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/*
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 * The simplest AC-3 encoder
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 * Copyright (c) 2000 Fabrice Bellard
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 * Copyright (c) 2006-2010 Justin Ruggles <justin.ruggles@gmail.com>
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 * Copyright (c) 2006-2010 Prakash Punnoor <prakash@punnoor.de>
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 *
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 * This file is part of Libav.
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 *
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 * Libav is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * Libav is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with Libav; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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/**
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 * @file
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 * The simplest AC-3 encoder.
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 */
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//#define DEBUG
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//#define ASSERT_LEVEL 2
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#include <stdint.h>
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#include "libavutil/audioconvert.h"
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#include "libavutil/avassert.h"
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#include "libavutil/avstring.h"
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#include "libavutil/crc.h"
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#include "libavutil/opt.h"
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#include "avcodec.h"
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#include "put_bits.h"
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#include "dsputil.h"
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#include "ac3dsp.h"
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#include "ac3.h"
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#include "audioconvert.h"
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#include "fft.h"
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47

    
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#ifndef CONFIG_AC3ENC_FLOAT
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#define CONFIG_AC3ENC_FLOAT 0
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#endif
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52

    
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/** Maximum number of exponent groups. +1 for separate DC exponent. */
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#define AC3_MAX_EXP_GROUPS 85
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#if CONFIG_AC3ENC_FLOAT
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#define MAC_COEF(d,a,b) ((d)+=(a)*(b))
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typedef float SampleType;
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typedef float CoefType;
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typedef float CoefSumType;
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#else
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#define MAC_COEF(d,a,b) MAC64(d,a,b)
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typedef int16_t SampleType;
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typedef int32_t CoefType;
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typedef int64_t CoefSumType;
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#endif
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typedef struct AC3MDCTContext {
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    const SampleType *window;           ///< MDCT window function
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    FFTContext fft;                     ///< FFT context for MDCT calculation
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} AC3MDCTContext;
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/**
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 * Encoding Options used by AVOption.
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 */
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typedef struct AC3EncOptions {
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    /* AC-3 metadata options*/
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    int dialogue_level;
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    int bitstream_mode;
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    float center_mix_level;
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    float surround_mix_level;
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    int dolby_surround_mode;
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    int audio_production_info;
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    int mixing_level;
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    int room_type;
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    int copyright;
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    int original;
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    int extended_bsi_1;
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    int preferred_stereo_downmix;
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    float ltrt_center_mix_level;
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    float ltrt_surround_mix_level;
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    float loro_center_mix_level;
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    float loro_surround_mix_level;
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    int extended_bsi_2;
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    int dolby_surround_ex_mode;
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    int dolby_headphone_mode;
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    int ad_converter_type;
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    /* other encoding options */
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    int allow_per_frame_metadata;
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    int stereo_rematrixing;
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} AC3EncOptions;
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/**
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 * Data for a single audio block.
106
 */
107
typedef struct AC3Block {
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    uint8_t  **bap;                             ///< bit allocation pointers (bap)
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    CoefType **mdct_coef;                       ///< MDCT coefficients
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    int32_t  **fixed_coef;                      ///< fixed-point MDCT coefficients
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    uint8_t  **exp;                             ///< original exponents
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    uint8_t  **grouped_exp;                     ///< grouped exponents
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    int16_t  **psd;                             ///< psd per frequency bin
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    int16_t  **band_psd;                        ///< psd per critical band
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    int16_t  **mask;                            ///< masking curve
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    uint16_t **qmant;                           ///< quantized mantissas
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    uint8_t  coeff_shift[AC3_MAX_CHANNELS];     ///< fixed-point coefficient shift values
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    uint8_t  new_rematrixing_strategy;          ///< send new rematrixing flags in this block
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    uint8_t  rematrixing_flags[4];              ///< rematrixing flags
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    struct AC3Block *exp_ref_block[AC3_MAX_CHANNELS]; ///< reference blocks for EXP_REUSE
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} AC3Block;
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/**
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 * AC-3 encoder private context.
125
 */
126
typedef struct AC3EncodeContext {
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    AVClass *av_class;                      ///< AVClass used for AVOption
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    AC3EncOptions options;                  ///< encoding options
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    PutBitContext pb;                       ///< bitstream writer context
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    DSPContext dsp;
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    AC3DSPContext ac3dsp;                   ///< AC-3 optimized functions
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    AC3MDCTContext mdct;                    ///< MDCT context
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    AC3Block blocks[AC3_MAX_BLOCKS];        ///< per-block info
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    int bitstream_id;                       ///< bitstream id                           (bsid)
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    int bitstream_mode;                     ///< bitstream mode                         (bsmod)
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    int bit_rate;                           ///< target bit rate, in bits-per-second
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    int sample_rate;                        ///< sampling frequency, in Hz
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    int frame_size_min;                     ///< minimum frame size in case rounding is necessary
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    int frame_size;                         ///< current frame size in bytes
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    int frame_size_code;                    ///< frame size code                        (frmsizecod)
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    uint16_t crc_inv[2];
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    int bits_written;                       ///< bit count    (used to avg. bitrate)
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    int samples_written;                    ///< sample count (used to avg. bitrate)
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    int fbw_channels;                       ///< number of full-bandwidth channels      (nfchans)
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    int channels;                           ///< total number of channels               (nchans)
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    int lfe_on;                             ///< indicates if there is an LFE channel   (lfeon)
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    int lfe_channel;                        ///< channel index of the LFE channel
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    int has_center;                         ///< indicates if there is a center channel
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    int has_surround;                       ///< indicates if there are one or more surround channels
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    int channel_mode;                       ///< channel mode                           (acmod)
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    const uint8_t *channel_map;             ///< channel map used to reorder channels
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    int center_mix_level;                   ///< center mix level code
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    int surround_mix_level;                 ///< surround mix level code
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    int ltrt_center_mix_level;              ///< Lt/Rt center mix level code
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    int ltrt_surround_mix_level;            ///< Lt/Rt surround mix level code
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    int loro_center_mix_level;              ///< Lo/Ro center mix level code
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    int loro_surround_mix_level;            ///< Lo/Ro surround mix level code
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    int cutoff;                             ///< user-specified cutoff frequency, in Hz
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    int bandwidth_code;                     ///< bandwidth code (0 to 60)               (chbwcod)
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    int nb_coefs[AC3_MAX_CHANNELS];
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    int rematrixing_enabled;                ///< stereo rematrixing enabled
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    int num_rematrixing_bands;              ///< number of rematrixing bands
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    /* bitrate allocation control */
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    int slow_gain_code;                     ///< slow gain code                         (sgaincod)
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    int slow_decay_code;                    ///< slow decay code                        (sdcycod)
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    int fast_decay_code;                    ///< fast decay code                        (fdcycod)
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    int db_per_bit_code;                    ///< dB/bit code                            (dbpbcod)
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    int floor_code;                         ///< floor code                             (floorcod)
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    AC3BitAllocParameters bit_alloc;        ///< bit allocation parameters
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    int coarse_snr_offset;                  ///< coarse SNR offsets                     (csnroffst)
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    int fast_gain_code[AC3_MAX_CHANNELS];   ///< fast gain codes (signal-to-mask ratio) (fgaincod)
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    int fine_snr_offset[AC3_MAX_CHANNELS];  ///< fine SNR offsets                       (fsnroffst)
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    int frame_bits_fixed;                   ///< number of non-coefficient bits for fixed parameters
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    int frame_bits;                         ///< all frame bits except exponents and mantissas
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    int exponent_bits;                      ///< number of bits used for exponents
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    SampleType **planar_samples;
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    uint8_t *bap_buffer;
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    uint8_t *bap1_buffer;
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    CoefType *mdct_coef_buffer;
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    int32_t *fixed_coef_buffer;
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    uint8_t *exp_buffer;
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    uint8_t *grouped_exp_buffer;
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    int16_t *psd_buffer;
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    int16_t *band_psd_buffer;
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    int16_t *mask_buffer;
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    uint16_t *qmant_buffer;
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    uint8_t exp_strategy[AC3_MAX_CHANNELS][AC3_MAX_BLOCKS]; ///< exponent strategies
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    DECLARE_ALIGNED(32, SampleType, windowed_samples)[AC3_WINDOW_SIZE];
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} AC3EncodeContext;
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typedef struct AC3Mant {
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    uint16_t *qmant1_ptr, *qmant2_ptr, *qmant4_ptr; ///< mantissa pointers for bap=1,2,4
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    int mant1_cnt, mant2_cnt, mant4_cnt;    ///< mantissa counts for bap=1,2,4
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} AC3Mant;
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#define CMIXLEV_NUM_OPTIONS 3
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static const float cmixlev_options[CMIXLEV_NUM_OPTIONS] = {
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    LEVEL_MINUS_3DB, LEVEL_MINUS_4POINT5DB, LEVEL_MINUS_6DB
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};
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#define SURMIXLEV_NUM_OPTIONS 3
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static const float surmixlev_options[SURMIXLEV_NUM_OPTIONS] = {
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    LEVEL_MINUS_3DB, LEVEL_MINUS_6DB, LEVEL_ZERO
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};
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#define EXTMIXLEV_NUM_OPTIONS 8
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static const float extmixlev_options[EXTMIXLEV_NUM_OPTIONS] = {
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    LEVEL_PLUS_3DB,  LEVEL_PLUS_1POINT5DB,  LEVEL_ONE,       LEVEL_MINUS_4POINT5DB,
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    LEVEL_MINUS_3DB, LEVEL_MINUS_4POINT5DB, LEVEL_MINUS_6DB, LEVEL_ZERO
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};
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#define OFFSET(param) offsetof(AC3EncodeContext, options.param)
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#define AC3ENC_PARAM (AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM)
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static const AVOption options[] = {
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/* Metadata Options */
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{"per_frame_metadata", "Allow Changing Metadata Per-Frame", OFFSET(allow_per_frame_metadata), FF_OPT_TYPE_INT, 0, 0, 1, AC3ENC_PARAM},
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/* downmix levels */
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{"center_mixlev", "Center Mix Level", OFFSET(center_mix_level), FF_OPT_TYPE_FLOAT, LEVEL_MINUS_4POINT5DB, 0.0, 1.0, AC3ENC_PARAM},
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{"surround_mixlev", "Surround Mix Level", OFFSET(surround_mix_level), FF_OPT_TYPE_FLOAT, LEVEL_MINUS_6DB, 0.0, 1.0, AC3ENC_PARAM},
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/* audio production information */
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{"mixing_level", "Mixing Level", OFFSET(mixing_level), FF_OPT_TYPE_INT, -1, -1, 111, AC3ENC_PARAM},
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{"room_type", "Room Type", OFFSET(room_type), FF_OPT_TYPE_INT, -1, -1, 2, AC3ENC_PARAM, "room_type"},
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    {"notindicated", "Not Indicated (default)", 0, FF_OPT_TYPE_CONST, 0, INT_MIN, INT_MAX, AC3ENC_PARAM, "room_type"},
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    {"large",        "Large Room",              0, FF_OPT_TYPE_CONST, 1, INT_MIN, INT_MAX, AC3ENC_PARAM, "room_type"},
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    {"small",        "Small Room",              0, FF_OPT_TYPE_CONST, 2, INT_MIN, INT_MAX, AC3ENC_PARAM, "room_type"},
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/* other metadata options */
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{"copyright", "Copyright Bit", OFFSET(copyright), FF_OPT_TYPE_INT, 0, 0, 1, AC3ENC_PARAM},
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{"dialnorm", "Dialogue Level (dB)", OFFSET(dialogue_level), FF_OPT_TYPE_INT, -31, -31, -1, AC3ENC_PARAM},
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{"dsur_mode", "Dolby Surround Mode", OFFSET(dolby_surround_mode), FF_OPT_TYPE_INT, 0, 0, 2, AC3ENC_PARAM, "dsur_mode"},
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    {"notindicated", "Not Indicated (default)",    0, FF_OPT_TYPE_CONST, 0, INT_MIN, INT_MAX, AC3ENC_PARAM, "dsur_mode"},
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    {"on",           "Dolby Surround Encoded",     0, FF_OPT_TYPE_CONST, 1, INT_MIN, INT_MAX, AC3ENC_PARAM, "dsur_mode"},
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    {"off",          "Not Dolby Surround Encoded", 0, FF_OPT_TYPE_CONST, 2, INT_MIN, INT_MAX, AC3ENC_PARAM, "dsur_mode"},
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{"original", "Original Bit Stream", OFFSET(original), FF_OPT_TYPE_INT, 1, 0, 1, AC3ENC_PARAM},
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/* extended bitstream information */
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{"dmix_mode", "Preferred Stereo Downmix Mode", OFFSET(preferred_stereo_downmix), FF_OPT_TYPE_INT, -1, -1, 2, AC3ENC_PARAM, "dmix_mode"},
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    {"notindicated", "Not Indicated (default)", 0, FF_OPT_TYPE_CONST, 0, INT_MIN, INT_MAX, AC3ENC_PARAM, "dmix_mode"},
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    {"ltrt", "Lt/Rt Downmix Preferred",         0, FF_OPT_TYPE_CONST, 1, INT_MIN, INT_MAX, AC3ENC_PARAM, "dmix_mode"},
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    {"loro", "Lo/Ro Downmix Preferred",         0, FF_OPT_TYPE_CONST, 2, INT_MIN, INT_MAX, AC3ENC_PARAM, "dmix_mode"},
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{"ltrt_cmixlev", "Lt/Rt Center Mix Level", OFFSET(ltrt_center_mix_level), FF_OPT_TYPE_FLOAT, -1.0, -1.0, 2.0, AC3ENC_PARAM},
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{"ltrt_surmixlev", "Lt/Rt Surround Mix Level", OFFSET(ltrt_surround_mix_level), FF_OPT_TYPE_FLOAT, -1.0, -1.0, 2.0, AC3ENC_PARAM},
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{"loro_cmixlev", "Lo/Ro Center Mix Level", OFFSET(loro_center_mix_level), FF_OPT_TYPE_FLOAT, -1.0, -1.0, 2.0, AC3ENC_PARAM},
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{"loro_surmixlev", "Lo/Ro Surround Mix Level", OFFSET(loro_surround_mix_level), FF_OPT_TYPE_FLOAT, -1.0, -1.0, 2.0, AC3ENC_PARAM},
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{"dsurex_mode", "Dolby Surround EX Mode", OFFSET(dolby_surround_ex_mode), FF_OPT_TYPE_INT, -1, -1, 2, AC3ENC_PARAM, "dsurex_mode"},
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    {"notindicated", "Not Indicated (default)",       0, FF_OPT_TYPE_CONST, 0, INT_MIN, INT_MAX, AC3ENC_PARAM, "dsurex_mode"},
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    {"on",           "Dolby Surround EX Encoded",     0, FF_OPT_TYPE_CONST, 1, INT_MIN, INT_MAX, AC3ENC_PARAM, "dsurex_mode"},
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    {"off",          "Not Dolby Surround EX Encoded", 0, FF_OPT_TYPE_CONST, 2, INT_MIN, INT_MAX, AC3ENC_PARAM, "dsurex_mode"},
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{"dheadphone_mode", "Dolby Headphone Mode", OFFSET(dolby_headphone_mode), FF_OPT_TYPE_INT, -1, -1, 2, AC3ENC_PARAM, "dheadphone_mode"},
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    {"notindicated", "Not Indicated (default)",     0, FF_OPT_TYPE_CONST, 0, INT_MIN, INT_MAX, AC3ENC_PARAM, "dheadphone_mode"},
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    {"on",           "Dolby Headphone Encoded",     0, FF_OPT_TYPE_CONST, 1, INT_MIN, INT_MAX, AC3ENC_PARAM, "dheadphone_mode"},
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    {"off",          "Not Dolby Headphone Encoded", 0, FF_OPT_TYPE_CONST, 2, INT_MIN, INT_MAX, AC3ENC_PARAM, "dheadphone_mode"},
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{"ad_conv_type", "A/D Converter Type", OFFSET(ad_converter_type), FF_OPT_TYPE_INT, -1, -1, 1, AC3ENC_PARAM, "ad_conv_type"},
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    {"standard", "Standard (default)", 0, FF_OPT_TYPE_CONST, 0, INT_MIN, INT_MAX, AC3ENC_PARAM, "ad_conv_type"},
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    {"hdcd",     "HDCD",               0, FF_OPT_TYPE_CONST, 1, INT_MIN, INT_MAX, AC3ENC_PARAM, "ad_conv_type"},
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/* Other Encoding Options */
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{"stereo_rematrixing", "Stereo Rematrixing", OFFSET(stereo_rematrixing), FF_OPT_TYPE_INT, 1, 0, 1, AC3ENC_PARAM},
270
{NULL}
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};
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#if CONFIG_AC3ENC_FLOAT
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static AVClass ac3enc_class = { "AC-3 Encoder", av_default_item_name,
275
                                options, LIBAVUTIL_VERSION_INT };
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#else
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static AVClass ac3enc_class = { "Fixed-Point AC-3 Encoder", av_default_item_name,
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                                options, LIBAVUTIL_VERSION_INT };
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#endif
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/* prototypes for functions in ac3enc_fixed.c and ac3enc_float.c */
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284
static av_cold void mdct_end(AC3MDCTContext *mdct);
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286
static av_cold int mdct_init(AVCodecContext *avctx, AC3MDCTContext *mdct,
287
                             int nbits);
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static void apply_window(DSPContext *dsp, SampleType *output, const SampleType *input,
290
                         const SampleType *window, unsigned int len);
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static int normalize_samples(AC3EncodeContext *s);
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294
static void scale_coefficients(AC3EncodeContext *s);
295

    
296

    
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/**
298
 * LUT for number of exponent groups.
299
 * exponent_group_tab[exponent strategy-1][number of coefficients]
300
 */
301
static uint8_t exponent_group_tab[3][256];
302

    
303

    
304
/**
305
 * List of supported channel layouts.
306
 */
307
static const int64_t ac3_channel_layouts[] = {
308
     AV_CH_LAYOUT_MONO,
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     AV_CH_LAYOUT_STEREO,
310
     AV_CH_LAYOUT_2_1,
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     AV_CH_LAYOUT_SURROUND,
312
     AV_CH_LAYOUT_2_2,
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     AV_CH_LAYOUT_QUAD,
314
     AV_CH_LAYOUT_4POINT0,
315
     AV_CH_LAYOUT_5POINT0,
316
     AV_CH_LAYOUT_5POINT0_BACK,
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    (AV_CH_LAYOUT_MONO     | AV_CH_LOW_FREQUENCY),
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    (AV_CH_LAYOUT_STEREO   | AV_CH_LOW_FREQUENCY),
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    (AV_CH_LAYOUT_2_1      | AV_CH_LOW_FREQUENCY),
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    (AV_CH_LAYOUT_SURROUND | AV_CH_LOW_FREQUENCY),
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    (AV_CH_LAYOUT_2_2      | AV_CH_LOW_FREQUENCY),
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    (AV_CH_LAYOUT_QUAD     | AV_CH_LOW_FREQUENCY),
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    (AV_CH_LAYOUT_4POINT0  | AV_CH_LOW_FREQUENCY),
324
     AV_CH_LAYOUT_5POINT1,
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     AV_CH_LAYOUT_5POINT1_BACK,
326
     0
327
};
328

    
329

    
330
/**
331
 * LUT to select the bandwidth code based on the bit rate, sample rate, and
332
 * number of full-bandwidth channels.
333
 * bandwidth_tab[fbw_channels-1][sample rate code][bit rate code]
334
 */
335
static const uint8_t ac3_bandwidth_tab[5][3][19] = {
336
//      32  40  48  56  64  80  96 112 128 160 192 224 256 320 384 448 512 576 640
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338
    { {  0,  0,  0, 12, 16, 32, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48 },
339
      {  0,  0,  0, 16, 20, 36, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56 },
340
      {  0,  0,  0, 32, 40, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60 } },
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342
    { {  0,  0,  0,  0,  0,  0,  0, 20, 24, 32, 48, 48, 48, 48, 48, 48, 48, 48, 48 },
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      {  0,  0,  0,  0,  0,  0,  4, 24, 28, 36, 56, 56, 56, 56, 56, 56, 56, 56, 56 },
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      {  0,  0,  0,  0,  0,  0, 20, 44, 52, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60 } },
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    { {  0,  0,  0,  0,  0,  0,  0,  0,  0, 16, 24, 32, 40, 48, 48, 48, 48, 48, 48 },
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      {  0,  0,  0,  0,  0,  0,  0,  0,  4, 20, 28, 36, 44, 56, 56, 56, 56, 56, 56 },
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      {  0,  0,  0,  0,  0,  0,  0,  0, 20, 40, 48, 60, 60, 60, 60, 60, 60, 60, 60 } },
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350
    { {  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, 12, 24, 32, 48, 48, 48, 48, 48, 48 },
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      {  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, 16, 28, 36, 56, 56, 56, 56, 56, 56 },
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      {  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, 32, 48, 60, 60, 60, 60, 60, 60, 60 } },
353

    
354
    { {  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  8, 20, 32, 40, 48, 48, 48, 48 },
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      {  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, 12, 24, 36, 44, 56, 56, 56, 56 },
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      {  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, 28, 44, 60, 60, 60, 60, 60, 60 } }
357
};
358

    
359

    
360
/**
361
 * Adjust the frame size to make the average bit rate match the target bit rate.
362
 * This is only needed for 11025, 22050, and 44100 sample rates.
363
 */
364
static void adjust_frame_size(AC3EncodeContext *s)
365
{
366
    while (s->bits_written >= s->bit_rate && s->samples_written >= s->sample_rate) {
367
        s->bits_written    -= s->bit_rate;
368
        s->samples_written -= s->sample_rate;
369
    }
370
    s->frame_size = s->frame_size_min +
371
                    2 * (s->bits_written * s->sample_rate < s->samples_written * s->bit_rate);
372
    s->bits_written    += s->frame_size * 8;
373
    s->samples_written += AC3_FRAME_SIZE;
374
}
375

    
376

    
377
/**
378
 * Deinterleave input samples.
379
 * Channels are reordered from Libav's default order to AC-3 order.
380
 */
381
static void deinterleave_input_samples(AC3EncodeContext *s,
382
                                       const SampleType *samples)
383
{
384
    int ch, i;
385

    
386
    /* deinterleave and remap input samples */
387
    for (ch = 0; ch < s->channels; ch++) {
388
        const SampleType *sptr;
389
        int sinc;
390

    
391
        /* copy last 256 samples of previous frame to the start of the current frame */
392
        memcpy(&s->planar_samples[ch][0], &s->planar_samples[ch][AC3_FRAME_SIZE],
393
               AC3_BLOCK_SIZE * sizeof(s->planar_samples[0][0]));
394

    
395
        /* deinterleave */
396
        sinc = s->channels;
397
        sptr = samples + s->channel_map[ch];
398
        for (i = AC3_BLOCK_SIZE; i < AC3_FRAME_SIZE+AC3_BLOCK_SIZE; i++) {
399
            s->planar_samples[ch][i] = *sptr;
400
            sptr += sinc;
401
        }
402
    }
403
}
404

    
405

    
406
/**
407
 * Apply the MDCT to input samples to generate frequency coefficients.
408
 * This applies the KBD window and normalizes the input to reduce precision
409
 * loss due to fixed-point calculations.
410
 */
411
static void apply_mdct(AC3EncodeContext *s)
412
{
413
    int blk, ch;
414

    
415
    for (ch = 0; ch < s->channels; ch++) {
416
        for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
417
            AC3Block *block = &s->blocks[blk];
418
            const SampleType *input_samples = &s->planar_samples[ch][blk * AC3_BLOCK_SIZE];
419

    
420
            apply_window(&s->dsp, s->windowed_samples, input_samples, s->mdct.window, AC3_WINDOW_SIZE);
421

    
422
            block->coeff_shift[ch] = normalize_samples(s);
423

    
424
            s->mdct.fft.mdct_calcw(&s->mdct.fft, block->mdct_coef[ch],
425
                                   s->windowed_samples);
426
        }
427
    }
428
}
429

    
430

    
431
/**
432
 * Determine rematrixing flags for each block and band.
433
 */
434
static void compute_rematrixing_strategy(AC3EncodeContext *s)
435
{
436
    int nb_coefs;
437
    int blk, bnd, i;
438
    AC3Block *block, *block0;
439

    
440
    if (s->channel_mode != AC3_CHMODE_STEREO)
441
        return;
442

    
443
    s->num_rematrixing_bands = 4;
444

    
445
    nb_coefs = FFMIN(s->nb_coefs[0], s->nb_coefs[1]);
446

    
447
    for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
448
        block = &s->blocks[blk];
449
        block->new_rematrixing_strategy = !blk;
450
        if (!s->rematrixing_enabled)
451
            continue;
452
        for (bnd = 0; bnd < s->num_rematrixing_bands; bnd++) {
453
            /* calculate calculate sum of squared coeffs for one band in one block */
454
            int start = ff_ac3_rematrix_band_tab[bnd];
455
            int end   = FFMIN(nb_coefs, ff_ac3_rematrix_band_tab[bnd+1]);
456
            CoefSumType sum[4] = {0,};
457
            for (i = start; i < end; i++) {
458
                CoefType lt = block->mdct_coef[0][i];
459
                CoefType rt = block->mdct_coef[1][i];
460
                CoefType md = lt + rt;
461
                CoefType sd = lt - rt;
462
                MAC_COEF(sum[0], lt, lt);
463
                MAC_COEF(sum[1], rt, rt);
464
                MAC_COEF(sum[2], md, md);
465
                MAC_COEF(sum[3], sd, sd);
466
            }
467

    
468
            /* compare sums to determine if rematrixing will be used for this band */
469
            if (FFMIN(sum[2], sum[3]) < FFMIN(sum[0], sum[1]))
470
                block->rematrixing_flags[bnd] = 1;
471
            else
472
                block->rematrixing_flags[bnd] = 0;
473

    
474
            /* determine if new rematrixing flags will be sent */
475
            if (blk &&
476
                block->rematrixing_flags[bnd] != block0->rematrixing_flags[bnd]) {
477
                block->new_rematrixing_strategy = 1;
478
            }
479
        }
480
        block0 = block;
481
    }
482
}
483

    
484

    
485
/**
486
 * Apply stereo rematrixing to coefficients based on rematrixing flags.
487
 */
488
static void apply_rematrixing(AC3EncodeContext *s)
489
{
490
    int nb_coefs;
491
    int blk, bnd, i;
492
    int start, end;
493
    uint8_t *flags;
494

    
495
    if (!s->rematrixing_enabled)
496
        return;
497

    
498
    nb_coefs = FFMIN(s->nb_coefs[0], s->nb_coefs[1]);
499

    
500
    for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
501
        AC3Block *block = &s->blocks[blk];
502
        if (block->new_rematrixing_strategy)
503
            flags = block->rematrixing_flags;
504
        for (bnd = 0; bnd < s->num_rematrixing_bands; bnd++) {
505
            if (flags[bnd]) {
506
                start = ff_ac3_rematrix_band_tab[bnd];
507
                end   = FFMIN(nb_coefs, ff_ac3_rematrix_band_tab[bnd+1]);
508
                for (i = start; i < end; i++) {
509
                    int32_t lt = block->fixed_coef[0][i];
510
                    int32_t rt = block->fixed_coef[1][i];
511
                    block->fixed_coef[0][i] = (lt + rt) >> 1;
512
                    block->fixed_coef[1][i] = (lt - rt) >> 1;
513
                }
514
            }
515
        }
516
    }
517
}
518

    
519

    
520
/**
521
 * Initialize exponent tables.
522
 */
523
static av_cold void exponent_init(AC3EncodeContext *s)
524
{
525
    int expstr, i, grpsize;
526

    
527
    for (expstr = EXP_D15-1; expstr <= EXP_D45-1; expstr++) {
528
        grpsize = 3 << expstr;
529
        for (i = 73; i < 256; i++) {
530
            exponent_group_tab[expstr][i] = (i + grpsize - 4) / grpsize;
531
        }
532
    }
533
    /* LFE */
534
    exponent_group_tab[0][7] = 2;
535
}
536

    
537

    
538
/**
539
 * Extract exponents from the MDCT coefficients.
540
 * This takes into account the normalization that was done to the input samples
541
 * by adjusting the exponents by the exponent shift values.
542
 */
543
static void extract_exponents(AC3EncodeContext *s)
544
{
545
    int blk, ch;
546

    
547
    for (ch = 0; ch < s->channels; ch++) {
548
        for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
549
            AC3Block *block = &s->blocks[blk];
550
            s->ac3dsp.extract_exponents(block->exp[ch], block->fixed_coef[ch],
551
                                        AC3_MAX_COEFS);
552
        }
553
    }
554
}
555

    
556

    
557
/**
558
 * Exponent Difference Threshold.
559
 * New exponents are sent if their SAD exceed this number.
560
 */
561
#define EXP_DIFF_THRESHOLD 500
562

    
563

    
564
/**
565
 * Calculate exponent strategies for all channels.
566
 * Array arrangement is reversed to simplify the per-channel calculation.
567
 */
568
static void compute_exp_strategy(AC3EncodeContext *s)
569
{
570
    int ch, blk, blk1;
571

    
572
    for (ch = 0; ch < s->fbw_channels; ch++) {
573
        uint8_t *exp_strategy = s->exp_strategy[ch];
574
        uint8_t *exp          = s->blocks[0].exp[ch];
575
        int exp_diff;
576

    
577
        /* estimate if the exponent variation & decide if they should be
578
           reused in the next frame */
579
        exp_strategy[0] = EXP_NEW;
580
        exp += AC3_MAX_COEFS;
581
        for (blk = 1; blk < AC3_MAX_BLOCKS; blk++) {
582
            exp_diff = s->dsp.sad[0](NULL, exp, exp - AC3_MAX_COEFS, 16, 16);
583
            if (exp_diff > EXP_DIFF_THRESHOLD)
584
                exp_strategy[blk] = EXP_NEW;
585
            else
586
                exp_strategy[blk] = EXP_REUSE;
587
            exp += AC3_MAX_COEFS;
588
        }
589

    
590
        /* now select the encoding strategy type : if exponents are often
591
           recoded, we use a coarse encoding */
592
        blk = 0;
593
        while (blk < AC3_MAX_BLOCKS) {
594
            blk1 = blk + 1;
595
            while (blk1 < AC3_MAX_BLOCKS && exp_strategy[blk1] == EXP_REUSE)
596
                blk1++;
597
            switch (blk1 - blk) {
598
            case 1:  exp_strategy[blk] = EXP_D45; break;
599
            case 2:
600
            case 3:  exp_strategy[blk] = EXP_D25; break;
601
            default: exp_strategy[blk] = EXP_D15; break;
602
            }
603
            blk = blk1;
604
        }
605
    }
606
    if (s->lfe_on) {
607
        ch = s->lfe_channel;
608
        s->exp_strategy[ch][0] = EXP_D15;
609
        for (blk = 1; blk < AC3_MAX_BLOCKS; blk++)
610
            s->exp_strategy[ch][blk] = EXP_REUSE;
611
    }
612
}
613

    
614

    
615
/**
616
 * Update the exponents so that they are the ones the decoder will decode.
617
 */
618
static void encode_exponents_blk_ch(uint8_t *exp, int nb_exps, int exp_strategy)
619
{
620
    int nb_groups, i, k;
621

    
622
    nb_groups = exponent_group_tab[exp_strategy-1][nb_exps] * 3;
623

    
624
    /* for each group, compute the minimum exponent */
625
    switch(exp_strategy) {
626
    case EXP_D25:
627
        for (i = 1, k = 1; i <= nb_groups; i++) {
628
            uint8_t exp_min = exp[k];
629
            if (exp[k+1] < exp_min)
630
                exp_min = exp[k+1];
631
            exp[i] = exp_min;
632
            k += 2;
633
        }
634
        break;
635
    case EXP_D45:
636
        for (i = 1, k = 1; i <= nb_groups; i++) {
637
            uint8_t exp_min = exp[k];
638
            if (exp[k+1] < exp_min)
639
                exp_min = exp[k+1];
640
            if (exp[k+2] < exp_min)
641
                exp_min = exp[k+2];
642
            if (exp[k+3] < exp_min)
643
                exp_min = exp[k+3];
644
            exp[i] = exp_min;
645
            k += 4;
646
        }
647
        break;
648
    }
649

    
650
    /* constraint for DC exponent */
651
    if (exp[0] > 15)
652
        exp[0] = 15;
653

    
654
    /* decrease the delta between each groups to within 2 so that they can be
655
       differentially encoded */
656
    for (i = 1; i <= nb_groups; i++)
657
        exp[i] = FFMIN(exp[i], exp[i-1] + 2);
658
    i--;
659
    while (--i >= 0)
660
        exp[i] = FFMIN(exp[i], exp[i+1] + 2);
661

    
662
    /* now we have the exponent values the decoder will see */
663
    switch (exp_strategy) {
664
    case EXP_D25:
665
        for (i = nb_groups, k = nb_groups * 2; i > 0; i--) {
666
            uint8_t exp1 = exp[i];
667
            exp[k--] = exp1;
668
            exp[k--] = exp1;
669
        }
670
        break;
671
    case EXP_D45:
672
        for (i = nb_groups, k = nb_groups * 4; i > 0; i--) {
673
            exp[k] = exp[k-1] = exp[k-2] = exp[k-3] = exp[i];
674
            k -= 4;
675
        }
676
        break;
677
    }
678
}
679

    
680

    
681
/**
682
 * Encode exponents from original extracted form to what the decoder will see.
683
 * This copies and groups exponents based on exponent strategy and reduces
684
 * deltas between adjacent exponent groups so that they can be differentially
685
 * encoded.
686
 */
687
static void encode_exponents(AC3EncodeContext *s)
688
{
689
    int blk, blk1, ch;
690
    uint8_t *exp, *exp_strategy;
691
    int nb_coefs, num_reuse_blocks;
692

    
693
    for (ch = 0; ch < s->channels; ch++) {
694
        exp          = s->blocks[0].exp[ch];
695
        exp_strategy = s->exp_strategy[ch];
696
        nb_coefs     = s->nb_coefs[ch];
697

    
698
        blk = 0;
699
        while (blk < AC3_MAX_BLOCKS) {
700
            blk1 = blk + 1;
701

    
702
            /* count the number of EXP_REUSE blocks after the current block
703
               and set exponent reference block pointers */
704
            s->blocks[blk].exp_ref_block[ch] = &s->blocks[blk];
705
            while (blk1 < AC3_MAX_BLOCKS && exp_strategy[blk1] == EXP_REUSE) {
706
                s->blocks[blk1].exp_ref_block[ch] = &s->blocks[blk];
707
                blk1++;
708
            }
709
            num_reuse_blocks = blk1 - blk - 1;
710

    
711
            /* for the EXP_REUSE case we select the min of the exponents */
712
            s->ac3dsp.ac3_exponent_min(exp, num_reuse_blocks, nb_coefs);
713

    
714
            encode_exponents_blk_ch(exp, nb_coefs, exp_strategy[blk]);
715

    
716
            exp += AC3_MAX_COEFS * (num_reuse_blocks + 1);
717
            blk = blk1;
718
        }
719
    }
720
}
721

    
722

    
723
/**
724
 * Group exponents.
725
 * 3 delta-encoded exponents are in each 7-bit group. The number of groups
726
 * varies depending on exponent strategy and bandwidth.
727
 */
728
static void group_exponents(AC3EncodeContext *s)
729
{
730
    int blk, ch, i;
731
    int group_size, nb_groups, bit_count;
732
    uint8_t *p;
733
    int delta0, delta1, delta2;
734
    int exp0, exp1;
735

    
736
    bit_count = 0;
737
    for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
738
        AC3Block *block = &s->blocks[blk];
739
        for (ch = 0; ch < s->channels; ch++) {
740
            int exp_strategy = s->exp_strategy[ch][blk];
741
            if (exp_strategy == EXP_REUSE)
742
                continue;
743
            group_size = exp_strategy + (exp_strategy == EXP_D45);
744
            nb_groups = exponent_group_tab[exp_strategy-1][s->nb_coefs[ch]];
745
            bit_count += 4 + (nb_groups * 7);
746
            p = block->exp[ch];
747

    
748
            /* DC exponent */
749
            exp1 = *p++;
750
            block->grouped_exp[ch][0] = exp1;
751

    
752
            /* remaining exponents are delta encoded */
753
            for (i = 1; i <= nb_groups; i++) {
754
                /* merge three delta in one code */
755
                exp0   = exp1;
756
                exp1   = p[0];
757
                p     += group_size;
758
                delta0 = exp1 - exp0 + 2;
759
                av_assert2(delta0 >= 0 && delta0 <= 4);
760

    
761
                exp0   = exp1;
762
                exp1   = p[0];
763
                p     += group_size;
764
                delta1 = exp1 - exp0 + 2;
765
                av_assert2(delta1 >= 0 && delta1 <= 4);
766

    
767
                exp0   = exp1;
768
                exp1   = p[0];
769
                p     += group_size;
770
                delta2 = exp1 - exp0 + 2;
771
                av_assert2(delta2 >= 0 && delta2 <= 4);
772

    
773
                block->grouped_exp[ch][i] = ((delta0 * 5 + delta1) * 5) + delta2;
774
            }
775
        }
776
    }
777

    
778
    s->exponent_bits = bit_count;
779
}
780

    
781

    
782
/**
783
 * Calculate final exponents from the supplied MDCT coefficients and exponent shift.
784
 * Extract exponents from MDCT coefficients, calculate exponent strategies,
785
 * and encode final exponents.
786
 */
787
static void process_exponents(AC3EncodeContext *s)
788
{
789
    extract_exponents(s);
790

    
791
    compute_exp_strategy(s);
792

    
793
    encode_exponents(s);
794

    
795
    group_exponents(s);
796

    
797
    emms_c();
798
}
799

    
800

    
801
/**
802
 * Count frame bits that are based solely on fixed parameters.
803
 * This only has to be run once when the encoder is initialized.
804
 */
805
static void count_frame_bits_fixed(AC3EncodeContext *s)
806
{
807
    static const int frame_bits_inc[8] = { 0, 0, 2, 2, 2, 4, 2, 4 };
808
    int blk;
809
    int frame_bits;
810

    
811
    /* assumptions:
812
     *   no dynamic range codes
813
     *   no channel coupling
814
     *   bit allocation parameters do not change between blocks
815
     *   SNR offsets do not change between blocks
816
     *   no delta bit allocation
817
     *   no skipped data
818
     *   no auxilliary data
819
     */
820

    
821
    /* header size */
822
    frame_bits = 65;
823
    frame_bits += frame_bits_inc[s->channel_mode];
824

    
825
    /* audio blocks */
826
    for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
827
        frame_bits += s->fbw_channels * 2 + 2; /* blksw * c, dithflag * c, dynrnge, cplstre */
828
        if (s->channel_mode == AC3_CHMODE_STEREO) {
829
            frame_bits++; /* rematstr */
830
        }
831
        frame_bits += 2 * s->fbw_channels; /* chexpstr[2] * c */
832
        if (s->lfe_on)
833
            frame_bits++; /* lfeexpstr */
834
        frame_bits++; /* baie */
835
        frame_bits++; /* snr */
836
        frame_bits += 2; /* delta / skip */
837
    }
838
    frame_bits++; /* cplinu for block 0 */
839
    /* bit alloc info */
840
    /* sdcycod[2], fdcycod[2], sgaincod[2], dbpbcod[2], floorcod[3] */
841
    /* csnroffset[6] */
842
    /* (fsnoffset[4] + fgaincod[4]) * c */
843
    frame_bits += 2*4 + 3 + 6 + s->channels * (4 + 3);
844

    
845
    /* auxdatae, crcrsv */
846
    frame_bits += 2;
847

    
848
    /* CRC */
849
    frame_bits += 16;
850

    
851
    s->frame_bits_fixed = frame_bits;
852
}
853

    
854

    
855
/**
856
 * Initialize bit allocation.
857
 * Set default parameter codes and calculate parameter values.
858
 */
859
static void bit_alloc_init(AC3EncodeContext *s)
860
{
861
    int ch;
862

    
863
    /* init default parameters */
864
    s->slow_decay_code = 2;
865
    s->fast_decay_code = 1;
866
    s->slow_gain_code  = 1;
867
    s->db_per_bit_code = 3;
868
    s->floor_code      = 7;
869
    for (ch = 0; ch < s->channels; ch++)
870
        s->fast_gain_code[ch] = 4;
871

    
872
    /* initial snr offset */
873
    s->coarse_snr_offset = 40;
874

    
875
    /* compute real values */
876
    /* currently none of these values change during encoding, so we can just
877
       set them once at initialization */
878
    s->bit_alloc.slow_decay = ff_ac3_slow_decay_tab[s->slow_decay_code] >> s->bit_alloc.sr_shift;
879
    s->bit_alloc.fast_decay = ff_ac3_fast_decay_tab[s->fast_decay_code] >> s->bit_alloc.sr_shift;
880
    s->bit_alloc.slow_gain  = ff_ac3_slow_gain_tab[s->slow_gain_code];
881
    s->bit_alloc.db_per_bit = ff_ac3_db_per_bit_tab[s->db_per_bit_code];
882
    s->bit_alloc.floor      = ff_ac3_floor_tab[s->floor_code];
883

    
884
    count_frame_bits_fixed(s);
885
}
886

    
887

    
888
/**
889
 * Count the bits used to encode the frame, minus exponents and mantissas.
890
 * Bits based on fixed parameters have already been counted, so now we just
891
 * have to add the bits based on parameters that change during encoding.
892
 */
893
static void count_frame_bits(AC3EncodeContext *s)
894
{
895
    AC3EncOptions *opt = &s->options;
896
    int blk, ch;
897
    int frame_bits = 0;
898

    
899
    if (opt->audio_production_info)
900
        frame_bits += 7;
901
    if (s->bitstream_id == 6) {
902
        if (opt->extended_bsi_1)
903
            frame_bits += 14;
904
        if (opt->extended_bsi_2)
905
            frame_bits += 14;
906
    }
907

    
908
    for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
909
        /* stereo rematrixing */
910
        if (s->channel_mode == AC3_CHMODE_STEREO &&
911
            s->blocks[blk].new_rematrixing_strategy) {
912
            frame_bits += s->num_rematrixing_bands;
913
        }
914

    
915
        for (ch = 0; ch < s->fbw_channels; ch++) {
916
            if (s->exp_strategy[ch][blk] != EXP_REUSE)
917
                frame_bits += 6 + 2; /* chbwcod[6], gainrng[2] */
918
        }
919
    }
920
    s->frame_bits = s->frame_bits_fixed + frame_bits;
921
}
922

    
923

    
924
/**
925
 * Finalize the mantissa bit count by adding in the grouped mantissas.
926
 */
927
static int compute_mantissa_size_final(int mant_cnt[5])
928
{
929
    // bap=1 : 3 mantissas in 5 bits
930
    int bits = (mant_cnt[1] / 3) * 5;
931
    // bap=2 : 3 mantissas in 7 bits
932
    // bap=4 : 2 mantissas in 7 bits
933
    bits += ((mant_cnt[2] / 3) + (mant_cnt[4] >> 1)) * 7;
934
    // bap=3 : each mantissa is 3 bits
935
    bits += mant_cnt[3] * 3;
936
    return bits;
937
}
938

    
939

    
940
/**
941
 * Calculate masking curve based on the final exponents.
942
 * Also calculate the power spectral densities to use in future calculations.
943
 */
944
static void bit_alloc_masking(AC3EncodeContext *s)
945
{
946
    int blk, ch;
947

    
948
    for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
949
        AC3Block *block = &s->blocks[blk];
950
        for (ch = 0; ch < s->channels; ch++) {
951
            /* We only need psd and mask for calculating bap.
952
               Since we currently do not calculate bap when exponent
953
               strategy is EXP_REUSE we do not need to calculate psd or mask. */
954
            if (s->exp_strategy[ch][blk] != EXP_REUSE) {
955
                ff_ac3_bit_alloc_calc_psd(block->exp[ch], 0,
956
                                          s->nb_coefs[ch],
957
                                          block->psd[ch], block->band_psd[ch]);
958
                ff_ac3_bit_alloc_calc_mask(&s->bit_alloc, block->band_psd[ch],
959
                                           0, s->nb_coefs[ch],
960
                                           ff_ac3_fast_gain_tab[s->fast_gain_code[ch]],
961
                                           ch == s->lfe_channel,
962
                                           DBA_NONE, 0, NULL, NULL, NULL,
963
                                           block->mask[ch]);
964
            }
965
        }
966
    }
967
}
968

    
969

    
970
/**
971
 * Ensure that bap for each block and channel point to the current bap_buffer.
972
 * They may have been switched during the bit allocation search.
973
 */
974
static void reset_block_bap(AC3EncodeContext *s)
975
{
976
    int blk, ch;
977
    if (s->blocks[0].bap[0] == s->bap_buffer)
978
        return;
979
    for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
980
        for (ch = 0; ch < s->channels; ch++) {
981
            s->blocks[blk].bap[ch] = &s->bap_buffer[AC3_MAX_COEFS * (blk * s->channels + ch)];
982
        }
983
    }
984
}
985

    
986

    
987
/**
988
 * Run the bit allocation with a given SNR offset.
989
 * This calculates the bit allocation pointers that will be used to determine
990
 * the quantization of each mantissa.
991
 * @return the number of bits needed for mantissas if the given SNR offset is
992
 *         is used.
993
 */
994
static int bit_alloc(AC3EncodeContext *s, int snr_offset)
995
{
996
    int blk, ch;
997
    int mantissa_bits;
998
    int mant_cnt[5];
999

    
1000
    snr_offset = (snr_offset - 240) << 2;
1001

    
1002
    reset_block_bap(s);
1003
    mantissa_bits = 0;
1004
    for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
1005
        AC3Block *block = &s->blocks[blk];
1006
        AC3Block *ref_block;
1007
        // initialize grouped mantissa counts. these are set so that they are
1008
        // padded to the next whole group size when bits are counted in
1009
        // compute_mantissa_size_final
1010
        mant_cnt[0] = mant_cnt[3] = 0;
1011
        mant_cnt[1] = mant_cnt[2] = 2;
1012
        mant_cnt[4] = 1;
1013
        for (ch = 0; ch < s->channels; ch++) {
1014
            /* Currently the only bit allocation parameters which vary across
1015
               blocks within a frame are the exponent values.  We can take
1016
               advantage of that by reusing the bit allocation pointers
1017
               whenever we reuse exponents. */
1018
            ref_block = block->exp_ref_block[ch];
1019
            if (s->exp_strategy[ch][blk] != EXP_REUSE) {
1020
                s->ac3dsp.bit_alloc_calc_bap(ref_block->mask[ch],
1021
                                             ref_block->psd[ch], 0,
1022
                                             s->nb_coefs[ch], snr_offset,
1023
                                             s->bit_alloc.floor, ff_ac3_bap_tab,
1024
                                             ref_block->bap[ch]);
1025
            }
1026
            mantissa_bits += s->ac3dsp.compute_mantissa_size(mant_cnt,
1027
                                                             ref_block->bap[ch],
1028
                                                             s->nb_coefs[ch]);
1029
        }
1030
        mantissa_bits += compute_mantissa_size_final(mant_cnt);
1031
    }
1032
    return mantissa_bits;
1033
}
1034

    
1035

    
1036
/**
1037
 * Constant bitrate bit allocation search.
1038
 * Find the largest SNR offset that will allow data to fit in the frame.
1039
 */
1040
static int cbr_bit_allocation(AC3EncodeContext *s)
1041
{
1042
    int ch;
1043
    int bits_left;
1044
    int snr_offset, snr_incr;
1045

    
1046
    bits_left = 8 * s->frame_size - (s->frame_bits + s->exponent_bits);
1047
    if (bits_left < 0)
1048
        return AVERROR(EINVAL);
1049

    
1050
    snr_offset = s->coarse_snr_offset << 4;
1051

    
1052
    /* if previous frame SNR offset was 1023, check if current frame can also
1053
       use SNR offset of 1023. if so, skip the search. */
1054
    if ((snr_offset | s->fine_snr_offset[0]) == 1023) {
1055
        if (bit_alloc(s, 1023) <= bits_left)
1056
            return 0;
1057
    }
1058

    
1059
    while (snr_offset >= 0 &&
1060
           bit_alloc(s, snr_offset) > bits_left) {
1061
        snr_offset -= 64;
1062
    }
1063
    if (snr_offset < 0)
1064
        return AVERROR(EINVAL);
1065

    
1066
    FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
1067
    for (snr_incr = 64; snr_incr > 0; snr_incr >>= 2) {
1068
        while (snr_offset + snr_incr <= 1023 &&
1069
               bit_alloc(s, snr_offset + snr_incr) <= bits_left) {
1070
            snr_offset += snr_incr;
1071
            FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
1072
        }
1073
    }
1074
    FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
1075
    reset_block_bap(s);
1076

    
1077
    s->coarse_snr_offset = snr_offset >> 4;
1078
    for (ch = 0; ch < s->channels; ch++)
1079
        s->fine_snr_offset[ch] = snr_offset & 0xF;
1080

    
1081
    return 0;
1082
}
1083

    
1084

    
1085
/**
1086
 * Downgrade exponent strategies to reduce the bits used by the exponents.
1087
 * This is a fallback for when bit allocation fails with the normal exponent
1088
 * strategies.  Each time this function is run it only downgrades the
1089
 * strategy in 1 channel of 1 block.
1090
 * @return non-zero if downgrade was unsuccessful
1091
 */
1092
static int downgrade_exponents(AC3EncodeContext *s)
1093
{
1094
    int ch, blk;
1095

    
1096
    for (ch = 0; ch < s->fbw_channels; ch++) {
1097
        for (blk = AC3_MAX_BLOCKS-1; blk >= 0; blk--) {
1098
            if (s->exp_strategy[ch][blk] == EXP_D15) {
1099
                s->exp_strategy[ch][blk] = EXP_D25;
1100
                return 0;
1101
            }
1102
        }
1103
    }
1104
    for (ch = 0; ch < s->fbw_channels; ch++) {
1105
        for (blk = AC3_MAX_BLOCKS-1; blk >= 0; blk--) {
1106
            if (s->exp_strategy[ch][blk] == EXP_D25) {
1107
                s->exp_strategy[ch][blk] = EXP_D45;
1108
                return 0;
1109
            }
1110
        }
1111
    }
1112
    for (ch = 0; ch < s->fbw_channels; ch++) {
1113
        /* block 0 cannot reuse exponents, so only downgrade D45 to REUSE if
1114
           the block number > 0 */
1115
        for (blk = AC3_MAX_BLOCKS-1; blk > 0; blk--) {
1116
            if (s->exp_strategy[ch][blk] > EXP_REUSE) {
1117
                s->exp_strategy[ch][blk] = EXP_REUSE;
1118
                return 0;
1119
            }
1120
        }
1121
    }
1122
    return -1;
1123
}
1124

    
1125

    
1126
/**
1127
 * Perform bit allocation search.
1128
 * Finds the SNR offset value that maximizes quality and fits in the specified
1129
 * frame size.  Output is the SNR offset and a set of bit allocation pointers
1130
 * used to quantize the mantissas.
1131
 */
1132
static int compute_bit_allocation(AC3EncodeContext *s)
1133
{
1134
    int ret;
1135

    
1136
    count_frame_bits(s);
1137

    
1138
    bit_alloc_masking(s);
1139

    
1140
    ret = cbr_bit_allocation(s);
1141
    while (ret) {
1142
        /* fallback 1: downgrade exponents */
1143
        if (!downgrade_exponents(s)) {
1144
            extract_exponents(s);
1145
            encode_exponents(s);
1146
            group_exponents(s);
1147
            ret = compute_bit_allocation(s);
1148
            continue;
1149
        }
1150

    
1151
        /* fallbacks were not enough... */
1152
        break;
1153
    }
1154

    
1155
    return ret;
1156
}
1157

    
1158

    
1159
/**
1160
 * Symmetric quantization on 'levels' levels.
1161
 */
1162
static inline int sym_quant(int c, int e, int levels)
1163
{
1164
    int v = (((levels * c) >> (24 - e)) + levels) >> 1;
1165
    av_assert2(v >= 0 && v < levels);
1166
    return v;
1167
}
1168

    
1169

    
1170
/**
1171
 * Asymmetric quantization on 2^qbits levels.
1172
 */
1173
static inline int asym_quant(int c, int e, int qbits)
1174
{
1175
    int lshift, m, v;
1176

    
1177
    lshift = e + qbits - 24;
1178
    if (lshift >= 0)
1179
        v = c << lshift;
1180
    else
1181
        v = c >> (-lshift);
1182
    /* rounding */
1183
    v = (v + 1) >> 1;
1184
    m = (1 << (qbits-1));
1185
    if (v >= m)
1186
        v = m - 1;
1187
    av_assert2(v >= -m);
1188
    return v & ((1 << qbits)-1);
1189
}
1190

    
1191

    
1192
/**
1193
 * Quantize a set of mantissas for a single channel in a single block.
1194
 */
1195
static void quantize_mantissas_blk_ch(AC3Mant *s, int32_t *fixed_coef,
1196
                                      uint8_t *exp,
1197
                                      uint8_t *bap, uint16_t *qmant, int n)
1198
{
1199
    int i;
1200

    
1201
    for (i = 0; i < n; i++) {
1202
        int v;
1203
        int c = fixed_coef[i];
1204
        int e = exp[i];
1205
        int b = bap[i];
1206
        switch (b) {
1207
        case 0:
1208
            v = 0;
1209
            break;
1210
        case 1:
1211
            v = sym_quant(c, e, 3);
1212
            switch (s->mant1_cnt) {
1213
            case 0:
1214
                s->qmant1_ptr = &qmant[i];
1215
                v = 9 * v;
1216
                s->mant1_cnt = 1;
1217
                break;
1218
            case 1:
1219
                *s->qmant1_ptr += 3 * v;
1220
                s->mant1_cnt = 2;
1221
                v = 128;
1222
                break;
1223
            default:
1224
                *s->qmant1_ptr += v;
1225
                s->mant1_cnt = 0;
1226
                v = 128;
1227
                break;
1228
            }
1229
            break;
1230
        case 2:
1231
            v = sym_quant(c, e, 5);
1232
            switch (s->mant2_cnt) {
1233
            case 0:
1234
                s->qmant2_ptr = &qmant[i];
1235
                v = 25 * v;
1236
                s->mant2_cnt = 1;
1237
                break;
1238
            case 1:
1239
                *s->qmant2_ptr += 5 * v;
1240
                s->mant2_cnt = 2;
1241
                v = 128;
1242
                break;
1243
            default:
1244
                *s->qmant2_ptr += v;
1245
                s->mant2_cnt = 0;
1246
                v = 128;
1247
                break;
1248
            }
1249
            break;
1250
        case 3:
1251
            v = sym_quant(c, e, 7);
1252
            break;
1253
        case 4:
1254
            v = sym_quant(c, e, 11);
1255
            switch (s->mant4_cnt) {
1256
            case 0:
1257
                s->qmant4_ptr = &qmant[i];
1258
                v = 11 * v;
1259
                s->mant4_cnt = 1;
1260
                break;
1261
            default:
1262
                *s->qmant4_ptr += v;
1263
                s->mant4_cnt = 0;
1264
                v = 128;
1265
                break;
1266
            }
1267
            break;
1268
        case 5:
1269
            v = sym_quant(c, e, 15);
1270
            break;
1271
        case 14:
1272
            v = asym_quant(c, e, 14);
1273
            break;
1274
        case 15:
1275
            v = asym_quant(c, e, 16);
1276
            break;
1277
        default:
1278
            v = asym_quant(c, e, b - 1);
1279
            break;
1280
        }
1281
        qmant[i] = v;
1282
    }
1283
}
1284

    
1285

    
1286
/**
1287
 * Quantize mantissas using coefficients, exponents, and bit allocation pointers.
1288
 */
1289
static void quantize_mantissas(AC3EncodeContext *s)
1290
{
1291
    int blk, ch;
1292

    
1293

    
1294
    for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
1295
        AC3Block *block = &s->blocks[blk];
1296
        AC3Block *ref_block;
1297
        AC3Mant m = { 0 };
1298

    
1299
        for (ch = 0; ch < s->channels; ch++) {
1300
            ref_block = block->exp_ref_block[ch];
1301
            quantize_mantissas_blk_ch(&m, block->fixed_coef[ch],
1302
                                      ref_block->exp[ch], ref_block->bap[ch],
1303
                                      block->qmant[ch], s->nb_coefs[ch]);
1304
        }
1305
    }
1306
}
1307

    
1308

    
1309
/**
1310
 * Write the AC-3 frame header to the output bitstream.
1311
 */
1312
static void output_frame_header(AC3EncodeContext *s)
1313
{
1314
    AC3EncOptions *opt = &s->options;
1315

    
1316
    put_bits(&s->pb, 16, 0x0b77);   /* frame header */
1317
    put_bits(&s->pb, 16, 0);        /* crc1: will be filled later */
1318
    put_bits(&s->pb, 2,  s->bit_alloc.sr_code);
1319
    put_bits(&s->pb, 6,  s->frame_size_code + (s->frame_size - s->frame_size_min) / 2);
1320
    put_bits(&s->pb, 5,  s->bitstream_id);
1321
    put_bits(&s->pb, 3,  s->bitstream_mode);
1322
    put_bits(&s->pb, 3,  s->channel_mode);
1323
    if ((s->channel_mode & 0x01) && s->channel_mode != AC3_CHMODE_MONO)
1324
        put_bits(&s->pb, 2, s->center_mix_level);
1325
    if (s->channel_mode & 0x04)
1326
        put_bits(&s->pb, 2, s->surround_mix_level);
1327
    if (s->channel_mode == AC3_CHMODE_STEREO)
1328
        put_bits(&s->pb, 2, opt->dolby_surround_mode);
1329
    put_bits(&s->pb, 1, s->lfe_on); /* LFE */
1330
    put_bits(&s->pb, 5, -opt->dialogue_level);
1331
    put_bits(&s->pb, 1, 0);         /* no compression control word */
1332
    put_bits(&s->pb, 1, 0);         /* no lang code */
1333
    put_bits(&s->pb, 1, opt->audio_production_info);
1334
    if (opt->audio_production_info) {
1335
        put_bits(&s->pb, 5, opt->mixing_level - 80);
1336
        put_bits(&s->pb, 2, opt->room_type);
1337
    }
1338
    put_bits(&s->pb, 1, opt->copyright);
1339
    put_bits(&s->pb, 1, opt->original);
1340
    if (s->bitstream_id == 6) {
1341
        /* alternate bit stream syntax */
1342
        put_bits(&s->pb, 1, opt->extended_bsi_1);
1343
        if (opt->extended_bsi_1) {
1344
            put_bits(&s->pb, 2, opt->preferred_stereo_downmix);
1345
            put_bits(&s->pb, 3, s->ltrt_center_mix_level);
1346
            put_bits(&s->pb, 3, s->ltrt_surround_mix_level);
1347
            put_bits(&s->pb, 3, s->loro_center_mix_level);
1348
            put_bits(&s->pb, 3, s->loro_surround_mix_level);
1349
        }
1350
        put_bits(&s->pb, 1, opt->extended_bsi_2);
1351
        if (opt->extended_bsi_2) {
1352
            put_bits(&s->pb, 2, opt->dolby_surround_ex_mode);
1353
            put_bits(&s->pb, 2, opt->dolby_headphone_mode);
1354
            put_bits(&s->pb, 1, opt->ad_converter_type);
1355
            put_bits(&s->pb, 9, 0);     /* xbsi2 and encinfo : reserved */
1356
        }
1357
    } else {
1358
    put_bits(&s->pb, 1, 0);         /* no time code 1 */
1359
    put_bits(&s->pb, 1, 0);         /* no time code 2 */
1360
    }
1361
    put_bits(&s->pb, 1, 0);         /* no additional bit stream info */
1362
}
1363

    
1364

    
1365
/**
1366
 * Write one audio block to the output bitstream.
1367
 */
1368
static void output_audio_block(AC3EncodeContext *s, int blk)
1369
{
1370
    int ch, i, baie, rbnd;
1371
    AC3Block *block = &s->blocks[blk];
1372

    
1373
    /* block switching */
1374
    for (ch = 0; ch < s->fbw_channels; ch++)
1375
        put_bits(&s->pb, 1, 0);
1376

    
1377
    /* dither flags */
1378
    for (ch = 0; ch < s->fbw_channels; ch++)
1379
        put_bits(&s->pb, 1, 1);
1380

    
1381
    /* dynamic range codes */
1382
    put_bits(&s->pb, 1, 0);
1383

    
1384
    /* channel coupling */
1385
    if (!blk) {
1386
        put_bits(&s->pb, 1, 1); /* coupling strategy present */
1387
        put_bits(&s->pb, 1, 0); /* no coupling strategy */
1388
    } else {
1389
        put_bits(&s->pb, 1, 0); /* no new coupling strategy */
1390
    }
1391

    
1392
    /* stereo rematrixing */
1393
    if (s->channel_mode == AC3_CHMODE_STEREO) {
1394
        put_bits(&s->pb, 1, block->new_rematrixing_strategy);
1395
        if (block->new_rematrixing_strategy) {
1396
            /* rematrixing flags */
1397
            for (rbnd = 0; rbnd < s->num_rematrixing_bands; rbnd++)
1398
                put_bits(&s->pb, 1, block->rematrixing_flags[rbnd]);
1399
        }
1400
    }
1401

    
1402
    /* exponent strategy */
1403
    for (ch = 0; ch < s->fbw_channels; ch++)
1404
        put_bits(&s->pb, 2, s->exp_strategy[ch][blk]);
1405
    if (s->lfe_on)
1406
        put_bits(&s->pb, 1, s->exp_strategy[s->lfe_channel][blk]);
1407

    
1408
    /* bandwidth */
1409
    for (ch = 0; ch < s->fbw_channels; ch++) {
1410
        if (s->exp_strategy[ch][blk] != EXP_REUSE)
1411
            put_bits(&s->pb, 6, s->bandwidth_code);
1412
    }
1413

    
1414
    /* exponents */
1415
    for (ch = 0; ch < s->channels; ch++) {
1416
        int nb_groups;
1417

    
1418
        if (s->exp_strategy[ch][blk] == EXP_REUSE)
1419
            continue;
1420

    
1421
        /* DC exponent */
1422
        put_bits(&s->pb, 4, block->grouped_exp[ch][0]);
1423

    
1424
        /* exponent groups */
1425
        nb_groups = exponent_group_tab[s->exp_strategy[ch][blk]-1][s->nb_coefs[ch]];
1426
        for (i = 1; i <= nb_groups; i++)
1427
            put_bits(&s->pb, 7, block->grouped_exp[ch][i]);
1428

    
1429
        /* gain range info */
1430
        if (ch != s->lfe_channel)
1431
            put_bits(&s->pb, 2, 0);
1432
    }
1433

    
1434
    /* bit allocation info */
1435
    baie = (blk == 0);
1436
    put_bits(&s->pb, 1, baie);
1437
    if (baie) {
1438
        put_bits(&s->pb, 2, s->slow_decay_code);
1439
        put_bits(&s->pb, 2, s->fast_decay_code);
1440
        put_bits(&s->pb, 2, s->slow_gain_code);
1441
        put_bits(&s->pb, 2, s->db_per_bit_code);
1442
        put_bits(&s->pb, 3, s->floor_code);
1443
    }
1444

    
1445
    /* snr offset */
1446
    put_bits(&s->pb, 1, baie);
1447
    if (baie) {
1448
        put_bits(&s->pb, 6, s->coarse_snr_offset);
1449
        for (ch = 0; ch < s->channels; ch++) {
1450
            put_bits(&s->pb, 4, s->fine_snr_offset[ch]);
1451
            put_bits(&s->pb, 3, s->fast_gain_code[ch]);
1452
        }
1453
    }
1454

    
1455
    put_bits(&s->pb, 1, 0); /* no delta bit allocation */
1456
    put_bits(&s->pb, 1, 0); /* no data to skip */
1457

    
1458
    /* mantissas */
1459
    for (ch = 0; ch < s->channels; ch++) {
1460
        int b, q;
1461
        AC3Block *ref_block = block->exp_ref_block[ch];
1462
        for (i = 0; i < s->nb_coefs[ch]; i++) {
1463
            q = block->qmant[ch][i];
1464
            b = ref_block->bap[ch][i];
1465
            switch (b) {
1466
            case 0:                                         break;
1467
            case 1: if (q != 128) put_bits(&s->pb,   5, q); break;
1468
            case 2: if (q != 128) put_bits(&s->pb,   7, q); break;
1469
            case 3:               put_bits(&s->pb,   3, q); break;
1470
            case 4: if (q != 128) put_bits(&s->pb,   7, q); break;
1471
            case 14:              put_bits(&s->pb,  14, q); break;
1472
            case 15:              put_bits(&s->pb,  16, q); break;
1473
            default:              put_bits(&s->pb, b-1, q); break;
1474
            }
1475
        }
1476
    }
1477
}
1478

    
1479

    
1480
/** CRC-16 Polynomial */
1481
#define CRC16_POLY ((1 << 0) | (1 << 2) | (1 << 15) | (1 << 16))
1482

    
1483

    
1484
static unsigned int mul_poly(unsigned int a, unsigned int b, unsigned int poly)
1485
{
1486
    unsigned int c;
1487

    
1488
    c = 0;
1489
    while (a) {
1490
        if (a & 1)
1491
            c ^= b;
1492
        a = a >> 1;
1493
        b = b << 1;
1494
        if (b & (1 << 16))
1495
            b ^= poly;
1496
    }
1497
    return c;
1498
}
1499

    
1500

    
1501
static unsigned int pow_poly(unsigned int a, unsigned int n, unsigned int poly)
1502
{
1503
    unsigned int r;
1504
    r = 1;
1505
    while (n) {
1506
        if (n & 1)
1507
            r = mul_poly(r, a, poly);
1508
        a = mul_poly(a, a, poly);
1509
        n >>= 1;
1510
    }
1511
    return r;
1512
}
1513

    
1514

    
1515
/**
1516
 * Fill the end of the frame with 0's and compute the two CRCs.
1517
 */
1518
static void output_frame_end(AC3EncodeContext *s)
1519
{
1520
    const AVCRC *crc_ctx = av_crc_get_table(AV_CRC_16_ANSI);
1521
    int frame_size_58, pad_bytes, crc1, crc2_partial, crc2, crc_inv;
1522
    uint8_t *frame;
1523

    
1524
    frame_size_58 = ((s->frame_size >> 2) + (s->frame_size >> 4)) << 1;
1525

    
1526
    /* pad the remainder of the frame with zeros */
1527
    av_assert2(s->frame_size * 8 - put_bits_count(&s->pb) >= 18);
1528
    flush_put_bits(&s->pb);
1529
    frame = s->pb.buf;
1530
    pad_bytes = s->frame_size - (put_bits_ptr(&s->pb) - frame) - 2;
1531
    av_assert2(pad_bytes >= 0);
1532
    if (pad_bytes > 0)
1533
        memset(put_bits_ptr(&s->pb), 0, pad_bytes);
1534

    
1535
    /* compute crc1 */
1536
    /* this is not so easy because it is at the beginning of the data... */
1537
    crc1    = av_bswap16(av_crc(crc_ctx, 0, frame + 4, frame_size_58 - 4));
1538
    crc_inv = s->crc_inv[s->frame_size > s->frame_size_min];
1539
    crc1    = mul_poly(crc_inv, crc1, CRC16_POLY);
1540
    AV_WB16(frame + 2, crc1);
1541

    
1542
    /* compute crc2 */
1543
    crc2_partial = av_crc(crc_ctx, 0, frame + frame_size_58,
1544
                          s->frame_size - frame_size_58 - 3);
1545
    crc2 = av_crc(crc_ctx, crc2_partial, frame + s->frame_size - 3, 1);
1546
    /* ensure crc2 does not match sync word by flipping crcrsv bit if needed */
1547
    if (crc2 == 0x770B) {
1548
        frame[s->frame_size - 3] ^= 0x1;
1549
        crc2 = av_crc(crc_ctx, crc2_partial, frame + s->frame_size - 3, 1);
1550
    }
1551
    crc2 = av_bswap16(crc2);
1552
    AV_WB16(frame + s->frame_size - 2, crc2);
1553
}
1554

    
1555

    
1556
/**
1557
 * Write the frame to the output bitstream.
1558
 */
1559
static void output_frame(AC3EncodeContext *s, unsigned char *frame)
1560
{
1561
    int blk;
1562

    
1563
    init_put_bits(&s->pb, frame, AC3_MAX_CODED_FRAME_SIZE);
1564

    
1565
    output_frame_header(s);
1566

    
1567
    for (blk = 0; blk < AC3_MAX_BLOCKS; blk++)
1568
        output_audio_block(s, blk);
1569

    
1570
    output_frame_end(s);
1571
}
1572

    
1573

    
1574
static void dprint_options(AVCodecContext *avctx)
1575
{
1576
#ifdef DEBUG
1577
    AC3EncodeContext *s = avctx->priv_data;
1578
    AC3EncOptions *opt = &s->options;
1579
    char strbuf[32];
1580

    
1581
    switch (s->bitstream_id) {
1582
    case  6:  av_strlcpy(strbuf, "AC-3 (alt syntax)", 32);      break;
1583
    case  8:  av_strlcpy(strbuf, "AC-3 (standard)", 32);        break;
1584
    case  9:  av_strlcpy(strbuf, "AC-3 (dnet half-rate)", 32);  break;
1585
    case 10:  av_strlcpy(strbuf, "AC-3 (dnet quater-rate", 32); break;
1586
    default: snprintf(strbuf, 32, "ERROR");
1587
    }
1588
    av_dlog(avctx, "bitstream_id: %s (%d)\n", strbuf, s->bitstream_id);
1589
    av_dlog(avctx, "sample_fmt: %s\n", av_get_sample_fmt_name(avctx->sample_fmt));
1590
    av_get_channel_layout_string(strbuf, 32, s->channels, avctx->channel_layout);
1591
    av_dlog(avctx, "channel_layout: %s\n", strbuf);
1592
    av_dlog(avctx, "sample_rate: %d\n", s->sample_rate);
1593
    av_dlog(avctx, "bit_rate: %d\n", s->bit_rate);
1594
    if (s->cutoff)
1595
        av_dlog(avctx, "cutoff: %d\n", s->cutoff);
1596

    
1597
    av_dlog(avctx, "per_frame_metadata: %s\n",
1598
            opt->allow_per_frame_metadata?"on":"off");
1599
    if (s->has_center)
1600
        av_dlog(avctx, "center_mixlev: %0.3f (%d)\n", opt->center_mix_level,
1601
                s->center_mix_level);
1602
    else
1603
        av_dlog(avctx, "center_mixlev: {not written}\n");
1604
    if (s->has_surround)
1605
        av_dlog(avctx, "surround_mixlev: %0.3f (%d)\n", opt->surround_mix_level,
1606
                s->surround_mix_level);
1607
    else
1608
        av_dlog(avctx, "surround_mixlev: {not written}\n");
1609
    if (opt->audio_production_info) {
1610
        av_dlog(avctx, "mixing_level: %ddB\n", opt->mixing_level);
1611
        switch (opt->room_type) {
1612
        case 0:  av_strlcpy(strbuf, "notindicated", 32); break;
1613
        case 1:  av_strlcpy(strbuf, "large", 32);        break;
1614
        case 2:  av_strlcpy(strbuf, "small", 32);        break;
1615
        default: snprintf(strbuf, 32, "ERROR (%d)", opt->room_type);
1616
        }
1617
        av_dlog(avctx, "room_type: %s\n", strbuf);
1618
    } else {
1619
        av_dlog(avctx, "mixing_level: {not written}\n");
1620
        av_dlog(avctx, "room_type: {not written}\n");
1621
    }
1622
    av_dlog(avctx, "copyright: %s\n", opt->copyright?"on":"off");
1623
    av_dlog(avctx, "dialnorm: %ddB\n", opt->dialogue_level);
1624
    if (s->channel_mode == AC3_CHMODE_STEREO) {
1625
        switch (opt->dolby_surround_mode) {
1626
        case 0:  av_strlcpy(strbuf, "notindicated", 32); break;
1627
        case 1:  av_strlcpy(strbuf, "on", 32);           break;
1628
        case 2:  av_strlcpy(strbuf, "off", 32);          break;
1629
        default: snprintf(strbuf, 32, "ERROR (%d)", opt->dolby_surround_mode);
1630
        }
1631
        av_dlog(avctx, "dsur_mode: %s\n", strbuf);
1632
    } else {
1633
        av_dlog(avctx, "dsur_mode: {not written}\n");
1634
    }
1635
    av_dlog(avctx, "original: %s\n", opt->original?"on":"off");
1636

    
1637
    if (s->bitstream_id == 6) {
1638
        if (opt->extended_bsi_1) {
1639
            switch (opt->preferred_stereo_downmix) {
1640
            case 0:  av_strlcpy(strbuf, "notindicated", 32); break;
1641
            case 1:  av_strlcpy(strbuf, "ltrt", 32);         break;
1642
            case 2:  av_strlcpy(strbuf, "loro", 32);         break;
1643
            default: snprintf(strbuf, 32, "ERROR (%d)", opt->preferred_stereo_downmix);
1644
            }
1645
            av_dlog(avctx, "dmix_mode: %s\n", strbuf);
1646
            av_dlog(avctx, "ltrt_cmixlev: %0.3f (%d)\n",
1647
                    opt->ltrt_center_mix_level, s->ltrt_center_mix_level);
1648
            av_dlog(avctx, "ltrt_surmixlev: %0.3f (%d)\n",
1649
                    opt->ltrt_surround_mix_level, s->ltrt_surround_mix_level);
1650
            av_dlog(avctx, "loro_cmixlev: %0.3f (%d)\n",
1651
                    opt->loro_center_mix_level, s->loro_center_mix_level);
1652
            av_dlog(avctx, "loro_surmixlev: %0.3f (%d)\n",
1653
                    opt->loro_surround_mix_level, s->loro_surround_mix_level);
1654
        } else {
1655
            av_dlog(avctx, "extended bitstream info 1: {not written}\n");
1656
        }
1657
        if (opt->extended_bsi_2) {
1658
            switch (opt->dolby_surround_ex_mode) {
1659
            case 0:  av_strlcpy(strbuf, "notindicated", 32); break;
1660
            case 1:  av_strlcpy(strbuf, "on", 32);           break;
1661
            case 2:  av_strlcpy(strbuf, "off", 32);          break;
1662
            default: snprintf(strbuf, 32, "ERROR (%d)", opt->dolby_surround_ex_mode);
1663
            }
1664
            av_dlog(avctx, "dsurex_mode: %s\n", strbuf);
1665
            switch (opt->dolby_headphone_mode) {
1666
            case 0:  av_strlcpy(strbuf, "notindicated", 32); break;
1667
            case 1:  av_strlcpy(strbuf, "on", 32);           break;
1668
            case 2:  av_strlcpy(strbuf, "off", 32);          break;
1669
            default: snprintf(strbuf, 32, "ERROR (%d)", opt->dolby_headphone_mode);
1670
            }
1671
            av_dlog(avctx, "dheadphone_mode: %s\n", strbuf);
1672

    
1673
            switch (opt->ad_converter_type) {
1674
            case 0:  av_strlcpy(strbuf, "standard", 32); break;
1675
            case 1:  av_strlcpy(strbuf, "hdcd", 32);     break;
1676
            default: snprintf(strbuf, 32, "ERROR (%d)", opt->ad_converter_type);
1677
            }
1678
            av_dlog(avctx, "ad_conv_type: %s\n", strbuf);
1679
        } else {
1680
            av_dlog(avctx, "extended bitstream info 2: {not written}\n");
1681
        }
1682
    }
1683
#endif
1684
}
1685

    
1686

    
1687
#define FLT_OPTION_THRESHOLD 0.01
1688

    
1689
static int validate_float_option(float v, const float *v_list, int v_list_size)
1690
{
1691
    int i;
1692

    
1693
    for (i = 0; i < v_list_size; i++) {
1694
        if (v < (v_list[i] + FLT_OPTION_THRESHOLD) &&
1695
            v > (v_list[i] - FLT_OPTION_THRESHOLD))
1696
            break;
1697
    }
1698
    if (i == v_list_size)
1699
        return -1;
1700

    
1701
    return i;
1702
}
1703

    
1704

    
1705
static void validate_mix_level(void *log_ctx, const char *opt_name,
1706
                               float *opt_param, const float *list,
1707
                               int list_size, int default_value, int min_value,
1708
                               int *ctx_param)
1709
{
1710
    int mixlev = validate_float_option(*opt_param, list, list_size);
1711
    if (mixlev < min_value) {
1712
        mixlev = default_value;
1713
        if (*opt_param >= 0.0) {
1714
            av_log(log_ctx, AV_LOG_WARNING, "requested %s is not valid. using "
1715
                   "default value: %0.3f\n", opt_name, list[mixlev]);
1716
        }
1717
    }
1718
    *opt_param = list[mixlev];
1719
    *ctx_param = mixlev;
1720
}
1721

    
1722

    
1723
/**
1724
 * Validate metadata options as set by AVOption system.
1725
 * These values can optionally be changed per-frame.
1726
 */
1727
static int validate_metadata(AVCodecContext *avctx)
1728
{
1729
    AC3EncodeContext *s = avctx->priv_data;
1730
    AC3EncOptions *opt = &s->options;
1731

    
1732
    /* validate mixing levels */
1733
    if (s->has_center) {
1734
        validate_mix_level(avctx, "center_mix_level", &opt->center_mix_level,
1735
                           cmixlev_options, CMIXLEV_NUM_OPTIONS, 1, 0,
1736
                           &s->center_mix_level);
1737
    }
1738
    if (s->has_surround) {
1739
        validate_mix_level(avctx, "surround_mix_level", &opt->surround_mix_level,
1740
                           surmixlev_options, SURMIXLEV_NUM_OPTIONS, 1, 0,
1741
                           &s->surround_mix_level);
1742
    }
1743

    
1744
    /* set audio production info flag */
1745
    if (opt->mixing_level >= 0 || opt->room_type >= 0) {
1746
        if (opt->mixing_level < 0) {
1747
            av_log(avctx, AV_LOG_ERROR, "mixing_level must be set if "
1748
                   "room_type is set\n");
1749
            return AVERROR(EINVAL);
1750
        }
1751
        if (opt->mixing_level < 80) {
1752
            av_log(avctx, AV_LOG_ERROR, "invalid mixing level. must be between "
1753
                   "80dB and 111dB\n");
1754
            return AVERROR(EINVAL);
1755
        }
1756
        /* default room type */
1757
        if (opt->room_type < 0)
1758
            opt->room_type = 0;
1759
        opt->audio_production_info = 1;
1760
    } else {
1761
        opt->audio_production_info = 0;
1762
    }
1763

    
1764
    /* set extended bsi 1 flag */
1765
    if ((s->has_center || s->has_surround) &&
1766
        (opt->preferred_stereo_downmix >= 0 ||
1767
         opt->ltrt_center_mix_level   >= 0 ||
1768
         opt->ltrt_surround_mix_level >= 0 ||
1769
         opt->loro_center_mix_level   >= 0 ||
1770
         opt->loro_surround_mix_level >= 0)) {
1771
        /* default preferred stereo downmix */
1772
        if (opt->preferred_stereo_downmix < 0)
1773
            opt->preferred_stereo_downmix = 0;
1774
        /* validate Lt/Rt center mix level */
1775
        validate_mix_level(avctx, "ltrt_center_mix_level",
1776
                           &opt->ltrt_center_mix_level, extmixlev_options,
1777
                           EXTMIXLEV_NUM_OPTIONS, 5, 0,
1778
                           &s->ltrt_center_mix_level);
1779
        /* validate Lt/Rt surround mix level */
1780
        validate_mix_level(avctx, "ltrt_surround_mix_level",
1781
                           &opt->ltrt_surround_mix_level, extmixlev_options,
1782
                           EXTMIXLEV_NUM_OPTIONS, 6, 3,
1783
                           &s->ltrt_surround_mix_level);
1784
        /* validate Lo/Ro center mix level */
1785
        validate_mix_level(avctx, "loro_center_mix_level",
1786
                           &opt->loro_center_mix_level, extmixlev_options,
1787
                           EXTMIXLEV_NUM_OPTIONS, 5, 0,
1788
                           &s->loro_center_mix_level);
1789
        /* validate Lo/Ro surround mix level */
1790
        validate_mix_level(avctx, "loro_surround_mix_level",
1791
                           &opt->loro_surround_mix_level, extmixlev_options,
1792
                           EXTMIXLEV_NUM_OPTIONS, 6, 3,
1793
                           &s->loro_surround_mix_level);
1794
        opt->extended_bsi_1 = 1;
1795
    } else {
1796
        opt->extended_bsi_1 = 0;
1797
    }
1798

    
1799
    /* set extended bsi 2 flag */
1800
    if (opt->dolby_surround_ex_mode >= 0 ||
1801
        opt->dolby_headphone_mode   >= 0 ||
1802
        opt->ad_converter_type      >= 0) {
1803
        /* default dolby surround ex mode */
1804
        if (opt->dolby_surround_ex_mode < 0)
1805
            opt->dolby_surround_ex_mode = 0;
1806
        /* default dolby headphone mode */
1807
        if (opt->dolby_headphone_mode < 0)
1808
            opt->dolby_headphone_mode = 0;
1809
        /* default A/D converter type */
1810
        if (opt->ad_converter_type < 0)
1811
            opt->ad_converter_type = 0;
1812
        opt->extended_bsi_2 = 1;
1813
    } else {
1814
        opt->extended_bsi_2 = 0;
1815
    }
1816

    
1817
    /* set bitstream id for alternate bitstream syntax */
1818
    if (opt->extended_bsi_1 || opt->extended_bsi_2) {
1819
        if (s->bitstream_id > 8 && s->bitstream_id < 11) {
1820
            static int warn_once = 1;
1821
            if (warn_once) {
1822
                av_log(avctx, AV_LOG_WARNING, "alternate bitstream syntax is "
1823
                       "not compatible with reduced samplerates. writing of "
1824
                       "extended bitstream information will be disabled.\n");
1825
                warn_once = 0;
1826
            }
1827
        } else {
1828
            s->bitstream_id = 6;
1829
        }
1830
    }
1831

    
1832
    return 0;
1833
}
1834

    
1835

    
1836
/**
1837
 * Encode a single AC-3 frame.
1838
 */
1839
static int ac3_encode_frame(AVCodecContext *avctx, unsigned char *frame,
1840
                            int buf_size, void *data)
1841
{
1842
    AC3EncodeContext *s = avctx->priv_data;
1843
    const SampleType *samples = data;
1844
    int ret;
1845

    
1846
    if (s->options.allow_per_frame_metadata) {
1847
        ret = validate_metadata(avctx);
1848
        if (ret)
1849
            return ret;
1850
    }
1851

    
1852
    if (s->bit_alloc.sr_code == 1)
1853
        adjust_frame_size(s);
1854

    
1855
    deinterleave_input_samples(s, samples);
1856

    
1857
    apply_mdct(s);
1858

    
1859
    scale_coefficients(s);
1860

    
1861
    compute_rematrixing_strategy(s);
1862

    
1863
    apply_rematrixing(s);
1864

    
1865
    process_exponents(s);
1866

    
1867
    ret = compute_bit_allocation(s);
1868
    if (ret) {
1869
        av_log(avctx, AV_LOG_ERROR, "Bit allocation failed. Try increasing the bitrate.\n");
1870
        return ret;
1871
    }
1872

    
1873
    quantize_mantissas(s);
1874

    
1875
    output_frame(s, frame);
1876

    
1877
    return s->frame_size;
1878
}
1879

    
1880

    
1881
/**
1882
 * Finalize encoding and free any memory allocated by the encoder.
1883
 */
1884
static av_cold int ac3_encode_close(AVCodecContext *avctx)
1885
{
1886
    int blk, ch;
1887
    AC3EncodeContext *s = avctx->priv_data;
1888

    
1889
    for (ch = 0; ch < s->channels; ch++)
1890
        av_freep(&s->planar_samples[ch]);
1891
    av_freep(&s->planar_samples);
1892
    av_freep(&s->bap_buffer);
1893
    av_freep(&s->bap1_buffer);
1894
    av_freep(&s->mdct_coef_buffer);
1895
    av_freep(&s->fixed_coef_buffer);
1896
    av_freep(&s->exp_buffer);
1897
    av_freep(&s->grouped_exp_buffer);
1898
    av_freep(&s->psd_buffer);
1899
    av_freep(&s->band_psd_buffer);
1900
    av_freep(&s->mask_buffer);
1901
    av_freep(&s->qmant_buffer);
1902
    for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
1903
        AC3Block *block = &s->blocks[blk];
1904
        av_freep(&block->bap);
1905
        av_freep(&block->mdct_coef);
1906
        av_freep(&block->fixed_coef);
1907
        av_freep(&block->exp);
1908
        av_freep(&block->grouped_exp);
1909
        av_freep(&block->psd);
1910
        av_freep(&block->band_psd);
1911
        av_freep(&block->mask);
1912
        av_freep(&block->qmant);
1913
    }
1914

    
1915
    mdct_end(&s->mdct);
1916

    
1917
    av_freep(&avctx->coded_frame);
1918
    return 0;
1919
}
1920

    
1921

    
1922
/**
1923
 * Set channel information during initialization.
1924
 */
1925
static av_cold int set_channel_info(AC3EncodeContext *s, int channels,
1926
                                    int64_t *channel_layout)
1927
{
1928
    int ch_layout;
1929

    
1930
    if (channels < 1 || channels > AC3_MAX_CHANNELS)
1931
        return AVERROR(EINVAL);
1932
    if ((uint64_t)*channel_layout > 0x7FF)
1933
        return AVERROR(EINVAL);
1934
    ch_layout = *channel_layout;
1935
    if (!ch_layout)
1936
        ch_layout = avcodec_guess_channel_layout(channels, CODEC_ID_AC3, NULL);
1937

    
1938
    s->lfe_on       = !!(ch_layout & AV_CH_LOW_FREQUENCY);
1939
    s->channels     = channels;
1940
    s->fbw_channels = channels - s->lfe_on;
1941
    s->lfe_channel  = s->lfe_on ? s->fbw_channels : -1;
1942
    if (s->lfe_on)
1943
        ch_layout -= AV_CH_LOW_FREQUENCY;
1944

    
1945
    switch (ch_layout) {
1946
    case AV_CH_LAYOUT_MONO:           s->channel_mode = AC3_CHMODE_MONO;   break;
1947
    case AV_CH_LAYOUT_STEREO:         s->channel_mode = AC3_CHMODE_STEREO; break;
1948
    case AV_CH_LAYOUT_SURROUND:       s->channel_mode = AC3_CHMODE_3F;     break;
1949
    case AV_CH_LAYOUT_2_1:            s->channel_mode = AC3_CHMODE_2F1R;   break;
1950
    case AV_CH_LAYOUT_4POINT0:        s->channel_mode = AC3_CHMODE_3F1R;   break;
1951
    case AV_CH_LAYOUT_QUAD:
1952
    case AV_CH_LAYOUT_2_2:            s->channel_mode = AC3_CHMODE_2F2R;   break;
1953
    case AV_CH_LAYOUT_5POINT0:
1954
    case AV_CH_LAYOUT_5POINT0_BACK:   s->channel_mode = AC3_CHMODE_3F2R;   break;
1955
    default:
1956
        return AVERROR(EINVAL);
1957
    }
1958
    s->has_center   = (s->channel_mode & 0x01) && s->channel_mode != AC3_CHMODE_MONO;
1959
    s->has_surround =  s->channel_mode & 0x04;
1960

    
1961
    s->channel_map  = ff_ac3_enc_channel_map[s->channel_mode][s->lfe_on];
1962
    *channel_layout = ch_layout;
1963
    if (s->lfe_on)
1964
        *channel_layout |= AV_CH_LOW_FREQUENCY;
1965

    
1966
    return 0;
1967
}
1968

    
1969

    
1970
static av_cold int validate_options(AVCodecContext *avctx, AC3EncodeContext *s)
1971
{
1972
    int i, ret;
1973

    
1974
    /* validate channel layout */
1975
    if (!avctx->channel_layout) {
1976
        av_log(avctx, AV_LOG_WARNING, "No channel layout specified. The "
1977
                                      "encoder will guess the layout, but it "
1978
                                      "might be incorrect.\n");
1979
    }
1980
    ret = set_channel_info(s, avctx->channels, &avctx->channel_layout);
1981
    if (ret) {
1982
        av_log(avctx, AV_LOG_ERROR, "invalid channel layout\n");
1983
        return ret;
1984
    }
1985

    
1986
    /* validate sample rate */
1987
    for (i = 0; i < 9; i++) {
1988
        if ((ff_ac3_sample_rate_tab[i / 3] >> (i % 3)) == avctx->sample_rate)
1989
            break;
1990
    }
1991
    if (i == 9) {
1992
        av_log(avctx, AV_LOG_ERROR, "invalid sample rate\n");
1993
        return AVERROR(EINVAL);
1994
    }
1995
    s->sample_rate        = avctx->sample_rate;
1996
    s->bit_alloc.sr_shift = i % 3;
1997
    s->bit_alloc.sr_code  = i / 3;
1998
    s->bitstream_id       = 8 + s->bit_alloc.sr_shift;
1999

    
2000
    /* validate bit rate */
2001
    for (i = 0; i < 19; i++) {
2002
        if ((ff_ac3_bitrate_tab[i] >> s->bit_alloc.sr_shift)*1000 == avctx->bit_rate)
2003
            break;
2004
    }
2005
    if (i == 19) {
2006
        av_log(avctx, AV_LOG_ERROR, "invalid bit rate\n");
2007
        return AVERROR(EINVAL);
2008
    }
2009
    s->bit_rate        = avctx->bit_rate;
2010
    s->frame_size_code = i << 1;
2011

    
2012
    /* validate cutoff */
2013
    if (avctx->cutoff < 0) {
2014
        av_log(avctx, AV_LOG_ERROR, "invalid cutoff frequency\n");
2015
        return AVERROR(EINVAL);
2016
    }
2017
    s->cutoff = avctx->cutoff;
2018
    if (s->cutoff > (s->sample_rate >> 1))
2019
        s->cutoff = s->sample_rate >> 1;
2020

    
2021
    /* validate audio service type / channels combination */
2022
    if ((avctx->audio_service_type == AV_AUDIO_SERVICE_TYPE_KARAOKE &&
2023
         avctx->channels == 1) ||
2024
        ((avctx->audio_service_type == AV_AUDIO_SERVICE_TYPE_COMMENTARY ||
2025
          avctx->audio_service_type == AV_AUDIO_SERVICE_TYPE_EMERGENCY  ||
2026
          avctx->audio_service_type == AV_AUDIO_SERVICE_TYPE_VOICE_OVER)
2027
         && avctx->channels > 1)) {
2028
        av_log(avctx, AV_LOG_ERROR, "invalid audio service type for the "
2029
                                    "specified number of channels\n");
2030
        return AVERROR(EINVAL);
2031
    }
2032

    
2033
    ret = validate_metadata(avctx);
2034
    if (ret)
2035
        return ret;
2036

    
2037
    s->rematrixing_enabled = s->options.stereo_rematrixing &&
2038
                             (s->channel_mode == AC3_CHMODE_STEREO);
2039

    
2040
    return 0;
2041
}
2042

    
2043

    
2044
/**
2045
 * Set bandwidth for all channels.
2046
 * The user can optionally supply a cutoff frequency. Otherwise an appropriate
2047
 * default value will be used.
2048
 */
2049
static av_cold void set_bandwidth(AC3EncodeContext *s)
2050
{
2051
    int ch;
2052

    
2053
    if (s->cutoff) {
2054
        /* calculate bandwidth based on user-specified cutoff frequency */
2055
        int fbw_coeffs;
2056
        fbw_coeffs     = s->cutoff * 2 * AC3_MAX_COEFS / s->sample_rate;
2057
        s->bandwidth_code = av_clip((fbw_coeffs - 73) / 3, 0, 60);
2058
    } else {
2059
        /* use default bandwidth setting */
2060
        s->bandwidth_code = ac3_bandwidth_tab[s->fbw_channels-1][s->bit_alloc.sr_code][s->frame_size_code/2];
2061
    }
2062

    
2063
    /* set number of coefficients for each channel */
2064
    for (ch = 0; ch < s->fbw_channels; ch++) {
2065
        s->nb_coefs[ch] = s->bandwidth_code * 3 + 73;
2066
    }
2067
    if (s->lfe_on)
2068
        s->nb_coefs[s->lfe_channel] = 7; /* LFE channel always has 7 coefs */
2069
}
2070

    
2071

    
2072
static av_cold int allocate_buffers(AVCodecContext *avctx)
2073
{
2074
    int blk, ch;
2075
    AC3EncodeContext *s = avctx->priv_data;
2076

    
2077
    FF_ALLOC_OR_GOTO(avctx, s->planar_samples, s->channels * sizeof(*s->planar_samples),
2078
                     alloc_fail);
2079
    for (ch = 0; ch < s->channels; ch++) {
2080
        FF_ALLOCZ_OR_GOTO(avctx, s->planar_samples[ch],
2081
                          (AC3_FRAME_SIZE+AC3_BLOCK_SIZE) * sizeof(**s->planar_samples),
2082
                          alloc_fail);
2083
    }
2084
    FF_ALLOC_OR_GOTO(avctx, s->bap_buffer,  AC3_MAX_BLOCKS * s->channels *
2085
                     AC3_MAX_COEFS * sizeof(*s->bap_buffer),  alloc_fail);
2086
    FF_ALLOC_OR_GOTO(avctx, s->bap1_buffer, AC3_MAX_BLOCKS * s->channels *
2087
                     AC3_MAX_COEFS * sizeof(*s->bap1_buffer), alloc_fail);
2088
    FF_ALLOC_OR_GOTO(avctx, s->mdct_coef_buffer, AC3_MAX_BLOCKS * s->channels *
2089
                     AC3_MAX_COEFS * sizeof(*s->mdct_coef_buffer), alloc_fail);
2090
    FF_ALLOC_OR_GOTO(avctx, s->exp_buffer, AC3_MAX_BLOCKS * s->channels *
2091
                     AC3_MAX_COEFS * sizeof(*s->exp_buffer), alloc_fail);
2092
    FF_ALLOC_OR_GOTO(avctx, s->grouped_exp_buffer, AC3_MAX_BLOCKS * s->channels *
2093
                     128 * sizeof(*s->grouped_exp_buffer), alloc_fail);
2094
    FF_ALLOC_OR_GOTO(avctx, s->psd_buffer, AC3_MAX_BLOCKS * s->channels *
2095
                     AC3_MAX_COEFS * sizeof(*s->psd_buffer), alloc_fail);
2096
    FF_ALLOC_OR_GOTO(avctx, s->band_psd_buffer, AC3_MAX_BLOCKS * s->channels *
2097
                     64 * sizeof(*s->band_psd_buffer), alloc_fail);
2098
    FF_ALLOC_OR_GOTO(avctx, s->mask_buffer, AC3_MAX_BLOCKS * s->channels *
2099
                     64 * sizeof(*s->mask_buffer), alloc_fail);
2100
    FF_ALLOC_OR_GOTO(avctx, s->qmant_buffer, AC3_MAX_BLOCKS * s->channels *
2101
                     AC3_MAX_COEFS * sizeof(*s->qmant_buffer), alloc_fail);
2102
    for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
2103
        AC3Block *block = &s->blocks[blk];
2104
        FF_ALLOC_OR_GOTO(avctx, block->bap, s->channels * sizeof(*block->bap),
2105
                         alloc_fail);
2106
        FF_ALLOCZ_OR_GOTO(avctx, block->mdct_coef, s->channels * sizeof(*block->mdct_coef),
2107
                          alloc_fail);
2108
        FF_ALLOCZ_OR_GOTO(avctx, block->exp, s->channels * sizeof(*block->exp),
2109
                          alloc_fail);
2110
        FF_ALLOCZ_OR_GOTO(avctx, block->grouped_exp, s->channels * sizeof(*block->grouped_exp),
2111
                          alloc_fail);
2112
        FF_ALLOCZ_OR_GOTO(avctx, block->psd, s->channels * sizeof(*block->psd),
2113
                          alloc_fail);
2114
        FF_ALLOCZ_OR_GOTO(avctx, block->band_psd, s->channels * sizeof(*block->band_psd),
2115
                          alloc_fail);
2116
        FF_ALLOCZ_OR_GOTO(avctx, block->mask, s->channels * sizeof(*block->mask),
2117
                          alloc_fail);
2118
        FF_ALLOCZ_OR_GOTO(avctx, block->qmant, s->channels * sizeof(*block->qmant),
2119
                          alloc_fail);
2120

    
2121
        for (ch = 0; ch < s->channels; ch++) {
2122
            /* arrangement: block, channel, coeff */
2123
            block->bap[ch]         = &s->bap_buffer        [AC3_MAX_COEFS * (blk * s->channels + ch)];
2124
            block->mdct_coef[ch]   = &s->mdct_coef_buffer  [AC3_MAX_COEFS * (blk * s->channels + ch)];
2125
            block->grouped_exp[ch] = &s->grouped_exp_buffer[128           * (blk * s->channels + ch)];
2126
            block->psd[ch]         = &s->psd_buffer        [AC3_MAX_COEFS * (blk * s->channels + ch)];
2127
            block->band_psd[ch]    = &s->band_psd_buffer   [64            * (blk * s->channels + ch)];
2128
            block->mask[ch]        = &s->mask_buffer       [64            * (blk * s->channels + ch)];
2129
            block->qmant[ch]       = &s->qmant_buffer      [AC3_MAX_COEFS * (blk * s->channels + ch)];
2130

    
2131
            /* arrangement: channel, block, coeff */
2132
            block->exp[ch]         = &s->exp_buffer        [AC3_MAX_COEFS * (AC3_MAX_BLOCKS * ch + blk)];
2133
        }
2134
    }
2135

    
2136
    if (CONFIG_AC3ENC_FLOAT) {
2137
        FF_ALLOC_OR_GOTO(avctx, s->fixed_coef_buffer, AC3_MAX_BLOCKS * s->channels *
2138
                         AC3_MAX_COEFS * sizeof(*s->fixed_coef_buffer), alloc_fail);
2139
        for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
2140
            AC3Block *block = &s->blocks[blk];
2141
            FF_ALLOCZ_OR_GOTO(avctx, block->fixed_coef, s->channels *
2142
                              sizeof(*block->fixed_coef), alloc_fail);
2143
            for (ch = 0; ch < s->channels; ch++)
2144
                block->fixed_coef[ch] = &s->fixed_coef_buffer[AC3_MAX_COEFS * (blk * s->channels + ch)];
2145
        }
2146
    } else {
2147
        for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
2148
            AC3Block *block = &s->blocks[blk];
2149
            FF_ALLOCZ_OR_GOTO(avctx, block->fixed_coef, s->channels *
2150
                              sizeof(*block->fixed_coef), alloc_fail);
2151
            for (ch = 0; ch < s->channels; ch++)
2152
                block->fixed_coef[ch] = (int32_t *)block->mdct_coef[ch];
2153
        }
2154
    }
2155

    
2156
    return 0;
2157
alloc_fail:
2158
    return AVERROR(ENOMEM);
2159
}
2160

    
2161

    
2162
/**
2163
 * Initialize the encoder.
2164
 */
2165
static av_cold int ac3_encode_init(AVCodecContext *avctx)
2166
{
2167
    AC3EncodeContext *s = avctx->priv_data;
2168
    int ret, frame_size_58;
2169

    
2170
    avctx->frame_size = AC3_FRAME_SIZE;
2171

    
2172
    ff_ac3_common_init();
2173

    
2174
    ret = validate_options(avctx, s);
2175
    if (ret)
2176
        return ret;
2177

    
2178
    s->bitstream_mode = avctx->audio_service_type;
2179
    if (s->bitstream_mode == AV_AUDIO_SERVICE_TYPE_KARAOKE)
2180
        s->bitstream_mode = 0x7;
2181

    
2182
    s->frame_size_min  = 2 * ff_ac3_frame_size_tab[s->frame_size_code][s->bit_alloc.sr_code];
2183
    s->bits_written    = 0;
2184
    s->samples_written = 0;
2185
    s->frame_size      = s->frame_size_min;
2186

    
2187
    /* calculate crc_inv for both possible frame sizes */
2188
    frame_size_58 = (( s->frame_size    >> 2) + ( s->frame_size    >> 4)) << 1;
2189
    s->crc_inv[0] = pow_poly((CRC16_POLY >> 1), (8 * frame_size_58) - 16, CRC16_POLY);
2190
    if (s->bit_alloc.sr_code == 1) {
2191
        frame_size_58 = (((s->frame_size+2) >> 2) + ((s->frame_size+2) >> 4)) << 1;
2192
        s->crc_inv[1] = pow_poly((CRC16_POLY >> 1), (8 * frame_size_58) - 16, CRC16_POLY);
2193
    }
2194

    
2195
    set_bandwidth(s);
2196

    
2197
    exponent_init(s);
2198

    
2199
    bit_alloc_init(s);
2200

    
2201
    ret = mdct_init(avctx, &s->mdct, 9);
2202
    if (ret)
2203
        goto init_fail;
2204

    
2205
    ret = allocate_buffers(avctx);
2206
    if (ret)
2207
        goto init_fail;
2208

    
2209
    avctx->coded_frame= avcodec_alloc_frame();
2210

    
2211
    dsputil_init(&s->dsp, avctx);
2212
    ff_ac3dsp_init(&s->ac3dsp, avctx->flags & CODEC_FLAG_BITEXACT);
2213

    
2214
    dprint_options(avctx);
2215

    
2216
    return 0;
2217
init_fail:
2218
    ac3_encode_close(avctx);
2219
    return ret;
2220
}