Rearrange loop structure for approx. 35-50% faster calc_transform_coeffs_cpl()
[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
8e33132b
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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
7417120b
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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
5aefe3eb
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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 */
caf0fbc8
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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/**
30f71adc
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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] = {
caf0fbc8
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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
c7cfc48f
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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
5aefe3eb
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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 */
602116df
JR
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);
5aefe3eb
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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
3357ff33
JR
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
5066f515
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182/**
183 * AVCodec initialization
184 */
98a6fff9 185static av_cold int ac3_decode_init(AVCodecContext *avctx)
1b293437 186{
d802d7ca
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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) {
d802d7ca
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200 s->add_bias = 385.0f;
201 s->mul_bias = 1.0f;
4e092320 202 } else {
d802d7ca
JR
203 s->add_bias = 0.0f;
204 s->mul_bias = 32767.0f;
4e092320
JR
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);
509fdb0b
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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{
4397d95c
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
4397d95c
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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);
9fc1ab72
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277 if(err)
278 return err;
279
280 /* get decoding parameters from header info */
d802d7ca
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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
JR
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
6e74513a
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++) {
8b11b44e 419 int band_start = bin;
3b6c5ad2 420 int band_end = bin + s->cpl_band_sizes[band];
8b11b44e
JR
421 for (ch = 1; ch <= s->fbw_channels; ch++) {
422 if (s->channel_in_cpl[ch]) {
423 int64_t cpl_coord = s->cpl_coords[ch][band];
424 for (bin = band_start; bin < band_end; bin++) {
02587373 425 s->fixed_coeffs[ch][bin] = ((int64_t)s->fixed_coeffs[CPL_CH][bin] *
8b11b44e
JR
426 cpl_coord) >> 23;
427 }
428 if (ch == 2 && s->phase_flags[band]) {
429 for (bin = band_start; bin < band_end; bin++)
430 s->fixed_coeffs[2][bin] = -s->fixed_coeffs[2][bin];
d7dc7ad0 431 }
b972c06a 432 }
60313902 433 }
8b11b44e 434 bin = band_end;
d7dc7ad0
JR
435 }
436}
437
5066f515
JR
438/**
439 * Grouped mantissas for 3-level 5-level and 11-level quantization
440 */
441typedef struct {
d869a460
JGG
442 int b1_mant[2];
443 int b2_mant[2];
444 int b4_mant;
445 int b1;
446 int b2;
447 int b4;
486637af
JR
448} mant_groups;
449
5066f515 450/**
e522bd49 451 * Decode the transform coefficients for a particular channel
5066f515
JR
452 * reference: Section 7.3 Quantization and Decoding of Mantissas
453 */
e43b29ab 454static void ac3_decode_transform_coeffs_ch(AC3DecodeContext *s, int ch_index, mant_groups *m)
1b293437 455{
d869a460
JGG
456 int start_freq = s->start_freq[ch_index];
457 int end_freq = s->end_freq[ch_index];
458 uint8_t *baps = s->bap[ch_index];
459 int8_t *exps = s->dexps[ch_index];
460 int *coeffs = s->fixed_coeffs[ch_index];
25dcd182 461 int dither = (ch_index == CPL_CH) || s->dither_flag[ch_index];
d802d7ca 462 GetBitContext *gbc = &s->gbc;
d869a460 463 int freq;
2fbbd087 464
d869a460
JGG
465 for(freq = start_freq; freq < end_freq; freq++){
466 int bap = baps[freq];
467 int mantissa;
468 switch(bap){
1b293437 469 case 0:
25dcd182 470 if (dither)
a521aadf 471 mantissa = (av_lfg_get(&s->dith_state) & 0x7FFFFF) - 0x400000;
25dcd182
JR
472 else
473 mantissa = 0;
d63f6fea 474 break;
1b293437 475 case 1:
d869a460
JGG
476 if(m->b1){
477 m->b1--;
478 mantissa = m->b1_mant[m->b1];
479 }
480 else{
481 int bits = get_bits(gbc, 5);
482 mantissa = b1_mantissas[bits][0];
483 m->b1_mant[1] = b1_mantissas[bits][1];
484 m->b1_mant[0] = b1_mantissas[bits][2];
485 m->b1 = 2;
1b293437 486 }
d63f6fea 487 break;
1b293437 488 case 2:
d869a460
JGG
489 if(m->b2){
490 m->b2--;
491 mantissa = m->b2_mant[m->b2];
492 }
493 else{
494 int bits = get_bits(gbc, 7);
495 mantissa = b2_mantissas[bits][0];
496 m->b2_mant[1] = b2_mantissas[bits][1];
497 m->b2_mant[0] = b2_mantissas[bits][2];
498 m->b2 = 2;
1b293437 499 }
d63f6fea 500 break;
1b293437 501 case 3:
d869a460 502 mantissa = b3_mantissas[get_bits(gbc, 3)];
d63f6fea 503 break;
1b293437 504 case 4:
d869a460
JGG
505 if(m->b4){
506 m->b4 = 0;
507 mantissa = m->b4_mant;
508 }
509 else{
510 int bits = get_bits(gbc, 7);
511 mantissa = b4_mantissas[bits][0];
512 m->b4_mant = b4_mantissas[bits][1];
513 m->b4 = 1;
1b293437 514 }
d63f6fea 515 break;
1b293437 516 case 5:
d869a460 517 mantissa = b5_mantissas[get_bits(gbc, 4)];
d63f6fea 518 break;
d869a460
JGG
519 default: /* 6 to 15 */
520 mantissa = get_bits(gbc, quantization_tab[bap]);
521 /* Shift mantissa and sign-extend it. */
522 mantissa = (mantissa << (32-quantization_tab[bap]))>>8;
d63f6fea 523 break;
1b293437 524 }
d869a460 525 coeffs[freq] = mantissa >> exps[freq];
1b293437 526 }
1b293437
JR
527}
528
60f07fad 529/**
25dcd182
JR
530 * Remove random dithering from coupling range coefficients with zero-bit
531 * mantissas for coupled channels which do not use dithering.
60f07fad
JR
532 * reference: Section 7.3.4 Dither for Zero Bit Mantissas (bap=0)
533 */
d802d7ca 534static void remove_dithering(AC3DecodeContext *s) {
60f07fad 535 int ch, i;
60f07fad 536
d802d7ca 537 for(ch=1; ch<=s->fbw_channels; ch++) {
25dcd182
JR
538 if(!s->dither_flag[ch] && s->channel_in_cpl[ch]) {
539 for(i = s->start_freq[CPL_CH]; i<s->end_freq[CPL_CH]; i++) {
540 if(!s->bap[CPL_CH][i])
541 s->fixed_coeffs[ch][i] = 0;
60f07fad
JR
542 }
543 }
544 }
545}
546
6a68105e 547static void decode_transform_coeffs_ch(AC3DecodeContext *s, int blk, int ch,
bf09b550
JR
548 mant_groups *m)
549{
550 if (!s->channel_uses_aht[ch]) {
6a68105e 551 ac3_decode_transform_coeffs_ch(s, ch, m);
bf09b550
JR
552 } else {
553 /* if AHT is used, mantissas for all blocks are encoded in the first
554 block of the frame. */
555 int bin;
d1515324 556 if (!blk && CONFIG_EAC3_DECODER)
6a68105e 557 ff_eac3_decode_transform_coeffs_aht_ch(s, ch);
bf09b550 558 for (bin = s->start_freq[ch]; bin < s->end_freq[ch]; bin++) {
ae04de31 559 s->fixed_coeffs[ch][bin] = s->pre_mantissa[ch][bin][blk] >> s->dexps[ch][bin];
bf09b550
JR
560 }
561 }
562}
bf09b550 563
5066f515 564/**
164e169f 565 * Decode the transform coefficients.
c7cfc48f 566 */
e43b29ab 567static void decode_transform_coeffs(AC3DecodeContext *s, int blk)
1b293437 568{
7b4076a7 569 int ch, end;
1b293437 570 int got_cplchan = 0;
486637af
JR
571 mant_groups m;
572
d869a460 573 m.b1 = m.b2 = m.b4 = 0;
1b293437 574
d802d7ca 575 for (ch = 1; ch <= s->channels; ch++) {
5066f515 576 /* transform coefficients for full-bandwidth channel */
e43b29ab 577 decode_transform_coeffs_ch(s, blk, ch, &m);
5066f515
JR
578 /* tranform coefficients for coupling channel come right after the
579 coefficients for the first coupled channel*/
d802d7ca 580 if (s->channel_in_cpl[ch]) {
486637af 581 if (!got_cplchan) {
e43b29ab 582 decode_transform_coeffs_ch(s, blk, CPL_CH, &m);
5e3e4075 583 calc_transform_coeffs_cpl(s);
486637af
JR
584 got_cplchan = 1;
585 }
d802d7ca 586 end = s->end_freq[CPL_CH];
eaf84d97 587 } else {
d802d7ca 588 end = s->end_freq[ch];
eaf84d97 589 }
486637af 590 do
bd98e9e2 591 s->fixed_coeffs[ch][end] = 0;
486637af
JR
592 while(++end < 256);
593 }
1b293437 594
ea364c74 595 /* zero the dithered coefficients for appropriate channels */
86662b1c 596 remove_dithering(s);
2aa2c5c4
JR
597}
598
8b60bbbf 599/**
5066f515 600 * Stereo rematrixing.
8b60bbbf
JR
601 * reference: Section 7.5.4 Rematrixing : Decoding Technique
602 */
d802d7ca 603static void do_rematrixing(AC3DecodeContext *s)
1b293437 604{
8b60bbbf 605 int bnd, i;
2fbbd087 606 int end, bndend;
a4de6dd2 607 int tmp0, tmp1;
2fbbd087 608
d802d7ca 609 end = FFMIN(s->end_freq[1], s->end_freq[2]);
1b293437 610
d802d7ca
JR
611 for(bnd=0; bnd<s->num_rematrixing_bands; bnd++) {
612 if(s->rematrixing_flags[bnd]) {
227322b8
JR
613 bndend = FFMIN(end, ff_ac3_rematrix_band_tab[bnd+1]);
614 for(i=ff_ac3_rematrix_band_tab[bnd]; i<bndend; i++) {
a4de6dd2
JR
615 tmp0 = s->fixed_coeffs[1][i];
616 tmp1 = s->fixed_coeffs[2][i];
617 s->fixed_coeffs[1][i] = tmp0 + tmp1;
618 s->fixed_coeffs[2][i] = tmp0 - tmp1;
8b60bbbf
JR
619 }
620 }
1b293437
JR
621 }
622}
2aa2c5c4 623
5066f515 624/**
5066f515
JR
625 * Inverse MDCT Transform.
626 * Convert frequency domain coefficients to time-domain audio samples.
627 * reference: Section 7.9.4 Transformation Equations
628 */
38dae9c3 629static inline void do_imdct(AC3DecodeContext *s, int channels)
486637af 630{
0de73a46 631 int ch;
3b6516f7
LM
632 float add_bias = s->add_bias;
633 if(s->out_channels==1 && channels>1)
634 add_bias *= LEVEL_MINUS_3DB; // compensate for the gain in downmix
7b4076a7 635
e2270b4e 636 for (ch=1; ch<=channels; ch++) {
d802d7ca 637 if (s->block_switch[ch]) {
916d5d6c
LM
638 int i;
639 float *x = s->tmp_output+128;
640 for(i=0; i<128; i++)
641 x[i] = s->transform_coeffs[ch][2*i];
642 ff_imdct_half(&s->imdct_256, s->tmp_output, x);
3b6516f7 643 s->dsp.vector_fmul_window(s->output[ch-1], s->delay[ch-1], s->tmp_output, s->window, add_bias, 128);
916d5d6c
LM
644 for(i=0; i<128; i++)
645 x[i] = s->transform_coeffs[ch][2*i+1];
646 ff_imdct_half(&s->imdct_256, s->delay[ch-1], x);
eaf84d97 647 } else {
916d5d6c 648 ff_imdct_half(&s->imdct_512, s->tmp_output, s->transform_coeffs[ch]);
3b6516f7 649 s->dsp.vector_fmul_window(s->output[ch-1], s->delay[ch-1], s->tmp_output, s->window, add_bias, 128);
916d5d6c 650 memcpy(s->delay[ch-1], s->tmp_output+128, 128*sizeof(float));
eaf84d97 651 }
486637af
JR
652 }
653}
654
3bbb0bf8 655/**
5066f515 656 * Downmix the output to mono or stereo.
3bbb0bf8 657 */
ac2e5564 658void ff_ac3_downmix_c(float (*samples)[256], float (*matrix)[2], int out_ch, int in_ch, int len)
3bbb0bf8
JR
659{
660 int i, j;
9d10e6e6 661 float v0, v1;
ac2e5564
LM
662 if(out_ch == 2) {
663 for(i=0; i<len; i++) {
557ac0c4 664 v0 = v1 = 0.0f;
ac2e5564
LM
665 for(j=0; j<in_ch; j++) {
666 v0 += samples[j][i] * matrix[j][0];
667 v1 += samples[j][i] * matrix[j][1];
557ac0c4
LM
668 }
669 samples[0][i] = v0;
670 samples[1][i] = v1;
3bbb0bf8 671 }
ac2e5564
LM
672 } else if(out_ch == 1) {
673 for(i=0; i<len; i++) {
557ac0c4 674 v0 = 0.0f;
ac2e5564
LM
675 for(j=0; j<in_ch; j++)
676 v0 += samples[j][i] * matrix[j][0];
557ac0c4 677 samples[0][i] = v0;
3bbb0bf8
JR
678 }
679 }
680}
681
5066f515 682/**
38dae9c3
JR
683 * Upmix delay samples from stereo to original channel layout.
684 */
685static void ac3_upmix_delay(AC3DecodeContext *s)
686{
e6300276 687 int channel_data_size = sizeof(s->delay[0]);
38dae9c3
JR
688 switch(s->channel_mode) {
689 case AC3_CHMODE_DUALMONO:
690 case AC3_CHMODE_STEREO:
691 /* upmix mono to stereo */
692 memcpy(s->delay[1], s->delay[0], channel_data_size);
693 break;
694 case AC3_CHMODE_2F2R:
695 memset(s->delay[3], 0, channel_data_size);
696 case AC3_CHMODE_2F1R:
697 memset(s->delay[2], 0, channel_data_size);
698 break;
699 case AC3_CHMODE_3F2R:
700 memset(s->delay[4], 0, channel_data_size);
701 case AC3_CHMODE_3F1R:
702 memset(s->delay[3], 0, channel_data_size);
703 case AC3_CHMODE_3F:
704 memcpy(s->delay[2], s->delay[1], channel_data_size);
705 memset(s->delay[1], 0, channel_data_size);
706 break;
707 }
708}
709
710/**
0c5d750d 711 * Decode band structure for coupling, spectral extension, or enhanced coupling.
eb98cdfa
JR
712 * The band structure defines how many subbands are in each band. For each
713 * subband in the range, 1 means it is combined with the previous band, and 0
714 * means that it starts a new band.
715 *
0c5d750d
JR
716 * @param[in] gbc bit reader context
717 * @param[in] blk block number
718 * @param[in] eac3 flag to indicate E-AC-3
719 * @param[in] ecpl flag to indicate enhanced coupling
720 * @param[in] start_subband subband number for start of range
721 * @param[in] end_subband subband number for end of range
722 * @param[in] default_band_struct default band structure table
0c5d750d
JR
723 * @param[out] num_bands number of bands (optionally NULL)
724 * @param[out] band_sizes array containing the number of bins in each band (optionally NULL)
725 */
726static void decode_band_structure(GetBitContext *gbc, int blk, int eac3,
727 int ecpl, int start_subband, int end_subband,
728 const uint8_t *default_band_struct,
c36ea060 729 int *num_bands, uint8_t *band_sizes)
0c5d750d 730{
f23dc1e1 731 int subbnd, bnd, n_subbands, n_bands=0;
75b53b21 732 uint8_t bnd_sz[22];
3f937168
JR
733 uint8_t coded_band_struct[22];
734 const uint8_t *band_struct;
0c5d750d
JR
735
736 n_subbands = end_subband - start_subband;
737
738 /* decode band structure from bitstream or use default */
739 if (!eac3 || get_bits1(gbc)) {
740 for (subbnd = 0; subbnd < n_subbands - 1; subbnd++) {
3f937168 741 coded_band_struct[subbnd] = get_bits1(gbc);
0c5d750d 742 }
3f937168 743 band_struct = coded_band_struct;
0c5d750d 744 } else if (!blk) {
3f937168
JR
745 band_struct = &default_band_struct[start_subband+1];
746 } else {
747 /* no change in band structure */
748 return;
0c5d750d 749 }
0c5d750d
JR
750
751 /* calculate number of bands and band sizes based on band structure.
752 note that the first 4 subbands in enhanced coupling span only 6 bins
753 instead of 12. */
754 if (num_bands || band_sizes ) {
e202cc25 755 n_bands = n_subbands;
0c5d750d
JR
756 bnd_sz[0] = ecpl ? 6 : 12;
757 for (bnd = 0, subbnd = 1; subbnd < n_subbands; subbnd++) {
758 int subbnd_size = (ecpl && subbnd < 4) ? 6 : 12;
759 if (band_struct[subbnd-1]) {
760 n_bands--;
761 bnd_sz[bnd] += subbnd_size;
762 } else {
763 bnd_sz[++bnd] = subbnd_size;
764 }
765 }
766 }
767
768 /* set optional output params */
0c5d750d
JR
769 if (num_bands)
770 *num_bands = n_bands;
771 if (band_sizes)
75b53b21 772 memcpy(band_sizes, bnd_sz, n_bands);
0c5d750d
JR
773}
774
775/**
022845ed 776 * Decode a single audio block from the AC-3 bitstream.
c7cfc48f 777 */
022845ed 778static int decode_audio_block(AC3DecodeContext *s, int blk)
2aa2c5c4 779{
d802d7ca
JR
780 int fbw_channels = s->fbw_channels;
781 int channel_mode = s->channel_mode;
0bff58a5 782 int i, bnd, seg, ch;
38dae9c3
JR
783 int different_transforms;
784 int downmix_output;
54624396 785 int cpl_in_use;
d802d7ca 786 GetBitContext *gbc = &s->gbc;
7b4076a7 787 uint8_t bit_alloc_stages[AC3_MAX_CHANNELS];
1b293437 788
7b4076a7
JR
789 memset(bit_alloc_stages, 0, AC3_MAX_CHANNELS);
790
5066f515 791 /* block switch flags */
38dae9c3 792 different_transforms = 0;
bf09b550 793 if (s->block_switch_syntax) {
ab2a942a
JR
794 for (ch = 1; ch <= fbw_channels; ch++) {
795 s->block_switch[ch] = get_bits1(gbc);
796 if(ch > 1 && s->block_switch[ch] != s->block_switch[1])
797 different_transforms = 1;
798 }
bf09b550 799 }
98a27a8a 800
5066f515 801 /* dithering flags */
bf09b550 802 if (s->dither_flag_syntax) {
ab2a942a
JR
803 for (ch = 1; ch <= fbw_channels; ch++) {
804 s->dither_flag[ch] = get_bits1(gbc);
ab2a942a 805 }
bf09b550 806 }
98a27a8a 807
77416325 808 /* dynamic range */
d802d7ca 809 i = !(s->channel_mode);
77416325 810 do {
23c8cb89 811 if(get_bits1(gbc)) {
d802d7ca 812 s->dynamic_range[i] = ((dynamic_range_tab[get_bits(gbc, 8)]-1.0) *
1b70d88b 813 s->avctx->drc_scale)+1.0;
9fc1ab72 814 } else if(blk == 0) {
d802d7ca 815 s->dynamic_range[i] = 1.0f;
9fc1ab72 816 }
77416325 817 } while(i--);
98a27a8a 818
6fafb020
JR
819 /* spectral extension strategy */
820 if (s->eac3 && (!blk || get_bits1(gbc))) {
e202cc25 821 if (get_bits1(gbc)) {
ce863d7f 822 av_log_missing_feature(s->avctx, "Spectral extension", 1);
e202cc25 823 return -1;
6fafb020 824 }
e202cc25 825 /* TODO: parse spectral extension strategy info */
6fafb020
JR
826 }
827
e202cc25 828 /* TODO: spectral extension coordinates */
6fafb020 829
5066f515 830 /* coupling strategy */
225c3042 831 if (s->eac3 ? s->cpl_strategy_exists[blk] : get_bits1(gbc)) {
7b4076a7 832 memset(bit_alloc_stages, 3, AC3_MAX_CHANNELS);
6fafb020 833 if (!s->eac3)
0569993e 834 s->cpl_in_use[blk] = get_bits1(gbc);
4760aec6 835 if (s->cpl_in_use[blk]) {
5066f515 836 /* coupling in use */
24834c19 837 int cpl_start_subband, cpl_end_subband;
b6acc57f 838
3af91313
JR
839 if (channel_mode < AC3_CHMODE_STEREO) {
840 av_log(s->avctx, AV_LOG_ERROR, "coupling not allowed in mono or dual-mono\n");
841 return -1;
842 }
843
6fafb020
JR
844 /* check for enhanced coupling */
845 if (s->eac3 && get_bits1(gbc)) {
846 /* TODO: parse enhanced coupling strategy info */
ce863d7f 847 av_log_missing_feature(s->avctx, "Enhanced coupling", 1);
6fafb020
JR
848 return -1;
849 }
850
5066f515 851 /* determine which channels are coupled */
6fafb020
JR
852 if (s->eac3 && s->channel_mode == AC3_CHMODE_STEREO) {
853 s->channel_in_cpl[1] = 1;
854 s->channel_in_cpl[2] = 1;
855 } else {
0569993e
JR
856 for (ch = 1; ch <= fbw_channels; ch++)
857 s->channel_in_cpl[ch] = get_bits1(gbc);
6fafb020 858 }
98a27a8a 859
5066f515 860 /* phase flags in use */
e59cc205 861 if (channel_mode == AC3_CHMODE_STEREO)
d802d7ca 862 s->phase_flags_in_use = get_bits1(gbc);
98a27a8a 863
6fafb020 864 /* coupling frequency range */
e202cc25 865 /* TODO: modify coupling end freq if spectral extension is used */
24834c19 866 cpl_start_subband = get_bits(gbc, 4);
e202cc25 867 cpl_end_subband = get_bits(gbc, 4) + 3;
1ac7d1ac
JR
868 if (cpl_start_subband >= cpl_end_subband) {
869 av_log(s->avctx, AV_LOG_ERROR, "invalid coupling range (%d >= %d)\n",
6ee6d068 870 cpl_start_subband, cpl_end_subband);
00585845 871 return -1;
98a27a8a 872 }
24834c19 873 s->start_freq[CPL_CH] = cpl_start_subband * 12 + 37;
6ee6d068 874 s->end_freq[CPL_CH] = cpl_end_subband * 12 + 37;
6fafb020 875
778bc09b
JR
876 decode_band_structure(gbc, blk, s->eac3, 0, cpl_start_subband,
877 cpl_end_subband,
878 ff_eac3_default_cpl_band_struct,
c36ea060 879 &s->num_cpl_bands, s->cpl_band_sizes);
878c40a1 880 } else {
5066f515 881 /* coupling not in use */
6fafb020 882 for (ch = 1; ch <= fbw_channels; ch++) {
d802d7ca 883 s->channel_in_cpl[ch] = 0;
6fafb020
JR
884 s->first_cpl_coords[ch] = 1;
885 }
63d72fb1 886 s->first_cpl_leak = s->eac3;
6fafb020 887 s->phase_flags_in_use = 0;
1b293437 888 }
6fafb020
JR
889 } else if (!s->eac3) {
890 if(!blk) {
0569993e
JR
891 av_log(s->avctx, AV_LOG_ERROR, "new coupling strategy must be present in block 0\n");
892 return -1;
893 } else {
894 s->cpl_in_use[blk] = s->cpl_in_use[blk-1];
895 }
6fafb020 896 }
4760aec6 897 cpl_in_use = s->cpl_in_use[blk];
98a27a8a 898
5066f515 899 /* coupling coordinates */
54624396 900 if (cpl_in_use) {
e2270b4e 901 int cpl_coords_exist = 0;
98a27a8a 902
e2270b4e 903 for (ch = 1; ch <= fbw_channels; ch++) {
d802d7ca 904 if (s->channel_in_cpl[ch]) {
225c3042 905 if ((s->eac3 && s->first_cpl_coords[ch]) || get_bits1(gbc)) {
e2270b4e 906 int master_cpl_coord, cpl_coord_exp, cpl_coord_mant;
225c3042 907 s->first_cpl_coords[ch] = 0;
e2270b4e 908 cpl_coords_exist = 1;
23c8cb89 909 master_cpl_coord = 3 * get_bits(gbc, 2);
d802d7ca 910 for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
23c8cb89
JR
911 cpl_coord_exp = get_bits(gbc, 4);
912 cpl_coord_mant = get_bits(gbc, 4);
e2270b4e 913 if (cpl_coord_exp == 15)
a4de6dd2 914 s->cpl_coords[ch][bnd] = cpl_coord_mant << 22;
486637af 915 else
a4de6dd2
JR
916 s->cpl_coords[ch][bnd] = (cpl_coord_mant + 16) << 21;
917 s->cpl_coords[ch][bnd] >>= (cpl_coord_exp + master_cpl_coord);
486637af 918 }
82a591d8
JR
919 } else if (!blk) {
920 av_log(s->avctx, AV_LOG_ERROR, "new coupling coordinates must be present in block 0\n");
921 return -1;
486637af 922 }
225c3042
JR
923 } else {
924 /* channel not in coupling */
925 s->first_cpl_coords[ch] = 1;
eaf84d97
JR
926 }
927 }
5066f515 928 /* phase flags */
b02fbf75 929 if (channel_mode == AC3_CHMODE_STEREO && cpl_coords_exist) {
d802d7ca 930 for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
b02fbf75 931 s->phase_flags[bnd] = s->phase_flags_in_use? get_bits1(gbc) : 0;
eaf84d97
JR
932 }
933 }
2aa2c5c4 934 }
98a27a8a 935
5066f515 936 /* stereo rematrixing strategy and band structure */
e59cc205 937 if (channel_mode == AC3_CHMODE_STEREO) {
6fafb020 938 if ((s->eac3 && !blk) || get_bits1(gbc)) {
d802d7ca 939 s->num_rematrixing_bands = 4;
e202cc25
JR
940 if(cpl_in_use && s->start_freq[CPL_CH] <= 61)
941 s->num_rematrixing_bands -= 1 + (s->start_freq[CPL_CH] == 37);
d802d7ca
JR
942 for(bnd=0; bnd<s->num_rematrixing_bands; bnd++)
943 s->rematrixing_flags[bnd] = get_bits1(gbc);
82a591d8
JR
944 } else if (!blk) {
945 av_log(s->avctx, AV_LOG_ERROR, "new rematrixing strategy must be present in block 0\n");
946 return -1;
1b293437 947 }
98a27a8a
JR
948 }
949
5066f515 950 /* exponent strategies for each channel */
54624396 951 for (ch = !cpl_in_use; ch <= s->channels; ch++) {
6b4bfed9 952 if (!s->eac3)
aec0407f 953 s->exp_strategy[blk][ch] = get_bits(gbc, 2 - (ch == s->lfe_ch));
da04be10 954 if(s->exp_strategy[blk][ch] != EXP_REUSE)
7b4076a7
JR
955 bit_alloc_stages[ch] = 3;
956 }
957
5066f515 958 /* channel bandwidth */
e2270b4e 959 for (ch = 1; ch <= fbw_channels; ch++) {
d802d7ca 960 s->start_freq[ch] = 0;
da04be10 961 if (s->exp_strategy[blk][ch] != EXP_REUSE) {
b85a15fe 962 int group_size;
d802d7ca
JR
963 int prev = s->end_freq[ch];
964 if (s->channel_in_cpl[ch])
965 s->end_freq[ch] = s->start_freq[CPL_CH];
00585845 966 else {
23c8cb89 967 int bandwidth_code = get_bits(gbc, 6);
e2270b4e 968 if (bandwidth_code > 60) {
6c6f9272 969 av_log(s->avctx, AV_LOG_ERROR, "bandwidth code = %d > 60\n", bandwidth_code);
00585845
JR
970 return -1;
971 }
d802d7ca 972 s->end_freq[ch] = bandwidth_code * 3 + 73;
1b293437 973 }
da04be10 974 group_size = 3 << (s->exp_strategy[blk][ch] - 1);
b85a15fe 975 s->num_exp_groups[ch] = (s->end_freq[ch]+group_size-4) / group_size;
d802d7ca 976 if(blk > 0 && s->end_freq[ch] != prev)
7b4076a7 977 memset(bit_alloc_stages, 3, AC3_MAX_CHANNELS);
00585845 978 }
eaf84d97 979 }
da04be10 980 if (cpl_in_use && s->exp_strategy[blk][CPL_CH] != EXP_REUSE) {
b85a15fe 981 s->num_exp_groups[CPL_CH] = (s->end_freq[CPL_CH] - s->start_freq[CPL_CH]) /
da04be10 982 (3 << (s->exp_strategy[blk][CPL_CH] - 1));
b85a15fe 983 }
7b4076a7 984
5066f515 985 /* decode exponents for each channel */
54624396 986 for (ch = !cpl_in_use; ch <= s->channels; ch++) {
da04be10 987 if (s->exp_strategy[blk][ch] != EXP_REUSE) {
d802d7ca 988 s->dexps[ch][0] = get_bits(gbc, 4) << !ch;
ce7d842f 989 if (decode_exponents(gbc, s->exp_strategy[blk][ch],
1cdd567f
JR
990 s->num_exp_groups[ch], s->dexps[ch][0],
991 &s->dexps[ch][s->start_freq[ch]+!!ch])) {
ce7d842f
JR
992 av_log(s->avctx, AV_LOG_ERROR, "exponent out-of-range\n");
993 return -1;
994 }
d802d7ca 995 if(ch != CPL_CH && ch != s->lfe_ch)
23c8cb89 996 skip_bits(gbc, 2); /* skip gainrng */
1b293437 997 }
eaf84d97 998 }
98a27a8a 999
5066f515 1000 /* bit allocation information */
bf09b550 1001 if (s->bit_allocation_syntax) {
ab2a942a
JR
1002 if (get_bits1(gbc)) {
1003 s->bit_alloc_params.slow_decay = ff_ac3_slow_decay_tab[get_bits(gbc, 2)] >> s->bit_alloc_params.sr_shift;
1004 s->bit_alloc_params.fast_decay = ff_ac3_fast_decay_tab[get_bits(gbc, 2)] >> s->bit_alloc_params.sr_shift;
1005 s->bit_alloc_params.slow_gain = ff_ac3_slow_gain_tab[get_bits(gbc, 2)];
1006 s->bit_alloc_params.db_per_bit = ff_ac3_db_per_bit_tab[get_bits(gbc, 2)];
e202cc25 1007 s->bit_alloc_params.floor = ff_ac3_floor_tab[get_bits(gbc, 3)];
ab2a942a
JR
1008 for(ch=!cpl_in_use; ch<=s->channels; ch++)
1009 bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 2);
1010 } else if (!blk) {
1011 av_log(s->avctx, AV_LOG_ERROR, "new bit allocation info must be present in block 0\n");
1012 return -1;
1013 }
bf09b550 1014 }
98a27a8a 1015
5066f515 1016 /* signal-to-noise ratio offsets and fast gains (signal-to-mask ratios) */
8dfc56ec
JR
1017 if(!s->eac3 || !blk){
1018 if(s->snr_offset_strategy && get_bits1(gbc)) {
f2e4eb62
JR
1019 int snr = 0;
1020 int csnr;
1021 csnr = (get_bits(gbc, 6) - 15) << 4;
1022 for (i = ch = !cpl_in_use; ch <= s->channels; ch++) {
1023 /* snr offset */
1024 if (ch == i || s->snr_offset_strategy == 2)
1025 snr = (csnr + get_bits(gbc, 4)) << 2;
1026 /* run at least last bit allocation stage if snr offset changes */
1027 if(blk && s->snr_offset[ch] != snr) {
1028 bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 1);
1029 }
1030 s->snr_offset[ch] = snr;
8dfc56ec
JR
1031
1032 /* fast gain (normal AC-3 only) */
1033 if (!s->eac3) {
1034 int prev = s->fast_gain[ch];
f2e4eb62 1035 s->fast_gain[ch] = ff_ac3_fast_gain_tab[get_bits(gbc, 3)];
8dfc56ec
JR
1036 /* run last 2 bit allocation stages if fast gain changes */
1037 if(blk && prev != s->fast_gain[ch])
1038 bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 2);
8dfc56ec 1039 }
f2e4eb62 1040 }
8dfc56ec 1041 } else if (!s->eac3 && !blk) {
f2e4eb62
JR
1042 av_log(s->avctx, AV_LOG_ERROR, "new snr offsets must be present in block 0\n");
1043 return -1;
8dfc56ec 1044 }
1b293437 1045 }
98a27a8a 1046
6fafb020
JR
1047 /* fast gain (E-AC-3 only) */
1048 if (s->fast_gain_syntax && get_bits1(gbc)) {
1049 for (ch = !cpl_in_use; ch <= s->channels; ch++) {
1050 int prev = s->fast_gain[ch];
1051 s->fast_gain[ch] = ff_ac3_fast_gain_tab[get_bits(gbc, 3)];
1052 /* run last 2 bit allocation stages if fast gain changes */
1053 if(blk && prev != s->fast_gain[ch])
1054 bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 2);
1055 }
1056 } else if (s->eac3 && !blk) {
1057 for (ch = !cpl_in_use; ch <= s->channels; ch++)
1058 s->fast_gain[ch] = ff_ac3_fast_gain_tab[4];
1059 }
1060
1061 /* E-AC-3 to AC-3 converter SNR offset */
1062 if (s->frame_type == EAC3_FRAME_TYPE_INDEPENDENT && get_bits1(gbc)) {
1063 skip_bits(gbc, 10); // skip converter snr offset
1064 }
1065
5066f515 1066 /* coupling leak information */
54624396 1067 if (cpl_in_use) {
8dfc56ec
JR
1068 if (s->first_cpl_leak || get_bits1(gbc)) {
1069 int fl = get_bits(gbc, 3);
1070 int sl = get_bits(gbc, 3);
1071 /* run last 2 bit allocation stages for coupling channel if
1072 coupling leak changes */
1073 if(blk && (fl != s->bit_alloc_params.cpl_fast_leak ||
1074 sl != s->bit_alloc_params.cpl_slow_leak)) {
f2e4eb62 1075 bit_alloc_stages[CPL_CH] = FFMAX(bit_alloc_stages[CPL_CH], 2);
8dfc56ec
JR
1076 }
1077 s->bit_alloc_params.cpl_fast_leak = fl;
1078 s->bit_alloc_params.cpl_slow_leak = sl;
1079 } else if (!s->eac3 && !blk) {
93a2c8c1
JR
1080 av_log(s->avctx, AV_LOG_ERROR, "new coupling leak info must be present in block 0\n");
1081 return -1;
1082 }
8dfc56ec 1083 s->first_cpl_leak = 0;
43ad93a4 1084 }
98a27a8a 1085
5066f515 1086 /* delta bit allocation information */
bf09b550 1087 if (s->dba_syntax && get_bits1(gbc)) {
5066f515 1088 /* delta bit allocation exists (strategy) */
54624396 1089 for (ch = !cpl_in_use; ch <= fbw_channels; ch++) {
d802d7ca
JR
1090 s->dba_mode[ch] = get_bits(gbc, 2);
1091 if (s->dba_mode[ch] == DBA_RESERVED) {
1092 av_log(s->avctx, AV_LOG_ERROR, "delta bit allocation strategy reserved\n");
1b293437
JR
1093 return -1;
1094 }
7b4076a7 1095 bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 2);
1b293437 1096 }
5066f515 1097 /* channel delta offset, len and bit allocation */
54624396 1098 for (ch = !cpl_in_use; ch <= fbw_channels; ch++) {
d802d7ca
JR
1099 if (s->dba_mode[ch] == DBA_NEW) {
1100 s->dba_nsegs[ch] = get_bits(gbc, 3);
1101 for (seg = 0; seg <= s->dba_nsegs[ch]; seg++) {
1102 s->dba_offsets[ch][seg] = get_bits(gbc, 5);
1103 s->dba_lengths[ch][seg] = get_bits(gbc, 4);
1104 s->dba_values[ch][seg] = get_bits(gbc, 3);
1b293437 1105 }
e25973a1
JR
1106 /* run last 2 bit allocation stages if new dba values */
1107 bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 2);
1b293437 1108 }
eaf84d97 1109 }
9fc1ab72 1110 } else if(blk == 0) {
d802d7ca
JR
1111 for(ch=0; ch<=s->channels; ch++) {
1112 s->dba_mode[ch] = DBA_NONE;
9fc1ab72 1113 }
1b293437 1114 }
00585845 1115
5066f515 1116 /* Bit allocation */
54624396 1117 for(ch=!cpl_in_use; ch<=s->channels; ch++) {
7b4076a7
JR
1118 if(bit_alloc_stages[ch] > 2) {
1119 /* Exponent mapping into PSD and PSD integration */
d802d7ca
JR
1120 ff_ac3_bit_alloc_calc_psd(s->dexps[ch],
1121 s->start_freq[ch], s->end_freq[ch],
1122 s->psd[ch], s->band_psd[ch]);
eaf84d97 1123 }
7b4076a7
JR
1124 if(bit_alloc_stages[ch] > 1) {
1125 /* Compute excitation function, Compute masking curve, and
1126 Apply delta bit allocation */
72a6244b 1127 if (ff_ac3_bit_alloc_calc_mask(&s->bit_alloc_params, s->band_psd[ch],
20e04726
JR
1128 s->start_freq[ch], s->end_freq[ch],
1129 s->fast_gain[ch], (ch == s->lfe_ch),
1130 s->dba_mode[ch], s->dba_nsegs[ch],
1131 s->dba_offsets[ch], s->dba_lengths[ch],
1132 s->dba_values[ch], s->mask[ch])) {
72a6244b
JR
1133 av_log(s->avctx, AV_LOG_ERROR, "error in bit allocation\n");
1134 return -1;
1135 }
eaf84d97 1136 }
7b4076a7
JR
1137 if(bit_alloc_stages[ch] > 0) {
1138 /* Compute bit allocation */
bf09b550
JR
1139 const uint8_t *bap_tab = s->channel_uses_aht[ch] ?
1140 ff_eac3_hebap_tab : ff_ac3_bap_tab;
d802d7ca
JR
1141 ff_ac3_bit_alloc_calc_bap(s->mask[ch], s->psd[ch],
1142 s->start_freq[ch], s->end_freq[ch],
1143 s->snr_offset[ch],
1144 s->bit_alloc_params.floor,
bf09b550 1145 bap_tab, s->bap[ch]);
eaf84d97 1146 }
2fbbd087 1147 }
98a27a8a 1148
5066f515 1149 /* unused dummy data */
bf09b550 1150 if (s->skip_syntax && get_bits1(gbc)) {
23c8cb89 1151 int skipl = get_bits(gbc, 9);
98a27a8a 1152 while(skipl--)
23c8cb89 1153 skip_bits(gbc, 8);
1b293437 1154 }
f5cefb21 1155
1b293437 1156 /* unpack the transform coefficients
5066f515 1157 this also uncouples channels if coupling is in use. */
e43b29ab 1158 decode_transform_coeffs(s, blk);
486637af 1159
bf09b550
JR
1160 /* TODO: generate enhanced coupling coordinates and uncouple */
1161
e202cc25
JR
1162 /* TODO: apply spectral extension */
1163
1b293437 1164 /* recover coefficients if rematrixing is in use */
d802d7ca
JR
1165 if(s->channel_mode == AC3_CHMODE_STEREO)
1166 do_rematrixing(s);
1b293437 1167
03726b70 1168 /* apply scaling to coefficients (headroom, dynrng) */
d802d7ca 1169 for(ch=1; ch<=s->channels; ch++) {
a4de6dd2 1170 float gain = s->mul_bias / 4194304.0f;
d802d7ca
JR
1171 if(s->channel_mode == AC3_CHMODE_DUALMONO) {
1172 gain *= s->dynamic_range[ch-1];
7bfd22f2 1173 } else {
d802d7ca 1174 gain *= s->dynamic_range[0];
7bfd22f2 1175 }
911e21a3 1176 s->dsp.int32_to_float_fmul_scalar(s->transform_coeffs[ch], s->fixed_coeffs[ch], gain, 256);
7bfd22f2 1177 }
d7bcc4ad 1178
38dae9c3
JR
1179 /* downmix and MDCT. order depends on whether block switching is used for
1180 any channel in this block. this is because coefficients for the long
1181 and short transforms cannot be mixed. */
1182 downmix_output = s->channels != s->out_channels &&
1183 !((s->output_mode & AC3_OUTPUT_LFEON) &&
1184 s->fbw_channels == s->out_channels);
1185 if(different_transforms) {
1186 /* the delay samples have already been downmixed, so we upmix the delay
1187 samples in order to reconstruct all channels before downmixing. */
1188 if(s->downmixed) {
1189 s->downmixed = 0;
1190 ac3_upmix_delay(s);
1191 }
1192
1193 do_imdct(s, s->channels);
1194
1195 if(downmix_output) {
ac2e5564 1196 s->dsp.ac3_downmix(s->output, s->downmix_coeffs, s->out_channels, s->fbw_channels, 256);
38dae9c3
JR
1197 }
1198 } else {
1199 if(downmix_output) {
ac2e5564 1200 s->dsp.ac3_downmix(s->transform_coeffs+1, s->downmix_coeffs, s->out_channels, s->fbw_channels, 256);
38dae9c3
JR
1201 }
1202
45d9d618 1203 if(downmix_output && !s->downmixed) {
38dae9c3 1204 s->downmixed = 1;
ac2e5564 1205 s->dsp.ac3_downmix(s->delay, s->downmix_coeffs, s->out_channels, s->fbw_channels, 128);
38dae9c3 1206 }
486637af 1207
38dae9c3 1208 do_imdct(s, s->out_channels);
3bbb0bf8
JR
1209 }
1210
4e092320 1211 return 0;
486637af
JR
1212}
1213
5066f515
JR
1214/**
1215 * Decode a single AC-3 frame.
c7cfc48f 1216 */
98f6dfa6 1217static int ac3_decode_frame(AVCodecContext * avctx, void *data, int *data_size,
7a00bbad 1218 AVPacket *avpkt)
1b293437 1219{
7a00bbad
TB
1220 const uint8_t *buf = avpkt->data;
1221 int buf_size = avpkt->size;
0345fade 1222 AC3DecodeContext *s = avctx->priv_data;
00585845 1223 int16_t *out_samples = (int16_t *)data;
72745cff 1224 int blk, ch, err;
95f3019a 1225 const uint8_t *channel_map;
13ec9428 1226 const float *output[AC3_MAX_CHANNELS];
d7bcc4ad 1227
5066f515 1228 /* initialize the GetBitContext with the start of valid AC-3 Frame */
509fdb0b 1229 if (s->input_buffer) {
c33a1967
JR
1230 /* copy input buffer to decoder context to avoid reading past the end
1231 of the buffer, which can be caused by a damaged input stream. */
8e33132b 1232 memcpy(s->input_buffer, buf, FFMIN(buf_size, AC3_FRAME_BUFFER_SIZE));
c33a1967
JR
1233 init_get_bits(&s->gbc, s->input_buffer, buf_size * 8);
1234 } else {
984ff38a 1235 init_get_bits(&s->gbc, buf, buf_size * 8);
c33a1967 1236 }
00585845 1237
5066f515 1238 /* parse the syncinfo */
c78c6d6c 1239 *data_size = 0;
4397d95c 1240 err = parse_frame_header(s);
c78c6d6c
JR
1241
1242 /* check that reported frame size fits in input buffer */
1243 if(s->frame_size > buf_size) {
1244 av_log(avctx, AV_LOG_ERROR, "incomplete frame\n");
11d6f38c 1245 err = AAC_AC3_PARSE_ERROR_FRAME_SIZE;
c78c6d6c
JR
1246 }
1247
1248 /* check for crc mismatch */
11d6f38c 1249 if(err != AAC_AC3_PARSE_ERROR_FRAME_SIZE && avctx->error_recognition >= FF_ER_CAREFUL) {
c78c6d6c
JR
1250 if(av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0, &buf[2], s->frame_size-2)) {
1251 av_log(avctx, AV_LOG_ERROR, "frame CRC mismatch\n");
11d6f38c 1252 err = AAC_AC3_PARSE_ERROR_CRC;
c78c6d6c
JR
1253 }
1254 }
1255
11d6f38c 1256 if(err && err != AAC_AC3_PARSE_ERROR_CRC) {
3df88093 1257 switch(err) {
11d6f38c 1258 case AAC_AC3_PARSE_ERROR_SYNC:
c78c6d6c 1259 av_log(avctx, AV_LOG_ERROR, "frame sync error\n");
7af26d14 1260 return -1;
11d6f38c 1261 case AAC_AC3_PARSE_ERROR_BSID:
3df88093
JR
1262 av_log(avctx, AV_LOG_ERROR, "invalid bitstream id\n");
1263 break;
11d6f38c 1264 case AAC_AC3_PARSE_ERROR_SAMPLE_RATE:
3df88093
JR
1265 av_log(avctx, AV_LOG_ERROR, "invalid sample rate\n");
1266 break;
11d6f38c 1267 case AAC_AC3_PARSE_ERROR_FRAME_SIZE:
3df88093
JR
1268 av_log(avctx, AV_LOG_ERROR, "invalid frame size\n");
1269 break;
11d6f38c 1270 case AAC_AC3_PARSE_ERROR_FRAME_TYPE:
aa5d6be8
JR
1271 /* skip frame if CRC is ok. otherwise use error concealment. */
1272 /* TODO: add support for substreams and dependent frames */
1273 if(s->frame_type == EAC3_FRAME_TYPE_DEPENDENT || s->substreamid) {
1274 av_log(avctx, AV_LOG_ERROR, "unsupported frame type : skipping frame\n");
1275 return s->frame_size;
1276 } else {
4921bbba 1277 av_log(avctx, AV_LOG_ERROR, "invalid frame type\n");
aa5d6be8 1278 }
4e6eeaf0 1279 break;
3df88093
JR
1280 default:
1281 av_log(avctx, AV_LOG_ERROR, "invalid header\n");
1282 break;
1283 }
1b293437 1284 }
2aa2c5c4 1285
eccba2bc
JR
1286 /* if frame is ok, set audio parameters */
1287 if (!err) {
3336110a
JR
1288 avctx->sample_rate = s->sample_rate;
1289 avctx->bit_rate = s->bit_rate;
1290
1291 /* channel config */
1292 s->out_channels = s->channels;
eccba2bc
JR
1293 s->output_mode = s->channel_mode;
1294 if(s->lfe_on)
1295 s->output_mode |= AC3_OUTPUT_LFEON;
3336110a
JR
1296 if (avctx->request_channels > 0 && avctx->request_channels <= 2 &&
1297 avctx->request_channels < s->channels) {
1298 s->out_channels = avctx->request_channels;
1299 s->output_mode = avctx->request_channels == 1 ? AC3_CHMODE_MONO : AC3_CHMODE_STEREO;
bfeca7be 1300 s->channel_layout = ff_ac3_channel_layout_tab[s->output_mode];
3336110a
JR
1301 }
1302 avctx->channels = s->out_channels;
bfeca7be 1303 avctx->channel_layout = s->channel_layout;
1b293437 1304
3336110a
JR
1305 /* set downmixing coefficients if needed */
1306 if(s->channels != s->out_channels && !((s->output_mode & AC3_OUTPUT_LFEON) &&
1307 s->fbw_channels == s->out_channels)) {
1308 set_downmix_coeffs(s);
1309 }
eccba2bc
JR
1310 } else if (!s->out_channels) {
1311 s->out_channels = avctx->channels;
1312 if(s->out_channels < s->channels)
1313 s->output_mode = s->out_channels == 1 ? AC3_CHMODE_MONO : AC3_CHMODE_STEREO;
ecfe94b2 1314 }
f0b3a7ba 1315
022845ed 1316 /* decode the audio blocks */
95f3019a 1317 channel_map = ff_ac3_dec_channel_map[s->output_mode & ~AC3_OUTPUT_LFEON][s->lfe_on];
52dc3fc8
JR
1318 for (ch = 0; ch < s->out_channels; ch++)
1319 output[ch] = s->output[channel_map[ch]];
6730e9f3 1320 for (blk = 0; blk < s->num_blocks; blk++) {
022845ed
JR
1321 if (!err && decode_audio_block(s, blk)) {
1322 av_log(avctx, AV_LOG_ERROR, "error decoding the audio block\n");
af2272b2 1323 err = 1;
1b293437 1324 }
72745cff
LM
1325 s->dsp.float_to_int16_interleave(out_samples, output, 256, s->out_channels);
1326 out_samples += 256 * s->out_channels;
1b293437 1327 }
6730e9f3 1328 *data_size = s->num_blocks * 256 * avctx->channels * sizeof (int16_t);
d802d7ca 1329 return s->frame_size;
2aa2c5c4 1330}
1b293437 1331
5066f515
JR
1332/**
1333 * Uninitialize the AC-3 decoder.
c7cfc48f 1334 */
98a6fff9 1335static av_cold int ac3_decode_end(AVCodecContext *avctx)
1b293437 1336{
0345fade 1337 AC3DecodeContext *s = avctx->priv_data;
d802d7ca
JR
1338 ff_mdct_end(&s->imdct_512);
1339 ff_mdct_end(&s->imdct_256);
c7cfc48f 1340
509fdb0b
JR
1341 av_freep(&s->input_buffer);
1342
1b293437
JR
1343 return 0;
1344}
1345
fa67992d 1346AVCodec ac3_decoder = {
e6bca37c
JR
1347 .name = "ac3",
1348 .type = CODEC_TYPE_AUDIO,
1349 .id = CODEC_ID_AC3,
1350 .priv_data_size = sizeof (AC3DecodeContext),
1351 .init = ac3_decode_init,
1352 .close = ac3_decode_end,
1353 .decode = ac3_decode_frame,
2988c93d
JR
1354 .long_name = NULL_IF_CONFIG_SMALL("ATSC A/52A (AC-3)"),
1355};
1356
89547cfb 1357#if CONFIG_EAC3_DECODER
2988c93d
JR
1358AVCodec eac3_decoder = {
1359 .name = "eac3",
1360 .type = CODEC_TYPE_AUDIO,
1361 .id = CODEC_ID_EAC3,
1362 .priv_data_size = sizeof (AC3DecodeContext),
1363 .init = ac3_decode_init,
1364 .close = ac3_decode_end,
1365 .decode = ac3_decode_frame,
1366 .long_name = NULL_IF_CONFIG_SMALL("ATSC A/52B (AC-3, E-AC-3)"),
1b293437 1367};
89547cfb 1368#endif