The internal header libavutil/internal.h should not be used outside libavutil.
[libav.git] / libavcodec / ac3dec.h
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 FFmpeg.
6 *
7 * FFmpeg 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 * FFmpeg 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 FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 /**
23 * @file libavcodec/ac3.h
24 * Common code between the AC-3 and E-AC-3 decoders.
25 */
26
27 #ifndef AVCODEC_AC3DEC_H
28 #define AVCODEC_AC3DEC_H
29
30 #include "libavutil/lfg.h"
31 #include "ac3.h"
32 #include "get_bits.h"
33 #include "dsputil.h"
34
35 /* override ac3.h to include coupling channel */
36 #undef AC3_MAX_CHANNELS
37 #define AC3_MAX_CHANNELS 7
38 #define CPL_CH 0
39
40 #define AC3_OUTPUT_LFEON 8
41
42 #define AC3_MAX_COEFS 256
43 #define AC3_BLOCK_SIZE 256
44 #define MAX_BLOCKS 6
45
46 typedef struct {
47 AVCodecContext *avctx; ///< parent context
48 GetBitContext gbc; ///< bitstream reader
49 uint8_t *input_buffer; ///< temp buffer to prevent overread
50
51 ///@defgroup bsi bit stream information
52 ///@{
53 int frame_type; ///< frame type (strmtyp)
54 int substreamid; ///< substream identification
55 int frame_size; ///< current frame size, in bytes
56 int bit_rate; ///< stream bit rate, in bits-per-second
57 int sample_rate; ///< sample frequency, in Hz
58 int num_blocks; ///< number of audio blocks
59 int channel_mode; ///< channel mode (acmod)
60 int channel_layout; ///< channel layout
61 int lfe_on; ///< lfe channel in use
62 int channel_map; ///< custom channel map
63 int center_mix_level; ///< Center mix level index
64 int surround_mix_level; ///< Surround mix level index
65 int eac3; ///< indicates if current frame is E-AC-3
66 ///@}
67
68 ///@defgroup audfrm frame syntax parameters
69 int snr_offset_strategy; ///< SNR offset strategy (snroffststr)
70 int block_switch_syntax; ///< block switch syntax enabled (blkswe)
71 int dither_flag_syntax; ///< dither flag syntax enabled (dithflage)
72 int bit_allocation_syntax; ///< bit allocation model syntax enabled (bamode)
73 int fast_gain_syntax; ///< fast gain codes enabled (frmfgaincode)
74 int dba_syntax; ///< delta bit allocation syntax enabled (dbaflde)
75 int skip_syntax; ///< skip field syntax enabled (skipflde)
76 ///@}
77
78 ///@defgroup cpl standard coupling
79 int cpl_in_use[MAX_BLOCKS]; ///< coupling in use (cplinu)
80 int cpl_strategy_exists[MAX_BLOCKS]; ///< coupling strategy exists (cplstre)
81 int channel_in_cpl[AC3_MAX_CHANNELS]; ///< channel in coupling (chincpl)
82 int phase_flags_in_use; ///< phase flags in use (phsflginu)
83 int phase_flags[18]; ///< phase flags (phsflg)
84 int num_cpl_bands; ///< number of coupling bands (ncplbnd)
85 uint8_t cpl_band_struct[18]; ///< coupling band structure (cplbndstrc)
86 int firstchincpl; ///< first channel in coupling
87 int first_cpl_coords[AC3_MAX_CHANNELS]; ///< first coupling coordinates states (firstcplcos)
88 int cpl_coords[AC3_MAX_CHANNELS][18]; ///< coupling coordinates (cplco)
89 ///@}
90
91 ///@defgroup aht adaptive hybrid transform
92 int channel_uses_aht[AC3_MAX_CHANNELS]; ///< channel AHT in use (chahtinu)
93 int pre_mantissa[AC3_MAX_CHANNELS][AC3_MAX_COEFS][MAX_BLOCKS]; ///< pre-IDCT mantissas
94 ///@}
95
96 ///@defgroup channel channel
97 int fbw_channels; ///< number of full-bandwidth channels
98 int channels; ///< number of total channels
99 int lfe_ch; ///< index of LFE channel
100 float downmix_coeffs[AC3_MAX_CHANNELS][2]; ///< stereo downmix coefficients
101 int downmixed; ///< indicates if coeffs are currently downmixed
102 int output_mode; ///< output channel configuration
103 int out_channels; ///< number of output channels
104 ///@}
105
106 ///@defgroup dynrng dynamic range
107 float dynamic_range[2]; ///< dynamic range
108 ///@}
109
110 ///@defgroup bandwidth bandwidth
111 int start_freq[AC3_MAX_CHANNELS]; ///< start frequency bin (strtmant)
112 int end_freq[AC3_MAX_CHANNELS]; ///< end frequency bin (endmant)
113 ///@}
114
115 ///@defgroup rematrixing rematrixing
116 int num_rematrixing_bands; ///< number of rematrixing bands (nrematbnd)
117 int rematrixing_flags[4]; ///< rematrixing flags (rematflg)
118 ///@}
119
120 ///@defgroup exponents exponents
121 int num_exp_groups[AC3_MAX_CHANNELS]; ///< Number of exponent groups (nexpgrp)
122 int8_t dexps[AC3_MAX_CHANNELS][AC3_MAX_COEFS]; ///< decoded exponents
123 int exp_strategy[MAX_BLOCKS][AC3_MAX_CHANNELS]; ///< exponent strategies (expstr)
124 ///@}
125
126 ///@defgroup bitalloc bit allocation
127 AC3BitAllocParameters bit_alloc_params; ///< bit allocation parameters
128 int first_cpl_leak; ///< first coupling leak state (firstcplleak)
129 int snr_offset[AC3_MAX_CHANNELS]; ///< signal-to-noise ratio offsets (snroffst)
130 int fast_gain[AC3_MAX_CHANNELS]; ///< fast gain values/SMR's (fgain)
131 uint8_t bap[AC3_MAX_CHANNELS][AC3_MAX_COEFS]; ///< bit allocation pointers
132 int16_t psd[AC3_MAX_CHANNELS][AC3_MAX_COEFS]; ///< scaled exponents
133 int16_t band_psd[AC3_MAX_CHANNELS][50]; ///< interpolated exponents
134 int16_t mask[AC3_MAX_CHANNELS][50]; ///< masking curve values
135 int dba_mode[AC3_MAX_CHANNELS]; ///< delta bit allocation mode
136 int dba_nsegs[AC3_MAX_CHANNELS]; ///< number of delta segments
137 uint8_t dba_offsets[AC3_MAX_CHANNELS][8]; ///< delta segment offsets
138 uint8_t dba_lengths[AC3_MAX_CHANNELS][8]; ///< delta segment lengths
139 uint8_t dba_values[AC3_MAX_CHANNELS][8]; ///< delta values for each segment
140 ///@}
141
142 ///@defgroup dithering zero-mantissa dithering
143 int dither_flag[AC3_MAX_CHANNELS]; ///< dither flags (dithflg)
144 AVLFG dith_state; ///< for dither generation
145 ///@}
146
147 ///@defgroup imdct IMDCT
148 int block_switch[AC3_MAX_CHANNELS]; ///< block switch flags (blksw)
149 MDCTContext imdct_512; ///< for 512 sample IMDCT
150 MDCTContext imdct_256; ///< for 256 sample IMDCT
151 ///@}
152
153 ///@defgroup opt optimization
154 DSPContext dsp; ///< for optimization
155 float add_bias; ///< offset for float_to_int16 conversion
156 float mul_bias; ///< scaling for float_to_int16 conversion
157 ///@}
158
159 DECLARE_ALIGNED_16(int, fixed_coeffs[AC3_MAX_CHANNELS][AC3_MAX_COEFS]); ///> fixed-point transform coefficients
160
161 ///@defgroup arrays aligned arrays
162 DECLARE_ALIGNED_16(float, transform_coeffs[AC3_MAX_CHANNELS][AC3_MAX_COEFS]); ///< transform coefficients
163 DECLARE_ALIGNED_16(float, delay[AC3_MAX_CHANNELS][AC3_BLOCK_SIZE]); ///< delay - added to the next block
164 DECLARE_ALIGNED_16(float, window[AC3_BLOCK_SIZE]); ///< window coefficients
165 DECLARE_ALIGNED_16(float, tmp_output[AC3_BLOCK_SIZE]); ///< temporary storage for output before windowing
166 DECLARE_ALIGNED_16(float, output[AC3_MAX_CHANNELS][AC3_BLOCK_SIZE]); ///< output after imdct transform and windowing
167 ///@}
168 } AC3DecodeContext;
169
170 /**
171 * Parse the E-AC-3 frame header.
172 * This parses both the bit stream info and audio frame header.
173 */
174 int ff_eac3_parse_header(AC3DecodeContext *s);
175
176 /**
177 * Decode mantissas in a single channel for the entire frame.
178 * This is used when AHT mode is enabled.
179 */
180 void ff_eac3_decode_transform_coeffs_aht_ch(AC3DecodeContext *s, int ch);
181
182 #endif /* AVCODEC_AC3DEC_H */