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 "bswapdsp.h"
58 #include "get_bits.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;
71  AVCodecContext *avctx;
72  GetBitContext gbc;
73 
76  int frame_type;
77  int substreamid;
78  int frame_size;
79  int bit_rate;
80  int sample_rate;
81  int num_blocks;
82  int bitstream_id;
83  int bitstream_mode;
84  int channel_mode;
85  int lfe_on;
86  int channel_map;
87  int preferred_downmix;
88  int center_mix_level;
89  int center_mix_level_ltrt;
90  int surround_mix_level;
91  int surround_mix_level_ltrt;
92  int lfe_mix_level_exists;
93  int lfe_mix_level;
94  int eac3;
95  int dolby_surround_mode;
96  int dolby_surround_ex_mode;
97  int dolby_headphone_mode;
98 
101  int snr_offset_strategy;
102  int block_switch_syntax;
103  int dither_flag_syntax;
104  int bit_allocation_syntax;
105  int fast_gain_syntax;
106  int dba_syntax;
107  int skip_syntax;
108 
111  int cpl_in_use[AC3_MAX_BLOCKS];
112  int cpl_strategy_exists[AC3_MAX_BLOCKS];
113  int channel_in_cpl[AC3_MAX_CHANNELS];
114  int phase_flags_in_use;
115  int phase_flags[AC3_MAX_CPL_BANDS];
116  int num_cpl_bands;
117  uint8_t cpl_band_sizes[AC3_MAX_CPL_BANDS];
118  int firstchincpl;
119  int first_cpl_coords[AC3_MAX_CHANNELS];
120  int cpl_coords[AC3_MAX_CHANNELS][AC3_MAX_CPL_BANDS];
121 
125  int spx_in_use;
126  uint8_t channel_uses_spx[AC3_MAX_CHANNELS];
127  int8_t spx_atten_code[AC3_MAX_CHANNELS];
128  int spx_src_start_freq;
129  int spx_dst_end_freq;
130  int spx_dst_start_freq;
131  int num_spx_bands;
133  uint8_t spx_band_sizes[SPX_MAX_BANDS];
134  uint8_t first_spx_coords[AC3_MAX_CHANNELS];
135  float spx_noise_blend[AC3_MAX_CHANNELS][SPX_MAX_BANDS];
136  float spx_signal_blend[AC3_MAX_CHANNELS][SPX_MAX_BANDS];
137 
140  int channel_uses_aht[AC3_MAX_CHANNELS];
141  int pre_mantissa[AC3_MAX_CHANNELS][AC3_MAX_COEFS][AC3_MAX_BLOCKS];
142 
145  int fbw_channels;
146  int channels;
147  int lfe_ch;
148  float downmix_coeffs[AC3_MAX_CHANNELS][2];
149  int downmixed;
150  int output_mode;
151  int out_channels;
152 
155  float dynamic_range[2];
156  float drc_scale;
157 
160  int start_freq[AC3_MAX_CHANNELS];
161  int end_freq[AC3_MAX_CHANNELS];
162 
165  int num_rematrixing_bands;
166  int rematrixing_flags[4];
167 
170  int num_exp_groups[AC3_MAX_CHANNELS];
171  int8_t dexps[AC3_MAX_CHANNELS][AC3_MAX_COEFS];
172  int exp_strategy[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS];
173 
176  AC3BitAllocParameters bit_alloc_params;
177  int first_cpl_leak;
178  int snr_offset[AC3_MAX_CHANNELS];
179  int fast_gain[AC3_MAX_CHANNELS];
181  int16_t psd[AC3_MAX_CHANNELS][AC3_MAX_COEFS];
182  int16_t band_psd[AC3_MAX_CHANNELS][AC3_CRITICAL_BANDS];
184  int dba_mode[AC3_MAX_CHANNELS];
185  int dba_nsegs[AC3_MAX_CHANNELS];
186  uint8_t dba_offsets[AC3_MAX_CHANNELS][8];
187  uint8_t dba_lengths[AC3_MAX_CHANNELS][8];
188  uint8_t dba_values[AC3_MAX_CHANNELS][8];
189 
192  int dither_flag[AC3_MAX_CHANNELS];
193  AVLFG dith_state;
194 
197  int block_switch[AC3_MAX_CHANNELS];
198  FFTContext imdct_512;
199  FFTContext imdct_256;
200 
203  BswapDSPContext bdsp;
204  AVFloatDSPContext fdsp;
205  AC3DSPContext ac3dsp;
206  FmtConvertContext fmt_conv;
207 
209  float *outptr[AC3_MAX_CHANNELS];
210  float *xcfptr[AC3_MAX_CHANNELS];
211  float *dlyptr[AC3_MAX_CHANNELS];
212 
215  DECLARE_ALIGNED(32, float, transform_coeffs)[AC3_MAX_CHANNELS][AC3_MAX_COEFS];
216  DECLARE_ALIGNED(32, float, delay)[AC3_MAX_CHANNELS][AC3_BLOCK_SIZE];
217  DECLARE_ALIGNED(32, float, window)[AC3_BLOCK_SIZE];
218  DECLARE_ALIGNED(32, float, tmp_output)[AC3_BLOCK_SIZE];
219  DECLARE_ALIGNED(32, float, output)[AC3_MAX_CHANNELS][AC3_BLOCK_SIZE];
220  DECLARE_ALIGNED(32, uint8_t, input_buffer)[AC3_FRAME_BUFFER_SIZE + FF_INPUT_BUFFER_PADDING_SIZE];
221 } AC3DecodeContext;
223 
228 int ff_eac3_parse_header(AC3DecodeContext *s);
229 
234 void ff_eac3_decode_transform_coeffs_aht_ch(AC3DecodeContext *s, int ch);
235 
241 void ff_eac3_apply_spectral_extension(AC3DecodeContext *s);
242 
243 #endif /* AVCODEC_AC3DEC_H */
Definition: lfg.h:25
#define AC3_MAX_COEFS
Definition: ac3.h:34
static const int fixed_coeffs[][3]
Definition: shorten.c:269
#define DECLARE_ALIGNED(n, t, v)
Definition: mem.h:58
uint8_t
bitstream reader API header.
static const uint8_t frame_size[4]
Definition: g723_1_data.h:47
static const uint16_t mask[17]
Definition: lzw.c:38
#define AC3_MAX_CHANNELS
maximum number of channels, including coupling channel
Definition: ac3.h:31
#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:531
Definition: fft.h:73
int32_t
void ff_eac3_apply_spectral_extension(AC3DecodeContext *s)
Definition: eac3dec.c:66
int ff_eac3_parse_header(AC3DecodeContext *s)
Definition: eac3dec.c:291
main external API structure.
Definition: avcodec.h:1050
#define AC3_CRITICAL_BANDS
Definition: ac3.h:39
Describe the class of an AVClass context structure.
Definition: log.h:33
#define AC3_MAX_BLOCKS
Definition: ac3.h:36
#define AC3_MAX_CPL_BANDS
Definition: ac3.h:40
void ff_eac3_decode_transform_coeffs_aht_ch(AC3DecodeContext *s, int ch)
Definition: eac3dec.c:198
Common code between the AC-3 encoder and decoder.