Looks like ZLib uncompress() cannot deal with some kinds of TIFF deflated data,
[libav.git] / libavcodec / ac3dec.c
CommitLineData
0ec2cc35
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1/*
2 * AC-3 Audio Decoder
bf09b550
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3 * This code was developed as part of Google Summer of Code 2006.
4 * E-AC-3 support was added as part of Google Summer of Code 2007.
032732d4 5 *
406792e7 6 * Copyright (c) 2006 Kartikey Mahendra BHATT (bhattkm at gmail dot com)
bf09b550 7 * Copyright (c) 2007-2008 Bartlomiej Wolowiec <bartek.wolowiec@gmail.com>
38c1a5c4 8 * Copyright (c) 2007 Justin Ruggles <justin.ruggles@gmail.com>
032732d4 9 *
0ec2cc35 10 * This file is part of FFmpeg.
2aa2c5c4 11 *
0ec2cc35 12 * FFmpeg is free software; you can redistribute it and/or
1754fe4d 13 * modify it under the terms of the GNU Lesser General Public
2aa2c5c4 14 * License as published by the Free Software Foundation; either
1754fe4d 15 * version 2.1 of the License, or (at your option) any later version.
2aa2c5c4 16 *
0ec2cc35 17 * FFmpeg is distributed in the hope that it will be useful,
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18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
1754fe4d 20 * Lesser General Public License for more details.
2aa2c5c4 21 *
1754fe4d 22 * You should have received a copy of the GNU Lesser General Public
0ec2cc35 23 * License along with FFmpeg; if not, write to the Free Software
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24 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25 */
26
27#include <stdio.h>
28#include <stddef.h>
29#include <math.h>
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30#include <string.h>
31
245976da 32#include "libavutil/crc.h"
dbbec0c2 33#include "internal.h"
11d6f38c 34#include "aac_ac3_parser.h"
9fc1ab72 35#include "ac3_parser.h"
58ce349f 36#include "ac3dec.h"
227322b8 37#include "ac3dec_data.h"
98a27a8a 38
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39/** Large enough for maximum possible frame size when the specification limit is ignored */
40#define AC3_FRAME_BUFFER_SIZE 32768
c33a1967 41
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42/**
43 * table for ungrouping 3 values in 7 bits.
44 * used for exponents and bap=2 mantissas
45 */
46static uint8_t ungroup_3_in_7_bits_tab[128][3];
967d397a 47
967d397a 48
5aefe3eb 49/** tables for ungrouping mantissas */
a4de6dd2
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50static int b1_mantissas[32][3];
51static int b2_mantissas[128][3];
52static int b3_mantissas[8];
53static int b4_mantissas[128][2];
54static int b5_mantissas[16];
967d397a 55
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56/**
57 * Quantization table: levels for symmetric. bits for asymmetric.
58 * reference: Table 7.18 Mapping of bap to Quantizer
59 */
e2270b4e 60static const uint8_t quantization_tab[16] = {
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61 0, 3, 5, 7, 11, 15,
62 5, 6, 7, 8, 9, 10, 11, 12, 14, 16
63};
967d397a 64
3357ff33 65/** dynamic range table. converts codes to scale factors. */
e2270b4e 66static float dynamic_range_tab[256];
3357ff33 67
5066f515 68/** Adjustments in dB gain */
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69#define LEVEL_PLUS_3DB 1.4142135623730950
70#define LEVEL_PLUS_1POINT5DB 1.1892071150027209
71#define LEVEL_MINUS_1POINT5DB 0.8408964152537145
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72#define LEVEL_MINUS_3DB 0.7071067811865476
73#define LEVEL_MINUS_4POINT5DB 0.5946035575013605
74#define LEVEL_MINUS_6DB 0.5000000000000000
3bbb0bf8 75#define LEVEL_MINUS_9DB 0.3535533905932738
967d397a 76#define LEVEL_ZERO 0.0000000000000000
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77#define LEVEL_ONE 1.0000000000000000
78
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79static const float gain_levels[9] = {
80 LEVEL_PLUS_3DB,
81 LEVEL_PLUS_1POINT5DB,
3bbb0bf8 82 LEVEL_ONE,
caf0fbc8 83 LEVEL_MINUS_1POINT5DB,
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84 LEVEL_MINUS_3DB,
85 LEVEL_MINUS_4POINT5DB,
86 LEVEL_MINUS_6DB,
caf0fbc8 87 LEVEL_ZERO,
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88 LEVEL_MINUS_9DB
89};
967d397a 90
3bbb0bf8 91/**
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92 * Table for center mix levels
93 * reference: Section 5.4.2.4 cmixlev
94 */
95static const uint8_t center_levels[4] = { 4, 5, 6, 5 };
96
97/**
98 * Table for surround mix levels
99 * reference: Section 5.4.2.5 surmixlev
100 */
101static const uint8_t surround_levels[4] = { 4, 6, 7, 6 };
102
103/**
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104 * Table for default stereo downmixing coefficients
105 * reference: Section 7.8.2 Downmixing Into Two Channels
106 */
107static const uint8_t ac3_default_coeffs[8][5][2] = {
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108 { { 2, 7 }, { 7, 2 }, },
109 { { 4, 4 }, },
110 { { 2, 7 }, { 7, 2 }, },
111 { { 2, 7 }, { 5, 5 }, { 7, 2 }, },
112 { { 2, 7 }, { 7, 2 }, { 6, 6 }, },
113 { { 2, 7 }, { 5, 5 }, { 7, 2 }, { 8, 8 }, },
114 { { 2, 7 }, { 7, 2 }, { 6, 7 }, { 7, 6 }, },
115 { { 2, 7 }, { 5, 5 }, { 7, 2 }, { 6, 7 }, { 7, 6 }, },
3bbb0bf8 116};
967d397a 117
2fbbd087 118/**
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119 * Symmetrical Dequantization
120 * reference: Section 7.3.3 Expansion of Mantissas for Symmetrical Quantization
121 * Tables 7.19 to 7.23
122 */
a4de6dd2 123static inline int
5aefe3eb 124symmetric_dequant(int code, int levels)
98a27a8a 125{
a4de6dd2 126 return ((code - (levels >> 1)) << 24) / levels;
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127}
128
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129/*
130 * Initialize tables at runtime.
131 */
98a6fff9 132static av_cold void ac3_tables_init(void)
00585845 133{
4415076f 134 int i;
98a27a8a 135
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136 /* generate table for ungrouping 3 values in 7 bits
137 reference: Section 7.1.3 Exponent Decoding */
138 for(i=0; i<128; i++) {
139 ungroup_3_in_7_bits_tab[i][0] = i / 25;
140 ungroup_3_in_7_bits_tab[i][1] = (i % 25) / 5;
141 ungroup_3_in_7_bits_tab[i][2] = (i % 25) % 5;
142 }
143
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144 /* generate grouped mantissa tables
145 reference: Section 7.3.5 Ungrouping of Mantissas */
146 for(i=0; i<32; i++) {
147 /* bap=1 mantissas */
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148 b1_mantissas[i][0] = symmetric_dequant(ff_ac3_ungroup_3_in_5_bits_tab[i][0], 3);
149 b1_mantissas[i][1] = symmetric_dequant(ff_ac3_ungroup_3_in_5_bits_tab[i][1], 3);
150 b1_mantissas[i][2] = symmetric_dequant(ff_ac3_ungroup_3_in_5_bits_tab[i][2], 3);
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151 }
152 for(i=0; i<128; i++) {
153 /* bap=2 mantissas */
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154 b2_mantissas[i][0] = symmetric_dequant(ungroup_3_in_7_bits_tab[i][0], 5);
155 b2_mantissas[i][1] = symmetric_dequant(ungroup_3_in_7_bits_tab[i][1], 5);
156 b2_mantissas[i][2] = symmetric_dequant(ungroup_3_in_7_bits_tab[i][2], 5);
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157
158 /* bap=4 mantissas */
159 b4_mantissas[i][0] = symmetric_dequant(i / 11, 11);
160 b4_mantissas[i][1] = symmetric_dequant(i % 11, 11);
161 }
162 /* generate ungrouped mantissa tables
163 reference: Tables 7.21 and 7.23 */
164 for(i=0; i<7; i++) {
165 /* bap=3 mantissas */
166 b3_mantissas[i] = symmetric_dequant(i, 7);
167 }
168 for(i=0; i<15; i++) {
169 /* bap=5 mantissas */
170 b5_mantissas[i] = symmetric_dequant(i, 15);
171 }
c7cfc48f 172
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173 /* generate dynamic range table
174 reference: Section 7.7.1 Dynamic Range Control */
175 for(i=0; i<256; i++) {
176 int v = (i >> 5) - ((i >> 7) << 3) - 5;
e2270b4e 177 dynamic_range_tab[i] = powf(2.0f, v) * ((i & 0x1F) | 0x20);
3357ff33 178 }
00585845
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179}
180
1b293437 181
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182/**
183 * AVCodec initialization
184 */
98a6fff9 185static av_cold int ac3_decode_init(AVCodecContext *avctx)
1b293437 186{
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187 AC3DecodeContext *s = avctx->priv_data;
188 s->avctx = avctx;
1b293437 189
cc2a8443 190 ac3_common_init();
98a27a8a 191 ac3_tables_init();
7d485f16
SS
192 ff_mdct_init(&s->imdct_256, 8, 1, 1.0);
193 ff_mdct_init(&s->imdct_512, 9, 1, 1.0);
3ed546fe 194 ff_kbd_window_init(s->window, 5.0, 256);
d802d7ca 195 dsputil_init(&s->dsp, avctx);
ec0350c9 196 av_lfg_init(&s->dith_state, 0);
2aa2c5c4 197
5066f515 198 /* set bias values for float to int16 conversion */
72745cff 199 if(s->dsp.float_to_int16_interleave == ff_float_to_int16_interleave_c) {
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200 s->add_bias = 385.0f;
201 s->mul_bias = 1.0f;
4e092320 202 } else {
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203 s->add_bias = 0.0f;
204 s->mul_bias = 32767.0f;
4e092320
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205 }
206
95283c17
JR
207 /* allow downmixing to stereo or mono */
208 if (avctx->channels > 0 && avctx->request_channels > 0 &&
209 avctx->request_channels < avctx->channels &&
210 avctx->request_channels <= 2) {
211 avctx->channels = avctx->request_channels;
212 }
38dae9c3 213 s->downmixed = 1;
95283c17 214
509fdb0b 215 /* allocate context input buffer */
047599a4 216 if (avctx->error_recognition >= FF_ER_CAREFUL) {
8e33132b 217 s->input_buffer = av_mallocz(AC3_FRAME_BUFFER_SIZE + FF_INPUT_BUFFER_PADDING_SIZE);
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218 if (!s->input_buffer)
219 return AVERROR_NOMEM;
220 }
221
fd76c37f 222 avctx->sample_fmt = SAMPLE_FMT_S16;
1b293437 223 return 0;
2aa2c5c4
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224}
225
9fc1ab72 226/**
5066f515 227 * Parse the 'sync info' and 'bit stream info' from the AC-3 bitstream.
c7cfc48f 228 * GetBitContext within AC3DecodeContext must point to
14b70628 229 * the start of the synchronized AC-3 bitstream.
c7cfc48f 230 */
d802d7ca 231static int ac3_parse_header(AC3DecodeContext *s)
2aa2c5c4 232{
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JR
233 GetBitContext *gbc = &s->gbc;
234 int i;
235
236 /* read the rest of the bsi. read twice for dual mono mode. */
237 i = !(s->channel_mode);
238 do {
239 skip_bits(gbc, 5); // skip dialog normalization
240 if (get_bits1(gbc))
241 skip_bits(gbc, 8); //skip compression
242 if (get_bits1(gbc))
243 skip_bits(gbc, 8); //skip language code
244 if (get_bits1(gbc))
245 skip_bits(gbc, 7); //skip audio production information
246 } while (i--);
247
248 skip_bits(gbc, 2); //skip copyright bit and original bitstream bit
249
250 /* skip the timecodes (or extra bitstream information for Alternate Syntax)
251 TODO: read & use the xbsi1 downmix levels */
252 if (get_bits1(gbc))
253 skip_bits(gbc, 14); //skip timecode1 / xbsi1
254 if (get_bits1(gbc))
255 skip_bits(gbc, 14); //skip timecode2 / xbsi2
256
257 /* skip additional bitstream info */
258 if (get_bits1(gbc)) {
259 i = get_bits(gbc, 6);
260 do {
261 skip_bits(gbc, 8);
262 } while(i--);
263 }
264
265 return 0;
266}
267
268/**
14b70628 269 * Common function to parse AC-3 or E-AC-3 frame header
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270 */
271static int parse_frame_header(AC3DecodeContext *s)
272{
9fc1ab72 273 AC3HeaderInfo hdr;
4397d95c 274 int err;
9fc1ab72 275
ba7f712c 276 err = ff_ac3_parse_header(&s->gbc, &hdr);
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277 if(err)
278 return err;
279
280 /* get decoding parameters from header info */
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281 s->bit_alloc_params.sr_code = hdr.sr_code;
282 s->channel_mode = hdr.channel_mode;
bfeca7be 283 s->channel_layout = hdr.channel_layout;
1b70d88b 284 s->lfe_on = hdr.lfe_on;
d802d7ca 285 s->bit_alloc_params.sr_shift = hdr.sr_shift;
866181e5 286 s->sample_rate = hdr.sample_rate;
d802d7ca
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287 s->bit_rate = hdr.bit_rate;
288 s->channels = hdr.channels;
289 s->fbw_channels = s->channels - s->lfe_on;
290 s->lfe_ch = s->fbw_channels + 1;
291 s->frame_size = hdr.frame_size;
55736cfb
BW
292 s->center_mix_level = hdr.center_mix_level;
293 s->surround_mix_level = hdr.surround_mix_level;
6730e9f3 294 s->num_blocks = hdr.num_blocks;
be5f17b9 295 s->frame_type = hdr.frame_type;
3596aa6f 296 s->substreamid = hdr.substreamid;
7bfd22f2 297
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JR
298 if(s->lfe_on) {
299 s->start_freq[s->lfe_ch] = 0;
300 s->end_freq[s->lfe_ch] = 7;
301 s->num_exp_groups[s->lfe_ch] = 2;
302 s->channel_in_cpl[s->lfe_ch] = 0;
303 }
304
bf09b550
JR
305 if (hdr.bitstream_id <= 10) {
306 s->eac3 = 0;
307 s->snr_offset_strategy = 2;
308 s->block_switch_syntax = 1;
309 s->dither_flag_syntax = 1;
310 s->bit_allocation_syntax = 1;
311 s->fast_gain_syntax = 0;
312 s->first_cpl_leak = 0;
313 s->dba_syntax = 1;
314 s->skip_syntax = 1;
315 memset(s->channel_uses_aht, 0, sizeof(s->channel_uses_aht));
ab2a942a 316 return ac3_parse_header(s);
d1515324 317 } else if (CONFIG_EAC3_DECODER) {
1f6a594d
JR
318 s->eac3 = 1;
319 return ff_eac3_parse_header(s);
d1515324
DB
320 } else {
321 av_log(s->avctx, AV_LOG_ERROR, "E-AC-3 support not compiled in\n");
322 return -1;
bf09b550 323 }
f0b3a7ba
JR
324}
325
326/**
327 * Set stereo downmixing coefficients based on frame header info.
328 * reference: Section 7.8.2 Downmixing Into Two Channels
329 */
330static void set_downmix_coeffs(AC3DecodeContext *s)
331{
332 int i;
30f71adc
JR
333 float cmix = gain_levels[center_levels[s->center_mix_level]];
334 float smix = gain_levels[surround_levels[s->surround_mix_level]];
557ac0c4 335 float norm0, norm1;
f0b3a7ba 336
d802d7ca
JR
337 for(i=0; i<s->fbw_channels; i++) {
338 s->downmix_coeffs[i][0] = gain_levels[ac3_default_coeffs[s->channel_mode][i][0]];
339 s->downmix_coeffs[i][1] = gain_levels[ac3_default_coeffs[s->channel_mode][i][1]];
3bbb0bf8 340 }
d802d7ca 341 if(s->channel_mode > 1 && s->channel_mode & 1) {
f0b3a7ba 342 s->downmix_coeffs[1][0] = s->downmix_coeffs[1][1] = cmix;
3bbb0bf8 343 }
d802d7ca
JR
344 if(s->channel_mode == AC3_CHMODE_2F1R || s->channel_mode == AC3_CHMODE_3F1R) {
345 int nf = s->channel_mode - 2;
f0b3a7ba 346 s->downmix_coeffs[nf][0] = s->downmix_coeffs[nf][1] = smix * LEVEL_MINUS_3DB;
3bbb0bf8 347 }
d802d7ca
JR
348 if(s->channel_mode == AC3_CHMODE_2F2R || s->channel_mode == AC3_CHMODE_3F2R) {
349 int nf = s->channel_mode - 4;
f0b3a7ba 350 s->downmix_coeffs[nf][0] = s->downmix_coeffs[nf+1][1] = smix;
3bbb0bf8 351 }
9d10e6e6 352
557ac0c4
LM
353 /* renormalize */
354 norm0 = norm1 = 0.0;
9d10e6e6 355 for(i=0; i<s->fbw_channels; i++) {
557ac0c4
LM
356 norm0 += s->downmix_coeffs[i][0];
357 norm1 += s->downmix_coeffs[i][1];
358 }
359 norm0 = 1.0f / norm0;
360 norm1 = 1.0f / norm1;
361 for(i=0; i<s->fbw_channels; i++) {
362 s->downmix_coeffs[i][0] *= norm0;
363 s->downmix_coeffs[i][1] *= norm1;
364 }
365
366 if(s->output_mode == AC3_CHMODE_MONO) {
367 for(i=0; i<s->fbw_channels; i++)
368 s->downmix_coeffs[i][0] = (s->downmix_coeffs[i][0] + s->downmix_coeffs[i][1]) * LEVEL_MINUS_3DB;
9d10e6e6 369 }
2aa2c5c4
JR
370}
371
3bb004fc 372/**
5066f515
JR
373 * Decode the grouped exponents according to exponent strategy.
374 * reference: Section 7.1.3 Exponent Decoding
2aa2c5c4 375 */
ce7d842f 376static int decode_exponents(GetBitContext *gbc, int exp_strategy, int ngrps,
80670324 377 uint8_t absexp, int8_t *dexps)
2aa2c5c4 378{
e2270b4e 379 int i, j, grp, group_size;
4415076f
JR
380 int dexp[256];
381 int expacc, prevexp;
382
383 /* unpack groups */
e2270b4e 384 group_size = exp_strategy + (exp_strategy == EXP_D45);
4415076f 385 for(grp=0,i=0; grp<ngrps; grp++) {
23c8cb89 386 expacc = get_bits(gbc, 7);
7417120b
JR
387 dexp[i++] = ungroup_3_in_7_bits_tab[expacc][0];
388 dexp[i++] = ungroup_3_in_7_bits_tab[expacc][1];
389 dexp[i++] = ungroup_3_in_7_bits_tab[expacc][2];
4415076f 390 }
2aa2c5c4 391
4415076f
JR
392 /* convert to absolute exps and expand groups */
393 prevexp = absexp;
96f229d6 394 for(i=0,j=0; i<ngrps*3; i++) {
ce7d842f 395 prevexp += dexp[i] - 2;
2ceccf04 396 if (prevexp > 24U)
ce7d842f 397 return -1;
96f229d6
JR
398 switch (group_size) {
399 case 4: dexps[j++] = prevexp;
400 dexps[j++] = prevexp;
401 case 2: dexps[j++] = prevexp;
402 case 1: dexps[j++] = prevexp;
1b293437 403 }
2aa2c5c4 404 }
ce7d842f 405 return 0;
2aa2c5c4
JR
406}
407
d7dc7ad0 408/**
5066f515 409 * Generate transform coefficients for each coupled channel in the coupling
d7dc7ad0
JR
410 * range using the coupling coefficients and coupling coordinates.
411 * reference: Section 7.4.3 Coupling Coordinate Format
412 */
5e3e4075 413static void calc_transform_coeffs_cpl(AC3DecodeContext *s)
d7dc7ad0 414{
3b6c5ad2 415 int bin, band, ch;
02587373
JR
416
417 bin = s->start_freq[CPL_CH];
418 for (band = 0; band < s->num_cpl_bands; band++) {
3b6c5ad2 419 int band_end = bin + s->cpl_band_sizes[band];
02587373
JR
420 for (; bin < band_end; bin++) {
421 for (ch = 1; ch <= s->fbw_channels; ch++) {
422 if (s->channel_in_cpl[ch]) {
423 s->fixed_coeffs[ch][bin] = ((int64_t)s->fixed_coeffs[CPL_CH][bin] *
424 (int64_t)s->cpl_coords[ch][band]) >> 23;
425 if (ch == 2 && s->phase_flags[band])
426 s->fixed_coeffs[ch][bin] = -s->fixed_coeffs[ch][bin];
d7dc7ad0 427 }
b972c06a 428 }
60313902 429 }
d7dc7ad0
JR
430 }
431}
432
5066f515
JR
433/**
434 * Grouped mantissas for 3-level 5-level and 11-level quantization
435 */
436typedef struct {
d869a460
JGG
437 int b1_mant[2];
438 int b2_mant[2];
439 int b4_mant;
440 int b1;
441 int b2;
442 int b4;
486637af
JR
443} mant_groups;
444
5066f515 445/**
e522bd49 446 * Decode the transform coefficients for a particular channel
5066f515
JR
447 * reference: Section 7.3 Quantization and Decoding of Mantissas
448 */
e43b29ab 449static void ac3_decode_transform_coeffs_ch(AC3DecodeContext *s, int ch_index, mant_groups *m)
1b293437 450{
d869a460
JGG
451 int start_freq = s->start_freq[ch_index];
452 int end_freq = s->end_freq[ch_index];
453 uint8_t *baps = s->bap[ch_index];
454 int8_t *exps = s->dexps[ch_index];
455 int *coeffs = s->fixed_coeffs[ch_index];
25dcd182 456 int dither = (ch_index == CPL_CH) || s->dither_flag[ch_index];
d802d7ca 457 GetBitContext *gbc = &s->gbc;
d869a460 458 int freq;
2fbbd087 459
d869a460
JGG
460 for(freq = start_freq; freq < end_freq; freq++){
461 int bap = baps[freq];
462 int mantissa;
463 switch(bap){
1b293437 464 case 0:
25dcd182 465 if (dither)
a521aadf 466 mantissa = (av_lfg_get(&s->dith_state) & 0x7FFFFF) - 0x400000;
25dcd182
JR
467 else
468 mantissa = 0;
d63f6fea 469 break;
1b293437 470 case 1:
d869a460
JGG
471 if(m->b1){
472 m->b1--;
473 mantissa = m->b1_mant[m->b1];
474 }
475 else{
476 int bits = get_bits(gbc, 5);
477 mantissa = b1_mantissas[bits][0];
478 m->b1_mant[1] = b1_mantissas[bits][1];
479 m->b1_mant[0] = b1_mantissas[bits][2];
480 m->b1 = 2;
1b293437 481 }
d63f6fea 482 break;
1b293437 483 case 2:
d869a460
JGG
484 if(m->b2){
485 m->b2--;
486 mantissa = m->b2_mant[m->b2];
487 }
488 else{
489 int bits = get_bits(gbc, 7);
490 mantissa = b2_mantissas[bits][0];
491 m->b2_mant[1] = b2_mantissas[bits][1];
492 m->b2_mant[0] = b2_mantissas[bits][2];
493 m->b2 = 2;
1b293437 494 }
d63f6fea 495 break;
1b293437 496 case 3:
d869a460 497 mantissa = b3_mantissas[get_bits(gbc, 3)];
d63f6fea 498 break;
1b293437 499 case 4:
d869a460
JGG
500 if(m->b4){
501 m->b4 = 0;
502 mantissa = m->b4_mant;
503 }
504 else{
505 int bits = get_bits(gbc, 7);
506 mantissa = b4_mantissas[bits][0];
507 m->b4_mant = b4_mantissas[bits][1];
508 m->b4 = 1;
1b293437 509 }
d63f6fea 510 break;
1b293437 511 case 5:
d869a460 512 mantissa = b5_mantissas[get_bits(gbc, 4)];
d63f6fea 513 break;
d869a460
JGG
514 default: /* 6 to 15 */
515 mantissa = get_bits(gbc, quantization_tab[bap]);
516 /* Shift mantissa and sign-extend it. */
517 mantissa = (mantissa << (32-quantization_tab[bap]))>>8;
d63f6fea 518 break;
1b293437 519 }
d869a460 520 coeffs[freq] = mantissa >> exps[freq];
1b293437 521 }
1b293437
JR
522}
523
60f07fad 524/**
25dcd182
JR
525 * Remove random dithering from coupling range coefficients with zero-bit
526 * mantissas for coupled channels which do not use dithering.
60f07fad
JR
527 * reference: Section 7.3.4 Dither for Zero Bit Mantissas (bap=0)
528 */
d802d7ca 529static void remove_dithering(AC3DecodeContext *s) {
60f07fad 530 int ch, i;
60f07fad 531
d802d7ca 532 for(ch=1; ch<=s->fbw_channels; ch++) {
25dcd182
JR
533 if(!s->dither_flag[ch] && s->channel_in_cpl[ch]) {
534 for(i = s->start_freq[CPL_CH]; i<s->end_freq[CPL_CH]; i++) {
535 if(!s->bap[CPL_CH][i])
536 s->fixed_coeffs[ch][i] = 0;
60f07fad
JR
537 }
538 }
539 }
540}
541
6a68105e 542static void decode_transform_coeffs_ch(AC3DecodeContext *s, int blk, int ch,
bf09b550
JR
543 mant_groups *m)
544{
545 if (!s->channel_uses_aht[ch]) {
6a68105e 546 ac3_decode_transform_coeffs_ch(s, ch, m);
bf09b550
JR
547 } else {
548 /* if AHT is used, mantissas for all blocks are encoded in the first
549 block of the frame. */
550 int bin;
d1515324 551 if (!blk && CONFIG_EAC3_DECODER)
6a68105e 552 ff_eac3_decode_transform_coeffs_aht_ch(s, ch);
bf09b550 553 for (bin = s->start_freq[ch]; bin < s->end_freq[ch]; bin++) {
ae04de31 554 s->fixed_coeffs[ch][bin] = s->pre_mantissa[ch][bin][blk] >> s->dexps[ch][bin];
bf09b550
JR
555 }
556 }
557}
bf09b550 558
5066f515 559/**
164e169f 560 * Decode the transform coefficients.
c7cfc48f 561 */
e43b29ab 562static void decode_transform_coeffs(AC3DecodeContext *s, int blk)
1b293437 563{
7b4076a7 564 int ch, end;
1b293437 565 int got_cplchan = 0;
486637af
JR
566 mant_groups m;
567
d869a460 568 m.b1 = m.b2 = m.b4 = 0;
1b293437 569
d802d7ca 570 for (ch = 1; ch <= s->channels; ch++) {
5066f515 571 /* transform coefficients for full-bandwidth channel */
e43b29ab 572 decode_transform_coeffs_ch(s, blk, ch, &m);
5066f515
JR
573 /* tranform coefficients for coupling channel come right after the
574 coefficients for the first coupled channel*/
d802d7ca 575 if (s->channel_in_cpl[ch]) {
486637af 576 if (!got_cplchan) {
e43b29ab 577 decode_transform_coeffs_ch(s, blk, CPL_CH, &m);
5e3e4075 578 calc_transform_coeffs_cpl(s);
486637af
JR
579 got_cplchan = 1;
580 }
d802d7ca 581 end = s->end_freq[CPL_CH];
eaf84d97 582 } else {
d802d7ca 583 end = s->end_freq[ch];
eaf84d97 584 }
486637af 585 do
bd98e9e2 586 s->fixed_coeffs[ch][end] = 0;
486637af
JR
587 while(++end < 256);
588 }
1b293437 589
ea364c74 590 /* zero the dithered coefficients for appropriate channels */
86662b1c 591 remove_dithering(s);
2aa2c5c4
JR
592}
593
8b60bbbf 594/**
5066f515 595 * Stereo rematrixing.
8b60bbbf
JR
596 * reference: Section 7.5.4 Rematrixing : Decoding Technique
597 */
d802d7ca 598static void do_rematrixing(AC3DecodeContext *s)
1b293437 599{
8b60bbbf 600 int bnd, i;
2fbbd087 601 int end, bndend;
a4de6dd2 602 int tmp0, tmp1;
2fbbd087 603
d802d7ca 604 end = FFMIN(s->end_freq[1], s->end_freq[2]);
1b293437 605
d802d7ca
JR
606 for(bnd=0; bnd<s->num_rematrixing_bands; bnd++) {
607 if(s->rematrixing_flags[bnd]) {
227322b8
JR
608 bndend = FFMIN(end, ff_ac3_rematrix_band_tab[bnd+1]);
609 for(i=ff_ac3_rematrix_band_tab[bnd]; i<bndend; i++) {
a4de6dd2
JR
610 tmp0 = s->fixed_coeffs[1][i];
611 tmp1 = s->fixed_coeffs[2][i];
612 s->fixed_coeffs[1][i] = tmp0 + tmp1;
613 s->fixed_coeffs[2][i] = tmp0 - tmp1;
8b60bbbf
JR
614 }
615 }
1b293437
JR
616 }
617}
2aa2c5c4 618
5066f515 619/**
5066f515
JR
620 * Inverse MDCT Transform.
621 * Convert frequency domain coefficients to time-domain audio samples.
622 * reference: Section 7.9.4 Transformation Equations
623 */
38dae9c3 624static inline void do_imdct(AC3DecodeContext *s, int channels)
486637af 625{
0de73a46 626 int ch;
3b6516f7
LM
627 float add_bias = s->add_bias;
628 if(s->out_channels==1 && channels>1)
629 add_bias *= LEVEL_MINUS_3DB; // compensate for the gain in downmix
7b4076a7 630
e2270b4e 631 for (ch=1; ch<=channels; ch++) {
d802d7ca 632 if (s->block_switch[ch]) {
916d5d6c
LM
633 int i;
634 float *x = s->tmp_output+128;
635 for(i=0; i<128; i++)
636 x[i] = s->transform_coeffs[ch][2*i];
637 ff_imdct_half(&s->imdct_256, s->tmp_output, x);
3b6516f7 638 s->dsp.vector_fmul_window(s->output[ch-1], s->delay[ch-1], s->tmp_output, s->window, add_bias, 128);
916d5d6c
LM
639 for(i=0; i<128; i++)
640 x[i] = s->transform_coeffs[ch][2*i+1];
641 ff_imdct_half(&s->imdct_256, s->delay[ch-1], x);
eaf84d97 642 } else {
916d5d6c 643 ff_imdct_half(&s->imdct_512, s->tmp_output, s->transform_coeffs[ch]);
3b6516f7 644 s->dsp.vector_fmul_window(s->output[ch-1], s->delay[ch-1], s->tmp_output, s->window, add_bias, 128);
916d5d6c 645 memcpy(s->delay[ch-1], s->tmp_output+128, 128*sizeof(float));
eaf84d97 646 }
486637af
JR
647 }
648}
649
3bbb0bf8 650/**
5066f515 651 * Downmix the output to mono or stereo.
3bbb0bf8 652 */
ac2e5564 653void ff_ac3_downmix_c(float (*samples)[256], float (*matrix)[2], int out_ch, int in_ch, int len)
3bbb0bf8
JR
654{
655 int i, j;
9d10e6e6 656 float v0, v1;
ac2e5564
LM
657 if(out_ch == 2) {
658 for(i=0; i<len; i++) {
557ac0c4 659 v0 = v1 = 0.0f;
ac2e5564
LM
660 for(j=0; j<in_ch; j++) {
661 v0 += samples[j][i] * matrix[j][0];
662 v1 += samples[j][i] * matrix[j][1];
557ac0c4
LM
663 }
664 samples[0][i] = v0;
665 samples[1][i] = v1;
3bbb0bf8 666 }
ac2e5564
LM
667 } else if(out_ch == 1) {
668 for(i=0; i<len; i++) {
557ac0c4 669 v0 = 0.0f;
ac2e5564
LM
670 for(j=0; j<in_ch; j++)
671 v0 += samples[j][i] * matrix[j][0];
557ac0c4 672 samples[0][i] = v0;
3bbb0bf8
JR
673 }
674 }
675}
676
5066f515 677/**
38dae9c3
JR
678 * Upmix delay samples from stereo to original channel layout.
679 */
680static void ac3_upmix_delay(AC3DecodeContext *s)
681{
e6300276 682 int channel_data_size = sizeof(s->delay[0]);
38dae9c3
JR
683 switch(s->channel_mode) {
684 case AC3_CHMODE_DUALMONO:
685 case AC3_CHMODE_STEREO:
686 /* upmix mono to stereo */
687 memcpy(s->delay[1], s->delay[0], channel_data_size);
688 break;
689 case AC3_CHMODE_2F2R:
690 memset(s->delay[3], 0, channel_data_size);
691 case AC3_CHMODE_2F1R:
692 memset(s->delay[2], 0, channel_data_size);
693 break;
694 case AC3_CHMODE_3F2R:
695 memset(s->delay[4], 0, channel_data_size);
696 case AC3_CHMODE_3F1R:
697 memset(s->delay[3], 0, channel_data_size);
698 case AC3_CHMODE_3F:
699 memcpy(s->delay[2], s->delay[1], channel_data_size);
700 memset(s->delay[1], 0, channel_data_size);
701 break;
702 }
703}
704
705/**
0c5d750d 706 * Decode band structure for coupling, spectral extension, or enhanced coupling.
eb98cdfa
JR
707 * The band structure defines how many subbands are in each band. For each
708 * subband in the range, 1 means it is combined with the previous band, and 0
709 * means that it starts a new band.
710 *
0c5d750d
JR
711 * @param[in] gbc bit reader context
712 * @param[in] blk block number
713 * @param[in] eac3 flag to indicate E-AC-3
714 * @param[in] ecpl flag to indicate enhanced coupling
715 * @param[in] start_subband subband number for start of range
716 * @param[in] end_subband subband number for end of range
717 * @param[in] default_band_struct default band structure table
0c5d750d
JR
718 * @param[out] num_bands number of bands (optionally NULL)
719 * @param[out] band_sizes array containing the number of bins in each band (optionally NULL)
720 */
721static void decode_band_structure(GetBitContext *gbc, int blk, int eac3,
722 int ecpl, int start_subband, int end_subband,
723 const uint8_t *default_band_struct,
c36ea060 724 int *num_bands, uint8_t *band_sizes)
0c5d750d 725{
f23dc1e1 726 int subbnd, bnd, n_subbands, n_bands=0;
75b53b21 727 uint8_t bnd_sz[22];
3f937168
JR
728 uint8_t coded_band_struct[22];
729 const uint8_t *band_struct;
0c5d750d
JR
730
731 n_subbands = end_subband - start_subband;
732
733 /* decode band structure from bitstream or use default */
734 if (!eac3 || get_bits1(gbc)) {
735 for (subbnd = 0; subbnd < n_subbands - 1; subbnd++) {
3f937168 736 coded_band_struct[subbnd] = get_bits1(gbc);
0c5d750d 737 }
3f937168 738 band_struct = coded_band_struct;
0c5d750d 739 } else if (!blk) {
3f937168
JR
740 band_struct = &default_band_struct[start_subband+1];
741 } else {
742 /* no change in band structure */
743 return;
0c5d750d 744 }
0c5d750d
JR
745
746 /* calculate number of bands and band sizes based on band structure.
747 note that the first 4 subbands in enhanced coupling span only 6 bins
748 instead of 12. */
749 if (num_bands || band_sizes ) {
e202cc25 750 n_bands = n_subbands;
0c5d750d
JR
751 bnd_sz[0] = ecpl ? 6 : 12;
752 for (bnd = 0, subbnd = 1; subbnd < n_subbands; subbnd++) {
753 int subbnd_size = (ecpl && subbnd < 4) ? 6 : 12;
754 if (band_struct[subbnd-1]) {
755 n_bands--;
756 bnd_sz[bnd] += subbnd_size;
757 } else {
758 bnd_sz[++bnd] = subbnd_size;
759 }
760 }
761 }
762
763 /* set optional output params */
0c5d750d
JR
764 if (num_bands)
765 *num_bands = n_bands;
766 if (band_sizes)
75b53b21 767 memcpy(band_sizes, bnd_sz, n_bands);
0c5d750d
JR
768}
769
770/**
022845ed 771 * Decode a single audio block from the AC-3 bitstream.
c7cfc48f 772 */
022845ed 773static int decode_audio_block(AC3DecodeContext *s, int blk)
2aa2c5c4 774{
d802d7ca
JR
775 int fbw_channels = s->fbw_channels;
776 int channel_mode = s->channel_mode;
0bff58a5 777 int i, bnd, seg, ch;
38dae9c3
JR
778 int different_transforms;
779 int downmix_output;
54624396 780 int cpl_in_use;
d802d7ca 781 GetBitContext *gbc = &s->gbc;
7b4076a7 782 uint8_t bit_alloc_stages[AC3_MAX_CHANNELS];
1b293437 783
7b4076a7
JR
784 memset(bit_alloc_stages, 0, AC3_MAX_CHANNELS);
785
5066f515 786 /* block switch flags */
38dae9c3 787 different_transforms = 0;
bf09b550 788 if (s->block_switch_syntax) {
ab2a942a
JR
789 for (ch = 1; ch <= fbw_channels; ch++) {
790 s->block_switch[ch] = get_bits1(gbc);
791 if(ch > 1 && s->block_switch[ch] != s->block_switch[1])
792 different_transforms = 1;
793 }
bf09b550 794 }
98a27a8a 795
5066f515 796 /* dithering flags */
bf09b550 797 if (s->dither_flag_syntax) {
ab2a942a
JR
798 for (ch = 1; ch <= fbw_channels; ch++) {
799 s->dither_flag[ch] = get_bits1(gbc);
ab2a942a 800 }
bf09b550 801 }
98a27a8a 802
77416325 803 /* dynamic range */
d802d7ca 804 i = !(s->channel_mode);
77416325 805 do {
23c8cb89 806 if(get_bits1(gbc)) {
d802d7ca 807 s->dynamic_range[i] = ((dynamic_range_tab[get_bits(gbc, 8)]-1.0) *
1b70d88b 808 s->avctx->drc_scale)+1.0;
9fc1ab72 809 } else if(blk == 0) {
d802d7ca 810 s->dynamic_range[i] = 1.0f;
9fc1ab72 811 }
77416325 812 } while(i--);
98a27a8a 813
6fafb020
JR
814 /* spectral extension strategy */
815 if (s->eac3 && (!blk || get_bits1(gbc))) {
e202cc25 816 if (get_bits1(gbc)) {
ce863d7f 817 av_log_missing_feature(s->avctx, "Spectral extension", 1);
e202cc25 818 return -1;
6fafb020 819 }
e202cc25 820 /* TODO: parse spectral extension strategy info */
6fafb020
JR
821 }
822
e202cc25 823 /* TODO: spectral extension coordinates */
6fafb020 824
5066f515 825 /* coupling strategy */
225c3042 826 if (s->eac3 ? s->cpl_strategy_exists[blk] : get_bits1(gbc)) {
7b4076a7 827 memset(bit_alloc_stages, 3, AC3_MAX_CHANNELS);
6fafb020 828 if (!s->eac3)
0569993e 829 s->cpl_in_use[blk] = get_bits1(gbc);
4760aec6 830 if (s->cpl_in_use[blk]) {
5066f515 831 /* coupling in use */
24834c19 832 int cpl_start_subband, cpl_end_subband;
b6acc57f 833
3af91313
JR
834 if (channel_mode < AC3_CHMODE_STEREO) {
835 av_log(s->avctx, AV_LOG_ERROR, "coupling not allowed in mono or dual-mono\n");
836 return -1;
837 }
838
6fafb020
JR
839 /* check for enhanced coupling */
840 if (s->eac3 && get_bits1(gbc)) {
841 /* TODO: parse enhanced coupling strategy info */
ce863d7f 842 av_log_missing_feature(s->avctx, "Enhanced coupling", 1);
6fafb020
JR
843 return -1;
844 }
845
5066f515 846 /* determine which channels are coupled */
6fafb020
JR
847 if (s->eac3 && s->channel_mode == AC3_CHMODE_STEREO) {
848 s->channel_in_cpl[1] = 1;
849 s->channel_in_cpl[2] = 1;
850 } else {
0569993e
JR
851 for (ch = 1; ch <= fbw_channels; ch++)
852 s->channel_in_cpl[ch] = get_bits1(gbc);
6fafb020 853 }
98a27a8a 854
5066f515 855 /* phase flags in use */
e59cc205 856 if (channel_mode == AC3_CHMODE_STEREO)
d802d7ca 857 s->phase_flags_in_use = get_bits1(gbc);
98a27a8a 858
6fafb020 859 /* coupling frequency range */
e202cc25 860 /* TODO: modify coupling end freq if spectral extension is used */
24834c19 861 cpl_start_subband = get_bits(gbc, 4);
e202cc25 862 cpl_end_subband = get_bits(gbc, 4) + 3;
1ac7d1ac
JR
863 if (cpl_start_subband >= cpl_end_subband) {
864 av_log(s->avctx, AV_LOG_ERROR, "invalid coupling range (%d >= %d)\n",
6ee6d068 865 cpl_start_subband, cpl_end_subband);
00585845 866 return -1;
98a27a8a 867 }
24834c19 868 s->start_freq[CPL_CH] = cpl_start_subband * 12 + 37;
6ee6d068 869 s->end_freq[CPL_CH] = cpl_end_subband * 12 + 37;
6fafb020 870
778bc09b
JR
871 decode_band_structure(gbc, blk, s->eac3, 0, cpl_start_subband,
872 cpl_end_subband,
873 ff_eac3_default_cpl_band_struct,
c36ea060 874 &s->num_cpl_bands, s->cpl_band_sizes);
878c40a1 875 } else {
5066f515 876 /* coupling not in use */
6fafb020 877 for (ch = 1; ch <= fbw_channels; ch++) {
d802d7ca 878 s->channel_in_cpl[ch] = 0;
6fafb020
JR
879 s->first_cpl_coords[ch] = 1;
880 }
63d72fb1 881 s->first_cpl_leak = s->eac3;
6fafb020 882 s->phase_flags_in_use = 0;
1b293437 883 }
6fafb020
JR
884 } else if (!s->eac3) {
885 if(!blk) {
0569993e
JR
886 av_log(s->avctx, AV_LOG_ERROR, "new coupling strategy must be present in block 0\n");
887 return -1;
888 } else {
889 s->cpl_in_use[blk] = s->cpl_in_use[blk-1];
890 }
6fafb020 891 }
4760aec6 892 cpl_in_use = s->cpl_in_use[blk];
98a27a8a 893
5066f515 894 /* coupling coordinates */
54624396 895 if (cpl_in_use) {
e2270b4e 896 int cpl_coords_exist = 0;
98a27a8a 897
e2270b4e 898 for (ch = 1; ch <= fbw_channels; ch++) {
d802d7ca 899 if (s->channel_in_cpl[ch]) {
225c3042 900 if ((s->eac3 && s->first_cpl_coords[ch]) || get_bits1(gbc)) {
e2270b4e 901 int master_cpl_coord, cpl_coord_exp, cpl_coord_mant;
225c3042 902 s->first_cpl_coords[ch] = 0;
e2270b4e 903 cpl_coords_exist = 1;
23c8cb89 904 master_cpl_coord = 3 * get_bits(gbc, 2);
d802d7ca 905 for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
23c8cb89
JR
906 cpl_coord_exp = get_bits(gbc, 4);
907 cpl_coord_mant = get_bits(gbc, 4);
e2270b4e 908 if (cpl_coord_exp == 15)
a4de6dd2 909 s->cpl_coords[ch][bnd] = cpl_coord_mant << 22;
486637af 910 else
a4de6dd2
JR
911 s->cpl_coords[ch][bnd] = (cpl_coord_mant + 16) << 21;
912 s->cpl_coords[ch][bnd] >>= (cpl_coord_exp + master_cpl_coord);
486637af 913 }
82a591d8
JR
914 } else if (!blk) {
915 av_log(s->avctx, AV_LOG_ERROR, "new coupling coordinates must be present in block 0\n");
916 return -1;
486637af 917 }
225c3042
JR
918 } else {
919 /* channel not in coupling */
920 s->first_cpl_coords[ch] = 1;
eaf84d97
JR
921 }
922 }
5066f515 923 /* phase flags */
b02fbf75 924 if (channel_mode == AC3_CHMODE_STEREO && cpl_coords_exist) {
d802d7ca 925 for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
b02fbf75 926 s->phase_flags[bnd] = s->phase_flags_in_use? get_bits1(gbc) : 0;
eaf84d97
JR
927 }
928 }
2aa2c5c4 929 }
98a27a8a 930
5066f515 931 /* stereo rematrixing strategy and band structure */
e59cc205 932 if (channel_mode == AC3_CHMODE_STEREO) {
6fafb020 933 if ((s->eac3 && !blk) || get_bits1(gbc)) {
d802d7ca 934 s->num_rematrixing_bands = 4;
e202cc25
JR
935 if(cpl_in_use && s->start_freq[CPL_CH] <= 61)
936 s->num_rematrixing_bands -= 1 + (s->start_freq[CPL_CH] == 37);
d802d7ca
JR
937 for(bnd=0; bnd<s->num_rematrixing_bands; bnd++)
938 s->rematrixing_flags[bnd] = get_bits1(gbc);
82a591d8
JR
939 } else if (!blk) {
940 av_log(s->avctx, AV_LOG_ERROR, "new rematrixing strategy must be present in block 0\n");
941 return -1;
1b293437 942 }
98a27a8a
JR
943 }
944
5066f515 945 /* exponent strategies for each channel */
54624396 946 for (ch = !cpl_in_use; ch <= s->channels; ch++) {
6b4bfed9 947 if (!s->eac3)
aec0407f 948 s->exp_strategy[blk][ch] = get_bits(gbc, 2 - (ch == s->lfe_ch));
da04be10 949 if(s->exp_strategy[blk][ch] != EXP_REUSE)
7b4076a7
JR
950 bit_alloc_stages[ch] = 3;
951 }
952
5066f515 953 /* channel bandwidth */
e2270b4e 954 for (ch = 1; ch <= fbw_channels; ch++) {
d802d7ca 955 s->start_freq[ch] = 0;
da04be10 956 if (s->exp_strategy[blk][ch] != EXP_REUSE) {
b85a15fe 957 int group_size;
d802d7ca
JR
958 int prev = s->end_freq[ch];
959 if (s->channel_in_cpl[ch])
960 s->end_freq[ch] = s->start_freq[CPL_CH];
00585845 961 else {
23c8cb89 962 int bandwidth_code = get_bits(gbc, 6);
e2270b4e 963 if (bandwidth_code > 60) {
6c6f9272 964 av_log(s->avctx, AV_LOG_ERROR, "bandwidth code = %d > 60\n", bandwidth_code);
00585845
JR
965 return -1;
966 }
d802d7ca 967 s->end_freq[ch] = bandwidth_code * 3 + 73;
1b293437 968 }
da04be10 969 group_size = 3 << (s->exp_strategy[blk][ch] - 1);
b85a15fe 970 s->num_exp_groups[ch] = (s->end_freq[ch]+group_size-4) / group_size;
d802d7ca 971 if(blk > 0 && s->end_freq[ch] != prev)
7b4076a7 972 memset(bit_alloc_stages, 3, AC3_MAX_CHANNELS);
00585845 973 }
eaf84d97 974 }
da04be10 975 if (cpl_in_use && s->exp_strategy[blk][CPL_CH] != EXP_REUSE) {
b85a15fe 976 s->num_exp_groups[CPL_CH] = (s->end_freq[CPL_CH] - s->start_freq[CPL_CH]) /
da04be10 977 (3 << (s->exp_strategy[blk][CPL_CH] - 1));
b85a15fe 978 }
7b4076a7 979
5066f515 980 /* decode exponents for each channel */
54624396 981 for (ch = !cpl_in_use; ch <= s->channels; ch++) {
da04be10 982 if (s->exp_strategy[blk][ch] != EXP_REUSE) {
d802d7ca 983 s->dexps[ch][0] = get_bits(gbc, 4) << !ch;
ce7d842f 984 if (decode_exponents(gbc, s->exp_strategy[blk][ch],
1cdd567f
JR
985 s->num_exp_groups[ch], s->dexps[ch][0],
986 &s->dexps[ch][s->start_freq[ch]+!!ch])) {
ce7d842f
JR
987 av_log(s->avctx, AV_LOG_ERROR, "exponent out-of-range\n");
988 return -1;
989 }
d802d7ca 990 if(ch != CPL_CH && ch != s->lfe_ch)
23c8cb89 991 skip_bits(gbc, 2); /* skip gainrng */
1b293437 992 }
eaf84d97 993 }
98a27a8a 994
5066f515 995 /* bit allocation information */
bf09b550 996 if (s->bit_allocation_syntax) {
ab2a942a
JR
997 if (get_bits1(gbc)) {
998 s->bit_alloc_params.slow_decay = ff_ac3_slow_decay_tab[get_bits(gbc, 2)] >> s->bit_alloc_params.sr_shift;
999 s->bit_alloc_params.fast_decay = ff_ac3_fast_decay_tab[get_bits(gbc, 2)] >> s->bit_alloc_params.sr_shift;
1000 s->bit_alloc_params.slow_gain = ff_ac3_slow_gain_tab[get_bits(gbc, 2)];
1001 s->bit_alloc_params.db_per_bit = ff_ac3_db_per_bit_tab[get_bits(gbc, 2)];
e202cc25 1002 s->bit_alloc_params.floor = ff_ac3_floor_tab[get_bits(gbc, 3)];
ab2a942a
JR
1003 for(ch=!cpl_in_use; ch<=s->channels; ch++)
1004 bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 2);
1005 } else if (!blk) {
1006 av_log(s->avctx, AV_LOG_ERROR, "new bit allocation info must be present in block 0\n");
1007 return -1;
1008 }
bf09b550 1009 }
98a27a8a 1010
5066f515 1011 /* signal-to-noise ratio offsets and fast gains (signal-to-mask ratios) */
8dfc56ec
JR
1012 if(!s->eac3 || !blk){
1013 if(s->snr_offset_strategy && get_bits1(gbc)) {
f2e4eb62
JR
1014 int snr = 0;
1015 int csnr;
1016 csnr = (get_bits(gbc, 6) - 15) << 4;
1017 for (i = ch = !cpl_in_use; ch <= s->channels; ch++) {
1018 /* snr offset */
1019 if (ch == i || s->snr_offset_strategy == 2)
1020 snr = (csnr + get_bits(gbc, 4)) << 2;
1021 /* run at least last bit allocation stage if snr offset changes */
1022 if(blk && s->snr_offset[ch] != snr) {
1023 bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 1);
1024 }
1025 s->snr_offset[ch] = snr;
8dfc56ec
JR
1026
1027 /* fast gain (normal AC-3 only) */
1028 if (!s->eac3) {
1029 int prev = s->fast_gain[ch];
f2e4eb62 1030 s->fast_gain[ch] = ff_ac3_fast_gain_tab[get_bits(gbc, 3)];
8dfc56ec
JR
1031 /* run last 2 bit allocation stages if fast gain changes */
1032 if(blk && prev != s->fast_gain[ch])
1033 bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 2);
8dfc56ec 1034 }
f2e4eb62 1035 }
8dfc56ec 1036 } else if (!s->eac3 && !blk) {
f2e4eb62
JR
1037 av_log(s->avctx, AV_LOG_ERROR, "new snr offsets must be present in block 0\n");
1038 return -1;
8dfc56ec 1039 }
1b293437 1040 }
98a27a8a 1041
6fafb020
JR
1042 /* fast gain (E-AC-3 only) */
1043 if (s->fast_gain_syntax && get_bits1(gbc)) {
1044 for (ch = !cpl_in_use; ch <= s->channels; ch++) {
1045 int prev = s->fast_gain[ch];
1046 s->fast_gain[ch] = ff_ac3_fast_gain_tab[get_bits(gbc, 3)];
1047 /* run last 2 bit allocation stages if fast gain changes */
1048 if(blk && prev != s->fast_gain[ch])
1049 bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 2);
1050 }
1051 } else if (s->eac3 && !blk) {
1052 for (ch = !cpl_in_use; ch <= s->channels; ch++)
1053 s->fast_gain[ch] = ff_ac3_fast_gain_tab[4];
1054 }
1055
1056 /* E-AC-3 to AC-3 converter SNR offset */
1057 if (s->frame_type == EAC3_FRAME_TYPE_INDEPENDENT && get_bits1(gbc)) {
1058 skip_bits(gbc, 10); // skip converter snr offset
1059 }
1060
5066f515 1061 /* coupling leak information */
54624396 1062 if (cpl_in_use) {
8dfc56ec
JR
1063 if (s->first_cpl_leak || get_bits1(gbc)) {
1064 int fl = get_bits(gbc, 3);
1065 int sl = get_bits(gbc, 3);
1066 /* run last 2 bit allocation stages for coupling channel if
1067 coupling leak changes */
1068 if(blk && (fl != s->bit_alloc_params.cpl_fast_leak ||
1069 sl != s->bit_alloc_params.cpl_slow_leak)) {
f2e4eb62 1070 bit_alloc_stages[CPL_CH] = FFMAX(bit_alloc_stages[CPL_CH], 2);
8dfc56ec
JR
1071 }
1072 s->bit_alloc_params.cpl_fast_leak = fl;
1073 s->bit_alloc_params.cpl_slow_leak = sl;
1074 } else if (!s->eac3 && !blk) {
93a2c8c1
JR
1075 av_log(s->avctx, AV_LOG_ERROR, "new coupling leak info must be present in block 0\n");
1076 return -1;
1077 }
8dfc56ec 1078 s->first_cpl_leak = 0;
43ad93a4 1079 }
98a27a8a 1080
5066f515 1081 /* delta bit allocation information */
bf09b550 1082 if (s->dba_syntax && get_bits1(gbc)) {
5066f515 1083 /* delta bit allocation exists (strategy) */
54624396 1084 for (ch = !cpl_in_use; ch <= fbw_channels; ch++) {
d802d7ca
JR
1085 s->dba_mode[ch] = get_bits(gbc, 2);
1086 if (s->dba_mode[ch] == DBA_RESERVED) {
1087 av_log(s->avctx, AV_LOG_ERROR, "delta bit allocation strategy reserved\n");
1b293437
JR
1088 return -1;
1089 }
7b4076a7 1090 bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 2);
1b293437 1091 }
5066f515 1092 /* channel delta offset, len and bit allocation */
54624396 1093 for (ch = !cpl_in_use; ch <= fbw_channels; ch++) {
d802d7ca
JR
1094 if (s->dba_mode[ch] == DBA_NEW) {
1095 s->dba_nsegs[ch] = get_bits(gbc, 3);
1096 for (seg = 0; seg <= s->dba_nsegs[ch]; seg++) {
1097 s->dba_offsets[ch][seg] = get_bits(gbc, 5);
1098 s->dba_lengths[ch][seg] = get_bits(gbc, 4);
1099 s->dba_values[ch][seg] = get_bits(gbc, 3);
1b293437 1100 }
e25973a1
JR
1101 /* run last 2 bit allocation stages if new dba values */
1102 bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 2);
1b293437 1103 }
eaf84d97 1104 }
9fc1ab72 1105 } else if(blk == 0) {
d802d7ca
JR
1106 for(ch=0; ch<=s->channels; ch++) {
1107 s->dba_mode[ch] = DBA_NONE;
9fc1ab72 1108 }
1b293437 1109 }
00585845 1110
5066f515 1111 /* Bit allocation */
54624396 1112 for(ch=!cpl_in_use; ch<=s->channels; ch++) {
7b4076a7
JR
1113 if(bit_alloc_stages[ch] > 2) {
1114 /* Exponent mapping into PSD and PSD integration */
d802d7ca
JR
1115 ff_ac3_bit_alloc_calc_psd(s->dexps[ch],
1116 s->start_freq[ch], s->end_freq[ch],
1117 s->psd[ch], s->band_psd[ch]);
eaf84d97 1118 }
7b4076a7
JR
1119 if(bit_alloc_stages[ch] > 1) {
1120 /* Compute excitation function, Compute masking curve, and
1121 Apply delta bit allocation */
72a6244b 1122 if (ff_ac3_bit_alloc_calc_mask(&s->bit_alloc_params, s->band_psd[ch],
20e04726
JR
1123 s->start_freq[ch], s->end_freq[ch],
1124 s->fast_gain[ch], (ch == s->lfe_ch),
1125 s->dba_mode[ch], s->dba_nsegs[ch],
1126 s->dba_offsets[ch], s->dba_lengths[ch],
1127 s->dba_values[ch], s->mask[ch])) {
72a6244b
JR
1128 av_log(s->avctx, AV_LOG_ERROR, "error in bit allocation\n");
1129 return -1;
1130 }
eaf84d97 1131 }
7b4076a7
JR
1132 if(bit_alloc_stages[ch] > 0) {
1133 /* Compute bit allocation */
bf09b550
JR
1134 const uint8_t *bap_tab = s->channel_uses_aht[ch] ?
1135 ff_eac3_hebap_tab : ff_ac3_bap_tab;
d802d7ca
JR
1136 ff_ac3_bit_alloc_calc_bap(s->mask[ch], s->psd[ch],
1137 s->start_freq[ch], s->end_freq[ch],
1138 s->snr_offset[ch],
1139 s->bit_alloc_params.floor,
bf09b550 1140 bap_tab, s->bap[ch]);
eaf84d97 1141 }
2fbbd087 1142 }
98a27a8a 1143
5066f515 1144 /* unused dummy data */
bf09b550 1145 if (s->skip_syntax && get_bits1(gbc)) {
23c8cb89 1146 int skipl = get_bits(gbc, 9);
98a27a8a 1147 while(skipl--)
23c8cb89 1148 skip_bits(gbc, 8);
1b293437 1149 }
f5cefb21 1150
1b293437 1151 /* unpack the transform coefficients
5066f515 1152 this also uncouples channels if coupling is in use. */
e43b29ab 1153 decode_transform_coeffs(s, blk);
486637af 1154
bf09b550
JR
1155 /* TODO: generate enhanced coupling coordinates and uncouple */
1156
e202cc25
JR
1157 /* TODO: apply spectral extension */
1158
1b293437 1159 /* recover coefficients if rematrixing is in use */
d802d7ca
JR
1160 if(s->channel_mode == AC3_CHMODE_STEREO)
1161 do_rematrixing(s);
1b293437 1162
03726b70 1163 /* apply scaling to coefficients (headroom, dynrng) */
d802d7ca 1164 for(ch=1; ch<=s->channels; ch++) {
a4de6dd2 1165 float gain = s->mul_bias / 4194304.0f;
d802d7ca
JR
1166 if(s->channel_mode == AC3_CHMODE_DUALMONO) {
1167 gain *= s->dynamic_range[ch-1];
7bfd22f2 1168 } else {
d802d7ca 1169 gain *= s->dynamic_range[0];
7bfd22f2 1170 }
911e21a3 1171 s->dsp.int32_to_float_fmul_scalar(s->transform_coeffs[ch], s->fixed_coeffs[ch], gain, 256);
7bfd22f2 1172 }
d7bcc4ad 1173
38dae9c3
JR
1174 /* downmix and MDCT. order depends on whether block switching is used for
1175 any channel in this block. this is because coefficients for the long
1176 and short transforms cannot be mixed. */
1177 downmix_output = s->channels != s->out_channels &&
1178 !((s->output_mode & AC3_OUTPUT_LFEON) &&
1179 s->fbw_channels == s->out_channels);
1180 if(different_transforms) {
1181 /* the delay samples have already been downmixed, so we upmix the delay
1182 samples in order to reconstruct all channels before downmixing. */
1183 if(s->downmixed) {
1184 s->downmixed = 0;
1185 ac3_upmix_delay(s);
1186 }
1187
1188 do_imdct(s, s->channels);
1189
1190 if(downmix_output) {
ac2e5564 1191 s->dsp.ac3_downmix(s->output, s->downmix_coeffs, s->out_channels, s->fbw_channels, 256);
38dae9c3
JR
1192 }
1193 } else {
1194 if(downmix_output) {
ac2e5564 1195 s->dsp.ac3_downmix(s->transform_coeffs+1, s->downmix_coeffs, s->out_channels, s->fbw_channels, 256);
38dae9c3
JR
1196 }
1197
45d9d618 1198 if(downmix_output && !s->downmixed) {
38dae9c3 1199 s->downmixed = 1;
ac2e5564 1200 s->dsp.ac3_downmix(s->delay, s->downmix_coeffs, s->out_channels, s->fbw_channels, 128);
38dae9c3 1201 }
486637af 1202
38dae9c3 1203 do_imdct(s, s->out_channels);
3bbb0bf8
JR
1204 }
1205
4e092320 1206 return 0;
486637af
JR
1207}
1208
5066f515
JR
1209/**
1210 * Decode a single AC-3 frame.
c7cfc48f 1211 */
98f6dfa6 1212static int ac3_decode_frame(AVCodecContext * avctx, void *data, int *data_size,
7a00bbad 1213 AVPacket *avpkt)
1b293437 1214{
7a00bbad
TB
1215 const uint8_t *buf = avpkt->data;
1216 int buf_size = avpkt->size;
0345fade 1217 AC3DecodeContext *s = avctx->priv_data;
00585845 1218 int16_t *out_samples = (int16_t *)data;
72745cff 1219 int blk, ch, err;
95f3019a 1220 const uint8_t *channel_map;
13ec9428 1221 const float *output[AC3_MAX_CHANNELS];
d7bcc4ad 1222
5066f515 1223 /* initialize the GetBitContext with the start of valid AC-3 Frame */
509fdb0b 1224 if (s->input_buffer) {
c33a1967
JR
1225 /* copy input buffer to decoder context to avoid reading past the end
1226 of the buffer, which can be caused by a damaged input stream. */
8e33132b 1227 memcpy(s->input_buffer, buf, FFMIN(buf_size, AC3_FRAME_BUFFER_SIZE));
c33a1967
JR
1228 init_get_bits(&s->gbc, s->input_buffer, buf_size * 8);
1229 } else {
984ff38a 1230 init_get_bits(&s->gbc, buf, buf_size * 8);
c33a1967 1231 }
00585845 1232
5066f515 1233 /* parse the syncinfo */
c78c6d6c 1234 *data_size = 0;
4397d95c 1235 err = parse_frame_header(s);
c78c6d6c
JR
1236
1237 /* check that reported frame size fits in input buffer */
1238 if(s->frame_size > buf_size) {
1239 av_log(avctx, AV_LOG_ERROR, "incomplete frame\n");
11d6f38c 1240 err = AAC_AC3_PARSE_ERROR_FRAME_SIZE;
c78c6d6c
JR
1241 }
1242
1243 /* check for crc mismatch */
11d6f38c 1244 if(err != AAC_AC3_PARSE_ERROR_FRAME_SIZE && avctx->error_recognition >= FF_ER_CAREFUL) {
c78c6d6c
JR
1245 if(av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0, &buf[2], s->frame_size-2)) {
1246 av_log(avctx, AV_LOG_ERROR, "frame CRC mismatch\n");
11d6f38c 1247 err = AAC_AC3_PARSE_ERROR_CRC;
c78c6d6c
JR
1248 }
1249 }
1250
11d6f38c 1251 if(err && err != AAC_AC3_PARSE_ERROR_CRC) {
3df88093 1252 switch(err) {
11d6f38c 1253 case AAC_AC3_PARSE_ERROR_SYNC:
c78c6d6c 1254 av_log(avctx, AV_LOG_ERROR, "frame sync error\n");
7af26d14 1255 return -1;
11d6f38c 1256 case AAC_AC3_PARSE_ERROR_BSID:
3df88093
JR
1257 av_log(avctx, AV_LOG_ERROR, "invalid bitstream id\n");
1258 break;
11d6f38c 1259 case AAC_AC3_PARSE_ERROR_SAMPLE_RATE:
3df88093
JR
1260 av_log(avctx, AV_LOG_ERROR, "invalid sample rate\n");
1261 break;
11d6f38c 1262 case AAC_AC3_PARSE_ERROR_FRAME_SIZE:
3df88093
JR
1263 av_log(avctx, AV_LOG_ERROR, "invalid frame size\n");
1264 break;
11d6f38c 1265 case AAC_AC3_PARSE_ERROR_FRAME_TYPE:
aa5d6be8
JR
1266 /* skip frame if CRC is ok. otherwise use error concealment. */
1267 /* TODO: add support for substreams and dependent frames */
1268 if(s->frame_type == EAC3_FRAME_TYPE_DEPENDENT || s->substreamid) {
1269 av_log(avctx, AV_LOG_ERROR, "unsupported frame type : skipping frame\n");
1270 return s->frame_size;
1271 } else {
4921bbba 1272 av_log(avctx, AV_LOG_ERROR, "invalid frame type\n");
aa5d6be8 1273 }
4e6eeaf0 1274 break;
3df88093
JR
1275 default:
1276 av_log(avctx, AV_LOG_ERROR, "invalid header\n");
1277 break;
1278 }
1b293437 1279 }
2aa2c5c4 1280
eccba2bc
JR
1281 /* if frame is ok, set audio parameters */
1282 if (!err) {
3336110a
JR
1283 avctx->sample_rate = s->sample_rate;
1284 avctx->bit_rate = s->bit_rate;
1285
1286 /* channel config */
1287 s->out_channels = s->channels;
eccba2bc
JR
1288 s->output_mode = s->channel_mode;
1289 if(s->lfe_on)
1290 s->output_mode |= AC3_OUTPUT_LFEON;
3336110a
JR
1291 if (avctx->request_channels > 0 && avctx->request_channels <= 2 &&
1292 avctx->request_channels < s->channels) {
1293 s->out_channels = avctx->request_channels;
1294 s->output_mode = avctx->request_channels == 1 ? AC3_CHMODE_MONO : AC3_CHMODE_STEREO;
bfeca7be 1295 s->channel_layout = ff_ac3_channel_layout_tab[s->output_mode];
3336110a
JR
1296 }
1297 avctx->channels = s->out_channels;
bfeca7be 1298 avctx->channel_layout = s->channel_layout;
1b293437 1299
3336110a
JR
1300 /* set downmixing coefficients if needed */
1301 if(s->channels != s->out_channels && !((s->output_mode & AC3_OUTPUT_LFEON) &&
1302 s->fbw_channels == s->out_channels)) {
1303 set_downmix_coeffs(s);
1304 }
eccba2bc
JR
1305 } else if (!s->out_channels) {
1306 s->out_channels = avctx->channels;
1307 if(s->out_channels < s->channels)
1308 s->output_mode = s->out_channels == 1 ? AC3_CHMODE_MONO : AC3_CHMODE_STEREO;
ecfe94b2 1309 }
f0b3a7ba 1310
022845ed 1311 /* decode the audio blocks */
95f3019a 1312 channel_map = ff_ac3_dec_channel_map[s->output_mode & ~AC3_OUTPUT_LFEON][s->lfe_on];
52dc3fc8
JR
1313 for (ch = 0; ch < s->out_channels; ch++)
1314 output[ch] = s->output[channel_map[ch]];
6730e9f3 1315 for (blk = 0; blk < s->num_blocks; blk++) {
022845ed
JR
1316 if (!err && decode_audio_block(s, blk)) {
1317 av_log(avctx, AV_LOG_ERROR, "error decoding the audio block\n");
af2272b2 1318 err = 1;
1b293437 1319 }
72745cff
LM
1320 s->dsp.float_to_int16_interleave(out_samples, output, 256, s->out_channels);
1321 out_samples += 256 * s->out_channels;
1b293437 1322 }
6730e9f3 1323 *data_size = s->num_blocks * 256 * avctx->channels * sizeof (int16_t);
d802d7ca 1324 return s->frame_size;
2aa2c5c4 1325}
1b293437 1326
5066f515
JR
1327/**
1328 * Uninitialize the AC-3 decoder.
c7cfc48f 1329 */
98a6fff9 1330static av_cold int ac3_decode_end(AVCodecContext *avctx)
1b293437 1331{
0345fade 1332 AC3DecodeContext *s = avctx->priv_data;
d802d7ca
JR
1333 ff_mdct_end(&s->imdct_512);
1334 ff_mdct_end(&s->imdct_256);
c7cfc48f 1335
509fdb0b
JR
1336 av_freep(&s->input_buffer);
1337
1b293437
JR
1338 return 0;
1339}
1340
fa67992d 1341AVCodec ac3_decoder = {
e6bca37c
JR
1342 .name = "ac3",
1343 .type = CODEC_TYPE_AUDIO,
1344 .id = CODEC_ID_AC3,
1345 .priv_data_size = sizeof (AC3DecodeContext),
1346 .init = ac3_decode_init,
1347 .close = ac3_decode_end,
1348 .decode = ac3_decode_frame,
2988c93d
JR
1349 .long_name = NULL_IF_CONFIG_SMALL("ATSC A/52A (AC-3)"),
1350};
1351
89547cfb 1352#if CONFIG_EAC3_DECODER
2988c93d
JR
1353AVCodec eac3_decoder = {
1354 .name = "eac3",
1355 .type = CODEC_TYPE_AUDIO,
1356 .id = CODEC_ID_EAC3,
1357 .priv_data_size = sizeof (AC3DecodeContext),
1358 .init = ac3_decode_init,
1359 .close = ac3_decode_end,
1360 .decode = ac3_decode_frame,
1361 .long_name = NULL_IF_CONFIG_SMALL("ATSC A/52B (AC-3, E-AC-3)"),
1b293437 1362};
89547cfb 1363#endif