ffmpeg / libavcodec / ac3enc.c @ 177fed4e
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/*


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* The simplest AC3 encoder

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* Copyright (c) 2000 Fabrice Bellard

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* Copyright (c) 20062010 Justin Ruggles <justin.ruggles@gmail.com>

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* Copyright (c) 20062010 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 021101301 USA

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*/

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/**

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* @file

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* The simplest AC3 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/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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#ifndef CONFIG_AC3ENC_FLOAT

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#define CONFIG_AC3ENC_FLOAT 0 
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#endif

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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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/* AC3 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.

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*/

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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; ///< fixedpoint 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]; ///< fixedpoint 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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* AC3 encoder private context.

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*/

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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; ///< AC3 optimized functions

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AC3MDCTContext mdct; ///< MDCT context

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AC3Block blocks[AC3_MAX_BLOCKS]; ///< perblock 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 bitspersecond 
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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 fullbandwidth 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; ///< userspecified 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 (signaltomask 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 noncoefficient 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 PerFrame", 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}, 
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{NULL}

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}; 
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#if CONFIG_AC3ENC_FLOAT

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static AVClass ac3enc_class = { "AC3 Encoder", av_default_item_name, 
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options, LIBAVUTIL_VERSION_INT }; 
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#else

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static AVClass ac3enc_class = { "FixedPoint AC3 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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static av_cold void mdct_end(AC3MDCTContext *mdct); 
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static av_cold int mdct_init(AVCodecContext *avctx, AC3MDCTContext *mdct, 
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int nbits);

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static void apply_window(DSPContext *dsp, SampleType *output, const SampleType *input, 
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const SampleType *window, unsigned int len); 
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static int normalize_samples(AC3EncodeContext *s); 
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static void scale_coefficients(AC3EncodeContext *s); 
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/**

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* LUT for number of exponent groups.

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* exponent_group_tab[exponent strategy1][number of coefficients]

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*/

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static uint8_t exponent_group_tab[3][256]; 
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/**

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* List of supported channel layouts.

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*/

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static const int64_t ac3_channel_layouts[] = { 
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AV_CH_LAYOUT_MONO, 
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AV_CH_LAYOUT_STEREO, 
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AV_CH_LAYOUT_2_1, 
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AV_CH_LAYOUT_SURROUND, 
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AV_CH_LAYOUT_2_2, 
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AV_CH_LAYOUT_QUAD, 
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AV_CH_LAYOUT_4POINT0, 
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AV_CH_LAYOUT_5POINT0, 
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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), 
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AV_CH_LAYOUT_5POINT1, 
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AV_CH_LAYOUT_5POINT1_BACK, 
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0

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}; 
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/**

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* LUT to select the bandwidth code based on the bit rate, sample rate, and

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* number of fullbandwidth channels.

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* bandwidth_tab[fbw_channels1][sample rate code][bit rate code]

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*/

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static const uint8_t ac3_bandwidth_tab[5][3][19] = { 
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// 32 40 48 56 64 80 96 112 128 160 192 224 256 320 384 448 512 576 640

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{ { 0, 0, 0, 12, 16, 32, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48 }, 
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{ 0, 0, 0, 16, 20, 36, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56 }, 
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{ 0, 0, 0, 32, 40, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60 } }, 
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{ { 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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{ { 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 } }, 
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{ { 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 } } 
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}; 
357  
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/**

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* Adjust the frame size to make the average bit rate match the target bit rate.

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* This is only needed for 11025, 22050, and 44100 sample rates.

362 
*/

363 
static void adjust_frame_size(AC3EncodeContext *s) 
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{ 
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while (s>bits_written >= s>bit_rate && s>samples_written >= s>sample_rate) {

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s>bits_written = s>bit_rate; 
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s>samples_written = s>sample_rate; 
368 
} 
369 
s>frame_size = s>frame_size_min + 
370 
2 * (s>bits_written * s>sample_rate < s>samples_written * s>bit_rate);

371 
s>bits_written += s>frame_size * 8;

372 
s>samples_written += AC3_FRAME_SIZE; 
373 
} 
374  
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/**

377 
* Deinterleave input samples.

378 
* Channels are reordered from Libav's default order to AC3 order.

379 
*/

380 
static void deinterleave_input_samples(AC3EncodeContext *s, 
381 
const SampleType *samples)

382 
{ 
383 
int ch, i;

384  
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/* deinterleave and remap input samples */

386 
for (ch = 0; ch < s>channels; ch++) { 
387 
const SampleType *sptr;

388 
int sinc;

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390 
/* copy last 256 samples of previous frame to the start of the current frame */

391 
memcpy(&s>planar_samples[ch][0], &s>planar_samples[ch][AC3_FRAME_SIZE],

392 
AC3_BLOCK_SIZE * sizeof(s>planar_samples[0][0])); 
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/* deinterleave */

395 
sinc = s>channels; 
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sptr = samples + s>channel_map[ch]; 
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for (i = AC3_BLOCK_SIZE; i < AC3_FRAME_SIZE+AC3_BLOCK_SIZE; i++) {

398 
s>planar_samples[ch][i] = *sptr; 
399 
sptr += sinc; 
400 
} 
401 
} 
402 
} 
403  
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/**

406 
* Apply the MDCT to input samples to generate frequency coefficients.

407 
* This applies the KBD window and normalizes the input to reduce precision

408 
* loss due to fixedpoint calculations.

409 
*/

410 
static void apply_mdct(AC3EncodeContext *s) 
411 
{ 
412 
int blk, ch;

413  
414 
for (ch = 0; ch < s>channels; ch++) { 
415 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { 
416 
AC3Block *block = &s>blocks[blk]; 
417 
const SampleType *input_samples = &s>planar_samples[ch][blk * AC3_BLOCK_SIZE];

418  
419 
apply_window(&s>dsp, s>windowed_samples, input_samples, s>mdct.window, AC3_WINDOW_SIZE); 
420  
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block>coeff_shift[ch] = normalize_samples(s); 
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423 
s>mdct.fft.mdct_calcw(&s>mdct.fft, block>mdct_coef[ch], 
424 
s>windowed_samples); 
425 
} 
426 
} 
427 
} 
428  
429  
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/**

431 
* Determine rematrixing flags for each block and band.

432 
*/

433 
static void compute_rematrixing_strategy(AC3EncodeContext *s) 
434 
{ 
435 
int nb_coefs;

436 
int blk, bnd, i;

437 
AC3Block *block, *block0; 
438  
439 
if (s>channel_mode != AC3_CHMODE_STEREO)

440 
return;

441  
442 
s>num_rematrixing_bands = 4;

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444 
nb_coefs = FFMIN(s>nb_coefs[0], s>nb_coefs[1]); 
445  
446 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { 
447 
block = &s>blocks[blk]; 
448 
block>new_rematrixing_strategy = !blk; 
449 
if (!s>rematrixing_enabled)

450 
continue;

451 
for (bnd = 0; bnd < s>num_rematrixing_bands; bnd++) { 
452 
/* calculate calculate sum of squared coeffs for one band in one block */

453 
int start = ff_ac3_rematrix_band_tab[bnd];

454 
int end = FFMIN(nb_coefs, ff_ac3_rematrix_band_tab[bnd+1]); 
455 
CoefSumType sum[4] = {0,}; 
456 
for (i = start; i < end; i++) {

457 
CoefType lt = block>mdct_coef[0][i];

458 
CoefType rt = block>mdct_coef[1][i];

459 
CoefType md = lt + rt; 
460 
CoefType sd = lt  rt; 
461 
MAC_COEF(sum[0], lt, lt);

462 
MAC_COEF(sum[1], rt, rt);

463 
MAC_COEF(sum[2], md, md);

464 
MAC_COEF(sum[3], sd, sd);

465 
} 
466  
467 
/* compare sums to determine if rematrixing will be used for this band */

468 
if (FFMIN(sum[2], sum[3]) < FFMIN(sum[0], sum[1])) 
469 
block>rematrixing_flags[bnd] = 1;

470 
else

471 
block>rematrixing_flags[bnd] = 0;

472  
473 
/* determine if new rematrixing flags will be sent */

474 
if (blk &&

475 
block>rematrixing_flags[bnd] != block0>rematrixing_flags[bnd]) { 
476 
block>new_rematrixing_strategy = 1;

477 
} 
478 
} 
479 
block0 = block; 
480 
} 
481 
} 
482  
483  
484 
/**

485 
* Apply stereo rematrixing to coefficients based on rematrixing flags.

486 
*/

487 
static void apply_rematrixing(AC3EncodeContext *s) 
488 
{ 
489 
int nb_coefs;

490 
int blk, bnd, i;

491 
int start, end;

492 
uint8_t *flags; 
493  
494 
if (!s>rematrixing_enabled)

495 
return;

496  
497 
nb_coefs = FFMIN(s>nb_coefs[0], s>nb_coefs[1]); 
498  
499 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { 
500 
AC3Block *block = &s>blocks[blk]; 
501 
if (block>new_rematrixing_strategy)

502 
flags = block>rematrixing_flags; 
503 
for (bnd = 0; bnd < s>num_rematrixing_bands; bnd++) { 
504 
if (flags[bnd]) {

505 
start = ff_ac3_rematrix_band_tab[bnd]; 
506 
end = FFMIN(nb_coefs, ff_ac3_rematrix_band_tab[bnd+1]);

507 
for (i = start; i < end; i++) {

508 
int32_t lt = block>fixed_coef[0][i];

509 
int32_t rt = block>fixed_coef[1][i];

510 
block>fixed_coef[0][i] = (lt + rt) >> 1; 
511 
block>fixed_coef[1][i] = (lt  rt) >> 1; 
512 
} 
513 
} 
514 
} 
515 
} 
516 
} 
517  
518  
519 
/**

520 
* Initialize exponent tables.

521 
*/

522 
static av_cold void exponent_init(AC3EncodeContext *s) 
523 
{ 
524 
int expstr, i, grpsize;

525  
526 
for (expstr = EXP_D151; expstr <= EXP_D451; expstr++) { 
527 
grpsize = 3 << expstr;

528 
for (i = 73; i < 256; i++) { 
529 
exponent_group_tab[expstr][i] = (i + grpsize  4) / grpsize;

530 
} 
531 
} 
532 
/* LFE */

533 
exponent_group_tab[0][7] = 2; 
534 
} 
535  
536  
537 
/**

538 
* Extract exponents from the MDCT coefficients.

539 
* This takes into account the normalization that was done to the input samples

540 
* by adjusting the exponents by the exponent shift values.

541 
*/

542 
static void extract_exponents(AC3EncodeContext *s) 
543 
{ 
544 
int blk, ch;

545  
546 
for (ch = 0; ch < s>channels; ch++) { 
547 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { 
548 
AC3Block *block = &s>blocks[blk]; 
549 
s>ac3dsp.extract_exponents(block>exp[ch], block>fixed_coef[ch], 
550 
AC3_MAX_COEFS); 
551 
} 
552 
} 
553 
} 
554  
555  
556 
/**

557 
* Exponent Difference Threshold.

558 
* New exponents are sent if their SAD exceed this number.

559 
*/

560 
#define EXP_DIFF_THRESHOLD 500 
561  
562  
563 
/**

564 
* Calculate exponent strategies for all channels.

565 
* Array arrangement is reversed to simplify the perchannel calculation.

566 
*/

567 
static void compute_exp_strategy(AC3EncodeContext *s) 
568 
{ 
569 
int ch, blk, blk1;

570  
571 
for (ch = 0; ch < s>fbw_channels; ch++) { 
572 
uint8_t *exp_strategy = s>exp_strategy[ch]; 
573 
uint8_t *exp = s>blocks[0].exp[ch];

574 
int exp_diff;

575  
576 
/* estimate if the exponent variation & decide if they should be

577 
reused in the next frame */

578 
exp_strategy[0] = EXP_NEW;

579 
exp += AC3_MAX_COEFS; 
580 
for (blk = 1; blk < AC3_MAX_BLOCKS; blk++) { 
581 
exp_diff = s>dsp.sad[0](NULL, exp, exp  AC3_MAX_COEFS, 16, 16); 
582 
if (exp_diff > EXP_DIFF_THRESHOLD)

583 
exp_strategy[blk] = EXP_NEW; 
584 
else

585 
exp_strategy[blk] = EXP_REUSE; 
586 
exp += AC3_MAX_COEFS; 
587 
} 
588  
589 
/* now select the encoding strategy type : if exponents are often

590 
recoded, we use a coarse encoding */

591 
blk = 0;

592 
while (blk < AC3_MAX_BLOCKS) {

593 
blk1 = blk + 1;

594 
while (blk1 < AC3_MAX_BLOCKS && exp_strategy[blk1] == EXP_REUSE)

595 
blk1++; 
596 
switch (blk1  blk) {

597 
case 1: exp_strategy[blk] = EXP_D45; break; 
598 
case 2: 
599 
case 3: exp_strategy[blk] = EXP_D25; break; 
600 
default: exp_strategy[blk] = EXP_D15; break; 
601 
} 
602 
blk = blk1; 
603 
} 
604 
} 
605 
if (s>lfe_on) {

606 
ch = s>lfe_channel; 
607 
s>exp_strategy[ch][0] = EXP_D15;

608 
for (blk = 1; blk < AC3_MAX_BLOCKS; blk++) 
609 
s>exp_strategy[ch][blk] = EXP_REUSE; 
610 
} 
611 
} 
612  
613  
614 
/**

615 
* Update the exponents so that they are the ones the decoder will decode.

616 
*/

617 
static void encode_exponents_blk_ch(uint8_t *exp, int nb_exps, int exp_strategy) 
618 
{ 
619 
int nb_groups, i, k;

620  
621 
nb_groups = exponent_group_tab[exp_strategy1][nb_exps] * 3; 
622  
623 
/* for each group, compute the minimum exponent */

624 
switch(exp_strategy) {

625 
case EXP_D25:

626 
for (i = 1, k = 1; i <= nb_groups; i++) { 
627 
uint8_t exp_min = exp[k]; 
628 
if (exp[k+1] < exp_min) 
629 
exp_min = exp[k+1];

630 
exp[i] = exp_min; 
631 
k += 2;

632 
} 
633 
break;

634 
case EXP_D45:

635 
for (i = 1, k = 1; i <= nb_groups; i++) { 
636 
uint8_t exp_min = exp[k]; 
637 
if (exp[k+1] < exp_min) 
638 
exp_min = exp[k+1];

639 
if (exp[k+2] < exp_min) 
640 
exp_min = exp[k+2];

641 
if (exp[k+3] < exp_min) 
642 
exp_min = exp[k+3];

643 
exp[i] = exp_min; 
644 
k += 4;

645 
} 
646 
break;

647 
} 
648  
649 
/* constraint for DC exponent */

650 
if (exp[0] > 15) 
651 
exp[0] = 15; 
652  
653 
/* decrease the delta between each groups to within 2 so that they can be

654 
differentially encoded */

655 
for (i = 1; i <= nb_groups; i++) 
656 
exp[i] = FFMIN(exp[i], exp[i1] + 2); 
657 
i; 
658 
while (i >= 0) 
659 
exp[i] = FFMIN(exp[i], exp[i+1] + 2); 
660  
661 
/* now we have the exponent values the decoder will see */

662 
switch (exp_strategy) {

663 
case EXP_D25:

664 
for (i = nb_groups, k = nb_groups * 2; i > 0; i) { 
665 
uint8_t exp1 = exp[i]; 
666 
exp[k] = exp1; 
667 
exp[k] = exp1; 
668 
} 
669 
break;

670 
case EXP_D45:

671 
for (i = nb_groups, k = nb_groups * 4; i > 0; i) { 
672 
exp[k] = exp[k1] = exp[k2] = exp[k3] = exp[i]; 
673 
k = 4;

674 
} 
675 
break;

676 
} 
677 
} 
678  
679  
680 
/**

681 
* Encode exponents from original extracted form to what the decoder will see.

682 
* This copies and groups exponents based on exponent strategy and reduces

683 
* deltas between adjacent exponent groups so that they can be differentially

684 
* encoded.

685 
*/

686 
static void encode_exponents(AC3EncodeContext *s) 
687 
{ 
688 
int blk, blk1, ch;

689 
uint8_t *exp, *exp_strategy; 
690 
int nb_coefs, num_reuse_blocks;

691  
692 
for (ch = 0; ch < s>channels; ch++) { 
693 
exp = s>blocks[0].exp[ch];

694 
exp_strategy = s>exp_strategy[ch]; 
695 
nb_coefs = s>nb_coefs[ch]; 
696  
697 
blk = 0;

698 
while (blk < AC3_MAX_BLOCKS) {

699 
blk1 = blk + 1;

700  
701 
/* count the number of EXP_REUSE blocks after the current block

702 
and set exponent reference block pointers */

703 
s>blocks[blk].exp_ref_block[ch] = &s>blocks[blk]; 
704 
while (blk1 < AC3_MAX_BLOCKS && exp_strategy[blk1] == EXP_REUSE) {

705 
s>blocks[blk1].exp_ref_block[ch] = &s>blocks[blk]; 
706 
blk1++; 
707 
} 
708 
num_reuse_blocks = blk1  blk  1;

709  
710 
/* for the EXP_REUSE case we select the min of the exponents */

711 
s>ac3dsp.ac3_exponent_min(exp, num_reuse_blocks, nb_coefs); 
712  
713 
encode_exponents_blk_ch(exp, nb_coefs, exp_strategy[blk]); 
714  
715 
exp += AC3_MAX_COEFS * (num_reuse_blocks + 1);

716 
blk = blk1; 
717 
} 
718 
} 
719 
} 
720  
721  
722 
/**

723 
* Group exponents.

724 
* 3 deltaencoded exponents are in each 7bit group. The number of groups

725 
* varies depending on exponent strategy and bandwidth.

726 
*/

727 
static void group_exponents(AC3EncodeContext *s) 
728 
{ 
729 
int blk, ch, i;

730 
int group_size, nb_groups, bit_count;

731 
uint8_t *p; 
732 
int delta0, delta1, delta2;

733 
int exp0, exp1;

734  
735 
bit_count = 0;

736 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { 
737 
AC3Block *block = &s>blocks[blk]; 
738 
for (ch = 0; ch < s>channels; ch++) { 
739 
int exp_strategy = s>exp_strategy[ch][blk];

740 
if (exp_strategy == EXP_REUSE)

741 
continue;

742 
group_size = exp_strategy + (exp_strategy == EXP_D45); 
743 
nb_groups = exponent_group_tab[exp_strategy1][s>nb_coefs[ch]];

744 
bit_count += 4 + (nb_groups * 7); 
745 
p = block>exp[ch]; 
746  
747 
/* DC exponent */

748 
exp1 = *p++; 
749 
block>grouped_exp[ch][0] = exp1;

750  
751 
/* remaining exponents are delta encoded */

752 
for (i = 1; i <= nb_groups; i++) { 
753 
/* merge three delta in one code */

754 
exp0 = exp1; 
755 
exp1 = p[0];

756 
p += group_size; 
757 
delta0 = exp1  exp0 + 2;

758 
av_assert2(delta0 >= 0 && delta0 <= 4); 
759  
760 
exp0 = exp1; 
761 
exp1 = p[0];

762 
p += group_size; 
763 
delta1 = exp1  exp0 + 2;

764 
av_assert2(delta1 >= 0 && delta1 <= 4); 
765  
766 
exp0 = exp1; 
767 
exp1 = p[0];

768 
p += group_size; 
769 
delta2 = exp1  exp0 + 2;

770 
av_assert2(delta2 >= 0 && delta2 <= 4); 
771  
772 
block>grouped_exp[ch][i] = ((delta0 * 5 + delta1) * 5) + delta2; 
773 
} 
774 
} 
775 
} 
776  
777 
s>exponent_bits = bit_count; 
778 
} 
779  
780  
781 
/**

782 
* Calculate final exponents from the supplied MDCT coefficients and exponent shift.

783 
* Extract exponents from MDCT coefficients, calculate exponent strategies,

784 
* and encode final exponents.

785 
*/

786 
static void process_exponents(AC3EncodeContext *s) 
787 
{ 
788 
extract_exponents(s); 
789  
790 
compute_exp_strategy(s); 
791  
792 
encode_exponents(s); 
793  
794 
group_exponents(s); 
795  
796 
emms_c(); 
797 
} 
798  
799  
800 
/**

801 
* Count frame bits that are based solely on fixed parameters.

802 
* This only has to be run once when the encoder is initialized.

803 
*/

804 
static void count_frame_bits_fixed(AC3EncodeContext *s) 
805 
{ 
806 
static const int frame_bits_inc[8] = { 0, 0, 2, 2, 2, 4, 2, 4 }; 
807 
int blk;

808 
int frame_bits;

809  
810 
/* assumptions:

811 
* no dynamic range codes

812 
* no channel coupling

813 
* bit allocation parameters do not change between blocks

814 
* SNR offsets do not change between blocks

815 
* no delta bit allocation

816 
* no skipped data

817 
* no auxilliary data

818 
*/

819  
820 
/* header size */

821 
frame_bits = 65;

822 
frame_bits += frame_bits_inc[s>channel_mode]; 
823  
824 
/* audio blocks */

825 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { 
826 
frame_bits += s>fbw_channels * 2 + 2; /* blksw * c, dithflag * c, dynrnge, cplstre */ 
827 
if (s>channel_mode == AC3_CHMODE_STEREO) {

828 
frame_bits++; /* rematstr */

829 
} 
830 
frame_bits += 2 * s>fbw_channels; /* chexpstr[2] * c */ 
831 
if (s>lfe_on)

832 
frame_bits++; /* lfeexpstr */

833 
frame_bits++; /* baie */

834 
frame_bits++; /* snr */

835 
frame_bits += 2; /* delta / skip */ 
836 
} 
837 
frame_bits++; /* cplinu for block 0 */

838 
/* bit alloc info */

839 
/* sdcycod[2], fdcycod[2], sgaincod[2], dbpbcod[2], floorcod[3] */

840 
/* csnroffset[6] */

841 
/* (fsnoffset[4] + fgaincod[4]) * c */

842 
frame_bits += 2*4 + 3 + 6 + s>channels * (4 + 3); 
843  
844 
/* auxdatae, crcrsv */

845 
frame_bits += 2;

846  
847 
/* CRC */

848 
frame_bits += 16;

849  
850 
s>frame_bits_fixed = frame_bits; 
851 
} 
852  
853  
854 
/**

855 
* Initialize bit allocation.

856 
* Set default parameter codes and calculate parameter values.

857 
*/

858 
static void bit_alloc_init(AC3EncodeContext *s) 
859 
{ 
860 
int ch;

861  
862 
/* init default parameters */

863 
s>slow_decay_code = 2;

864 
s>fast_decay_code = 1;

865 
s>slow_gain_code = 1;

866 
s>db_per_bit_code = 3;

867 
s>floor_code = 7;

868 
for (ch = 0; ch < s>channels; ch++) 
869 
s>fast_gain_code[ch] = 4;

870  
871 
/* initial snr offset */

872 
s>coarse_snr_offset = 40;

873  
874 
/* compute real values */

875 
/* currently none of these values change during encoding, so we can just

876 
set them once at initialization */

877 
s>bit_alloc.slow_decay = ff_ac3_slow_decay_tab[s>slow_decay_code] >> s>bit_alloc.sr_shift; 
878 
s>bit_alloc.fast_decay = ff_ac3_fast_decay_tab[s>fast_decay_code] >> s>bit_alloc.sr_shift; 
879 
s>bit_alloc.slow_gain = ff_ac3_slow_gain_tab[s>slow_gain_code]; 
880 
s>bit_alloc.db_per_bit = ff_ac3_db_per_bit_tab[s>db_per_bit_code]; 
881 
s>bit_alloc.floor = ff_ac3_floor_tab[s>floor_code]; 
882  
883 
count_frame_bits_fixed(s); 
884 
} 
885  
886  
887 
/**

888 
* Count the bits used to encode the frame, minus exponents and mantissas.

889 
* Bits based on fixed parameters have already been counted, so now we just

890 
* have to add the bits based on parameters that change during encoding.

891 
*/

892 
static void count_frame_bits(AC3EncodeContext *s) 
893 
{ 
894 
AC3EncOptions *opt = &s>options; 
895 
int blk, ch;

896 
int frame_bits = 0; 
897  
898 
if (opt>audio_production_info)

899 
frame_bits += 7;

900 
if (s>bitstream_id == 6) { 
901 
if (opt>extended_bsi_1)

902 
frame_bits += 14;

903 
if (opt>extended_bsi_2)

904 
frame_bits += 14;

905 
} 
906  
907 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { 
908 
/* stereo rematrixing */

909 
if (s>channel_mode == AC3_CHMODE_STEREO &&

910 
s>blocks[blk].new_rematrixing_strategy) { 
911 
frame_bits += s>num_rematrixing_bands; 
912 
} 
913  
914 
for (ch = 0; ch < s>fbw_channels; ch++) { 
915 
if (s>exp_strategy[ch][blk] != EXP_REUSE)

916 
frame_bits += 6 + 2; /* chbwcod[6], gainrng[2] */ 
917 
} 
918 
} 
919 
s>frame_bits = s>frame_bits_fixed + frame_bits; 
920 
} 
921  
922  
923 
/**

924 
* Finalize the mantissa bit count by adding in the grouped mantissas.

925 
*/

926 
static int compute_mantissa_size_final(int mant_cnt[5]) 
927 
{ 
928 
// bap=1 : 3 mantissas in 5 bits

929 
int bits = (mant_cnt[1] / 3) * 5; 
930 
// bap=2 : 3 mantissas in 7 bits

931 
// bap=4 : 2 mantissas in 7 bits

932 
bits += ((mant_cnt[2] / 3) + (mant_cnt[4] >> 1)) * 7; 
933 
// bap=3 : each mantissa is 3 bits

934 
bits += mant_cnt[3] * 3; 
935 
return bits;

936 
} 
937  
938  
939 
/**

940 
* Calculate masking curve based on the final exponents.

941 
* Also calculate the power spectral densities to use in future calculations.

942 
*/

943 
static void bit_alloc_masking(AC3EncodeContext *s) 
944 
{ 
945 
int blk, ch;

946  
947 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { 
948 
AC3Block *block = &s>blocks[blk]; 
949 
for (ch = 0; ch < s>channels; ch++) { 
950 
/* We only need psd and mask for calculating bap.

951 
Since we currently do not calculate bap when exponent

952 
strategy is EXP_REUSE we do not need to calculate psd or mask. */

953 
if (s>exp_strategy[ch][blk] != EXP_REUSE) {

954 
ff_ac3_bit_alloc_calc_psd(block>exp[ch], 0,

955 
s>nb_coefs[ch], 
956 
block>psd[ch], block>band_psd[ch]); 
957 
ff_ac3_bit_alloc_calc_mask(&s>bit_alloc, block>band_psd[ch], 
958 
0, s>nb_coefs[ch],

959 
ff_ac3_fast_gain_tab[s>fast_gain_code[ch]], 
960 
ch == s>lfe_channel, 
961 
DBA_NONE, 0, NULL, NULL, NULL, 
962 
block>mask[ch]); 
963 
} 
964 
} 
965 
} 
966 
} 
967  
968  
969 
/**

970 
* Ensure that bap for each block and channel point to the current bap_buffer.

971 
* They may have been switched during the bit allocation search.

972 
*/

973 
static void reset_block_bap(AC3EncodeContext *s) 
974 
{ 
975 
int blk, ch;

976 
if (s>blocks[0].bap[0] == s>bap_buffer) 
977 
return;

978 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { 
979 
for (ch = 0; ch < s>channels; ch++) { 
980 
s>blocks[blk].bap[ch] = &s>bap_buffer[AC3_MAX_COEFS * (blk * s>channels + ch)]; 
981 
} 
982 
} 
983 
} 
984  
985  
986 
/**

987 
* Run the bit allocation with a given SNR offset.

988 
* This calculates the bit allocation pointers that will be used to determine

989 
* the quantization of each mantissa.

990 
* @return the number of bits needed for mantissas if the given SNR offset is

991 
* is used.

992 
*/

993 
static int bit_alloc(AC3EncodeContext *s, int snr_offset) 
994 
{ 
995 
int blk, ch;

996 
int mantissa_bits;

997 
int mant_cnt[5]; 
998  
999 
snr_offset = (snr_offset  240) << 2; 
1000  
1001 
reset_block_bap(s); 
1002 
mantissa_bits = 0;

1003 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { 
1004 
AC3Block *block = &s>blocks[blk]; 
1005 
AC3Block *ref_block; 
1006 
// initialize grouped mantissa counts. these are set so that they are

1007 
// padded to the next whole group size when bits are counted in

1008 
// compute_mantissa_size_final

1009 
mant_cnt[0] = mant_cnt[3] = 0; 
1010 
mant_cnt[1] = mant_cnt[2] = 2; 
1011 
mant_cnt[4] = 1; 
1012 
for (ch = 0; ch < s>channels; ch++) { 
1013 
/* Currently the only bit allocation parameters which vary across

1014 
blocks within a frame are the exponent values. We can take

1015 
advantage of that by reusing the bit allocation pointers

1016 
whenever we reuse exponents. */

1017 
ref_block = block>exp_ref_block[ch]; 
1018 
if (s>exp_strategy[ch][blk] != EXP_REUSE) {

1019 
s>ac3dsp.bit_alloc_calc_bap(ref_block>mask[ch], 
1020 
ref_block>psd[ch], 0,

1021 
s>nb_coefs[ch], snr_offset, 
1022 
s>bit_alloc.floor, ff_ac3_bap_tab, 
1023 
ref_block>bap[ch]); 
1024 
} 
1025 
mantissa_bits += s>ac3dsp.compute_mantissa_size(mant_cnt, 
1026 
ref_block>bap[ch], 
1027 
s>nb_coefs[ch]); 
1028 
} 
1029 
mantissa_bits += compute_mantissa_size_final(mant_cnt); 
1030 
} 
1031 
return mantissa_bits;

1032 
} 
1033  
1034  
1035 
/**

1036 
* Constant bitrate bit allocation search.

1037 
* Find the largest SNR offset that will allow data to fit in the frame.

1038 
*/

1039 
static int cbr_bit_allocation(AC3EncodeContext *s) 
1040 
{ 
1041 
int ch;

1042 
int bits_left;

1043 
int snr_offset, snr_incr;

1044  
1045 
bits_left = 8 * s>frame_size  (s>frame_bits + s>exponent_bits);

1046 
if (bits_left < 0) 
1047 
return AVERROR(EINVAL);

1048  
1049 
snr_offset = s>coarse_snr_offset << 4;

1050  
1051 
/* if previous frame SNR offset was 1023, check if current frame can also

1052 
use SNR offset of 1023. if so, skip the search. */

1053 
if ((snr_offset  s>fine_snr_offset[0]) == 1023) { 
1054 
if (bit_alloc(s, 1023) <= bits_left) 
1055 
return 0; 
1056 
} 
1057  
1058 
while (snr_offset >= 0 && 
1059 
bit_alloc(s, snr_offset) > bits_left) { 
1060 
snr_offset = 64;

1061 
} 
1062 
if (snr_offset < 0) 
1063 
return AVERROR(EINVAL);

1064  
1065 
FFSWAP(uint8_t *, s>bap_buffer, s>bap1_buffer); 
1066 
for (snr_incr = 64; snr_incr > 0; snr_incr >>= 2) { 
1067 
while (snr_offset + snr_incr <= 1023 && 
1068 
bit_alloc(s, snr_offset + snr_incr) <= bits_left) { 
1069 
snr_offset += snr_incr; 
1070 
FFSWAP(uint8_t *, s>bap_buffer, s>bap1_buffer); 
1071 
} 
1072 
} 
1073 
FFSWAP(uint8_t *, s>bap_buffer, s>bap1_buffer); 
1074 
reset_block_bap(s); 
1075  
1076 
s>coarse_snr_offset = snr_offset >> 4;

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

1079  
1080 
return 0; 
1081 
} 
1082  
1083  
1084 
/**

1085 
* Downgrade exponent strategies to reduce the bits used by the exponents.

1086 
* This is a fallback for when bit allocation fails with the normal exponent

1087 
* strategies. Each time this function is run it only downgrades the

1088 
* strategy in 1 channel of 1 block.

1089 
* @return nonzero if downgrade was unsuccessful

1090 
*/

1091 
static int downgrade_exponents(AC3EncodeContext *s) 
1092 
{ 
1093 
int ch, blk;

1094  
1095 
for (ch = 0; ch < s>fbw_channels; ch++) { 
1096 
for (blk = AC3_MAX_BLOCKS1; blk >= 0; blk) { 
1097 
if (s>exp_strategy[ch][blk] == EXP_D15) {

1098 
s>exp_strategy[ch][blk] = EXP_D25; 
1099 
return 0; 
1100 
} 
1101 
} 
1102 
} 
1103 
for (ch = 0; ch < s>fbw_channels; ch++) { 
1104 
for (blk = AC3_MAX_BLOCKS1; blk >= 0; blk) { 
1105 
if (s>exp_strategy[ch][blk] == EXP_D25) {

1106 
s>exp_strategy[ch][blk] = EXP_D45; 
1107 
return 0; 
1108 
} 
1109 
} 
1110 
} 
1111 
for (ch = 0; ch < s>fbw_channels; ch++) { 
1112 
/* block 0 cannot reuse exponents, so only downgrade D45 to REUSE if

1113 
the block number > 0 */

1114 
for (blk = AC3_MAX_BLOCKS1; blk > 0; blk) { 
1115 
if (s>exp_strategy[ch][blk] > EXP_REUSE) {

1116 
s>exp_strategy[ch][blk] = EXP_REUSE; 
1117 
return 0; 
1118 
} 
1119 
} 
1120 
} 
1121 
return 1; 
1122 
} 
1123  
1124  
1125 
/**

1126 
* Perform bit allocation search.

1127 
* Finds the SNR offset value that maximizes quality and fits in the specified

1128 
* frame size. Output is the SNR offset and a set of bit allocation pointers

1129 
* used to quantize the mantissas.

1130 
*/

1131 
static int compute_bit_allocation(AC3EncodeContext *s) 
1132 
{ 
1133 
int ret;

1134  
1135 
count_frame_bits(s); 
1136  
1137 
bit_alloc_masking(s); 
1138  
1139 
ret = cbr_bit_allocation(s); 
1140 
while (ret) {

1141 
/* fallback 1: downgrade exponents */

1142 
if (!downgrade_exponents(s)) {

1143 
extract_exponents(s); 
1144 
encode_exponents(s); 
1145 
group_exponents(s); 
1146 
ret = compute_bit_allocation(s); 
1147 
continue;

1148 
} 
1149  
1150 
/* fallbacks were not enough... */

1151 
break;

1152 
} 
1153  
1154 
return ret;

1155 
} 
1156  
1157  
1158 
/**

1159 
* Symmetric quantization on 'levels' levels.

1160 
*/

1161 
static inline int sym_quant(int c, int e, int levels) 
1162 
{ 
1163 
int v = (((levels * c) >> (24  e)) + levels) >> 1; 
1164 
av_assert2(v >= 0 && v < levels);

1165 
return v;

1166 
} 
1167  
1168  
1169 
/**

1170 
* Asymmetric quantization on 2^qbits levels.

1171 
*/

1172 
static inline int asym_quant(int c, int e, int qbits) 
1173 
{ 
1174 
int lshift, m, v;

1175  
1176 
lshift = e + qbits  24;

1177 
if (lshift >= 0) 
1178 
v = c << lshift; 
1179 
else

1180 
v = c >> (lshift); 
1181 
/* rounding */

1182 
v = (v + 1) >> 1; 
1183 
m = (1 << (qbits1)); 
1184 
if (v >= m)

1185 
v = m  1;

1186 
av_assert2(v >= m); 
1187 
return v & ((1 << qbits)1); 
1188 
} 
1189  
1190  
1191 
/**

1192 
* Quantize a set of mantissas for a single channel in a single block.

1193 
*/

1194 
static void quantize_mantissas_blk_ch(AC3Mant *s, int32_t *fixed_coef, 
1195 
uint8_t *exp, 
1196 
uint8_t *bap, uint16_t *qmant, int n)

1197 
{ 
1198 
int i;

1199  
1200 
for (i = 0; i < n; i++) { 
1201 
int v;

1202 
int c = fixed_coef[i];

1203 
int e = exp[i];

1204 
int b = bap[i];

1205 
switch (b) {

1206 
case 0: 
1207 
v = 0;

1208 
break;

1209 
case 1: 
1210 
v = sym_quant(c, e, 3);

1211 
switch (s>mant1_cnt) {

1212 
case 0: 
1213 
s>qmant1_ptr = &qmant[i]; 
1214 
v = 9 * v;

1215 
s>mant1_cnt = 1;

1216 
break;

1217 
case 1: 
1218 
*s>qmant1_ptr += 3 * v;

1219 
s>mant1_cnt = 2;

1220 
v = 128;

1221 
break;

1222 
default:

1223 
*s>qmant1_ptr += v; 
1224 
s>mant1_cnt = 0;

1225 
v = 128;

1226 
break;

1227 
} 
1228 
break;

1229 
case 2: 
1230 
v = sym_quant(c, e, 5);

1231 
switch (s>mant2_cnt) {

1232 
case 0: 
1233 
s>qmant2_ptr = &qmant[i]; 
1234 
v = 25 * v;

1235 
s>mant2_cnt = 1;

1236 
break;

1237 
case 1: 
1238 
*s>qmant2_ptr += 5 * v;

1239 
s>mant2_cnt = 2;

1240 
v = 128;

1241 
break;

1242 
default:

1243 
*s>qmant2_ptr += v; 
1244 
s>mant2_cnt = 0;

1245 
v = 128;

1246 
break;

1247 
} 
1248 
break;

1249 
case 3: 
1250 
v = sym_quant(c, e, 7);

1251 
break;

1252 
case 4: 
1253 
v = sym_quant(c, e, 11);

1254 
switch (s>mant4_cnt) {

1255 
case 0: 
1256 
s>qmant4_ptr = &qmant[i]; 
1257 
v = 11 * v;

1258 
s>mant4_cnt = 1;

1259 
break;

1260 
default:

1261 
*s>qmant4_ptr += v; 
1262 
s>mant4_cnt = 0;

1263 
v = 128;

1264 
break;

1265 
} 
1266 
break;

1267 
case 5: 
1268 
v = sym_quant(c, e, 15);

1269 
break;

1270 
case 14: 
1271 
v = asym_quant(c, e, 14);

1272 
break;

1273 
case 15: 
1274 
v = asym_quant(c, e, 16);

1275 
break;

1276 
default:

1277 
v = asym_quant(c, e, b  1);

1278 
break;

1279 
} 
1280 
qmant[i] = v; 
1281 
} 
1282 
} 
1283  
1284  
1285 
/**

1286 
* Quantize mantissas using coefficients, exponents, and bit allocation pointers.

1287 
*/

1288 
static void quantize_mantissas(AC3EncodeContext *s) 
1289 
{ 
1290 
int blk, ch;

1291  
1292  
1293 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { 
1294 
AC3Block *block = &s>blocks[blk]; 
1295 
AC3Block *ref_block; 
1296 
AC3Mant m = { 0 };

1297  
1298 
for (ch = 0; ch < s>channels; ch++) { 
1299 
ref_block = block>exp_ref_block[ch]; 
1300 
quantize_mantissas_blk_ch(&m, block>fixed_coef[ch], 
1301 
ref_block>exp[ch], ref_block>bap[ch], 
1302 
block>qmant[ch], s>nb_coefs[ch]); 
1303 
} 
1304 
} 
1305 
} 
1306  
1307  
1308 
/**

1309 
* Write the AC3 frame header to the output bitstream.

1310 
*/

1311 
static void output_frame_header(AC3EncodeContext *s) 
1312 
{ 
1313 
AC3EncOptions *opt = &s>options; 
1314  
1315 
put_bits(&s>pb, 16, 0x0b77); /* frame header */ 
1316 
put_bits(&s>pb, 16, 0); /* crc1: will be filled later */ 
1317 
put_bits(&s>pb, 2, s>bit_alloc.sr_code);

1318 
put_bits(&s>pb, 6, s>frame_size_code + (s>frame_size  s>frame_size_min) / 2); 
1319 
put_bits(&s>pb, 5, s>bitstream_id);

1320 
put_bits(&s>pb, 3, s>bitstream_mode);

1321 
put_bits(&s>pb, 3, s>channel_mode);

1322 
if ((s>channel_mode & 0x01) && s>channel_mode != AC3_CHMODE_MONO) 
1323 
put_bits(&s>pb, 2, s>center_mix_level);

1324 
if (s>channel_mode & 0x04) 
1325 
put_bits(&s>pb, 2, s>surround_mix_level);

1326 
if (s>channel_mode == AC3_CHMODE_STEREO)

1327 
put_bits(&s>pb, 2, opt>dolby_surround_mode);

1328 
put_bits(&s>pb, 1, s>lfe_on); /* LFE */ 
1329 
put_bits(&s>pb, 5, opt>dialogue_level);

1330 
put_bits(&s>pb, 1, 0); /* no compression control word */ 
1331 
put_bits(&s>pb, 1, 0); /* no lang code */ 
1332 
put_bits(&s>pb, 1, opt>audio_production_info);

1333 
if (opt>audio_production_info) {

1334 
put_bits(&s>pb, 5, opt>mixing_level  80); 
1335 
put_bits(&s>pb, 2, opt>room_type);

1336 
} 
1337 
put_bits(&s>pb, 1, opt>copyright);

1338 
put_bits(&s>pb, 1, opt>original);

1339 
if (s>bitstream_id == 6) { 
1340 
/* alternate bit stream syntax */

1341 
put_bits(&s>pb, 1, opt>extended_bsi_1);

1342 
if (opt>extended_bsi_1) {

1343 
put_bits(&s>pb, 2, opt>preferred_stereo_downmix);

1344 
put_bits(&s>pb, 3, s>ltrt_center_mix_level);

1345 
put_bits(&s>pb, 3, s>ltrt_surround_mix_level);

1346 
put_bits(&s>pb, 3, s>loro_center_mix_level);

1347 
put_bits(&s>pb, 3, s>loro_surround_mix_level);

1348 
} 
1349 
put_bits(&s>pb, 1, opt>extended_bsi_2);

1350 
if (opt>extended_bsi_2) {

1351 
put_bits(&s>pb, 2, opt>dolby_surround_ex_mode);

1352 
put_bits(&s>pb, 2, opt>dolby_headphone_mode);

1353 
put_bits(&s>pb, 1, opt>ad_converter_type);

1354 
put_bits(&s>pb, 9, 0); /* xbsi2 and encinfo : reserved */ 
1355 
} 
1356 
} else {

1357 
put_bits(&s>pb, 1, 0); /* no time code 1 */ 
1358 
put_bits(&s>pb, 1, 0); /* no time code 2 */ 
1359 
} 
1360 
put_bits(&s>pb, 1, 0); /* no additional bit stream info */ 
1361 
} 
1362  
1363  
1364 
/**

1365 
* Write one audio block to the output bitstream.

1366 
*/

1367 
static void output_audio_block(AC3EncodeContext *s, int blk) 
1368 
{ 
1369 
int ch, i, baie, rbnd;

1370 
AC3Block *block = &s>blocks[blk]; 
1371  
1372 
/* block switching */

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

1377 
for (ch = 0; ch < s>fbw_channels; ch++) 
1378 
put_bits(&s>pb, 1, 1); 
1379  
1380 
/* dynamic range codes */

1381 
put_bits(&s>pb, 1, 0); 
1382  
1383 
/* channel coupling */

1384 
if (!blk) {

1385 
put_bits(&s>pb, 1, 1); /* coupling strategy present */ 
1386 
put_bits(&s>pb, 1, 0); /* no coupling strategy */ 
1387 
} else {

1388 
put_bits(&s>pb, 1, 0); /* no new coupling strategy */ 
1389 
} 
1390  
1391 
/* stereo rematrixing */

1392 
if (s>channel_mode == AC3_CHMODE_STEREO) {

1393 
put_bits(&s>pb, 1, block>new_rematrixing_strategy);

1394 
if (block>new_rematrixing_strategy) {

1395 
/* rematrixing flags */

1396 
for (rbnd = 0; rbnd < s>num_rematrixing_bands; rbnd++) 
1397 
put_bits(&s>pb, 1, block>rematrixing_flags[rbnd]);

1398 
} 
1399 
} 
1400  
1401 
/* exponent strategy */

1402 
for (ch = 0; ch < s>fbw_channels; ch++) 
1403 
put_bits(&s>pb, 2, s>exp_strategy[ch][blk]);

1404 
if (s>lfe_on)

1405 
put_bits(&s>pb, 1, s>exp_strategy[s>lfe_channel][blk]);

1406  
1407 
/* bandwidth */

1408 
for (ch = 0; ch < s>fbw_channels; ch++) { 
1409 
if (s>exp_strategy[ch][blk] != EXP_REUSE)

1410 
put_bits(&s>pb, 6, s>bandwidth_code);

1411 
} 
1412  
1413 
/* exponents */

1414 
for (ch = 0; ch < s>channels; ch++) { 
1415 
int nb_groups;

1416  
1417 
if (s>exp_strategy[ch][blk] == EXP_REUSE)

1418 
continue;

1419  
1420 
/* DC exponent */

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

1424 
nb_groups = exponent_group_tab[s>exp_strategy[ch][blk]1][s>nb_coefs[ch]];

1425 
for (i = 1; i <= nb_groups; i++) 
1426 
put_bits(&s>pb, 7, block>grouped_exp[ch][i]);

1427  
1428 
/* gain range info */

1429 
if (ch != s>lfe_channel)

1430 
put_bits(&s>pb, 2, 0); 
1431 
} 
1432  
1433 
/* bit allocation info */

1434 
baie = (blk == 0);

1435 
put_bits(&s>pb, 1, baie);

1436 
if (baie) {

1437 
put_bits(&s>pb, 2, s>slow_decay_code);

1438 
put_bits(&s>pb, 2, s>fast_decay_code);

1439 
put_bits(&s>pb, 2, s>slow_gain_code);

1440 
put_bits(&s>pb, 2, s>db_per_bit_code);

1441 
put_bits(&s>pb, 3, s>floor_code);

1442 
} 
1443  
1444 
/* snr offset */

1445 
put_bits(&s>pb, 1, baie);

1446 
if (baie) {

1447 
put_bits(&s>pb, 6, s>coarse_snr_offset);

1448 
for (ch = 0; ch < s>channels; ch++) { 
1449 
put_bits(&s>pb, 4, s>fine_snr_offset[ch]);

1450 
put_bits(&s>pb, 3, s>fast_gain_code[ch]);

1451 
} 
1452 
} 
1453  
1454 
put_bits(&s>pb, 1, 0); /* no delta bit allocation */ 
1455 
put_bits(&s>pb, 1, 0); /* no data to skip */ 
1456  
1457 
/* mantissas */

1458 
for (ch = 0; ch < s>channels; ch++) { 
1459 
int b, q;

1460 
AC3Block *ref_block = block>exp_ref_block[ch]; 
1461 
for (i = 0; i < s>nb_coefs[ch]; i++) { 
1462 
q = block>qmant[ch][i]; 
1463 
b = ref_block>bap[ch][i]; 
1464 
switch (b) {

1465 
case 0: break; 
1466 
case 1: if (q != 128) put_bits(&s>pb, 5, q); break; 
1467 
case 2: if (q != 128) put_bits(&s>pb, 7, q); break; 
1468 
case 3: put_bits(&s>pb, 3, q); break; 
1469 
case 4: if (q != 128) put_bits(&s>pb, 7, q); break; 
1470 
case 14: put_bits(&s>pb, 14, q); break; 
1471 
case 15: put_bits(&s>pb, 16, q); break; 
1472 
default: put_bits(&s>pb, b1, q); break; 
1473 
} 
1474 
} 
1475 
} 
1476 
} 
1477  
1478  
1479 
/** CRC16 Polynomial */

1480 
#define CRC16_POLY ((1 << 0)  (1 << 2)  (1 << 15)  (1 << 16)) 
1481  
1482  
1483 
static unsigned int mul_poly(unsigned int a, unsigned int b, unsigned int poly) 
1484 
{ 
1485 
unsigned int c; 
1486  
1487 
c = 0;

1488 
while (a) {

1489 
if (a & 1) 
1490 
c ^= b; 
1491 
a = a >> 1;

1492 
b = b << 1;

1493 
if (b & (1 << 16)) 
1494 
b ^= poly; 
1495 
} 
1496 
return c;

1497 
} 
1498  
1499  
1500 
static unsigned int pow_poly(unsigned int a, unsigned int n, unsigned int poly) 
1501 
{ 
1502 
unsigned int r; 
1503 
r = 1;

1504 
while (n) {

1505 
if (n & 1) 
1506 
r = mul_poly(r, a, poly); 
1507 
a = mul_poly(a, a, poly); 
1508 
n >>= 1;

1509 
} 
1510 
return r;

1511 
} 
1512  
1513  
1514 
/**

1515 
* Fill the end of the frame with 0's and compute the two CRCs.

1516 
*/

1517 
static void output_frame_end(AC3EncodeContext *s) 
1518 
{ 
1519 
const AVCRC *crc_ctx = av_crc_get_table(AV_CRC_16_ANSI);

1520 
int frame_size_58, pad_bytes, crc1, crc2_partial, crc2, crc_inv;

1521 
uint8_t *frame; 
1522  
1523 
frame_size_58 = ((s>frame_size >> 2) + (s>frame_size >> 4)) << 1; 
1524  
1525 
/* pad the remainder of the frame with zeros */

1526 
av_assert2(s>frame_size * 8  put_bits_count(&s>pb) >= 18); 
1527 
flush_put_bits(&s>pb); 
1528 
frame = s>pb.buf; 
1529 
pad_bytes = s>frame_size  (put_bits_ptr(&s>pb)  frame)  2;

1530 
av_assert2(pad_bytes >= 0);

1531 
if (pad_bytes > 0) 
1532 
memset(put_bits_ptr(&s>pb), 0, pad_bytes);

1533  
1534 
/* compute crc1 */

1535 
/* this is not so easy because it is at the beginning of the data... */

1536 
crc1 = av_bswap16(av_crc(crc_ctx, 0, frame + 4, frame_size_58  4)); 
1537 
crc_inv = s>crc_inv[s>frame_size > s>frame_size_min]; 
1538 
crc1 = mul_poly(crc_inv, crc1, CRC16_POLY); 
1539 
AV_WB16(frame + 2, crc1);

1540  
1541 
/* compute crc2 */

1542 
crc2_partial = av_crc(crc_ctx, 0, frame + frame_size_58,

1543 
s>frame_size  frame_size_58  3);

1544 
crc2 = av_crc(crc_ctx, crc2_partial, frame + s>frame_size  3, 1); 
1545 
/* ensure crc2 does not match sync word by flipping crcrsv bit if needed */

1546 
if (crc2 == 0x770B) { 
1547 
frame[s>frame_size  3] ^= 0x1; 
1548 
crc2 = av_crc(crc_ctx, crc2_partial, frame + s>frame_size  3, 1); 
1549 
} 
1550 
crc2 = av_bswap16(crc2); 
1551 
AV_WB16(frame + s>frame_size  2, crc2);

1552 
} 
1553  
1554  
1555 
/**

1556 
* Write the frame to the output bitstream.

1557 
*/

1558 
static void output_frame(AC3EncodeContext *s, unsigned char *frame) 
1559 
{ 
1560 
int blk;

1561  
1562 
init_put_bits(&s>pb, frame, AC3_MAX_CODED_FRAME_SIZE); 
1563  
1564 
output_frame_header(s); 
1565  
1566 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) 
1567 
output_audio_block(s, blk); 
1568  
1569 
output_frame_end(s); 
1570 
} 
1571  
1572  
1573 
static void dprint_options(AVCodecContext *avctx) 
1574 
{ 
1575 
#ifdef DEBUG

1576 
AC3EncodeContext *s = avctx>priv_data; 
1577 
AC3EncOptions *opt = &s>options; 
1578 
char strbuf[32]; 
1579  
1580 
switch (s>bitstream_id) {

1581 
case 6: strncpy(strbuf, "AC3 (alt syntax)", 32); break; 
1582 
case 8: strncpy(strbuf, "AC3 (standard)", 32); break; 
1583 
case 9: strncpy(strbuf, "AC3 (dnet halfrate)", 32); break; 
1584 
case 10: strncpy(strbuf, "AC3 (dnet quaterrate", 32); break; 
1585 
default: snprintf(strbuf, 32, "ERROR"); 
1586 
} 
1587 
av_dlog(avctx, "bitstream_id: %s (%d)\n", strbuf, s>bitstream_id);

1588 
av_dlog(avctx, "sample_fmt: %s\n", av_get_sample_fmt_name(avctx>sample_fmt));

1589 
av_get_channel_layout_string(strbuf, 32, s>channels, avctx>channel_layout);

1590 
av_dlog(avctx, "channel_layout: %s\n", strbuf);

1591 
av_dlog(avctx, "sample_rate: %d\n", s>sample_rate);

1592 
av_dlog(avctx, "bit_rate: %d\n", s>bit_rate);

1593 
if (s>cutoff)

1594 
av_dlog(avctx, "cutoff: %d\n", s>cutoff);

1595  
1596 
av_dlog(avctx, "per_frame_metadata: %s\n",

1597 
opt>allow_per_frame_metadata?"on":"off"); 
1598 
if (s>has_center)

1599 
av_dlog(avctx, "center_mixlev: %0.3f (%d)\n", opt>center_mix_level,

1600 
s>center_mix_level); 
1601 
else

1602 
av_dlog(avctx, "center_mixlev: {not written}\n");

1603 
if (s>has_surround)

1604 
av_dlog(avctx, "surround_mixlev: %0.3f (%d)\n", opt>surround_mix_level,

1605 
s>surround_mix_level); 
1606 
else

1607 
av_dlog(avctx, "surround_mixlev: {not written}\n");

1608 
if (opt>audio_production_info) {

1609 
av_dlog(avctx, "mixing_level: %ddB\n", opt>mixing_level);

1610 
switch (opt>room_type) {

1611 
case 0: strncpy(strbuf, "notindicated", 32); break; 
1612 
case 1: strncpy(strbuf, "large", 32); break; 
1613 
case 2: strncpy(strbuf, "small", 32); break; 
1614 
default: snprintf(strbuf, 32, "ERROR (%d)", opt>room_type); 
1615 
} 
1616 
av_dlog(avctx, "room_type: %s\n", strbuf);

1617 
} else {

1618 
av_dlog(avctx, "mixing_level: {not written}\n");

1619 
av_dlog(avctx, "room_type: {not written}\n");

1620 
} 
1621 
av_dlog(avctx, "copyright: %s\n", opt>copyright?"on":"off"); 
1622 
av_dlog(avctx, "dialnorm: %ddB\n", opt>dialogue_level);

1623 
if (s>channel_mode == AC3_CHMODE_STEREO) {

1624 
switch (opt>dolby_surround_mode) {

1625 
case 0: strncpy(strbuf, "notindicated", 32); break; 
1626 
case 1: strncpy(strbuf, "on", 32); break; 
1627 
case 2: strncpy(strbuf, "off", 32); break; 
1628 
default: snprintf(strbuf, 32, "ERROR (%d)", opt>dolby_surround_mode); 
1629 
} 
1630 
av_dlog(avctx, "dsur_mode: %s\n", strbuf);

1631 
} else {

1632 
av_dlog(avctx, "dsur_mode: {not written}\n");

1633 
} 
1634 
av_dlog(avctx, "original: %s\n", opt>original?"on":"off"); 
1635  
1636 
if (s>bitstream_id == 6) { 
1637 
if (opt>extended_bsi_1) {

1638 
switch (opt>preferred_stereo_downmix) {

1639 
case 0: strncpy(strbuf, "notindicated", 32); break; 
1640 
case 1: strncpy(strbuf, "ltrt", 32); break; 
1641 
case 2: strncpy(strbuf, "loro", 32); break; 
1642 
default: snprintf(strbuf, 32, "ERROR (%d)", opt>preferred_stereo_downmix); 
1643 
} 
1644 
av_dlog(avctx, "dmix_mode: %s\n", strbuf);

1645 
av_dlog(avctx, "ltrt_cmixlev: %0.3f (%d)\n",

1646 
opt>ltrt_center_mix_level, s>ltrt_center_mix_level); 
1647 
av_dlog(avctx, "ltrt_surmixlev: %0.3f (%d)\n",

1648 
opt>ltrt_surround_mix_level, s>ltrt_surround_mix_level); 
1649 
av_dlog(avctx, "loro_cmixlev: %0.3f (%d)\n",

1650 
opt>loro_center_mix_level, s>loro_center_mix_level); 
1651 
av_dlog(avctx, "loro_surmixlev: %0.3f (%d)\n",

1652 
opt>loro_surround_mix_level, s>loro_surround_mix_level); 
1653 
} else {

1654 
av_dlog(avctx, "extended bitstream info 1: {not written}\n");

1655 
} 
1656 
if (opt>extended_bsi_2) {

1657 
switch (opt>dolby_surround_ex_mode) {

1658 
case 0: strncpy(strbuf, "notindicated", 32); break; 
1659 
case 1: strncpy(strbuf, "on", 32); break; 
1660 
case 2: strncpy(strbuf, "off", 32); break; 
1661 
default: snprintf(strbuf, 32, "ERROR (%d)", opt>dolby_surround_ex_mode); 
1662 
} 
1663 
av_dlog(avctx, "dsurex_mode: %s\n", strbuf);

1664 
switch (opt>dolby_headphone_mode) {

1665 
case 0: strncpy(strbuf, "notindicated", 32); break; 
1666 
case 1: strncpy(strbuf, "on", 32); break; 
1667 
case 2: strncpy(strbuf, "off", 32); break; 
1668 
default: snprintf(strbuf, 32, "ERROR (%d)", opt>dolby_headphone_mode); 
1669 
} 
1670 
av_dlog(avctx, "dheadphone_mode: %s\n", strbuf);

1671  
1672 
switch (opt>ad_converter_type) {

1673 
case 0: strncpy(strbuf, "standard", 32); break; 
1674 
case 1: strncpy(strbuf, "hdcd", 32); break; 
1675 
default: snprintf(strbuf, 32, "ERROR (%d)", opt>ad_converter_type); 
1676 
} 
1677 
av_dlog(avctx, "ad_conv_type: %s\n", strbuf);

1678 
} else {

1679 
av_dlog(avctx, "extended bitstream info 2: {not written}\n");

1680 
} 
1681 
} 
1682 
#endif

1683 
} 
1684  
1685  
1686 
#define FLT_OPTION_THRESHOLD 0.01 
1687  
1688 
static int validate_float_option(float v, const float *v_list, int v_list_size) 
1689 
{ 
1690 
int i;

1691  
1692 
for (i = 0; i < v_list_size; i++) { 
1693 
if (v < (v_list[i] + FLT_OPTION_THRESHOLD) &&

1694 
v > (v_list[i]  FLT_OPTION_THRESHOLD)) 
1695 
break;

1696 
} 
1697 
if (i == v_list_size)

1698 
return 1; 
1699  
1700 
return i;

1701 
} 
1702  
1703  
1704 
static void validate_mix_level(void *log_ctx, const char *opt_name, 
1705 
float *opt_param, const float *list, 
1706 
int list_size, int default_value, int min_value, 
1707 
int *ctx_param)

1708 
{ 
1709 
int mixlev = validate_float_option(*opt_param, list, list_size);

1710 
if (mixlev < min_value) {

1711 
mixlev = default_value; 
1712 
if (*opt_param >= 0.0) { 
1713 
av_log(log_ctx, AV_LOG_WARNING, "requested %s is not valid. using "

1714 
"default value: %0.3f\n", opt_name, list[mixlev]);

1715 
} 
1716 
} 
1717 
*opt_param = list[mixlev]; 
1718 
*ctx_param = mixlev; 
1719 
} 
1720  
1721  
1722 
/**

1723 
* Validate metadata options as set by AVOption system.

1724 
* These values can optionally be changed perframe.

1725 
*/

1726 
static int validate_metadata(AVCodecContext *avctx) 
1727 
{ 
1728 
AC3EncodeContext *s = avctx>priv_data; 
1729 
AC3EncOptions *opt = &s>options; 
1730  
1731 
/* validate mixing levels */

1732 
if (s>has_center) {

1733 
validate_mix_level(avctx, "center_mix_level", &opt>center_mix_level,

1734 
cmixlev_options, CMIXLEV_NUM_OPTIONS, 1, 0, 
1735 
&s>center_mix_level); 
1736 
} 
1737 
if (s>has_surround) {

1738 
validate_mix_level(avctx, "surround_mix_level", &opt>surround_mix_level,

1739 
surmixlev_options, SURMIXLEV_NUM_OPTIONS, 1, 0, 
1740 
&s>surround_mix_level); 
1741 
} 
1742  
1743 
/* set audio production info flag */

1744 
if (opt>mixing_level >= 0  opt>room_type >= 0) { 
1745 
if (opt>mixing_level < 0) { 
1746 
av_log(avctx, AV_LOG_ERROR, "mixing_level must be set if "

1747 
"room_type is set\n");

1748 
return AVERROR(EINVAL);

1749 
} 
1750 
if (opt>mixing_level < 80) { 
1751 
av_log(avctx, AV_LOG_ERROR, "invalid mixing level. must be between "

1752 
"80dB and 111dB\n");

1753 
return AVERROR(EINVAL);

1754 
} 
1755 
/* default room type */

1756 
if (opt>room_type < 0) 
1757 
opt>room_type = 0;

1758 
opt>audio_production_info = 1;

1759 
} else {

1760 
opt>audio_production_info = 0;

1761 
} 
1762  
1763 
/* set extended bsi 1 flag */

1764 
if ((s>has_center  s>has_surround) &&

1765 
(opt>preferred_stereo_downmix >= 0 

1766 
opt>ltrt_center_mix_level >= 0 

1767 
opt>ltrt_surround_mix_level >= 0 

1768 
opt>loro_center_mix_level >= 0 

1769 
opt>loro_surround_mix_level >= 0)) {

1770 
/* default preferred stereo downmix */

1771 
if (opt>preferred_stereo_downmix < 0) 
1772 
opt>preferred_stereo_downmix = 0;

1773 
/* validate Lt/Rt center mix level */

1774 
validate_mix_level(avctx, "ltrt_center_mix_level",

1775 
&opt>ltrt_center_mix_level, extmixlev_options, 
1776 
EXTMIXLEV_NUM_OPTIONS, 5, 0, 
1777 
&s>ltrt_center_mix_level); 
1778 
/* validate Lt/Rt surround mix level */

1779 
validate_mix_level(avctx, "ltrt_surround_mix_level",

1780 
&opt>ltrt_surround_mix_level, extmixlev_options, 
1781 
EXTMIXLEV_NUM_OPTIONS, 6, 3, 
1782 
&s>ltrt_surround_mix_level); 
1783 
/* validate Lo/Ro center mix level */

1784 
validate_mix_level(avctx, "loro_center_mix_level",

1785 
&opt>loro_center_mix_level, extmixlev_options, 
1786 
EXTMIXLEV_NUM_OPTIONS, 5, 0, 
1787 
&s>loro_center_mix_level); 
1788 
/* validate Lo/Ro surround mix level */

1789 
validate_mix_level(avctx, "loro_surround_mix_level",

1790 
&opt>loro_surround_mix_level, extmixlev_options, 
1791 
EXTMIXLEV_NUM_OPTIONS, 6, 3, 
1792 
&s>loro_surround_mix_level); 
1793 
opt>extended_bsi_1 = 1;

1794 
} else {

1795 
opt>extended_bsi_1 = 0;

1796 
} 
1797  
1798 
/* set extended bsi 2 flag */

1799 
if (opt>dolby_surround_ex_mode >= 0  
1800 
opt>dolby_headphone_mode >= 0 

1801 
opt>ad_converter_type >= 0) {

1802 
/* default dolby surround ex mode */

1803 
if (opt>dolby_surround_ex_mode < 0) 
1804 
opt>dolby_surround_ex_mode = 0;

1805 
/* default dolby headphone mode */

1806 
if (opt>dolby_headphone_mode < 0) 
1807 
opt>dolby_headphone_mode = 0;

1808 
/* default A/D converter type */

1809 
if (opt>ad_converter_type < 0) 
1810 
opt>ad_converter_type = 0;

1811 
opt>extended_bsi_2 = 1;

1812 
} else {

1813 
opt>extended_bsi_2 = 0;

1814 
} 
1815  
1816 
/* set bitstream id for alternate bitstream syntax */

1817 
if (opt>extended_bsi_1  opt>extended_bsi_2) {

1818 
if (s>bitstream_id > 8 && s>bitstream_id < 11) { 
1819 
static int warn_once = 1; 
1820 
if (warn_once) {

1821 
av_log(avctx, AV_LOG_WARNING, "alternate bitstream syntax is "

1822 
"not compatible with reduced samplerates. writing of "

1823 
"extended bitstream information will be disabled.\n");

1824 
warn_once = 0;

1825 
} 
1826 
} else {

1827 
s>bitstream_id = 6;

1828 
} 
1829 
} 
1830  
1831 
return 0; 
1832 
} 
1833  
1834  
1835 
/**

1836 
* Encode a single AC3 frame.

1837 
*/

1838 
static int ac3_encode_frame(AVCodecContext *avctx, unsigned char *frame, 
1839 
int buf_size, void *data) 
1840 
{ 
1841 
AC3EncodeContext *s = avctx>priv_data; 
1842 
const SampleType *samples = data;

1843 
int ret;

1844  
1845 
if (s>options.allow_per_frame_metadata) {

1846 
ret = validate_metadata(avctx); 
1847 
if (ret)

1848 
return ret;

1849 
} 
1850  
1851 
if (s>bit_alloc.sr_code == 1) 
1852 
adjust_frame_size(s); 
1853  
1854 
deinterleave_input_samples(s, samples); 
1855  
1856 
apply_mdct(s); 
1857  
1858 
scale_coefficients(s); 
1859  
1860 
compute_rematrixing_strategy(s); 
1861  
1862 
apply_rematrixing(s); 
1863  
1864 
process_exponents(s); 
1865  
1866 
ret = compute_bit_allocation(s); 
1867 
if (ret) {

1868 
av_log(avctx, AV_LOG_ERROR, "Bit allocation failed. Try increasing the bitrate.\n");

1869 
return ret;

1870 
} 
1871  
1872 
quantize_mantissas(s); 
1873  
1874 
output_frame(s, frame); 
1875  
1876 
return s>frame_size;

1877 
} 
1878  
1879  
1880 
/**

1881 
* Finalize encoding and free any memory allocated by the encoder.

1882 
*/

1883 
static av_cold int ac3_encode_close(AVCodecContext *avctx) 
1884 
{ 
1885 
int blk, ch;

1886 
AC3EncodeContext *s = avctx>priv_data; 
1887  
1888 
for (ch = 0; ch < s>channels; ch++) 
1889 
av_freep(&s>planar_samples[ch]); 
1890 
av_freep(&s>planar_samples); 
1891 
av_freep(&s>bap_buffer); 
1892 
av_freep(&s>bap1_buffer); 
1893 
av_freep(&s>mdct_coef_buffer); 
1894 
av_freep(&s>fixed_coef_buffer); 
1895 
av_freep(&s>exp_buffer); 
1896 
av_freep(&s>grouped_exp_buffer); 
1897 
av_freep(&s>psd_buffer); 
1898 
av_freep(&s>band_psd_buffer); 
1899 
av_freep(&s>mask_buffer); 
1900 
av_freep(&s>qmant_buffer); 
1901 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { 
1902 
AC3Block *block = &s>blocks[blk]; 
1903 
av_freep(&block>bap); 
1904 
av_freep(&block>mdct_coef); 
1905 
av_freep(&block>fixed_coef); 
1906 
av_freep(&block>exp); 
1907 
av_freep(&block>grouped_exp); 
1908 
av_freep(&block>psd); 
1909 
av_freep(&block>band_psd); 
1910 
av_freep(&block>mask); 
1911 
av_freep(&block>qmant); 
1912 
} 
1913  
1914 
mdct_end(&s>mdct); 
1915  
1916 
av_freep(&avctx>coded_frame); 
1917 
return 0; 
1918 
} 
1919  
1920  
1921 
/**

1922 
* Set channel information during initialization.

1923 
*/

1924 
static av_cold int set_channel_info(AC3EncodeContext *s, int channels, 
1925 
int64_t *channel_layout) 
1926 
{ 
1927 
int ch_layout;

1928  
1929 
if (channels < 1  channels > AC3_MAX_CHANNELS) 
1930 
return AVERROR(EINVAL);

1931 
if ((uint64_t)*channel_layout > 0x7FF) 
1932 
return AVERROR(EINVAL);

1933 
ch_layout = *channel_layout; 
1934 
if (!ch_layout)

1935 
ch_layout = avcodec_guess_channel_layout(channels, CODEC_ID_AC3, NULL);

1936  
1937 
s>lfe_on = !!(ch_layout & AV_CH_LOW_FREQUENCY); 
1938 
s>channels = channels; 
1939 
s>fbw_channels = channels  s>lfe_on; 
1940 
s>lfe_channel = s>lfe_on ? s>fbw_channels : 1;

1941 
if (s>lfe_on)

1942 
ch_layout = AV_CH_LOW_FREQUENCY; 
1943  
1944 
switch (ch_layout) {

1945 
case AV_CH_LAYOUT_MONO: s>channel_mode = AC3_CHMODE_MONO; break; 
1946 
case AV_CH_LAYOUT_STEREO: s>channel_mode = AC3_CHMODE_STEREO; break; 
1947 
case AV_CH_LAYOUT_SURROUND: s>channel_mode = AC3_CHMODE_3F; break; 
1948 
case AV_CH_LAYOUT_2_1: s>channel_mode = AC3_CHMODE_2F1R; break; 
1949 
case AV_CH_LAYOUT_4POINT0: s>channel_mode = AC3_CHMODE_3F1R; break; 
1950 
case AV_CH_LAYOUT_QUAD:

1951 
case AV_CH_LAYOUT_2_2: s>channel_mode = AC3_CHMODE_2F2R; break; 
1952 
case AV_CH_LAYOUT_5POINT0:

1953 
case AV_CH_LAYOUT_5POINT0_BACK: s>channel_mode = AC3_CHMODE_3F2R; break; 
1954 
default:

1955 
return AVERROR(EINVAL);

1956 
} 
1957 
s>has_center = (s>channel_mode & 0x01) && s>channel_mode != AC3_CHMODE_MONO;

1958 
s>has_surround = s>channel_mode & 0x04;

1959  
1960 
s>channel_map = ff_ac3_enc_channel_map[s>channel_mode][s>lfe_on]; 
1961 
*channel_layout = ch_layout; 
1962 
if (s>lfe_on)

1963 
*channel_layout = AV_CH_LOW_FREQUENCY; 
1964  
1965 
return 0; 
1966 
} 
1967  
1968  
1969 
static av_cold int validate_options(AVCodecContext *avctx, AC3EncodeContext *s) 
1970 
{ 
1971 
int i, ret;

1972  
1973 
/* validate channel layout */

1974 
if (!avctx>channel_layout) {

1975 
av_log(avctx, AV_LOG_WARNING, "No channel layout specified. The "

1976 
"encoder will guess the layout, but it "

1977 
"might be incorrect.\n");

1978 
} 
1979 
ret = set_channel_info(s, avctx>channels, &avctx>channel_layout); 
1980 
if (ret) {

1981 
av_log(avctx, AV_LOG_ERROR, "invalid channel layout\n");

1982 
return ret;

1983 
} 
1984  
1985 
/* validate sample rate */

1986 
for (i = 0; i < 9; i++) { 
1987 
if ((ff_ac3_sample_rate_tab[i / 3] >> (i % 3)) == avctx>sample_rate) 
1988 
break;

1989 
} 
1990 
if (i == 9) { 
1991 
av_log(avctx, AV_LOG_ERROR, "invalid sample rate\n");

1992 
return AVERROR(EINVAL);

1993 
} 
1994 
s>sample_rate = avctx>sample_rate; 
1995 
s>bit_alloc.sr_shift = i % 3;

1996 
s>bit_alloc.sr_code = i / 3;

1997 
s>bitstream_id = 8 + s>bit_alloc.sr_shift;

1998  
1999 
/* validate bit rate */

2000 
for (i = 0; i < 19; i++) { 
2001 
if ((ff_ac3_bitrate_tab[i] >> s>bit_alloc.sr_shift)*1000 == avctx>bit_rate) 
2002 
break;

2003 
} 
2004 
if (i == 19) { 
2005 
av_log(avctx, AV_LOG_ERROR, "invalid bit rate\n");

2006 
return AVERROR(EINVAL);

2007 
} 
2008 
s>bit_rate = avctx>bit_rate; 
2009 
s>frame_size_code = i << 1;

2010  
2011 
/* validate cutoff */

2012 
if (avctx>cutoff < 0) { 
2013 
av_log(avctx, AV_LOG_ERROR, "invalid cutoff frequency\n");

2014 
return AVERROR(EINVAL);

2015 
} 
2016 
s>cutoff = avctx>cutoff; 
2017 
if (s>cutoff > (s>sample_rate >> 1)) 
2018 
s>cutoff = s>sample_rate >> 1;

2019  
2020 
/* validate audio service type / channels combination */

2021 
if ((avctx>audio_service_type == AV_AUDIO_SERVICE_TYPE_KARAOKE &&

2022 
avctx>channels == 1) 

2023 
((avctx>audio_service_type == AV_AUDIO_SERVICE_TYPE_COMMENTARY  
2024 
avctx>audio_service_type == AV_AUDIO_SERVICE_TYPE_EMERGENCY  
2025 
avctx>audio_service_type == AV_AUDIO_SERVICE_TYPE_VOICE_OVER) 
2026 
&& avctx>channels > 1)) {

2027 
av_log(avctx, AV_LOG_ERROR, "invalid audio service type for the "

2028 
"specified number of channels\n");

2029 
return AVERROR(EINVAL);

2030 
} 
2031  
2032 
ret = validate_metadata(avctx); 
2033 
if (ret)

2034 
return ret;

2035  
2036 
s>rematrixing_enabled = s>options.stereo_rematrixing && 
2037 
(s>channel_mode == AC3_CHMODE_STEREO); 
2038  
2039 
return 0; 
2040 
} 
2041  
2042  
2043 
/**

2044 
* Set bandwidth for all channels.

2045 
* The user can optionally supply a cutoff frequency. Otherwise an appropriate

2046 
* default value will be used.

2047 
*/

2048 
static av_cold void set_bandwidth(AC3EncodeContext *s) 
2049 
{ 
2050 
int ch;

2051  
2052 
if (s>cutoff) {

2053 
/* calculate bandwidth based on userspecified cutoff frequency */

2054 
int fbw_coeffs;

2055 
fbw_coeffs = s>cutoff * 2 * AC3_MAX_COEFS / s>sample_rate;

2056 
s>bandwidth_code = av_clip((fbw_coeffs  73) / 3, 0, 60); 
2057 
} else {

2058 
/* use default bandwidth setting */

2059 
s>bandwidth_code = ac3_bandwidth_tab[s>fbw_channels1][s>bit_alloc.sr_code][s>frame_size_code/2]; 
2060 
} 
2061  
2062 
/* set number of coefficients for each channel */

2063 
for (ch = 0; ch < s>fbw_channels; ch++) { 
2064 
s>nb_coefs[ch] = s>bandwidth_code * 3 + 73; 
2065 
} 
2066 
if (s>lfe_on)

2067 
s>nb_coefs[s>lfe_channel] = 7; /* LFE channel always has 7 coefs */ 
2068 
} 
2069  
2070  
2071 
static av_cold int allocate_buffers(AVCodecContext *avctx) 
2072 
{ 
2073 
int blk, ch;

2074 
AC3EncodeContext *s = avctx>priv_data; 
2075  
2076 
FF_ALLOC_OR_GOTO(avctx, s>planar_samples, s>channels * sizeof(*s>planar_samples),

2077 
alloc_fail); 
2078 
for (ch = 0; ch < s>channels; ch++) { 
2079 
FF_ALLOCZ_OR_GOTO(avctx, s>planar_samples[ch], 
2080 
(AC3_FRAME_SIZE+AC3_BLOCK_SIZE) * sizeof(**s>planar_samples),

2081 
alloc_fail); 
2082 
} 
2083 
FF_ALLOC_OR_GOTO(avctx, s>bap_buffer, AC3_MAX_BLOCKS * s>channels * 
2084 
AC3_MAX_COEFS * sizeof(*s>bap_buffer), alloc_fail);

2085 
FF_ALLOC_OR_GOTO(avctx, s>bap1_buffer, AC3_MAX_BLOCKS * s>channels * 
2086 
AC3_MAX_COEFS * sizeof(*s>bap1_buffer), alloc_fail);

2087 
FF_ALLOC_OR_GOTO(avctx, s>mdct_coef_buffer, AC3_MAX_BLOCKS * s>channels * 
2088 
AC3_MAX_COEFS * sizeof(*s>mdct_coef_buffer), alloc_fail);

2089 
FF_ALLOC_OR_GOTO(avctx, s>exp_buffer, AC3_MAX_BLOCKS * s>channels * 
2090 
AC3_MAX_COEFS * sizeof(*s>exp_buffer), alloc_fail);

2091 
FF_ALLOC_OR_GOTO(avctx, s>grouped_exp_buffer, AC3_MAX_BLOCKS * s>channels * 
2092 
128 * sizeof(*s>grouped_exp_buffer), alloc_fail); 
2093 
FF_ALLOC_OR_GOTO(avctx, s>psd_buffer, AC3_MAX_BLOCKS * s>channels * 
2094 
AC3_MAX_COEFS * sizeof(*s>psd_buffer), alloc_fail);

2095 
FF_ALLOC_OR_GOTO(avctx, s>band_psd_buffer, AC3_MAX_BLOCKS * s>channels * 
2096 
64 * sizeof(*s>band_psd_buffer), alloc_fail); 
2097 
FF_ALLOC_OR_GOTO(avctx, s>mask_buffer, AC3_MAX_BLOCKS * s>channels * 
2098 
64 * sizeof(*s>mask_buffer), alloc_fail); 
2099 
FF_ALLOC_OR_GOTO(avctx, s>qmant_buffer, AC3_MAX_BLOCKS * s>channels * 
2100 
AC3_MAX_COEFS * sizeof(*s>qmant_buffer), alloc_fail);

2101 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { 
2102 
AC3Block *block = &s>blocks[blk]; 
2103 
FF_ALLOC_OR_GOTO(avctx, block>bap, s>channels * sizeof(*block>bap),

2104 
alloc_fail); 
2105 
FF_ALLOCZ_OR_GOTO(avctx, block>mdct_coef, s>channels * sizeof(*block>mdct_coef),

2106 
alloc_fail); 
2107 
FF_ALLOCZ_OR_GOTO(avctx, block>exp, s>channels * sizeof(*block>exp),

2108 
alloc_fail); 
2109 
FF_ALLOCZ_OR_GOTO(avctx, block>grouped_exp, s>channels * sizeof(*block>grouped_exp),

2110 
alloc_fail); 
2111 
FF_ALLOCZ_OR_GOTO(avctx, block>psd, s>channels * sizeof(*block>psd),

2112 
alloc_fail); 
2113 
FF_ALLOCZ_OR_GOTO(avctx, block>band_psd, s>channels * sizeof(*block>band_psd),

2114 
alloc_fail); 
2115 
FF_ALLOCZ_OR_GOTO(avctx, block>mask, s>channels * sizeof(*block>mask),

2116 
alloc_fail); 
2117 
FF_ALLOCZ_OR_GOTO(avctx, block>qmant, s>channels * sizeof(*block>qmant),

2118 
alloc_fail); 
2119  
2120 
for (ch = 0; ch < s>channels; ch++) { 
2121 
/* arrangement: block, channel, coeff */

2122 
block>bap[ch] = &s>bap_buffer [AC3_MAX_COEFS * (blk * s>channels + ch)]; 
2123 
block>mdct_coef[ch] = &s>mdct_coef_buffer [AC3_MAX_COEFS * (blk * s>channels + ch)]; 
2124 
block>grouped_exp[ch] = &s>grouped_exp_buffer[128 * (blk * s>channels + ch)];

2125 
block>psd[ch] = &s>psd_buffer [AC3_MAX_COEFS * (blk * s>channels + ch)]; 
2126 
block>band_psd[ch] = &s>band_psd_buffer [64 * (blk * s>channels + ch)];

2127 
block>mask[ch] = &s>mask_buffer [64 * (blk * s>channels + ch)];

2128 
block>qmant[ch] = &s>qmant_buffer [AC3_MAX_COEFS * (blk * s>channels + ch)]; 
2129  
2130 
/* arrangement: channel, block, coeff */

2131 
block>exp[ch] = &s>exp_buffer [AC3_MAX_COEFS * (AC3_MAX_BLOCKS * ch + blk)]; 
2132 
} 
2133 
} 
2134  
2135 
if (CONFIG_AC3ENC_FLOAT) {

2136 
FF_ALLOC_OR_GOTO(avctx, s>fixed_coef_buffer, AC3_MAX_BLOCKS * s>channels * 
2137 
AC3_MAX_COEFS * sizeof(*s>fixed_coef_buffer), alloc_fail);

2138 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { 
2139 
AC3Block *block = &s>blocks[blk]; 
2140 
FF_ALLOCZ_OR_GOTO(avctx, block>fixed_coef, s>channels * 
2141 
sizeof(*block>fixed_coef), alloc_fail);

2142 
for (ch = 0; ch < s>channels; ch++) 
2143 
block>fixed_coef[ch] = &s>fixed_coef_buffer[AC3_MAX_COEFS * (blk * s>channels + ch)]; 
2144 
} 
2145 
} else {

2146 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { 
2147 
AC3Block *block = &s>blocks[blk]; 
2148 
FF_ALLOCZ_OR_GOTO(avctx, block>fixed_coef, s>channels * 
2149 
sizeof(*block>fixed_coef), alloc_fail);

2150 
for (ch = 0; ch < s>channels; ch++) 
2151 
block>fixed_coef[ch] = (int32_t *)block>mdct_coef[ch]; 
2152 
} 
2153 
} 
2154  
2155 
return 0; 
2156 
alloc_fail:

2157 
return AVERROR(ENOMEM);

2158 
} 
2159  
2160  
2161 
/**

2162 
* Initialize the encoder.

2163 
*/

2164 
static av_cold int ac3_encode_init(AVCodecContext *avctx) 
2165 
{ 
2166 
AC3EncodeContext *s = avctx>priv_data; 
2167 
int ret, frame_size_58;

2168  
2169 
avctx>frame_size = AC3_FRAME_SIZE; 
2170  
2171 
ff_ac3_common_init(); 
2172  
2173 
ret = validate_options(avctx, s); 
2174 
if (ret)

2175 
return ret;

2176  
2177 
s>bitstream_mode = avctx>audio_service_type; 
2178 
if (s>bitstream_mode == AV_AUDIO_SERVICE_TYPE_KARAOKE)

2179 
s>bitstream_mode = 0x7;

2180  
2181 
s>frame_size_min = 2 * ff_ac3_frame_size_tab[s>frame_size_code][s>bit_alloc.sr_code];

2182 
s>bits_written = 0;

2183 
s>samples_written = 0;

2184 
s>frame_size = s>frame_size_min; 
2185  
2186 
/* calculate crc_inv for both possible frame sizes */

2187 
frame_size_58 = (( s>frame_size >> 2) + ( s>frame_size >> 4)) << 1; 
2188 
s>crc_inv[0] = pow_poly((CRC16_POLY >> 1), (8 * frame_size_58)  16, CRC16_POLY); 
2189 
if (s>bit_alloc.sr_code == 1) { 
2190 
frame_size_58 = (((s>frame_size+2) >> 2) + ((s>frame_size+2) >> 4)) << 1; 
2191 
s>crc_inv[1] = pow_poly((CRC16_POLY >> 1), (8 * frame_size_58)  16, CRC16_POLY); 
2192 
} 
2193  
2194 
set_bandwidth(s); 
2195  
2196 
exponent_init(s); 
2197  
2198 
bit_alloc_init(s); 
2199  
2200 
ret = mdct_init(avctx, &s>mdct, 9);

2201 
if (ret)

2202 
goto init_fail;

2203  
2204 
ret = allocate_buffers(avctx); 
2205 
if (ret)

2206 
goto init_fail;

2207  
2208 
avctx>coded_frame= avcodec_alloc_frame(); 
2209  
2210 
dsputil_init(&s>dsp, avctx); 
2211 
ff_ac3dsp_init(&s>ac3dsp, avctx>flags & CODEC_FLAG_BITEXACT); 
2212  
2213 
dprint_options(avctx); 
2214  
2215 
return 0; 
2216 
init_fail:

2217 
ac3_encode_close(avctx); 
2218 
return ret;

2219 
} 