FFmpeg: libavcodec/ac3dec.h Source File

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 
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 
00066 #define AC3_FRAME_BUFFER_SIZE 32768
00067 
00068 typedef struct {
00069     AVCodecContext *avctx;                  
00070     GetBitContext gbc;                      
00071 
00074     int frame_type;                         
00075     int substreamid;                        
00076     int frame_size;                         
00077     int bit_rate;                           
00078     int sample_rate;                        
00079     int num_blocks;                         
00080     int bitstream_mode;                     
00081     int channel_mode;                       
00082     int channel_layout;                     
00083     int lfe_on;                             
00084     int channel_map;                        
00085     int center_mix_level;                   
00086     int surround_mix_level;                 
00087     int eac3;                               
00088 
00089 
00091     int snr_offset_strategy;                
00092     int block_switch_syntax;                
00093     int dither_flag_syntax;                 
00094     int bit_allocation_syntax;              
00095     int fast_gain_syntax;                   
00096     int dba_syntax;                         
00097     int skip_syntax;                        
00098 
00099 
00101     int cpl_in_use[AC3_MAX_BLOCKS];         
00102     int cpl_strategy_exists[AC3_MAX_BLOCKS];
00103     int channel_in_cpl[AC3_MAX_CHANNELS];   
00104     int phase_flags_in_use;                 
00105     int phase_flags[AC3_MAX_CPL_BANDS];     
00106     int num_cpl_bands;                      
00107     uint8_t cpl_band_sizes[AC3_MAX_CPL_BANDS]; 
00108     int firstchincpl;                       
00109     int first_cpl_coords[AC3_MAX_CHANNELS]; 
00110     int cpl_coords[AC3_MAX_CHANNELS][AC3_MAX_CPL_BANDS]; 
00111 
00112 
00115     int spx_in_use;                             
00116     uint8_t channel_uses_spx[AC3_MAX_CHANNELS]; 
00117     int8_t spx_atten_code[AC3_MAX_CHANNELS];    
00118     int spx_src_start_freq;                     
00119     int spx_dst_end_freq;                       
00120     int spx_dst_start_freq;                     
00121 
00122     int num_spx_bands;                          
00123     uint8_t spx_band_sizes[SPX_MAX_BANDS];      
00124     uint8_t first_spx_coords[AC3_MAX_CHANNELS]; 
00125     float spx_noise_blend[AC3_MAX_CHANNELS][SPX_MAX_BANDS]; 
00126     float spx_signal_blend[AC3_MAX_CHANNELS][SPX_MAX_BANDS];
00127 
00128 
00130     int channel_uses_aht[AC3_MAX_CHANNELS];                         
00131     int pre_mantissa[AC3_MAX_CHANNELS][AC3_MAX_COEFS][AC3_MAX_BLOCKS];  
00132 
00133 
00135     int fbw_channels;                           
00136     int channels;                               
00137     int lfe_ch;                                 
00138     float downmix_coeffs[AC3_MAX_CHANNELS][2];  
00139     int downmixed;                              
00140     int output_mode;                            
00141     int out_channels;                           
00142 
00143 
00145     float dynamic_range[2];                 
00146 
00147 
00149     int start_freq[AC3_MAX_CHANNELS];       
00150     int end_freq[AC3_MAX_CHANNELS];         
00151 
00152 
00154     int num_rematrixing_bands;              
00155     int rematrixing_flags[4];               
00156 
00157 
00159     int num_exp_groups[AC3_MAX_CHANNELS];           
00160     int8_t dexps[AC3_MAX_CHANNELS][AC3_MAX_COEFS];  
00161     int exp_strategy[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS]; 
00162 
00163 
00165     AC3BitAllocParameters bit_alloc_params;         
00166     int first_cpl_leak;                             
00167     int snr_offset[AC3_MAX_CHANNELS];               
00168     int fast_gain[AC3_MAX_CHANNELS];                
00169     uint8_t bap[AC3_MAX_CHANNELS][AC3_MAX_COEFS];   
00170     int16_t psd[AC3_MAX_CHANNELS][AC3_MAX_COEFS];   
00171     int16_t band_psd[AC3_MAX_CHANNELS][AC3_CRITICAL_BANDS]; 
00172     int16_t mask[AC3_MAX_CHANNELS][AC3_CRITICAL_BANDS];     
00173     int dba_mode[AC3_MAX_CHANNELS];                 
00174     int dba_nsegs[AC3_MAX_CHANNELS];                
00175     uint8_t dba_offsets[AC3_MAX_CHANNELS][8];       
00176     uint8_t dba_lengths[AC3_MAX_CHANNELS][8];       
00177     uint8_t dba_values[AC3_MAX_CHANNELS][8];        
00178 
00179 
00181     int dither_flag[AC3_MAX_CHANNELS];      
00182     AVLFG dith_state;                       
00183 
00184 
00186     int block_switch[AC3_MAX_CHANNELS];     
00187     FFTContext imdct_512;                   
00188     FFTContext imdct_256;                   
00189 
00190 
00192     DSPContext dsp;                         
00193     AC3DSPContext ac3dsp;
00194     FmtConvertContext fmt_conv;             
00195     float mul_bias;                         
00196 
00197 
00199     DECLARE_ALIGNED(16, int,   fixed_coeffs)[AC3_MAX_CHANNELS][AC3_MAX_COEFS];       
00200     DECLARE_ALIGNED(32, float, transform_coeffs)[AC3_MAX_CHANNELS][AC3_MAX_COEFS];   
00201     DECLARE_ALIGNED(32, float, delay)[AC3_MAX_CHANNELS][AC3_BLOCK_SIZE];             
00202     DECLARE_ALIGNED(32, float, window)[AC3_BLOCK_SIZE];                              
00203     DECLARE_ALIGNED(32, float, tmp_output)[AC3_BLOCK_SIZE];                          
00204     DECLARE_ALIGNED(32, float, output)[AC3_MAX_CHANNELS][AC3_BLOCK_SIZE];            
00205     DECLARE_ALIGNED(32, uint8_t, input_buffer)[AC3_FRAME_BUFFER_SIZE + FF_INPUT_BUFFER_PADDING_SIZE]; 
00206 
00207 } AC3DecodeContext;
00208 
00213 int ff_eac3_parse_header(AC3DecodeContext *s);
00214 
00219 void ff_eac3_decode_transform_coeffs_aht_ch(AC3DecodeContext *s, int ch);
00220 
00221 void ff_ac3_downmix_c(float (*samples)[256], float (*matrix)[2],
00222                       int out_ch, int in_ch, int len);
00223 
00229 void ff_eac3_apply_spectral_extension(AC3DecodeContext *s);
00230 
00231 #endif /* AVCODEC_AC3DEC_H */