->max_order);
1688 ctx->lpc_cof_reversed_buffer = av_malloc(sizeof(*ctx->lpc_cof_buffer) *
1689 sconf->max_order);
1690
1691 if (!ctx->quant_cof || !ctx->lpc_cof ||
1692 !ctx->quant_cof_buffer || !ctx->lpc_cof_buffer ||
1693 !ctx->lpc_cof_reversed_buffer) {
1694 av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
1695 ret = AVERROR(ENOMEM);
1696 goto fail;
1697 }
1698
1699 // assign quantized parcor coefficient buffers
1700 for (c = 0; c < num_buffers; c++) {
1701 ctx->quant_cof[c] = ctx->quant_cof_buffer + c * sconf->max_order;
1702 ctx->lpc_cof[c] = ctx->lpc_cof_buffer + c * sconf->max_order;
1703 }
1704
1705 // allocate and assign lag and gain data buffer for ltp mode
1706 ctx->const_block = av_malloc (sizeof(*ctx->const_block) * num_buffers);
1707 ctx->shift_lsbs = av_malloc (sizeof(*ctx->shift_lsbs) * num_buffers);
1708 ctx->opt_order = av_malloc (sizeof(*ctx->opt_order) * num_buffers);
1709 ctx->store_prev_samples = av_malloc(sizeof(*ctx->store_prev_samples) * num_buffers);
1710 ctx->use_ltp = av_mallocz(sizeof(*ctx->use_ltp) * num_buffers);
1711 ctx->ltp_lag = av_malloc (sizeof(*ctx->ltp_lag) * num_buffers);
1712 ctx->ltp_gain = av_malloc (sizeof(*ctx->ltp_gain) * num_buffers);
1713 ctx->ltp_gain_buffer = av_malloc (sizeof(*ctx->ltp_gain_buffer) *
1714 num_buffers * 5);
1715
1716 if (!ctx->const_block || !ctx->shift_lsbs ||
1717 !ctx->opt_order || !ctx->store_prev_samples ||
1718 !ctx->use_ltp || !ctx->ltp_lag ||
1719 !ctx->ltp_gain || !ctx->ltp_gain_buffer) {
1720 av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
1721 ret = AVERROR(ENOMEM);
1722 goto fail;
1723 }
1724
1725 for (c = 0; c < num_buffers; c++)
1726 ctx->ltp_gain[c] = ctx->ltp_gain_buffer + c * 5;
1727
1728 // allocate and assign channel data buffer for mcc mode
1729 if (sconf->mc_coding) {
1730 ctx->chan_data_buffer = av_malloc(sizeof(*ctx->chan_data_buffer) *
1731 num_buffers * num_buffers);
1732 ctx->chan_data = av_malloc(sizeof(*ctx->chan_data) *
1733 num_buffers);
1734 ctx->reverted_channels = av_malloc(sizeof(*ctx->reverted_channels) *
1735 num_buffers);
1736
1737 if (!ctx->chan_data_buffer || !ctx->chan_data || !ctx->reverted_channels) {
1738 av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
1739 ret = AVERROR(ENOMEM);
1740 goto fail;
1741 }
1742
1743 for (c = 0; c < num_buffers; c++)
1744 ctx->chan_data[c] = ctx->chan_data_buffer + c * num_buffers;
1745 } else {
1746 ctx->chan_data = NULL;
1747 ctx->chan_data_buffer = NULL;
1748 ctx->reverted_channels = NULL;
1749 }
1750
1751 channel_size = sconf->frame_length + sconf->max_order;
1752
1753 ctx->prev_raw_samples = av_malloc (sizeof(*ctx->prev_raw_samples) * sconf->max_order);
1754 ctx->raw_buffer = av_mallocz(sizeof(*ctx-> raw_buffer) * avctx->channels * channel_size);
1755 ctx->raw_samples = av_malloc (sizeof(*ctx-> raw_samples) * avctx->channels);
1756
1757 // allocate previous raw sample buffer
1758 if (!ctx->prev_raw_samples || !ctx->raw_buffer|| !ctx->raw_samples) {
1759 av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
1760 ret = AVERROR(ENOMEM);
1761 goto fail;
1762 }
1763
1764 // assign raw samples buffers
1765 ctx->raw_samples[0] = ctx->raw_buffer + sconf->max_order;
1766 for (c = 1; c < avctx->channels; c++)
1767 ctx->raw_samples[c] = ctx->raw_samples[c - 1] + channel_size;
1768
1769 // allocate crc buffer
1770 if (HAVE_BIGENDIAN != sconf->msb_first && sconf->crc_enabled &&
1771 (avctx->err_recognition & (AV_EF_CRCCHECK|AV_EF_CAREFUL))) {
1772 ctx->crc_buffer = av_malloc(sizeof(*ctx->crc_buffer) *
1773 ctx->cur_frame_length *
1774 avctx->channels *
1775 av_get_bytes_per_sample(avctx->sample_fmt));
1776 if (!ctx->crc_buffer) {
1777 av_log(avctx, AV_LOG_ERROR, "Allocating buffer memory failed.\n");
1778 ret = AVERROR(ENOMEM);
1779 goto fail;
1780 }
1781 }
1782
1783 ff_bswapdsp_init(&ctx->bdsp);
1784
1785 return 0;
1786
1787fail:
1788 decode_end(avctx);
1789 return ret;
1790}
1791
1792
1793/** Flush (reset) the frame ID after seeking.
1794 */
1795static av_cold void flush(AVCodecContext *avctx)
1796{
1797 ALSDecContext *ctx = avctx->priv_data;
1798
1799 ctx->frame_id = 0;
1800}
1801
1802
1803AVCodec ff_als_decoder = {
1804 .name = "als",
1805 .long_name = NULL_IF_CONFIG_SMALL("MPEG-4 Audio Lossless Coding (ALS)"),
1806 .type = AVMEDIA_TYPE_AUDIO,
1807 .id = AV_CODEC_ID_MP4ALS,
1808 .priv_data_size = sizeof(ALSDecContext),
1809 .init = decode_init,
1810 .close = decode_end,
1811 .decode = decode_frame,
1812 .flush = flush,
1813 .capabilities = CODEC_CAP_SUBFRAMES | CODEC_CAP_DR1,
1814};
ffmpeg Piment Noir Debian package repository