Libav 0.7.1
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 Libav.
00006  *
00007  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00050 #ifndef AVCODEC_AC3DEC_H
00051 #define AVCODEC_AC3DEC_H
00052 
00053 #include "libavutil/lfg.h"
00054 #include "ac3.h"
00055 #include "ac3dsp.h"
00056 #include "get_bits.h"
00057 #include "dsputil.h"
00058 #include "fft.h"
00059 #include "fmtconvert.h"
00060 
00061 #define AC3_OUTPUT_LFEON  8
00062 
00063 #define SPX_MAX_BANDS    17
00064 
00065 typedef struct {
00066     AVCodecContext *avctx;                  
00067     GetBitContext gbc;                      
00068     uint8_t *input_buffer;                  
00069 
00072     int frame_type;                         
00073     int substreamid;                        
00074     int frame_size;                         
00075     int bit_rate;                           
00076     int sample_rate;                        
00077     int num_blocks;                         
00078     int bitstream_mode;                     
00079     int channel_mode;                       
00080     int channel_layout;                     
00081     int lfe_on;                             
00082     int channel_map;                        
00083     int center_mix_level;                   
00084     int surround_mix_level;                 
00085     int eac3;                               
00086 
00087 
00089     int snr_offset_strategy;                
00090     int block_switch_syntax;                
00091     int dither_flag_syntax;                 
00092     int bit_allocation_syntax;              
00093     int fast_gain_syntax;                   
00094     int dba_syntax;                         
00095     int skip_syntax;                        
00096 
00097 
00099     int cpl_in_use[AC3_MAX_BLOCKS];         
00100     int cpl_strategy_exists[AC3_MAX_BLOCKS];
00101     int channel_in_cpl[AC3_MAX_CHANNELS];   
00102     int phase_flags_in_use;                 
00103     int phase_flags[AC3_MAX_CPL_BANDS];     
00104     int num_cpl_bands;                      
00105     uint8_t cpl_band_sizes[AC3_MAX_CPL_BANDS]; 
00106     int firstchincpl;                       
00107     int first_cpl_coords[AC3_MAX_CHANNELS]; 
00108     int cpl_coords[AC3_MAX_CHANNELS][AC3_MAX_CPL_BANDS]; 
00109 
00110 
00113     int spx_in_use;                             
00114     uint8_t channel_uses_spx[AC3_MAX_CHANNELS]; 
00115     int8_t spx_atten_code[AC3_MAX_CHANNELS];    
00116     int spx_src_start_freq;                     
00117     int spx_dst_end_freq;                       
00118     int spx_dst_start_freq;                     
00119 
00120     int num_spx_bands;                          
00121     uint8_t spx_band_sizes[SPX_MAX_BANDS];      
00122     uint8_t first_spx_coords[AC3_MAX_CHANNELS]; 
00123     float spx_noise_blend[AC3_MAX_CHANNELS][SPX_MAX_BANDS]; 
00124     float spx_signal_blend[AC3_MAX_CHANNELS][SPX_MAX_BANDS];
00125 
00126 
00128     int channel_uses_aht[AC3_MAX_CHANNELS];                         
00129     int pre_mantissa[AC3_MAX_CHANNELS][AC3_MAX_COEFS][AC3_MAX_BLOCKS];  
00130 
00131 
00133     int fbw_channels;                           
00134     int channels;                               
00135     int lfe_ch;                                 
00136     float downmix_coeffs[AC3_MAX_CHANNELS][2];  
00137     int downmixed;                              
00138     int output_mode;                            
00139     int out_channels;                           
00140 
00141 
00143     float dynamic_range[2];                 
00144 
00145 
00147     int start_freq[AC3_MAX_CHANNELS];       
00148     int end_freq[AC3_MAX_CHANNELS];         
00149 
00150 
00152     int num_rematrixing_bands;              
00153     int rematrixing_flags[4];               
00154 
00155 
00157     int num_exp_groups[AC3_MAX_CHANNELS];           
00158     int8_t dexps[AC3_MAX_CHANNELS][AC3_MAX_COEFS];  
00159     int exp_strategy[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS]; 
00160 
00161 
00163     AC3BitAllocParameters bit_alloc_params;         
00164     int first_cpl_leak;                             
00165     int snr_offset[AC3_MAX_CHANNELS];               
00166     int fast_gain[AC3_MAX_CHANNELS];                
00167     uint8_t bap[AC3_MAX_CHANNELS][AC3_MAX_COEFS];   
00168     int16_t psd[AC3_MAX_CHANNELS][AC3_MAX_COEFS];   
00169     int16_t band_psd[AC3_MAX_CHANNELS][AC3_CRITICAL_BANDS]; 
00170     int16_t mask[AC3_MAX_CHANNELS][AC3_CRITICAL_BANDS];     
00171     int dba_mode[AC3_MAX_CHANNELS];                 
00172     int dba_nsegs[AC3_MAX_CHANNELS];                
00173     uint8_t dba_offsets[AC3_MAX_CHANNELS][8];       
00174     uint8_t dba_lengths[AC3_MAX_CHANNELS][8];       
00175     uint8_t dba_values[AC3_MAX_CHANNELS][8];        
00176 
00177 
00179     int dither_flag[AC3_MAX_CHANNELS];      
00180     AVLFG dith_state;                       
00181 
00182 
00184     int block_switch[AC3_MAX_CHANNELS];     
00185     FFTContext imdct_512;                   
00186     FFTContext imdct_256;                   
00187 
00188 
00190     DSPContext dsp;                         
00191     AC3DSPContext ac3dsp;
00192     FmtConvertContext fmt_conv;             
00193     float mul_bias;                         
00194 
00195 
00197     DECLARE_ALIGNED(16, int,   fixed_coeffs)[AC3_MAX_CHANNELS][AC3_MAX_COEFS];       
00198     DECLARE_ALIGNED(32, float, transform_coeffs)[AC3_MAX_CHANNELS][AC3_MAX_COEFS];   
00199     DECLARE_ALIGNED(32, float, delay)[AC3_MAX_CHANNELS][AC3_BLOCK_SIZE];             
00200     DECLARE_ALIGNED(32, float, window)[AC3_BLOCK_SIZE];                              
00201     DECLARE_ALIGNED(32, float, tmp_output)[AC3_BLOCK_SIZE];                          
00202     DECLARE_ALIGNED(32, float, output)[AC3_MAX_CHANNELS][AC3_BLOCK_SIZE];            
00203 
00204 } AC3DecodeContext;
00205 
00210 int ff_eac3_parse_header(AC3DecodeContext *s);
00211 
00216 void ff_eac3_decode_transform_coeffs_aht_ch(AC3DecodeContext *s, int ch);
00217 
00218 void ff_ac3_downmix_c(float (*samples)[256], float (*matrix)[2],
00219                       int out_ch, int in_ch, int len);
00220 
00226 void ff_eac3_apply_spectral_extension(AC3DecodeContext *s);
00227 
00228 #endif /* AVCODEC_AC3DEC_H */