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libavcodec/ac3dec.h

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00001 /*
00002  * Common code between the AC-3 and E-AC-3 decoders
00003  * Copyright (c) 2007 Bartlomiej Wolowiec <bartek.wolowiec@gmail.com>
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00027 #ifndef AVCODEC_AC3DEC_H
00028 #define AVCODEC_AC3DEC_H
00029 
00030 #include "libavutil/internal.h"
00031 #include "libavutil/lfg.h"
00032 #include "ac3.h"
00033 #include "bitstream.h"
00034 #include "dsputil.h"
00035 
00036 /* override ac3.h to include coupling channel */
00037 #undef AC3_MAX_CHANNELS
00038 #define AC3_MAX_CHANNELS 7
00039 #define CPL_CH 0
00040 
00041 #define AC3_OUTPUT_LFEON  8
00042 
00043 #define AC3_MAX_COEFS   256
00044 #define AC3_BLOCK_SIZE  256
00045 #define MAX_BLOCKS        6
00046 
00047 typedef struct {
00048     AVCodecContext *avctx;                  
00049     GetBitContext gbc;                      
00050     uint8_t *input_buffer;                  
00051 
00054     int frame_type;                         
00055     int substreamid;                        
00056     int frame_size;                         
00057     int bit_rate;                           
00058     int sample_rate;                        
00059     int num_blocks;                         
00060     int channel_mode;                       
00061     int lfe_on;                             
00062     int channel_map;                        
00063     int center_mix_level;                   
00064     int surround_mix_level;                 
00065     int eac3;                               
00066 
00067 
00069     int snr_offset_strategy;                
00070     int block_switch_syntax;                
00071     int dither_flag_syntax;                 
00072     int bit_allocation_syntax;              
00073     int fast_gain_syntax;                   
00074     int dba_syntax;                         
00075     int skip_syntax;                        
00076 
00077 
00079     int cpl_in_use[MAX_BLOCKS];             
00080     int cpl_strategy_exists[MAX_BLOCKS];    
00081     int channel_in_cpl[AC3_MAX_CHANNELS];   
00082     int phase_flags_in_use;                 
00083     int phase_flags[18];                    
00084     int num_cpl_subbands;                   
00085     int num_cpl_bands;                      
00086     uint8_t cpl_band_struct[18];            
00087     int firstchincpl;                       
00088     int first_cpl_coords[AC3_MAX_CHANNELS]; 
00089     int cpl_coords[AC3_MAX_CHANNELS][18];   
00090 
00091 
00093     int channel_uses_aht[AC3_MAX_CHANNELS];                         
00094     int pre_mantissa[AC3_MAX_CHANNELS][AC3_MAX_COEFS][MAX_BLOCKS];  
00095 
00096 
00098     int fbw_channels;                           
00099     int channels;                               
00100     int lfe_ch;                                 
00101     float downmix_coeffs[AC3_MAX_CHANNELS][2];  
00102     int downmixed;                              
00103     int output_mode;                            
00104     int out_channels;                           
00105 
00106 
00108     float dynamic_range[2];                 
00109 
00110 
00112     int start_freq[AC3_MAX_CHANNELS];       
00113     int end_freq[AC3_MAX_CHANNELS];         
00114 
00115 
00117     int num_rematrixing_bands;              
00118     int rematrixing_flags[4];               
00119 
00120 
00122     int num_exp_groups[AC3_MAX_CHANNELS];           
00123     int8_t dexps[AC3_MAX_CHANNELS][AC3_MAX_COEFS];  
00124     int exp_strategy[MAX_BLOCKS][AC3_MAX_CHANNELS]; 
00125 
00126 
00128     AC3BitAllocParameters bit_alloc_params;         
00129     int first_cpl_leak;                             
00130     int snr_offset[AC3_MAX_CHANNELS];               
00131     int fast_gain[AC3_MAX_CHANNELS];                
00132     uint8_t bap[AC3_MAX_CHANNELS][AC3_MAX_COEFS];   
00133     int16_t psd[AC3_MAX_CHANNELS][AC3_MAX_COEFS];   
00134     int16_t band_psd[AC3_MAX_CHANNELS][50];         
00135     int16_t mask[AC3_MAX_CHANNELS][50];             
00136     int dba_mode[AC3_MAX_CHANNELS];                 
00137     int dba_nsegs[AC3_MAX_CHANNELS];                
00138     uint8_t dba_offsets[AC3_MAX_CHANNELS][8];       
00139     uint8_t dba_lengths[AC3_MAX_CHANNELS][8];       
00140     uint8_t dba_values[AC3_MAX_CHANNELS][8];        
00141 
00142 
00144     int dither_flag[AC3_MAX_CHANNELS];      
00145     AVLFG dith_state;                       
00146 
00147 
00149     int block_switch[AC3_MAX_CHANNELS];     
00150     MDCTContext imdct_512;                  
00151     MDCTContext imdct_256;                  
00152 
00153 
00155     DSPContext dsp;                         
00156     float add_bias;                         
00157     float mul_bias;                         
00158 
00159 
00160     DECLARE_ALIGNED_16(int, fixed_coeffs[AC3_MAX_CHANNELS][AC3_MAX_COEFS]);  
00161 
00163     DECLARE_ALIGNED_16(float, transform_coeffs[AC3_MAX_CHANNELS][AC3_MAX_COEFS]);   
00164     DECLARE_ALIGNED_16(float, delay[AC3_MAX_CHANNELS][AC3_BLOCK_SIZE]);             
00165     DECLARE_ALIGNED_16(float, window[AC3_BLOCK_SIZE]);                              
00166     DECLARE_ALIGNED_16(float, tmp_output[AC3_BLOCK_SIZE]);                          
00167     DECLARE_ALIGNED_16(float, output[AC3_MAX_CHANNELS][AC3_BLOCK_SIZE]);            
00168 
00169 } AC3DecodeContext;
00170 
00175 int ff_eac3_parse_header(AC3DecodeContext *s);
00176 
00181 void ff_eac3_decode_transform_coeffs_aht_ch(AC3DecodeContext *s, int ch);
00182 
00183 #endif /* AVCODEC_AC3DEC_H */

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