Libav
ac3dec.h
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1 /*
2  * Common code between the AC-3 and E-AC-3 decoders
3  * Copyright (c) 2007 Bartlomiej Wolowiec <bartek.wolowiec@gmail.com>
4  *
5  * This file is part of Libav.
6  *
7  * Libav is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * Libav is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
50 #ifndef AVCODEC_AC3DEC_H
51 #define AVCODEC_AC3DEC_H
52 
53 #include "libavutil/float_dsp.h"
54 #include "libavutil/lfg.h"
55 #include "ac3.h"
56 #include "ac3dsp.h"
57 #include "get_bits.h"
58 #include "dsputil.h"
59 #include "fft.h"
60 #include "fmtconvert.h"
61 
62 #define AC3_OUTPUT_LFEON 8
63 
64 #define SPX_MAX_BANDS 17
65 
67 #define AC3_FRAME_BUFFER_SIZE 32768
68 
69 typedef struct AC3DecodeContext {
70  AVClass *class;
73 
76  int frame_type;
78  int frame_size;
79  int bit_rate;
81  int num_blocks;
85  int lfe_on;
94  int eac3;
98 
108 
121 
131  int num_spx_bands;
137 
142 
146  int channels;
147  int lfe_ch;
149  int downmixed;
152 
155  float dynamic_range[2];
156  float drc_scale;
157 
162 
167 
173 
189 
194 
200 
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223 
229 
235 
242 
243 #endif /* AVCODEC_AC3DEC_H */
Definition: lfg.h:25
int dba_nsegs[AC3_MAX_CHANNELS]
number of delta segments
Definition: ac3dec.h:185
float * dlyptr[AC3_MAX_CHANNELS]
Definition: ac3dec.h:211
int16_t psd[AC3_MAX_CHANNELS][AC3_MAX_COEFS]
scaled exponents
Definition: ac3dec.h:181
int spx_in_use
spectral extension in use (spxinu)
Definition: ac3dec.h:125
uint8_t dba_offsets[AC3_MAX_CHANNELS][8]
delta segment offsets
Definition: ac3dec.h:186
int dither_flag[AC3_MAX_CHANNELS]
dither flags (dithflg)
Definition: ac3dec.h:192
int16_t mask[AC3_MAX_CHANNELS][AC3_CRITICAL_BANDS]
masking curve values
Definition: ac3dec.h:183
int preferred_downmix
Preferred 2-channel downmix mode (dmixmod)
Definition: ac3dec.h:87
#define AC3_MAX_COEFS
Definition: ac3.h:34
AVFloatDSPContext fdsp
Definition: ac3dec.h:204
int channels
number of total channels
Definition: ac3dec.h:146
#define DECLARE_ALIGNED(n, t, v)
Definition: mem.h:58
int spx_dst_end_freq
spx end frequency bin
Definition: ac3dec.h:129
int exp_strategy[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS]
exponent strategies (expstr)
Definition: ac3dec.h:172
float dynamic_range[2]
dynamic range
Definition: ac3dec.h:155
int lfe_on
lfe channel in use
Definition: ac3dec.h:85
float spx_signal_blend[AC3_MAX_CHANNELS][SPX_MAX_BANDS]
spx signal blending factor (sblendfact)
Definition: ac3dec.h:136
int block_switch[AC3_MAX_CHANNELS]
block switch flags (blksw)
Definition: ac3dec.h:197
float * xcfptr[AC3_MAX_CHANNELS]
Definition: ac3dec.h:210
int dba_syntax
delta bit allocation syntax enabled (dbaflde)
Definition: ac3dec.h:106
int spx_src_start_freq
spx start frequency bin
Definition: ac3dec.h:128
uint8_t cpl_band_sizes[AC3_MAX_CPL_BANDS]
number of coeffs in each coupling band
Definition: ac3dec.h:117
#define AC3_FRAME_BUFFER_SIZE
Large enough for maximum possible frame size when the specification limit is ignored.
Definition: ac3dec.h:67
int lfe_mix_level_exists
indicates if lfemixlevcod is specified (lfemixlevcode)
Definition: ac3dec.h:92
float downmix_coeffs[AC3_MAX_CHANNELS][2]
stereo downmix coefficients
Definition: ac3dec.h:148
uint8_t
int first_cpl_coords[AC3_MAX_CHANNELS]
first coupling coordinates states (firstcplcos)
Definition: ac3dec.h:119
float output[AC3_MAX_CHANNELS][AC3_BLOCK_SIZE]
output after imdct transform and windowing
Definition: ac3dec.h:219
int num_rematrixing_bands
number of rematrixing bands (nrematbnd)
Definition: ac3dec.h:165
int fast_gain[AC3_MAX_CHANNELS]
fast gain values/SMR's (fgain)
Definition: ac3dec.h:179
int ff_eac3_parse_header(AC3DecodeContext *s)
Parse the E-AC-3 frame header.
Definition: eac3dec.c:291
int cpl_coords[AC3_MAX_CHANNELS][AC3_MAX_CPL_BANDS]
coupling coordinates (cplco)
Definition: ac3dec.h:120
int num_exp_groups[AC3_MAX_CHANNELS]
Number of exponent groups (nexpgrp)
Definition: ac3dec.h:170
bitstream reader API header.
float delay[AC3_MAX_CHANNELS][AC3_BLOCK_SIZE]
delay - added to the next block
Definition: ac3dec.h:216
int bit_allocation_syntax
bit allocation model syntax enabled (bamode)
Definition: ac3dec.h:104
int phase_flags_in_use
phase flags in use (phsflginu)
Definition: ac3dec.h:114
int phase_flags[AC3_MAX_CPL_BANDS]
phase flags (phsflg)
Definition: ac3dec.h:115
int out_channels
number of output channels
Definition: ac3dec.h:151
int channel_map
custom channel map
Definition: ac3dec.h:86
int substreamid
substream identification
Definition: ac3dec.h:77
FFTContext imdct_256
for 256 sample IMDCT
Definition: ac3dec.h:199
DSPContext dsp
for optimization
Definition: ac3dec.h:203
int bit_rate
stream bit rate, in bits-per-second
Definition: ac3dec.h:79
float * outptr[AC3_MAX_CHANNELS]
Definition: ac3dec.h:209
int lfe_ch
index of LFE channel
Definition: ac3dec.h:147
uint8_t first_spx_coords[AC3_MAX_CHANNELS]
first spx coordinates states (firstspxcos)
Definition: ac3dec.h:134
AC3BitAllocParameters bit_alloc_params
bit allocation parameters
Definition: ac3dec.h:176
int dolby_surround_mode
dolby surround mode (dsurmod)
Definition: ac3dec.h:95
GetBitContext gbc
bitstream reader
Definition: ac3dec.h:72
AC3DSPContext ac3dsp
Definition: ac3dec.h:205
#define AC3_MAX_CHANNELS
maximum number of channels, including coupling channel
Definition: ac3.h:31
int dolby_headphone_mode
dolby headphone mode (dheadphonmod)
Definition: ac3dec.h:97
int block_switch_syntax
block switch syntax enabled (blkswe)
Definition: ac3dec.h:102
int fast_gain_syntax
fast gain codes enabled (frmfgaincode)
Definition: ac3dec.h:105
int16_t band_psd[AC3_MAX_CHANNELS][AC3_CRITICAL_BANDS]
interpolated exponents
Definition: ac3dec.h:182
uint8_t channel_uses_spx[AC3_MAX_CHANNELS]
channel uses spectral extension (chinspx)
Definition: ac3dec.h:126
#define AC3_BLOCK_SIZE
Definition: ac3.h:35
#define FF_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding...
Definition: avcodec.h:509
uint8_t input_buffer[AC3_FRAME_BUFFER_SIZE+FF_INPUT_BUFFER_PADDING_SIZE]
temp buffer to prevent overread
Definition: ac3dec.h:220
Definition: fft.h:62
int surround_mix_level_ltrt
Surround mix level index for Lt/Rt (ltrtsurmixlev)
Definition: ac3dec.h:91
int dither_flag_syntax
dither flag syntax enabled (dithflage)
Definition: ac3dec.h:103
int end_freq[AC3_MAX_CHANNELS]
end frequency bin (endmant)
Definition: ac3dec.h:161
uint8_t dba_values[AC3_MAX_CHANNELS][8]
delta values for each segment
Definition: ac3dec.h:188
FFTContext imdct_512
for 512 sample IMDCT
Definition: ac3dec.h:198
int32_t
void ff_eac3_decode_transform_coeffs_aht_ch(AC3DecodeContext *s, int ch)
Decode mantissas in a single channel for the entire frame.
Definition: eac3dec.c:198
float drc_scale
percentage of dynamic range compression to be applied
Definition: ac3dec.h:156
int32_t fixed_coeffs[AC3_MAX_CHANNELS][AC3_MAX_COEFS]
fixed-point transform coefficients
Definition: ac3dec.h:214
AVCodecContext * avctx
parent context
Definition: ac3dec.h:71
int channel_in_cpl[AC3_MAX_CHANNELS]
channel in coupling (chincpl)
Definition: ac3dec.h:113
int fbw_channels
number of full-bandwidth channels
Definition: ac3dec.h:145
int8_t spx_atten_code[AC3_MAX_CHANNELS]
spx attenuation code (spxattencod)
Definition: ac3dec.h:127
uint8_t bap[AC3_MAX_CHANNELS][AC3_MAX_COEFS]
bit allocation pointers
Definition: ac3dec.h:180
main external API structure.
Definition: avcodec.h:1054
#define AC3_CRITICAL_BANDS
Definition: ac3.h:39
int num_cpl_bands
number of coupling bands (ncplbnd)
Definition: ac3dec.h:116
int num_spx_bands
number of spx bands (nspxbnds)
Definition: ac3dec.h:132
float tmp_output[AC3_BLOCK_SIZE]
temporary storage for output before windowing
Definition: ac3dec.h:218
void ff_eac3_apply_spectral_extension(AC3DecodeContext *s)
Apply spectral extension to each channel by copying lower frequency coefficients to higher frequency ...
Definition: eac3dec.c:66
Describe the class of an AVClass context structure.
Definition: log.h:33
int bitstream_mode
bitstream mode (bsmod)
Definition: ac3dec.h:83
int center_mix_level_ltrt
Center mix level index for Lt/Rt (ltrtcmixlev)
Definition: ac3dec.h:89
int frame_type
frame type (strmtyp)
Definition: ac3dec.h:76
#define AC3_MAX_BLOCKS
Definition: ac3.h:36
int eac3
indicates if current frame is E-AC-3
Definition: ac3dec.h:94
int channel_uses_aht[AC3_MAX_CHANNELS]
channel AHT in use (chahtinu)
Definition: ac3dec.h:140
uint8_t dba_lengths[AC3_MAX_CHANNELS][8]
delta segment lengths
Definition: ac3dec.h:187
int cpl_in_use[AC3_MAX_BLOCKS]
coupling in use (cplinu)
Definition: ac3dec.h:111
int firstchincpl
first channel in coupling
Definition: ac3dec.h:118
int dba_mode[AC3_MAX_CHANNELS]
delta bit allocation mode
Definition: ac3dec.h:184
int first_cpl_leak
first coupling leak state (firstcplleak)
Definition: ac3dec.h:177
int surround_mix_level
Surround mix level index.
Definition: ac3dec.h:90
int snr_offset[AC3_MAX_CHANNELS]
signal-to-noise ratio offsets (snroffst)
Definition: ac3dec.h:178
int downmixed
indicates if coeffs are currently downmixed
Definition: ac3dec.h:149
float window[AC3_BLOCK_SIZE]
window coefficients
Definition: ac3dec.h:217
#define AC3_MAX_CPL_BANDS
Definition: ac3.h:40
int num_blocks
number of audio blocks
Definition: ac3dec.h:81
FmtConvertContext fmt_conv
optimized conversion functions
Definition: ac3dec.h:206
float transform_coeffs[AC3_MAX_CHANNELS][AC3_MAX_COEFS]
transform coefficients
Definition: ac3dec.h:215
#define SPX_MAX_BANDS
Definition: ac3dec.h:64
DSP utils.
int pre_mantissa[AC3_MAX_CHANNELS][AC3_MAX_COEFS][AC3_MAX_BLOCKS]
pre-IDCT mantissas
Definition: ac3dec.h:141
float spx_noise_blend[AC3_MAX_CHANNELS][SPX_MAX_BANDS]
spx noise blending factor (nblendfact)
Definition: ac3dec.h:135
int rematrixing_flags[4]
rematrixing flags (rematflg)
Definition: ac3dec.h:166
uint8_t spx_band_sizes[SPX_MAX_BANDS]
number of bins in each spx band
Definition: ac3dec.h:133
int lfe_mix_level
LFE mix level index (lfemixlevcod)
Definition: ac3dec.h:93
int snr_offset_strategy
SNR offset strategy (snroffststr)
Definition: ac3dec.h:101
int start_freq[AC3_MAX_CHANNELS]
start frequency bin (strtmant)
Definition: ac3dec.h:160
int sample_rate
sample frequency, in Hz
Definition: ac3dec.h:80
int center_mix_level
Center mix level index.
Definition: ac3dec.h:88
int output_mode
output channel configuration
Definition: ac3dec.h:150
int frame_size
current frame size, in bytes
Definition: ac3dec.h:78
int dolby_surround_ex_mode
dolby surround ex mode (dsurexmod)
Definition: ac3dec.h:96
AVLFG dith_state
for dither generation
Definition: ac3dec.h:193
int cpl_strategy_exists[AC3_MAX_BLOCKS]
coupling strategy exists (cplstre)
Definition: ac3dec.h:112
int bitstream_id
bitstream id (bsid)
Definition: ac3dec.h:82
Common code between the AC-3 encoder and decoder.
int channel_mode
channel mode (acmod)
Definition: ac3dec.h:84
int spx_dst_start_freq
spx starting frequency bin for copying (copystartmant) the copy region ends at the start of the spx r...
Definition: ac3dec.h:130
int skip_syntax
skip field syntax enabled (skipflde)
Definition: ac3dec.h:107
DSPContext.
Definition: dsputil.h:124
int8_t dexps[AC3_MAX_CHANNELS][AC3_MAX_COEFS]
decoded exponents
Definition: ac3dec.h:171