Define ARCH_MIPS64 when building for MIPS64
[libav.git] / libavcodec / ac3dec.c
CommitLineData
0ec2cc35
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1/*
2 * AC-3 Audio Decoder
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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 *
36266421 10 * Portions of this code are derived from liba52
032732d4 11 * http://liba52.sourceforge.net
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12 * Copyright (C) 2000-2003 Michel Lespinasse <walken@zoy.org>
13 * Copyright (C) 1999-2000 Aaron Holtzman <aholtzma@ess.engr.uvic.ca>
032732d4 14 *
0ec2cc35 15 * This file is part of FFmpeg.
2aa2c5c4 16 *
0ec2cc35 17 * FFmpeg is free software; you can redistribute it and/or
9d109601 18 * modify it under the terms of the GNU General Public
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19 * License as published by the Free Software Foundation; either
20 * version 2 of the License, or (at your option) any later version.
21 *
0ec2cc35 22 * FFmpeg is distributed in the hope that it will be useful,
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23 * but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
283614b5 25 * General Public License for more details.
2aa2c5c4 26 *
283614b5 27 * You should have received a copy of the GNU General Public
0ec2cc35 28 * License along with FFmpeg; if not, write to the Free Software
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29 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
30 */
31
32#include <stdio.h>
33#include <stddef.h>
34#include <math.h>
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35#include <string.h>
36
245976da 37#include "libavutil/crc.h"
dbbec0c2 38#include "internal.h"
11d6f38c 39#include "aac_ac3_parser.h"
9fc1ab72 40#include "ac3_parser.h"
58ce349f 41#include "ac3dec.h"
227322b8 42#include "ac3dec_data.h"
98a27a8a 43
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44/** Large enough for maximum possible frame size when the specification limit is ignored */
45#define AC3_FRAME_BUFFER_SIZE 32768
c33a1967 46
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47/**
48 * table for ungrouping 3 values in 7 bits.
49 * used for exponents and bap=2 mantissas
50 */
51static uint8_t ungroup_3_in_7_bits_tab[128][3];
967d397a 52
967d397a 53
5aefe3eb 54/** tables for ungrouping mantissas */
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55static int b1_mantissas[32][3];
56static int b2_mantissas[128][3];
57static int b3_mantissas[8];
58static int b4_mantissas[128][2];
59static int b5_mantissas[16];
967d397a 60
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61/**
62 * Quantization table: levels for symmetric. bits for asymmetric.
63 * reference: Table 7.18 Mapping of bap to Quantizer
64 */
e2270b4e 65static const uint8_t quantization_tab[16] = {
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66 0, 3, 5, 7, 11, 15,
67 5, 6, 7, 8, 9, 10, 11, 12, 14, 16
68};
967d397a 69
3357ff33 70/** dynamic range table. converts codes to scale factors. */
e2270b4e 71static float dynamic_range_tab[256];
3357ff33 72
5066f515 73/** Adjustments in dB gain */
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74#define LEVEL_PLUS_3DB 1.4142135623730950
75#define LEVEL_PLUS_1POINT5DB 1.1892071150027209
76#define LEVEL_MINUS_1POINT5DB 0.8408964152537145
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77#define LEVEL_MINUS_3DB 0.7071067811865476
78#define LEVEL_MINUS_4POINT5DB 0.5946035575013605
79#define LEVEL_MINUS_6DB 0.5000000000000000
3bbb0bf8 80#define LEVEL_MINUS_9DB 0.3535533905932738
967d397a 81#define LEVEL_ZERO 0.0000000000000000
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82#define LEVEL_ONE 1.0000000000000000
83
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84static const float gain_levels[9] = {
85 LEVEL_PLUS_3DB,
86 LEVEL_PLUS_1POINT5DB,
3bbb0bf8 87 LEVEL_ONE,
caf0fbc8 88 LEVEL_MINUS_1POINT5DB,
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89 LEVEL_MINUS_3DB,
90 LEVEL_MINUS_4POINT5DB,
91 LEVEL_MINUS_6DB,
caf0fbc8 92 LEVEL_ZERO,
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93 LEVEL_MINUS_9DB
94};
967d397a 95
3bbb0bf8 96/**
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97 * Table for center mix levels
98 * reference: Section 5.4.2.4 cmixlev
99 */
100static const uint8_t center_levels[4] = { 4, 5, 6, 5 };
101
102/**
103 * Table for surround mix levels
104 * reference: Section 5.4.2.5 surmixlev
105 */
106static const uint8_t surround_levels[4] = { 4, 6, 7, 6 };
107
108/**
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109 * Table for default stereo downmixing coefficients
110 * reference: Section 7.8.2 Downmixing Into Two Channels
111 */
112static const uint8_t ac3_default_coeffs[8][5][2] = {
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113 { { 2, 7 }, { 7, 2 }, },
114 { { 4, 4 }, },
115 { { 2, 7 }, { 7, 2 }, },
116 { { 2, 7 }, { 5, 5 }, { 7, 2 }, },
117 { { 2, 7 }, { 7, 2 }, { 6, 6 }, },
118 { { 2, 7 }, { 5, 5 }, { 7, 2 }, { 8, 8 }, },
119 { { 2, 7 }, { 7, 2 }, { 6, 7 }, { 7, 6 }, },
120 { { 2, 7 }, { 5, 5 }, { 7, 2 }, { 6, 7 }, { 7, 6 }, },
3bbb0bf8 121};
967d397a 122
2fbbd087 123/**
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124 * Symmetrical Dequantization
125 * reference: Section 7.3.3 Expansion of Mantissas for Symmetrical Quantization
126 * Tables 7.19 to 7.23
127 */
a4de6dd2 128static inline int
5aefe3eb 129symmetric_dequant(int code, int levels)
98a27a8a 130{
a4de6dd2 131 return ((code - (levels >> 1)) << 24) / levels;
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132}
133
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134/*
135 * Initialize tables at runtime.
136 */
98a6fff9 137static av_cold void ac3_tables_init(void)
00585845 138{
4415076f 139 int i;
98a27a8a 140
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141 /* generate table for ungrouping 3 values in 7 bits
142 reference: Section 7.1.3 Exponent Decoding */
143 for(i=0; i<128; i++) {
144 ungroup_3_in_7_bits_tab[i][0] = i / 25;
145 ungroup_3_in_7_bits_tab[i][1] = (i % 25) / 5;
146 ungroup_3_in_7_bits_tab[i][2] = (i % 25) % 5;
147 }
148
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149 /* generate grouped mantissa tables
150 reference: Section 7.3.5 Ungrouping of Mantissas */
151 for(i=0; i<32; i++) {
152 /* bap=1 mantissas */
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153 b1_mantissas[i][0] = symmetric_dequant(ff_ac3_ungroup_3_in_5_bits_tab[i][0], 3);
154 b1_mantissas[i][1] = symmetric_dequant(ff_ac3_ungroup_3_in_5_bits_tab[i][1], 3);
155 b1_mantissas[i][2] = symmetric_dequant(ff_ac3_ungroup_3_in_5_bits_tab[i][2], 3);
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156 }
157 for(i=0; i<128; i++) {
158 /* bap=2 mantissas */
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159 b2_mantissas[i][0] = symmetric_dequant(ungroup_3_in_7_bits_tab[i][0], 5);
160 b2_mantissas[i][1] = symmetric_dequant(ungroup_3_in_7_bits_tab[i][1], 5);
161 b2_mantissas[i][2] = symmetric_dequant(ungroup_3_in_7_bits_tab[i][2], 5);
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162
163 /* bap=4 mantissas */
164 b4_mantissas[i][0] = symmetric_dequant(i / 11, 11);
165 b4_mantissas[i][1] = symmetric_dequant(i % 11, 11);
166 }
167 /* generate ungrouped mantissa tables
168 reference: Tables 7.21 and 7.23 */
169 for(i=0; i<7; i++) {
170 /* bap=3 mantissas */
171 b3_mantissas[i] = symmetric_dequant(i, 7);
172 }
173 for(i=0; i<15; i++) {
174 /* bap=5 mantissas */
175 b5_mantissas[i] = symmetric_dequant(i, 15);
176 }
c7cfc48f 177
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178 /* generate dynamic range table
179 reference: Section 7.7.1 Dynamic Range Control */
180 for(i=0; i<256; i++) {
181 int v = (i >> 5) - ((i >> 7) << 3) - 5;
e2270b4e 182 dynamic_range_tab[i] = powf(2.0f, v) * ((i & 0x1F) | 0x20);
3357ff33 183 }
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184}
185
1b293437 186
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187/**
188 * AVCodec initialization
189 */
98a6fff9 190static av_cold int ac3_decode_init(AVCodecContext *avctx)
1b293437 191{
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192 AC3DecodeContext *s = avctx->priv_data;
193 s->avctx = avctx;
1b293437 194
cc2a8443 195 ac3_common_init();
98a27a8a 196 ac3_tables_init();
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197 ff_mdct_init(&s->imdct_256, 8, 1, 1.0);
198 ff_mdct_init(&s->imdct_512, 9, 1, 1.0);
3ed546fe 199 ff_kbd_window_init(s->window, 5.0, 256);
d802d7ca 200 dsputil_init(&s->dsp, avctx);
ec0350c9 201 av_lfg_init(&s->dith_state, 0);
2aa2c5c4 202
5066f515 203 /* set bias values for float to int16 conversion */
72745cff 204 if(s->dsp.float_to_int16_interleave == ff_float_to_int16_interleave_c) {
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205 s->add_bias = 385.0f;
206 s->mul_bias = 1.0f;
4e092320 207 } else {
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208 s->add_bias = 0.0f;
209 s->mul_bias = 32767.0f;
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210 }
211
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212 /* allow downmixing to stereo or mono */
213 if (avctx->channels > 0 && avctx->request_channels > 0 &&
214 avctx->request_channels < avctx->channels &&
215 avctx->request_channels <= 2) {
216 avctx->channels = avctx->request_channels;
217 }
38dae9c3 218 s->downmixed = 1;
95283c17 219
509fdb0b 220 /* allocate context input buffer */
047599a4 221 if (avctx->error_recognition >= FF_ER_CAREFUL) {
8e33132b 222 s->input_buffer = av_mallocz(AC3_FRAME_BUFFER_SIZE + FF_INPUT_BUFFER_PADDING_SIZE);
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223 if (!s->input_buffer)
224 return AVERROR_NOMEM;
225 }
226
fd76c37f 227 avctx->sample_fmt = SAMPLE_FMT_S16;
1b293437 228 return 0;
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229}
230
9fc1ab72 231/**
5066f515 232 * Parse the 'sync info' and 'bit stream info' from the AC-3 bitstream.
c7cfc48f 233 * GetBitContext within AC3DecodeContext must point to
14b70628 234 * the start of the synchronized AC-3 bitstream.
c7cfc48f 235 */
d802d7ca 236static int ac3_parse_header(AC3DecodeContext *s)
2aa2c5c4 237{
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238 GetBitContext *gbc = &s->gbc;
239 int i;
240
241 /* read the rest of the bsi. read twice for dual mono mode. */
242 i = !(s->channel_mode);
243 do {
244 skip_bits(gbc, 5); // skip dialog normalization
245 if (get_bits1(gbc))
246 skip_bits(gbc, 8); //skip compression
247 if (get_bits1(gbc))
248 skip_bits(gbc, 8); //skip language code
249 if (get_bits1(gbc))
250 skip_bits(gbc, 7); //skip audio production information
251 } while (i--);
252
253 skip_bits(gbc, 2); //skip copyright bit and original bitstream bit
254
255 /* skip the timecodes (or extra bitstream information for Alternate Syntax)
256 TODO: read & use the xbsi1 downmix levels */
257 if (get_bits1(gbc))
258 skip_bits(gbc, 14); //skip timecode1 / xbsi1
259 if (get_bits1(gbc))
260 skip_bits(gbc, 14); //skip timecode2 / xbsi2
261
262 /* skip additional bitstream info */
263 if (get_bits1(gbc)) {
264 i = get_bits(gbc, 6);
265 do {
266 skip_bits(gbc, 8);
267 } while(i--);
268 }
269
270 return 0;
271}
272
273/**
14b70628 274 * Common function to parse AC-3 or E-AC-3 frame header
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275 */
276static int parse_frame_header(AC3DecodeContext *s)
277{
9fc1ab72 278 AC3HeaderInfo hdr;
4397d95c 279 int err;
9fc1ab72 280
ba7f712c 281 err = ff_ac3_parse_header(&s->gbc, &hdr);
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282 if(err)
283 return err;
284
285 /* get decoding parameters from header info */
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286 s->bit_alloc_params.sr_code = hdr.sr_code;
287 s->channel_mode = hdr.channel_mode;
bfeca7be 288 s->channel_layout = hdr.channel_layout;
1b70d88b 289 s->lfe_on = hdr.lfe_on;
d802d7ca 290 s->bit_alloc_params.sr_shift = hdr.sr_shift;
866181e5 291 s->sample_rate = hdr.sample_rate;
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292 s->bit_rate = hdr.bit_rate;
293 s->channels = hdr.channels;
294 s->fbw_channels = s->channels - s->lfe_on;
295 s->lfe_ch = s->fbw_channels + 1;
296 s->frame_size = hdr.frame_size;
55736cfb
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297 s->center_mix_level = hdr.center_mix_level;
298 s->surround_mix_level = hdr.surround_mix_level;
6730e9f3 299 s->num_blocks = hdr.num_blocks;
be5f17b9 300 s->frame_type = hdr.frame_type;
3596aa6f 301 s->substreamid = hdr.substreamid;
7bfd22f2 302
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JR
303 if(s->lfe_on) {
304 s->start_freq[s->lfe_ch] = 0;
305 s->end_freq[s->lfe_ch] = 7;
306 s->num_exp_groups[s->lfe_ch] = 2;
307 s->channel_in_cpl[s->lfe_ch] = 0;
308 }
309
bf09b550
JR
310 if (hdr.bitstream_id <= 10) {
311 s->eac3 = 0;
312 s->snr_offset_strategy = 2;
313 s->block_switch_syntax = 1;
314 s->dither_flag_syntax = 1;
315 s->bit_allocation_syntax = 1;
316 s->fast_gain_syntax = 0;
317 s->first_cpl_leak = 0;
318 s->dba_syntax = 1;
319 s->skip_syntax = 1;
320 memset(s->channel_uses_aht, 0, sizeof(s->channel_uses_aht));
ab2a942a 321 return ac3_parse_header(s);
bf09b550 322 } else {
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323 s->eac3 = 1;
324 return ff_eac3_parse_header(s);
bf09b550 325 }
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326}
327
328/**
329 * Set stereo downmixing coefficients based on frame header info.
330 * reference: Section 7.8.2 Downmixing Into Two Channels
331 */
332static void set_downmix_coeffs(AC3DecodeContext *s)
333{
334 int i;
30f71adc
JR
335 float cmix = gain_levels[center_levels[s->center_mix_level]];
336 float smix = gain_levels[surround_levels[s->surround_mix_level]];
557ac0c4 337 float norm0, norm1;
f0b3a7ba 338
d802d7ca
JR
339 for(i=0; i<s->fbw_channels; i++) {
340 s->downmix_coeffs[i][0] = gain_levels[ac3_default_coeffs[s->channel_mode][i][0]];
341 s->downmix_coeffs[i][1] = gain_levels[ac3_default_coeffs[s->channel_mode][i][1]];
3bbb0bf8 342 }
d802d7ca 343 if(s->channel_mode > 1 && s->channel_mode & 1) {
f0b3a7ba 344 s->downmix_coeffs[1][0] = s->downmix_coeffs[1][1] = cmix;
3bbb0bf8 345 }
d802d7ca
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346 if(s->channel_mode == AC3_CHMODE_2F1R || s->channel_mode == AC3_CHMODE_3F1R) {
347 int nf = s->channel_mode - 2;
f0b3a7ba 348 s->downmix_coeffs[nf][0] = s->downmix_coeffs[nf][1] = smix * LEVEL_MINUS_3DB;
3bbb0bf8 349 }
d802d7ca
JR
350 if(s->channel_mode == AC3_CHMODE_2F2R || s->channel_mode == AC3_CHMODE_3F2R) {
351 int nf = s->channel_mode - 4;
f0b3a7ba 352 s->downmix_coeffs[nf][0] = s->downmix_coeffs[nf+1][1] = smix;
3bbb0bf8 353 }
9d10e6e6 354
557ac0c4
LM
355 /* renormalize */
356 norm0 = norm1 = 0.0;
9d10e6e6 357 for(i=0; i<s->fbw_channels; i++) {
557ac0c4
LM
358 norm0 += s->downmix_coeffs[i][0];
359 norm1 += s->downmix_coeffs[i][1];
360 }
361 norm0 = 1.0f / norm0;
362 norm1 = 1.0f / norm1;
363 for(i=0; i<s->fbw_channels; i++) {
364 s->downmix_coeffs[i][0] *= norm0;
365 s->downmix_coeffs[i][1] *= norm1;
366 }
367
368 if(s->output_mode == AC3_CHMODE_MONO) {
369 for(i=0; i<s->fbw_channels; i++)
370 s->downmix_coeffs[i][0] = (s->downmix_coeffs[i][0] + s->downmix_coeffs[i][1]) * LEVEL_MINUS_3DB;
9d10e6e6 371 }
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372}
373
3bb004fc 374/**
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375 * Decode the grouped exponents according to exponent strategy.
376 * reference: Section 7.1.3 Exponent Decoding
2aa2c5c4 377 */
ce7d842f 378static int decode_exponents(GetBitContext *gbc, int exp_strategy, int ngrps,
80670324 379 uint8_t absexp, int8_t *dexps)
2aa2c5c4 380{
e2270b4e 381 int i, j, grp, group_size;
4415076f
JR
382 int dexp[256];
383 int expacc, prevexp;
384
385 /* unpack groups */
e2270b4e 386 group_size = exp_strategy + (exp_strategy == EXP_D45);
4415076f 387 for(grp=0,i=0; grp<ngrps; grp++) {
23c8cb89 388 expacc = get_bits(gbc, 7);
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389 dexp[i++] = ungroup_3_in_7_bits_tab[expacc][0];
390 dexp[i++] = ungroup_3_in_7_bits_tab[expacc][1];
391 dexp[i++] = ungroup_3_in_7_bits_tab[expacc][2];
4415076f 392 }
2aa2c5c4 393
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JR
394 /* convert to absolute exps and expand groups */
395 prevexp = absexp;
96f229d6 396 for(i=0,j=0; i<ngrps*3; i++) {
ce7d842f 397 prevexp += dexp[i] - 2;
2ceccf04 398 if (prevexp > 24U)
ce7d842f 399 return -1;
96f229d6
JR
400 switch (group_size) {
401 case 4: dexps[j++] = prevexp;
402 dexps[j++] = prevexp;
403 case 2: dexps[j++] = prevexp;
404 case 1: dexps[j++] = prevexp;
1b293437 405 }
2aa2c5c4 406 }
ce7d842f 407 return 0;
2aa2c5c4
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408}
409
d7dc7ad0 410/**
5066f515 411 * Generate transform coefficients for each coupled channel in the coupling
d7dc7ad0
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412 * range using the coupling coefficients and coupling coordinates.
413 * reference: Section 7.4.3 Coupling Coordinate Format
414 */
5e3e4075 415static void calc_transform_coeffs_cpl(AC3DecodeContext *s)
d7dc7ad0
JR
416{
417 int i, j, ch, bnd, subbnd;
418
419 subbnd = -1;
d802d7ca
JR
420 i = s->start_freq[CPL_CH];
421 for(bnd=0; bnd<s->num_cpl_bands; bnd++) {
d7dc7ad0
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422 do {
423 subbnd++;
424 for(j=0; j<12; j++) {
d802d7ca 425 for(ch=1; ch<=s->fbw_channels; ch++) {
b02fbf75 426 if(s->channel_in_cpl[ch]) {
a4de6dd2 427 s->fixed_coeffs[ch][i] = ((int64_t)s->fixed_coeffs[CPL_CH][i] * (int64_t)s->cpl_coords[ch][bnd]) >> 23;
b02fbf75 428 if (ch == 2 && s->phase_flags[bnd])
a4de6dd2 429 s->fixed_coeffs[ch][i] = -s->fixed_coeffs[ch][i];
b02fbf75 430 }
d7dc7ad0
JR
431 }
432 i++;
433 }
d802d7ca 434 } while(s->cpl_band_struct[subbnd]);
d7dc7ad0
JR
435 }
436}
437
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438/**
439 * Grouped mantissas for 3-level 5-level and 11-level quantization
440 */
441typedef struct {
a4de6dd2
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442 int b1_mant[3];
443 int b2_mant[3];
444 int b4_mant[2];
5aefe3eb
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445 int b1ptr;
446 int b2ptr;
447 int b4ptr;
486637af
JR
448} mant_groups;
449
5066f515 450/**
e522bd49 451 * Decode the transform coefficients for a particular channel
5066f515
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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{
d802d7ca 456 GetBitContext *gbc = &s->gbc;
60f07fad 457 int i, gcode, tbap, start, end;
2fbbd087
JR
458 uint8_t *exps;
459 uint8_t *bap;
a4de6dd2 460 int *coeffs;
2fbbd087 461
d802d7ca
JR
462 exps = s->dexps[ch_index];
463 bap = s->bap[ch_index];
a4de6dd2 464 coeffs = s->fixed_coeffs[ch_index];
d802d7ca
JR
465 start = s->start_freq[ch_index];
466 end = s->end_freq[ch_index];
1b293437 467
285bf28c 468 for (i = start; i < end; i++) {
98a27a8a
JR
469 tbap = bap[i];
470 switch (tbap) {
1b293437 471 case 0:
ec0350c9 472 coeffs[i] = (av_lfg_get(&s->dith_state) & 0x7FFFFF) - 0x400000;
d63f6fea 473 break;
1b293437
JR
474
475 case 1:
5aefe3eb 476 if(m->b1ptr > 2) {
23c8cb89 477 gcode = get_bits(gbc, 5);
5aefe3eb
JR
478 m->b1_mant[0] = b1_mantissas[gcode][0];
479 m->b1_mant[1] = b1_mantissas[gcode][1];
480 m->b1_mant[2] = b1_mantissas[gcode][2];
481 m->b1ptr = 0;
1b293437 482 }
5aefe3eb 483 coeffs[i] = m->b1_mant[m->b1ptr++];
d63f6fea 484 break;
1b293437
JR
485
486 case 2:
5aefe3eb 487 if(m->b2ptr > 2) {
23c8cb89 488 gcode = get_bits(gbc, 7);
5aefe3eb
JR
489 m->b2_mant[0] = b2_mantissas[gcode][0];
490 m->b2_mant[1] = b2_mantissas[gcode][1];
491 m->b2_mant[2] = b2_mantissas[gcode][2];
492 m->b2ptr = 0;
1b293437 493 }
5aefe3eb 494 coeffs[i] = m->b2_mant[m->b2ptr++];
d63f6fea 495 break;
1b293437
JR
496
497 case 3:
23c8cb89 498 coeffs[i] = b3_mantissas[get_bits(gbc, 3)];
d63f6fea 499 break;
1b293437
JR
500
501 case 4:
5aefe3eb 502 if(m->b4ptr > 1) {
23c8cb89 503 gcode = get_bits(gbc, 7);
5aefe3eb
JR
504 m->b4_mant[0] = b4_mantissas[gcode][0];
505 m->b4_mant[1] = b4_mantissas[gcode][1];
506 m->b4ptr = 0;
1b293437 507 }
5aefe3eb 508 coeffs[i] = m->b4_mant[m->b4ptr++];
d63f6fea 509 break;
1b293437
JR
510
511 case 5:
23c8cb89 512 coeffs[i] = b5_mantissas[get_bits(gbc, 4)];
d63f6fea 513 break;
1b293437 514
a4de6dd2 515 default: {
5066f515 516 /* asymmetric dequantization */
a4de6dd2
JR
517 int qlevel = quantization_tab[tbap];
518 coeffs[i] = get_sbits(gbc, qlevel) << (24 - qlevel);
d63f6fea 519 break;
a4de6dd2 520 }
1b293437 521 }
a4de6dd2 522 coeffs[i] >>= exps[i];
1b293437 523 }
1b293437
JR
524}
525
60f07fad 526/**
5066f515 527 * Remove random dithering from coefficients with zero-bit mantissas
60f07fad
JR
528 * reference: Section 7.3.4 Dither for Zero Bit Mantissas (bap=0)
529 */
d802d7ca 530static void remove_dithering(AC3DecodeContext *s) {
60f07fad
JR
531 int ch, i;
532 int end=0;
a4de6dd2 533 int *coeffs;
60f07fad
JR
534 uint8_t *bap;
535
d802d7ca
JR
536 for(ch=1; ch<=s->fbw_channels; ch++) {
537 if(!s->dither_flag[ch]) {
a4de6dd2 538 coeffs = s->fixed_coeffs[ch];
d802d7ca
JR
539 bap = s->bap[ch];
540 if(s->channel_in_cpl[ch])
541 end = s->start_freq[CPL_CH];
60f07fad 542 else
d802d7ca 543 end = s->end_freq[ch];
60f07fad 544 for(i=0; i<end; i++) {
12eaa3b7 545 if(!bap[i])
a4de6dd2 546 coeffs[i] = 0;
60f07fad 547 }
d802d7ca
JR
548 if(s->channel_in_cpl[ch]) {
549 bap = s->bap[CPL_CH];
550 for(; i<s->end_freq[CPL_CH]; i++) {
12eaa3b7 551 if(!bap[i])
a4de6dd2 552 coeffs[i] = 0;
60f07fad
JR
553 }
554 }
555 }
556 }
557}
558
6a68105e 559static void decode_transform_coeffs_ch(AC3DecodeContext *s, int blk, int ch,
bf09b550
JR
560 mant_groups *m)
561{
562 if (!s->channel_uses_aht[ch]) {
6a68105e 563 ac3_decode_transform_coeffs_ch(s, ch, m);
bf09b550
JR
564 } else {
565 /* if AHT is used, mantissas for all blocks are encoded in the first
566 block of the frame. */
567 int bin;
568 if (!blk)
6a68105e 569 ff_eac3_decode_transform_coeffs_aht_ch(s, ch);
bf09b550 570 for (bin = s->start_freq[ch]; bin < s->end_freq[ch]; bin++) {
9a7a71ed 571 s->fixed_coeffs[ch][bin] = (s->pre_mantissa[ch][bin][blk] << 8) >> s->dexps[ch][bin];
bf09b550
JR
572 }
573 }
574}
bf09b550 575
5066f515 576/**
164e169f 577 * Decode the transform coefficients.
c7cfc48f 578 */
e43b29ab 579static void decode_transform_coeffs(AC3DecodeContext *s, int blk)
1b293437 580{
7b4076a7 581 int ch, end;
1b293437 582 int got_cplchan = 0;
486637af
JR
583 mant_groups m;
584
5aefe3eb 585 m.b1ptr = m.b2ptr = m.b4ptr = 3;
1b293437 586
d802d7ca 587 for (ch = 1; ch <= s->channels; ch++) {
5066f515 588 /* transform coefficients for full-bandwidth channel */
e43b29ab 589 decode_transform_coeffs_ch(s, blk, ch, &m);
5066f515
JR
590 /* tranform coefficients for coupling channel come right after the
591 coefficients for the first coupled channel*/
d802d7ca 592 if (s->channel_in_cpl[ch]) {
486637af 593 if (!got_cplchan) {
e43b29ab 594 decode_transform_coeffs_ch(s, blk, CPL_CH, &m);
5e3e4075 595 calc_transform_coeffs_cpl(s);
486637af
JR
596 got_cplchan = 1;
597 }
d802d7ca 598 end = s->end_freq[CPL_CH];
eaf84d97 599 } else {
d802d7ca 600 end = s->end_freq[ch];
eaf84d97 601 }
486637af 602 do
bd98e9e2 603 s->fixed_coeffs[ch][end] = 0;
486637af
JR
604 while(++end < 256);
605 }
1b293437 606
ea364c74 607 /* zero the dithered coefficients for appropriate channels */
86662b1c 608 remove_dithering(s);
2aa2c5c4
JR
609}
610
8b60bbbf 611/**
5066f515 612 * Stereo rematrixing.
8b60bbbf
JR
613 * reference: Section 7.5.4 Rematrixing : Decoding Technique
614 */
d802d7ca 615static void do_rematrixing(AC3DecodeContext *s)
1b293437 616{
8b60bbbf 617 int bnd, i;
2fbbd087 618 int end, bndend;
a4de6dd2 619 int tmp0, tmp1;
2fbbd087 620
d802d7ca 621 end = FFMIN(s->end_freq[1], s->end_freq[2]);
1b293437 622
d802d7ca
JR
623 for(bnd=0; bnd<s->num_rematrixing_bands; bnd++) {
624 if(s->rematrixing_flags[bnd]) {
227322b8
JR
625 bndend = FFMIN(end, ff_ac3_rematrix_band_tab[bnd+1]);
626 for(i=ff_ac3_rematrix_band_tab[bnd]; i<bndend; i++) {
a4de6dd2
JR
627 tmp0 = s->fixed_coeffs[1][i];
628 tmp1 = s->fixed_coeffs[2][i];
629 s->fixed_coeffs[1][i] = tmp0 + tmp1;
630 s->fixed_coeffs[2][i] = tmp0 - tmp1;
8b60bbbf
JR
631 }
632 }
1b293437
JR
633 }
634}
2aa2c5c4 635
5066f515 636/**
5066f515
JR
637 * Inverse MDCT Transform.
638 * Convert frequency domain coefficients to time-domain audio samples.
639 * reference: Section 7.9.4 Transformation Equations
640 */
38dae9c3 641static inline void do_imdct(AC3DecodeContext *s, int channels)
486637af 642{
0de73a46 643 int ch;
3b6516f7
LM
644 float add_bias = s->add_bias;
645 if(s->out_channels==1 && channels>1)
646 add_bias *= LEVEL_MINUS_3DB; // compensate for the gain in downmix
7b4076a7 647
e2270b4e 648 for (ch=1; ch<=channels; ch++) {
d802d7ca 649 if (s->block_switch[ch]) {
916d5d6c
LM
650 int i;
651 float *x = s->tmp_output+128;
652 for(i=0; i<128; i++)
653 x[i] = s->transform_coeffs[ch][2*i];
654 ff_imdct_half(&s->imdct_256, s->tmp_output, x);
3b6516f7 655 s->dsp.vector_fmul_window(s->output[ch-1], s->delay[ch-1], s->tmp_output, s->window, add_bias, 128);
916d5d6c
LM
656 for(i=0; i<128; i++)
657 x[i] = s->transform_coeffs[ch][2*i+1];
658 ff_imdct_half(&s->imdct_256, s->delay[ch-1], x);
eaf84d97 659 } else {
916d5d6c 660 ff_imdct_half(&s->imdct_512, s->tmp_output, s->transform_coeffs[ch]);
3b6516f7 661 s->dsp.vector_fmul_window(s->output[ch-1], s->delay[ch-1], s->tmp_output, s->window, add_bias, 128);
916d5d6c 662 memcpy(s->delay[ch-1], s->tmp_output+128, 128*sizeof(float));
eaf84d97 663 }
486637af
JR
664 }
665}
666
3bbb0bf8 667/**
5066f515 668 * Downmix the output to mono or stereo.
3bbb0bf8 669 */
ac2e5564 670void ff_ac3_downmix_c(float (*samples)[256], float (*matrix)[2], int out_ch, int in_ch, int len)
3bbb0bf8
JR
671{
672 int i, j;
9d10e6e6 673 float v0, v1;
ac2e5564
LM
674 if(out_ch == 2) {
675 for(i=0; i<len; i++) {
557ac0c4 676 v0 = v1 = 0.0f;
ac2e5564
LM
677 for(j=0; j<in_ch; j++) {
678 v0 += samples[j][i] * matrix[j][0];
679 v1 += samples[j][i] * matrix[j][1];
557ac0c4
LM
680 }
681 samples[0][i] = v0;
682 samples[1][i] = v1;
3bbb0bf8 683 }
ac2e5564
LM
684 } else if(out_ch == 1) {
685 for(i=0; i<len; i++) {
557ac0c4 686 v0 = 0.0f;
ac2e5564
LM
687 for(j=0; j<in_ch; j++)
688 v0 += samples[j][i] * matrix[j][0];
557ac0c4 689 samples[0][i] = v0;
3bbb0bf8
JR
690 }
691 }
692}
693
5066f515 694/**
38dae9c3
JR
695 * Upmix delay samples from stereo to original channel layout.
696 */
697static void ac3_upmix_delay(AC3DecodeContext *s)
698{
e6300276 699 int channel_data_size = sizeof(s->delay[0]);
38dae9c3
JR
700 switch(s->channel_mode) {
701 case AC3_CHMODE_DUALMONO:
702 case AC3_CHMODE_STEREO:
703 /* upmix mono to stereo */
704 memcpy(s->delay[1], s->delay[0], channel_data_size);
705 break;
706 case AC3_CHMODE_2F2R:
707 memset(s->delay[3], 0, channel_data_size);
708 case AC3_CHMODE_2F1R:
709 memset(s->delay[2], 0, channel_data_size);
710 break;
711 case AC3_CHMODE_3F2R:
712 memset(s->delay[4], 0, channel_data_size);
713 case AC3_CHMODE_3F1R:
714 memset(s->delay[3], 0, channel_data_size);
715 case AC3_CHMODE_3F:
716 memcpy(s->delay[2], s->delay[1], channel_data_size);
717 memset(s->delay[1], 0, channel_data_size);
718 break;
719 }
720}
721
722/**
0c5d750d
JR
723 * Decode band structure for coupling, spectral extension, or enhanced coupling.
724 * @param[in] gbc bit reader context
725 * @param[in] blk block number
726 * @param[in] eac3 flag to indicate E-AC-3
727 * @param[in] ecpl flag to indicate enhanced coupling
728 * @param[in] start_subband subband number for start of range
729 * @param[in] end_subband subband number for end of range
730 * @param[in] default_band_struct default band structure table
731 * @param[out] band_struct decoded band structure
0c5d750d
JR
732 * @param[out] num_bands number of bands (optionally NULL)
733 * @param[out] band_sizes array containing the number of bins in each band (optionally NULL)
734 */
735static void decode_band_structure(GetBitContext *gbc, int blk, int eac3,
736 int ecpl, int start_subband, int end_subband,
737 const uint8_t *default_band_struct,
778bc09b
JR
738 uint8_t *band_struct, int *num_bands,
739 uint8_t *band_sizes)
0c5d750d 740{
f23dc1e1 741 int subbnd, bnd, n_subbands, n_bands=0;
75b53b21 742 uint8_t bnd_sz[22];
0c5d750d
JR
743
744 n_subbands = end_subband - start_subband;
745
746 /* decode band structure from bitstream or use default */
747 if (!eac3 || get_bits1(gbc)) {
748 for (subbnd = 0; subbnd < n_subbands - 1; subbnd++) {
749 band_struct[subbnd] = get_bits1(gbc);
750 }
751 } else if (!blk) {
752 memcpy(band_struct,
753 &default_band_struct[start_subband+1],
754 n_subbands-1);
755 }
756 band_struct[n_subbands-1] = 0;
757
758 /* calculate number of bands and band sizes based on band structure.
759 note that the first 4 subbands in enhanced coupling span only 6 bins
760 instead of 12. */
761 if (num_bands || band_sizes ) {
e202cc25 762 n_bands = n_subbands;
0c5d750d
JR
763 bnd_sz[0] = ecpl ? 6 : 12;
764 for (bnd = 0, subbnd = 1; subbnd < n_subbands; subbnd++) {
765 int subbnd_size = (ecpl && subbnd < 4) ? 6 : 12;
766 if (band_struct[subbnd-1]) {
767 n_bands--;
768 bnd_sz[bnd] += subbnd_size;
769 } else {
770 bnd_sz[++bnd] = subbnd_size;
771 }
772 }
773 }
774
775 /* set optional output params */
0c5d750d
JR
776 if (num_bands)
777 *num_bands = n_bands;
778 if (band_sizes)
75b53b21 779 memcpy(band_sizes, bnd_sz, n_bands);
0c5d750d
JR
780}
781
782/**
022845ed 783 * Decode a single audio block from the AC-3 bitstream.
c7cfc48f 784 */
022845ed 785static int decode_audio_block(AC3DecodeContext *s, int blk)
2aa2c5c4 786{
d802d7ca
JR
787 int fbw_channels = s->fbw_channels;
788 int channel_mode = s->channel_mode;
0bff58a5 789 int i, bnd, seg, ch;
38dae9c3
JR
790 int different_transforms;
791 int downmix_output;
54624396 792 int cpl_in_use;
d802d7ca 793 GetBitContext *gbc = &s->gbc;
7b4076a7 794 uint8_t bit_alloc_stages[AC3_MAX_CHANNELS];
1b293437 795
7b4076a7
JR
796 memset(bit_alloc_stages, 0, AC3_MAX_CHANNELS);
797
5066f515 798 /* block switch flags */
38dae9c3 799 different_transforms = 0;
bf09b550 800 if (s->block_switch_syntax) {
ab2a942a
JR
801 for (ch = 1; ch <= fbw_channels; ch++) {
802 s->block_switch[ch] = get_bits1(gbc);
803 if(ch > 1 && s->block_switch[ch] != s->block_switch[1])
804 different_transforms = 1;
805 }
bf09b550 806 }
98a27a8a 807
5066f515 808 /* dithering flags */
bf09b550 809 if (s->dither_flag_syntax) {
ab2a942a
JR
810 for (ch = 1; ch <= fbw_channels; ch++) {
811 s->dither_flag[ch] = get_bits1(gbc);
ab2a942a 812 }
bf09b550 813 }
98a27a8a 814
77416325 815 /* dynamic range */
d802d7ca 816 i = !(s->channel_mode);
77416325 817 do {
23c8cb89 818 if(get_bits1(gbc)) {
d802d7ca 819 s->dynamic_range[i] = ((dynamic_range_tab[get_bits(gbc, 8)]-1.0) *
1b70d88b 820 s->avctx->drc_scale)+1.0;
9fc1ab72 821 } else if(blk == 0) {
d802d7ca 822 s->dynamic_range[i] = 1.0f;
9fc1ab72 823 }
77416325 824 } while(i--);
98a27a8a 825
6fafb020
JR
826 /* spectral extension strategy */
827 if (s->eac3 && (!blk || get_bits1(gbc))) {
e202cc25 828 if (get_bits1(gbc)) {
dbbec0c2 829 ff_log_missing_feature(s->avctx, "Spectral extension", 1);
e202cc25 830 return -1;
6fafb020 831 }
e202cc25 832 /* TODO: parse spectral extension strategy info */
6fafb020
JR
833 }
834
e202cc25 835 /* TODO: spectral extension coordinates */
6fafb020 836
5066f515 837 /* coupling strategy */
225c3042 838 if (s->eac3 ? s->cpl_strategy_exists[blk] : get_bits1(gbc)) {
7b4076a7 839 memset(bit_alloc_stages, 3, AC3_MAX_CHANNELS);
6fafb020 840 if (!s->eac3)
0569993e 841 s->cpl_in_use[blk] = get_bits1(gbc);
4760aec6 842 if (s->cpl_in_use[blk]) {
5066f515 843 /* coupling in use */
24834c19 844 int cpl_start_subband, cpl_end_subband;
b6acc57f 845
3af91313
JR
846 if (channel_mode < AC3_CHMODE_STEREO) {
847 av_log(s->avctx, AV_LOG_ERROR, "coupling not allowed in mono or dual-mono\n");
848 return -1;
849 }
850
6fafb020
JR
851 /* check for enhanced coupling */
852 if (s->eac3 && get_bits1(gbc)) {
853 /* TODO: parse enhanced coupling strategy info */
dbbec0c2 854 ff_log_missing_feature(s->avctx, "Enhanced coupling", 1);
6fafb020
JR
855 return -1;
856 }
857
5066f515 858 /* determine which channels are coupled */
6fafb020
JR
859 if (s->eac3 && s->channel_mode == AC3_CHMODE_STEREO) {
860 s->channel_in_cpl[1] = 1;
861 s->channel_in_cpl[2] = 1;
862 } else {
0569993e
JR
863 for (ch = 1; ch <= fbw_channels; ch++)
864 s->channel_in_cpl[ch] = get_bits1(gbc);
6fafb020 865 }
98a27a8a 866
5066f515 867 /* phase flags in use */
e59cc205 868 if (channel_mode == AC3_CHMODE_STEREO)
d802d7ca 869 s->phase_flags_in_use = get_bits1(gbc);
98a27a8a 870
6fafb020 871 /* coupling frequency range */
e202cc25 872 /* TODO: modify coupling end freq if spectral extension is used */
24834c19 873 cpl_start_subband = get_bits(gbc, 4);
e202cc25 874 cpl_end_subband = get_bits(gbc, 4) + 3;
1ac7d1ac
JR
875 if (cpl_start_subband >= cpl_end_subband) {
876 av_log(s->avctx, AV_LOG_ERROR, "invalid coupling range (%d >= %d)\n",
6ee6d068 877 cpl_start_subband, cpl_end_subband);
00585845 878 return -1;
98a27a8a 879 }
24834c19 880 s->start_freq[CPL_CH] = cpl_start_subband * 12 + 37;
6ee6d068 881 s->end_freq[CPL_CH] = cpl_end_subband * 12 + 37;
6fafb020 882
778bc09b
JR
883 decode_band_structure(gbc, blk, s->eac3, 0, cpl_start_subband,
884 cpl_end_subband,
885 ff_eac3_default_cpl_band_struct,
886 s->cpl_band_struct, &s->num_cpl_bands, NULL);
878c40a1 887 } else {
5066f515 888 /* coupling not in use */
6fafb020 889 for (ch = 1; ch <= fbw_channels; ch++) {
d802d7ca 890 s->channel_in_cpl[ch] = 0;
6fafb020
JR
891 s->first_cpl_coords[ch] = 1;
892 }
63d72fb1 893 s->first_cpl_leak = s->eac3;
6fafb020 894 s->phase_flags_in_use = 0;
1b293437 895 }
6fafb020
JR
896 } else if (!s->eac3) {
897 if(!blk) {
0569993e
JR
898 av_log(s->avctx, AV_LOG_ERROR, "new coupling strategy must be present in block 0\n");
899 return -1;
900 } else {
901 s->cpl_in_use[blk] = s->cpl_in_use[blk-1];
902 }
6fafb020 903 }
4760aec6 904 cpl_in_use = s->cpl_in_use[blk];
98a27a8a 905
5066f515 906 /* coupling coordinates */
54624396 907 if (cpl_in_use) {
e2270b4e 908 int cpl_coords_exist = 0;
98a27a8a 909
e2270b4e 910 for (ch = 1; ch <= fbw_channels; ch++) {
d802d7ca 911 if (s->channel_in_cpl[ch]) {
225c3042 912 if ((s->eac3 && s->first_cpl_coords[ch]) || get_bits1(gbc)) {
e2270b4e 913 int master_cpl_coord, cpl_coord_exp, cpl_coord_mant;
225c3042 914 s->first_cpl_coords[ch] = 0;
e2270b4e 915 cpl_coords_exist = 1;
23c8cb89 916 master_cpl_coord = 3 * get_bits(gbc, 2);
d802d7ca 917 for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
23c8cb89
JR
918 cpl_coord_exp = get_bits(gbc, 4);
919 cpl_coord_mant = get_bits(gbc, 4);
e2270b4e 920 if (cpl_coord_exp == 15)
a4de6dd2 921 s->cpl_coords[ch][bnd] = cpl_coord_mant << 22;
486637af 922 else
a4de6dd2
JR
923 s->cpl_coords[ch][bnd] = (cpl_coord_mant + 16) << 21;
924 s->cpl_coords[ch][bnd] >>= (cpl_coord_exp + master_cpl_coord);
486637af 925 }
82a591d8
JR
926 } else if (!blk) {
927 av_log(s->avctx, AV_LOG_ERROR, "new coupling coordinates must be present in block 0\n");
928 return -1;
486637af 929 }
225c3042
JR
930 } else {
931 /* channel not in coupling */
932 s->first_cpl_coords[ch] = 1;
eaf84d97
JR
933 }
934 }
5066f515 935 /* phase flags */
b02fbf75 936 if (channel_mode == AC3_CHMODE_STEREO && cpl_coords_exist) {
d802d7ca 937 for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
b02fbf75 938 s->phase_flags[bnd] = s->phase_flags_in_use? get_bits1(gbc) : 0;
eaf84d97
JR
939 }
940 }
2aa2c5c4 941 }
98a27a8a 942
5066f515 943 /* stereo rematrixing strategy and band structure */
e59cc205 944 if (channel_mode == AC3_CHMODE_STEREO) {
6fafb020 945 if ((s->eac3 && !blk) || get_bits1(gbc)) {
d802d7ca 946 s->num_rematrixing_bands = 4;
e202cc25
JR
947 if(cpl_in_use && s->start_freq[CPL_CH] <= 61)
948 s->num_rematrixing_bands -= 1 + (s->start_freq[CPL_CH] == 37);
d802d7ca
JR
949 for(bnd=0; bnd<s->num_rematrixing_bands; bnd++)
950 s->rematrixing_flags[bnd] = get_bits1(gbc);
82a591d8
JR
951 } else if (!blk) {
952 av_log(s->avctx, AV_LOG_ERROR, "new rematrixing strategy must be present in block 0\n");
953 return -1;
1b293437 954 }
98a27a8a
JR
955 }
956
5066f515 957 /* exponent strategies for each channel */
54624396 958 for (ch = !cpl_in_use; ch <= s->channels; ch++) {
6b4bfed9 959 if (!s->eac3)
aec0407f 960 s->exp_strategy[blk][ch] = get_bits(gbc, 2 - (ch == s->lfe_ch));
da04be10 961 if(s->exp_strategy[blk][ch] != EXP_REUSE)
7b4076a7
JR
962 bit_alloc_stages[ch] = 3;
963 }
964
5066f515 965 /* channel bandwidth */
e2270b4e 966 for (ch = 1; ch <= fbw_channels; ch++) {
d802d7ca 967 s->start_freq[ch] = 0;
da04be10 968 if (s->exp_strategy[blk][ch] != EXP_REUSE) {
b85a15fe 969 int group_size;
d802d7ca
JR
970 int prev = s->end_freq[ch];
971 if (s->channel_in_cpl[ch])
972 s->end_freq[ch] = s->start_freq[CPL_CH];
00585845 973 else {
23c8cb89 974 int bandwidth_code = get_bits(gbc, 6);
e2270b4e 975 if (bandwidth_code > 60) {
6c6f9272 976 av_log(s->avctx, AV_LOG_ERROR, "bandwidth code = %d > 60\n", bandwidth_code);
00585845
JR
977 return -1;
978 }
d802d7ca 979 s->end_freq[ch] = bandwidth_code * 3 + 73;
1b293437 980 }
da04be10 981 group_size = 3 << (s->exp_strategy[blk][ch] - 1);
b85a15fe 982 s->num_exp_groups[ch] = (s->end_freq[ch]+group_size-4) / group_size;
d802d7ca 983 if(blk > 0 && s->end_freq[ch] != prev)
7b4076a7 984 memset(bit_alloc_stages, 3, AC3_MAX_CHANNELS);
00585845 985 }
eaf84d97 986 }
da04be10 987 if (cpl_in_use && s->exp_strategy[blk][CPL_CH] != EXP_REUSE) {
b85a15fe 988 s->num_exp_groups[CPL_CH] = (s->end_freq[CPL_CH] - s->start_freq[CPL_CH]) /
da04be10 989 (3 << (s->exp_strategy[blk][CPL_CH] - 1));
b85a15fe 990 }
7b4076a7 991
5066f515 992 /* decode exponents for each channel */
54624396 993 for (ch = !cpl_in_use; ch <= s->channels; ch++) {
da04be10 994 if (s->exp_strategy[blk][ch] != EXP_REUSE) {
d802d7ca 995 s->dexps[ch][0] = get_bits(gbc, 4) << !ch;
ce7d842f 996 if (decode_exponents(gbc, s->exp_strategy[blk][ch],
1cdd567f
JR
997 s->num_exp_groups[ch], s->dexps[ch][0],
998 &s->dexps[ch][s->start_freq[ch]+!!ch])) {
ce7d842f
JR
999 av_log(s->avctx, AV_LOG_ERROR, "exponent out-of-range\n");
1000 return -1;
1001 }
d802d7ca 1002 if(ch != CPL_CH && ch != s->lfe_ch)
23c8cb89 1003 skip_bits(gbc, 2); /* skip gainrng */
1b293437 1004 }
eaf84d97 1005 }
98a27a8a 1006
5066f515 1007 /* bit allocation information */
bf09b550 1008 if (s->bit_allocation_syntax) {
ab2a942a
JR
1009 if (get_bits1(gbc)) {
1010 s->bit_alloc_params.slow_decay = ff_ac3_slow_decay_tab[get_bits(gbc, 2)] >> s->bit_alloc_params.sr_shift;
1011 s->bit_alloc_params.fast_decay = ff_ac3_fast_decay_tab[get_bits(gbc, 2)] >> s->bit_alloc_params.sr_shift;
1012 s->bit_alloc_params.slow_gain = ff_ac3_slow_gain_tab[get_bits(gbc, 2)];
1013 s->bit_alloc_params.db_per_bit = ff_ac3_db_per_bit_tab[get_bits(gbc, 2)];
e202cc25 1014 s->bit_alloc_params.floor = ff_ac3_floor_tab[get_bits(gbc, 3)];
ab2a942a
JR
1015 for(ch=!cpl_in_use; ch<=s->channels; ch++)
1016 bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 2);
1017 } else if (!blk) {
1018 av_log(s->avctx, AV_LOG_ERROR, "new bit allocation info must be present in block 0\n");
1019 return -1;
1020 }
bf09b550 1021 }
98a27a8a 1022
5066f515 1023 /* signal-to-noise ratio offsets and fast gains (signal-to-mask ratios) */
8dfc56ec
JR
1024 if(!s->eac3 || !blk){
1025 if(s->snr_offset_strategy && get_bits1(gbc)) {
f2e4eb62
JR
1026 int snr = 0;
1027 int csnr;
1028 csnr = (get_bits(gbc, 6) - 15) << 4;
1029 for (i = ch = !cpl_in_use; ch <= s->channels; ch++) {
1030 /* snr offset */
1031 if (ch == i || s->snr_offset_strategy == 2)
1032 snr = (csnr + get_bits(gbc, 4)) << 2;
1033 /* run at least last bit allocation stage if snr offset changes */
1034 if(blk && s->snr_offset[ch] != snr) {
1035 bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 1);
1036 }
1037 s->snr_offset[ch] = snr;
8dfc56ec
JR
1038
1039 /* fast gain (normal AC-3 only) */
1040 if (!s->eac3) {
1041 int prev = s->fast_gain[ch];
f2e4eb62 1042 s->fast_gain[ch] = ff_ac3_fast_gain_tab[get_bits(gbc, 3)];
8dfc56ec
JR
1043 /* run last 2 bit allocation stages if fast gain changes */
1044 if(blk && prev != s->fast_gain[ch])
1045 bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 2);
8dfc56ec 1046 }
f2e4eb62 1047 }
8dfc56ec 1048 } else if (!s->eac3 && !blk) {
f2e4eb62
JR
1049 av_log(s->avctx, AV_LOG_ERROR, "new snr offsets must be present in block 0\n");
1050 return -1;
8dfc56ec 1051 }
1b293437 1052 }
98a27a8a 1053
6fafb020
JR
1054 /* fast gain (E-AC-3 only) */
1055 if (s->fast_gain_syntax && get_bits1(gbc)) {
1056 for (ch = !cpl_in_use; ch <= s->channels; ch++) {
1057 int prev = s->fast_gain[ch];
1058 s->fast_gain[ch] = ff_ac3_fast_gain_tab[get_bits(gbc, 3)];
1059 /* run last 2 bit allocation stages if fast gain changes */
1060 if(blk && prev != s->fast_gain[ch])
1061 bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 2);
1062 }
1063 } else if (s->eac3 && !blk) {
1064 for (ch = !cpl_in_use; ch <= s->channels; ch++)
1065 s->fast_gain[ch] = ff_ac3_fast_gain_tab[4];
1066 }
1067
1068 /* E-AC-3 to AC-3 converter SNR offset */
1069 if (s->frame_type == EAC3_FRAME_TYPE_INDEPENDENT && get_bits1(gbc)) {
1070 skip_bits(gbc, 10); // skip converter snr offset
1071 }
1072
5066f515 1073 /* coupling leak information */
54624396 1074 if (cpl_in_use) {
8dfc56ec
JR
1075 if (s->first_cpl_leak || get_bits1(gbc)) {
1076 int fl = get_bits(gbc, 3);
1077 int sl = get_bits(gbc, 3);
1078 /* run last 2 bit allocation stages for coupling channel if
1079 coupling leak changes */
1080 if(blk && (fl != s->bit_alloc_params.cpl_fast_leak ||
1081 sl != s->bit_alloc_params.cpl_slow_leak)) {
f2e4eb62 1082 bit_alloc_stages[CPL_CH] = FFMAX(bit_alloc_stages[CPL_CH], 2);
8dfc56ec
JR
1083 }
1084 s->bit_alloc_params.cpl_fast_leak = fl;
1085 s->bit_alloc_params.cpl_slow_leak = sl;
1086 } else if (!s->eac3 && !blk) {
93a2c8c1
JR
1087 av_log(s->avctx, AV_LOG_ERROR, "new coupling leak info must be present in block 0\n");
1088 return -1;
1089 }
8dfc56ec 1090 s->first_cpl_leak = 0;
43ad93a4 1091 }
98a27a8a 1092
5066f515 1093 /* delta bit allocation information */
bf09b550 1094 if (s->dba_syntax && get_bits1(gbc)) {
5066f515 1095 /* delta bit allocation exists (strategy) */
54624396 1096 for (ch = !cpl_in_use; ch <= fbw_channels; ch++) {
d802d7ca
JR
1097 s->dba_mode[ch] = get_bits(gbc, 2);
1098 if (s->dba_mode[ch] == DBA_RESERVED) {
1099 av_log(s->avctx, AV_LOG_ERROR, "delta bit allocation strategy reserved\n");
1b293437
JR
1100 return -1;
1101 }
7b4076a7 1102 bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 2);
1b293437 1103 }
5066f515 1104 /* channel delta offset, len and bit allocation */
54624396 1105 for (ch = !cpl_in_use; ch <= fbw_channels; ch++) {
d802d7ca
JR
1106 if (s->dba_mode[ch] == DBA_NEW) {
1107 s->dba_nsegs[ch] = get_bits(gbc, 3);
1108 for (seg = 0; seg <= s->dba_nsegs[ch]; seg++) {
1109 s->dba_offsets[ch][seg] = get_bits(gbc, 5);
1110 s->dba_lengths[ch][seg] = get_bits(gbc, 4);
1111 s->dba_values[ch][seg] = get_bits(gbc, 3);
1b293437 1112 }
e25973a1
JR
1113 /* run last 2 bit allocation stages if new dba values */
1114 bit_alloc_stages[ch] = FFMAX(bit_alloc_stages[ch], 2);
1b293437 1115 }
eaf84d97 1116 }
9fc1ab72 1117 } else if(blk == 0) {
d802d7ca
JR
1118 for(ch=0; ch<=s->channels; ch++) {
1119 s->dba_mode[ch] = DBA_NONE;
9fc1ab72 1120 }
1b293437 1121 }
00585845 1122
5066f515 1123 /* Bit allocation */
54624396 1124 for(ch=!cpl_in_use; ch<=s->channels; ch++) {
7b4076a7
JR
1125 if(bit_alloc_stages[ch] > 2) {
1126 /* Exponent mapping into PSD and PSD integration */
d802d7ca
JR
1127 ff_ac3_bit_alloc_calc_psd(s->dexps[ch],
1128 s->start_freq[ch], s->end_freq[ch],
1129 s->psd[ch], s->band_psd[ch]);
eaf84d97 1130 }
7b4076a7
JR
1131 if(bit_alloc_stages[ch] > 1) {
1132 /* Compute excitation function, Compute masking curve, and
1133 Apply delta bit allocation */
72a6244b 1134 if (ff_ac3_bit_alloc_calc_mask(&s->bit_alloc_params, s->band_psd[ch],
20e04726
JR
1135 s->start_freq[ch], s->end_freq[ch],
1136 s->fast_gain[ch], (ch == s->lfe_ch),
1137 s->dba_mode[ch], s->dba_nsegs[ch],
1138 s->dba_offsets[ch], s->dba_lengths[ch],
1139 s->dba_values[ch], s->mask[ch])) {
72a6244b
JR
1140 av_log(s->avctx, AV_LOG_ERROR, "error in bit allocation\n");
1141 return -1;
1142 }
eaf84d97 1143 }
7b4076a7
JR
1144 if(bit_alloc_stages[ch] > 0) {
1145 /* Compute bit allocation */
bf09b550
JR
1146 const uint8_t *bap_tab = s->channel_uses_aht[ch] ?
1147 ff_eac3_hebap_tab : ff_ac3_bap_tab;
d802d7ca
JR
1148 ff_ac3_bit_alloc_calc_bap(s->mask[ch], s->psd[ch],
1149 s->start_freq[ch], s->end_freq[ch],
1150 s->snr_offset[ch],
1151 s->bit_alloc_params.floor,
bf09b550 1152 bap_tab, s->bap[ch]);
eaf84d97 1153 }
2fbbd087 1154 }
98a27a8a 1155
5066f515 1156 /* unused dummy data */
bf09b550 1157 if (s->skip_syntax && get_bits1(gbc)) {
23c8cb89 1158 int skipl = get_bits(gbc, 9);
98a27a8a 1159 while(skipl--)
23c8cb89 1160 skip_bits(gbc, 8);
1b293437 1161 }
f5cefb21 1162
1b293437 1163 /* unpack the transform coefficients
5066f515 1164 this also uncouples channels if coupling is in use. */
e43b29ab 1165 decode_transform_coeffs(s, blk);
486637af 1166
bf09b550
JR
1167 /* TODO: generate enhanced coupling coordinates and uncouple */
1168
e202cc25
JR
1169 /* TODO: apply spectral extension */
1170
1b293437 1171 /* recover coefficients if rematrixing is in use */
d802d7ca
JR
1172 if(s->channel_mode == AC3_CHMODE_STEREO)
1173 do_rematrixing(s);
1b293437 1174
03726b70 1175 /* apply scaling to coefficients (headroom, dynrng) */
d802d7ca 1176 for(ch=1; ch<=s->channels; ch++) {
a4de6dd2 1177 float gain = s->mul_bias / 4194304.0f;
d802d7ca
JR
1178 if(s->channel_mode == AC3_CHMODE_DUALMONO) {
1179 gain *= s->dynamic_range[ch-1];
7bfd22f2 1180 } else {
d802d7ca 1181 gain *= s->dynamic_range[0];
7bfd22f2 1182 }
911e21a3 1183 s->dsp.int32_to_float_fmul_scalar(s->transform_coeffs[ch], s->fixed_coeffs[ch], gain, 256);
7bfd22f2 1184 }
d7bcc4ad 1185
38dae9c3
JR
1186 /* downmix and MDCT. order depends on whether block switching is used for
1187 any channel in this block. this is because coefficients for the long
1188 and short transforms cannot be mixed. */
1189 downmix_output = s->channels != s->out_channels &&
1190 !((s->output_mode & AC3_OUTPUT_LFEON) &&
1191 s->fbw_channels == s->out_channels);
1192 if(different_transforms) {
1193 /* the delay samples have already been downmixed, so we upmix the delay
1194 samples in order to reconstruct all channels before downmixing. */
1195 if(s->downmixed) {
1196 s->downmixed = 0;
1197 ac3_upmix_delay(s);
1198 }
1199
1200 do_imdct(s, s->channels);
1201
1202 if(downmix_output) {
ac2e5564 1203 s->dsp.ac3_downmix(s->output, s->downmix_coeffs, s->out_channels, s->fbw_channels, 256);
38dae9c3
JR
1204 }
1205 } else {
1206 if(downmix_output) {
ac2e5564 1207 s->dsp.ac3_downmix(s->transform_coeffs+1, s->downmix_coeffs, s->out_channels, s->fbw_channels, 256);
38dae9c3
JR
1208 }
1209
45d9d618 1210 if(downmix_output && !s->downmixed) {
38dae9c3 1211 s->downmixed = 1;
ac2e5564 1212 s->dsp.ac3_downmix(s->delay, s->downmix_coeffs, s->out_channels, s->fbw_channels, 128);
38dae9c3 1213 }
486637af 1214
38dae9c3 1215 do_imdct(s, s->out_channels);
3bbb0bf8
JR
1216 }
1217
4e092320 1218 return 0;
486637af
JR
1219}
1220
5066f515
JR
1221/**
1222 * Decode a single AC-3 frame.
c7cfc48f 1223 */
98f6dfa6 1224static int ac3_decode_frame(AVCodecContext * avctx, void *data, int *data_size,
7a00bbad 1225 AVPacket *avpkt)
1b293437 1226{
7a00bbad
TB
1227 const uint8_t *buf = avpkt->data;
1228 int buf_size = avpkt->size;
0345fade 1229 AC3DecodeContext *s = avctx->priv_data;
00585845 1230 int16_t *out_samples = (int16_t *)data;
72745cff 1231 int blk, ch, err;
95f3019a 1232 const uint8_t *channel_map;
13ec9428 1233 const float *output[AC3_MAX_CHANNELS];
d7bcc4ad 1234
5066f515 1235 /* initialize the GetBitContext with the start of valid AC-3 Frame */
509fdb0b 1236 if (s->input_buffer) {
c33a1967
JR
1237 /* copy input buffer to decoder context to avoid reading past the end
1238 of the buffer, which can be caused by a damaged input stream. */
8e33132b 1239 memcpy(s->input_buffer, buf, FFMIN(buf_size, AC3_FRAME_BUFFER_SIZE));
c33a1967
JR
1240 init_get_bits(&s->gbc, s->input_buffer, buf_size * 8);
1241 } else {
984ff38a 1242 init_get_bits(&s->gbc, buf, buf_size * 8);
c33a1967 1243 }
00585845 1244
5066f515 1245 /* parse the syncinfo */
c78c6d6c 1246 *data_size = 0;
4397d95c 1247 err = parse_frame_header(s);
c78c6d6c
JR
1248
1249 /* check that reported frame size fits in input buffer */
1250 if(s->frame_size > buf_size) {
1251 av_log(avctx, AV_LOG_ERROR, "incomplete frame\n");
11d6f38c 1252 err = AAC_AC3_PARSE_ERROR_FRAME_SIZE;
c78c6d6c
JR
1253 }
1254
1255 /* check for crc mismatch */
11d6f38c 1256 if(err != AAC_AC3_PARSE_ERROR_FRAME_SIZE && avctx->error_recognition >= FF_ER_CAREFUL) {
c78c6d6c
JR
1257 if(av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0, &buf[2], s->frame_size-2)) {
1258 av_log(avctx, AV_LOG_ERROR, "frame CRC mismatch\n");
11d6f38c 1259 err = AAC_AC3_PARSE_ERROR_CRC;
c78c6d6c
JR
1260 }
1261 }
1262
11d6f38c 1263 if(err && err != AAC_AC3_PARSE_ERROR_CRC) {
3df88093 1264 switch(err) {
11d6f38c 1265 case AAC_AC3_PARSE_ERROR_SYNC:
c78c6d6c 1266 av_log(avctx, AV_LOG_ERROR, "frame sync error\n");
7af26d14 1267 return -1;
11d6f38c 1268 case AAC_AC3_PARSE_ERROR_BSID:
3df88093
JR
1269 av_log(avctx, AV_LOG_ERROR, "invalid bitstream id\n");
1270 break;
11d6f38c 1271 case AAC_AC3_PARSE_ERROR_SAMPLE_RATE:
3df88093
JR
1272 av_log(avctx, AV_LOG_ERROR, "invalid sample rate\n");
1273 break;
11d6f38c 1274 case AAC_AC3_PARSE_ERROR_FRAME_SIZE:
3df88093
JR
1275 av_log(avctx, AV_LOG_ERROR, "invalid frame size\n");
1276 break;
11d6f38c 1277 case AAC_AC3_PARSE_ERROR_FRAME_TYPE:
aa5d6be8
JR
1278 /* skip frame if CRC is ok. otherwise use error concealment. */
1279 /* TODO: add support for substreams and dependent frames */
1280 if(s->frame_type == EAC3_FRAME_TYPE_DEPENDENT || s->substreamid) {
1281 av_log(avctx, AV_LOG_ERROR, "unsupported frame type : skipping frame\n");
1282 return s->frame_size;
1283 } else {
4921bbba 1284 av_log(avctx, AV_LOG_ERROR, "invalid frame type\n");
aa5d6be8 1285 }
4e6eeaf0 1286 break;
3df88093
JR
1287 default:
1288 av_log(avctx, AV_LOG_ERROR, "invalid header\n");
1289 break;
1290 }
1b293437 1291 }
2aa2c5c4 1292
eccba2bc
JR
1293 /* if frame is ok, set audio parameters */
1294 if (!err) {
3336110a
JR
1295 avctx->sample_rate = s->sample_rate;
1296 avctx->bit_rate = s->bit_rate;
1297
1298 /* channel config */
1299 s->out_channels = s->channels;
eccba2bc
JR
1300 s->output_mode = s->channel_mode;
1301 if(s->lfe_on)
1302 s->output_mode |= AC3_OUTPUT_LFEON;
3336110a
JR
1303 if (avctx->request_channels > 0 && avctx->request_channels <= 2 &&
1304 avctx->request_channels < s->channels) {
1305 s->out_channels = avctx->request_channels;
1306 s->output_mode = avctx->request_channels == 1 ? AC3_CHMODE_MONO : AC3_CHMODE_STEREO;
bfeca7be 1307 s->channel_layout = ff_ac3_channel_layout_tab[s->output_mode];
3336110a
JR
1308 }
1309 avctx->channels = s->out_channels;
bfeca7be 1310 avctx->channel_layout = s->channel_layout;
1b293437 1311
3336110a
JR
1312 /* set downmixing coefficients if needed */
1313 if(s->channels != s->out_channels && !((s->output_mode & AC3_OUTPUT_LFEON) &&
1314 s->fbw_channels == s->out_channels)) {
1315 set_downmix_coeffs(s);
1316 }
eccba2bc
JR
1317 } else if (!s->out_channels) {
1318 s->out_channels = avctx->channels;
1319 if(s->out_channels < s->channels)
1320 s->output_mode = s->out_channels == 1 ? AC3_CHMODE_MONO : AC3_CHMODE_STEREO;
ecfe94b2 1321 }
f0b3a7ba 1322
022845ed 1323 /* decode the audio blocks */
95f3019a 1324 channel_map = ff_ac3_dec_channel_map[s->output_mode & ~AC3_OUTPUT_LFEON][s->lfe_on];
52dc3fc8
JR
1325 for (ch = 0; ch < s->out_channels; ch++)
1326 output[ch] = s->output[channel_map[ch]];
6730e9f3 1327 for (blk = 0; blk < s->num_blocks; blk++) {
022845ed
JR
1328 if (!err && decode_audio_block(s, blk)) {
1329 av_log(avctx, AV_LOG_ERROR, "error decoding the audio block\n");
af2272b2 1330 err = 1;
1b293437 1331 }
72745cff
LM
1332 s->dsp.float_to_int16_interleave(out_samples, output, 256, s->out_channels);
1333 out_samples += 256 * s->out_channels;
1b293437 1334 }
6730e9f3 1335 *data_size = s->num_blocks * 256 * avctx->channels * sizeof (int16_t);
d802d7ca 1336 return s->frame_size;
2aa2c5c4 1337}
1b293437 1338
5066f515
JR
1339/**
1340 * Uninitialize the AC-3 decoder.
c7cfc48f 1341 */
98a6fff9 1342static av_cold int ac3_decode_end(AVCodecContext *avctx)
1b293437 1343{
0345fade 1344 AC3DecodeContext *s = avctx->priv_data;
d802d7ca
JR
1345 ff_mdct_end(&s->imdct_512);
1346 ff_mdct_end(&s->imdct_256);
c7cfc48f 1347
509fdb0b
JR
1348 av_freep(&s->input_buffer);
1349
1b293437
JR
1350 return 0;
1351}
1352
fa67992d 1353AVCodec ac3_decoder = {
e6bca37c
JR
1354 .name = "ac3",
1355 .type = CODEC_TYPE_AUDIO,
1356 .id = CODEC_ID_AC3,
1357 .priv_data_size = sizeof (AC3DecodeContext),
1358 .init = ac3_decode_init,
1359 .close = ac3_decode_end,
1360 .decode = ac3_decode_frame,
2988c93d
JR
1361 .long_name = NULL_IF_CONFIG_SMALL("ATSC A/52A (AC-3)"),
1362};
1363
1364AVCodec eac3_decoder = {
1365 .name = "eac3",
1366 .type = CODEC_TYPE_AUDIO,
1367 .id = CODEC_ID_EAC3,
1368 .priv_data_size = sizeof (AC3DecodeContext),
1369 .init = ac3_decode_init,
1370 .close = ac3_decode_end,
1371 .decode = ac3_decode_frame,
1372 .long_name = NULL_IF_CONFIG_SMALL("ATSC A/52B (AC-3, E-AC-3)"),
1b293437 1373};