/*

  * Common code between the AC-3 and E-AC-3 decoders

  * Copyright (c) 2007 Bartlomiej Wolowiec <bartek.wolowiec@gmail.com>
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 /**

  * @file libavcodec/ac3.h

  * Common code between the AC-3 and E-AC-3 decoders.

  */
 

 #ifndef AVCODEC_AC3DEC_H
 #define AVCODEC_AC3DEC_H

 #include "libavutil/internal.h"

 #include "libavutil/lfg.h"

 #include "ac3.h"
 #include "bitstream.h"
 #include "dsputil.h"
 
 /* override ac3.h to include coupling channel */
 #undef AC3_MAX_CHANNELS
 #define AC3_MAX_CHANNELS 7
 #define CPL_CH 0
 
 #define AC3_OUTPUT_LFEON  8
 

 #define AC3_MAX_COEFS   256
 #define AC3_BLOCK_SIZE  256

 #define MAX_BLOCKS        6

 typedef struct {

     AVCodecContext *avctx;                  ///< parent context
     GetBitContext gbc;                      ///< bitstream reader
     uint8_t *input_buffer;                  ///< temp buffer to prevent overread
 
 ///@defgroup bsi bit stream information
 ///@{

     int frame_type;                         ///< frame type                             (strmtyp)

     int substreamid;                        ///< substream identification
     int frame_size;                         ///< current frame size, in bytes
     int bit_rate;                           ///< stream bit rate, in bits-per-second
     int sample_rate;                        ///< sample frequency, in Hz

     int num_blocks;                         ///< number of audio blocks

     int channel_mode;                       ///< channel mode                           (acmod)

     int lfe_on;                             ///< lfe channel in use

     int channel_map;                        ///< custom channel map

     int center_mix_level;                   ///< Center mix level index
     int surround_mix_level;                 ///< Surround mix level index

     int eac3;                               ///< indicates if current frame is E-AC-3

 ///@}
 

 ///@defgroup audfrm frame syntax parameters
     int snr_offset_strategy;                ///< SNR offset strategy                    (snroffststr)
     int block_switch_syntax;                ///< block switch syntax enabled            (blkswe)
     int dither_flag_syntax;                 ///< dither flag syntax enabled             (dithflage)
     int bit_allocation_syntax;              ///< bit allocation model syntax enabled    (bamode)
     int fast_gain_syntax;                   ///< fast gain codes enabled                (frmfgaincode)
     int dba_syntax;                         ///< delta bit allocation syntax enabled    (dbaflde)
     int skip_syntax;                        ///< skip field syntax enabled              (skipflde)
  ///@}
 

 ///@defgroup cpl standard coupling

     int cpl_in_use[MAX_BLOCKS];             ///< coupling in use                        (cplinu)

     int cpl_strategy_exists[MAX_BLOCKS];    ///< coupling strategy exists               (cplstre)

     int channel_in_cpl[AC3_MAX_CHANNELS];   ///< channel in coupling                    (chincpl)
     int phase_flags_in_use;                 ///< phase flags in use                     (phsflginu)
     int phase_flags[18];                    ///< phase flags                            (phsflg)
     int num_cpl_subbands;                   ///< number of coupling sub bands           (ncplsubnd)
     int num_cpl_bands;                      ///< number of coupling bands               (ncplbnd)

     uint8_t cpl_band_struct[18];            ///< coupling band structure                (cplbndstrc)

     int firstchincpl;                       ///< first channel in coupling
     int first_cpl_coords[AC3_MAX_CHANNELS]; ///< first coupling coordinates states      (firstcplcos)

     int cpl_coords[AC3_MAX_CHANNELS][18];   ///< coupling coordinates                   (cplco)

 ///@}

 ///@defgroup aht adaptive hybrid transform

     int channel_uses_aht[AC3_MAX_CHANNELS];                         ///< channel AHT in use (chahtinu)

     int pre_mantissa[AC3_MAX_CHANNELS][AC3_MAX_COEFS][MAX_BLOCKS];  ///< pre-IDCT mantissas

 ///@}
 

 ///@defgroup channel channel

     int fbw_channels;                           ///< number of full-bandwidth channels
     int channels;                               ///< number of total channels
     int lfe_ch;                                 ///< index of LFE channel

     float downmix_coeffs[AC3_MAX_CHANNELS][2];  ///< stereo downmix coefficients
     int downmixed;                              ///< indicates if coeffs are currently downmixed

     int output_mode;                            ///< output channel configuration
     int out_channels;                           ///< number of output channels

 ///@}

 ///@defgroup dynrng dynamic range

     float dynamic_range[2];                 ///< dynamic range

 ///@}
 
 ///@defgroup bandwidth bandwidth

     int start_freq[AC3_MAX_CHANNELS];       ///< start frequency bin                    (strtmant)
     int end_freq[AC3_MAX_CHANNELS];         ///< end frequency bin                      (endmant)

 ///@}

 ///@defgroup rematrixing rematrixing

     int num_rematrixing_bands;              ///< number of rematrixing bands            (nrematbnd)
     int rematrixing_flags[4];               ///< rematrixing flags                      (rematflg)

 ///@}
 
 ///@defgroup exponents exponents

     int num_exp_groups[AC3_MAX_CHANNELS];           ///< Number of exponent groups      (nexpgrp)

     int8_t dexps[AC3_MAX_CHANNELS][AC3_MAX_COEFS];  ///< decoded exponents

     int exp_strategy[MAX_BLOCKS][AC3_MAX_CHANNELS]; ///< exponent strategies            (expstr)

 ///@}
 
 ///@defgroup bitalloc bit allocation

     AC3BitAllocParameters bit_alloc_params;         ///< bit allocation parameters

     int first_cpl_leak;                             ///< first coupling leak state      (firstcplleak)

     int snr_offset[AC3_MAX_CHANNELS];               ///< signal-to-noise ratio offsets  (snroffst)
     int fast_gain[AC3_MAX_CHANNELS];                ///< fast gain values/SMR's         (fgain)

     uint8_t bap[AC3_MAX_CHANNELS][AC3_MAX_COEFS];   ///< bit allocation pointers
     int16_t psd[AC3_MAX_CHANNELS][AC3_MAX_COEFS];   ///< scaled exponents

     int16_t band_psd[AC3_MAX_CHANNELS][50];         ///< interpolated exponents
     int16_t mask[AC3_MAX_CHANNELS][50];             ///< masking curve values
     int dba_mode[AC3_MAX_CHANNELS];                 ///< delta bit allocation mode
     int dba_nsegs[AC3_MAX_CHANNELS];                ///< number of delta segments
     uint8_t dba_offsets[AC3_MAX_CHANNELS][8];       ///< delta segment offsets
     uint8_t dba_lengths[AC3_MAX_CHANNELS][8];       ///< delta segment lengths
     uint8_t dba_values[AC3_MAX_CHANNELS][8];        ///< delta values for each segment

 ///@}

 ///@defgroup dithering zero-mantissa dithering

     int dither_flag[AC3_MAX_CHANNELS];      ///< dither flags                           (dithflg)

     AVLFG dith_state;                       ///< for dither generation

 ///@}

 ///@defgroup imdct IMDCT

     int block_switch[AC3_MAX_CHANNELS];     ///< block switch flags                     (blksw)

     MDCTContext imdct_512;                  ///< for 512 sample IMDCT
     MDCTContext imdct_256;                  ///< for 256 sample IMDCT

 ///@}
 
 ///@defgroup opt optimization

     DSPContext dsp;                         ///< for optimization
     float add_bias;                         ///< offset for float_to_int16 conversion
     float mul_bias;                         ///< scaling for float_to_int16 conversion

 ///@}

     DECLARE_ALIGNED_16(int, fixed_coeffs[AC3_MAX_CHANNELS][AC3_MAX_COEFS]);  ///> fixed-point transform coefficients

 
 ///@defgroup arrays aligned arrays

     DECLARE_ALIGNED_16(float, transform_coeffs[AC3_MAX_CHANNELS][AC3_MAX_COEFS]);   ///< transform coefficients
     DECLARE_ALIGNED_16(float, delay[AC3_MAX_CHANNELS][AC3_BLOCK_SIZE]);             ///< delay - added to the next block
     DECLARE_ALIGNED_16(float, window[AC3_BLOCK_SIZE]);                              ///< window coefficients

     DECLARE_ALIGNED_16(float, tmp_output[AC3_BLOCK_SIZE]);                          ///< temporary storage for output before windowing

     DECLARE_ALIGNED_16(float, output[AC3_MAX_CHANNELS][AC3_BLOCK_SIZE]);            ///< output after imdct transform and windowing

 ///@}

 } AC3DecodeContext;
 

 /**
  * Parse the E-AC-3 frame header.
  * This parses both the bit stream info and audio frame header.
  */
 int ff_eac3_parse_header(AC3DecodeContext *s);
 
 /**
  * Decode mantissas in a single channel for the entire frame.
  * This is used when AHT mode is enabled.
  */
 void ff_eac3_decode_transform_coeffs_aht_ch(AC3DecodeContext *s, int ch);
 

 #endif /* AVCODEC_AC3DEC_H */