ffmpeg / libavcodec / ac3enc.c @ e05a3ac7
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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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/* stereo rematrixing algorithms */

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#define AC3_REMATRIXING_IS_STATIC 0x1 
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#define AC3_REMATRIXING_SUMS 0 
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#define AC3_REMATRIXING_NONE 1 
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#define AC3_REMATRIXING_ALWAYS 3 
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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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} 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[AC3_MAX_CHANNELS]; ///< bandwidth code (0 to 60) (chbwcod) 
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int nb_coefs[AC3_MAX_CHANNELS];

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int rematrixing; ///< determines how rematrixing strategy is calculated 
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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(16, 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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{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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}; 
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/**

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

364 
* This is only needed for 11025, 22050, and 44100 sample rates.

365 
*/

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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; 
371 
} 
372 
s>frame_size = s>frame_size_min + 
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2 * (s>bits_written * s>sample_rate < s>samples_written * s>bit_rate);

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s>bits_written += s>frame_size * 8;

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s>samples_written += AC3_FRAME_SIZE; 
376 
} 
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/**

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* Deinterleave input samples.

381 
* Channels are reordered from Libav's default order to AC3 order.

382 
*/

383 
static void deinterleave_input_samples(AC3EncodeContext *s, 
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const SampleType *samples)

385 
{ 
386 
int ch, i;

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/* deinterleave and remap input samples */

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

391 
int sinc;

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

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

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

398 
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++) {

401 
s>planar_samples[ch][i] = *sptr; 
402 
sptr += sinc; 
403 
} 
404 
} 
405 
} 
406  
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/**

409 
* Apply the MDCT to input samples to generate frequency coefficients.

410 
* This applies the KBD window and normalizes the input to reduce precision

411 
* loss due to fixedpoint calculations.

412 
*/

413 
static void apply_mdct(AC3EncodeContext *s) 
414 
{ 
415 
int blk, ch;

416  
417 
for (ch = 0; ch < s>channels; ch++) { 
418 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { 
419 
AC3Block *block = &s>blocks[blk]; 
420 
const SampleType *input_samples = &s>planar_samples[ch][blk * AC3_BLOCK_SIZE];

421  
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apply_window(&s>dsp, s>windowed_samples, input_samples, s>mdct.window, AC3_WINDOW_SIZE); 
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block>coeff_shift[ch] = normalize_samples(s); 
425  
426 
s>mdct.fft.mdct_calcw(&s>mdct.fft, block>mdct_coef[ch], 
427 
s>windowed_samples); 
428 
} 
429 
} 
430 
} 
431  
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/**

434 
* Initialize stereo rematrixing.

435 
* If the strategy does not change for each frame, set the rematrixing flags.

436 
*/

437 
static void rematrixing_init(AC3EncodeContext *s) 
438 
{ 
439 
if (s>channel_mode == AC3_CHMODE_STEREO)

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s>rematrixing = AC3_REMATRIXING_SUMS; 
441 
else

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s>rematrixing = AC3_REMATRIXING_NONE; 
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/* NOTE: AC3_REMATRIXING_ALWAYS might be used in

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the future in conjunction with channel coupling. */

445  
446 
if (s>rematrixing & AC3_REMATRIXING_IS_STATIC) {

447 
int flag = (s>rematrixing == AC3_REMATRIXING_ALWAYS);

448 
s>blocks[0].new_rematrixing_strategy = 1; 
449 
memset(s>blocks[0].rematrixing_flags, flag,

450 
sizeof(s>blocks[0].rematrixing_flags)); 
451 
} 
452 
} 
453  
454  
455 
/**

456 
* Determine rematrixing flags for each block and band.

457 
*/

458 
static void compute_rematrixing_strategy(AC3EncodeContext *s) 
459 
{ 
460 
int nb_coefs;

461 
int blk, bnd, i;

462 
AC3Block *block, *block0; 
463  
464 
s>num_rematrixing_bands = 4;

465  
466 
if (s>rematrixing & AC3_REMATRIXING_IS_STATIC)

467 
return;

468  
469 
nb_coefs = FFMIN(s>nb_coefs[0], s>nb_coefs[1]); 
470  
471 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { 
472 
block = &s>blocks[blk]; 
473 
block>new_rematrixing_strategy = !blk; 
474 
for (bnd = 0; bnd < s>num_rematrixing_bands; bnd++) { 
475 
/* calculate calculate sum of squared coeffs for one band in one block */

476 
int start = ff_ac3_rematrix_band_tab[bnd];

477 
int end = FFMIN(nb_coefs, ff_ac3_rematrix_band_tab[bnd+1]); 
478 
CoefSumType sum[4] = {0,}; 
479 
for (i = start; i < end; i++) {

480 
CoefType lt = block>mdct_coef[0][i];

481 
CoefType rt = block>mdct_coef[1][i];

482 
CoefType md = lt + rt; 
483 
CoefType sd = lt  rt; 
484 
MAC_COEF(sum[0], lt, lt);

485 
MAC_COEF(sum[1], rt, rt);

486 
MAC_COEF(sum[2], md, md);

487 
MAC_COEF(sum[3], sd, sd);

488 
} 
489  
490 
/* compare sums to determine if rematrixing will be used for this band */

491 
if (FFMIN(sum[2], sum[3]) < FFMIN(sum[0], sum[1])) 
492 
block>rematrixing_flags[bnd] = 1;

493 
else

494 
block>rematrixing_flags[bnd] = 0;

495  
496 
/* determine if new rematrixing flags will be sent */

497 
if (blk &&

498 
block>rematrixing_flags[bnd] != block0>rematrixing_flags[bnd]) { 
499 
block>new_rematrixing_strategy = 1;

500 
} 
501 
} 
502 
block0 = block; 
503 
} 
504 
} 
505  
506  
507 
/**

508 
* Apply stereo rematrixing to coefficients based on rematrixing flags.

509 
*/

510 
static void apply_rematrixing(AC3EncodeContext *s) 
511 
{ 
512 
int nb_coefs;

513 
int blk, bnd, i;

514 
int start, end;

515 
uint8_t *flags; 
516  
517 
if (s>rematrixing == AC3_REMATRIXING_NONE)

518 
return;

519  
520 
nb_coefs = FFMIN(s>nb_coefs[0], s>nb_coefs[1]); 
521  
522 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { 
523 
AC3Block *block = &s>blocks[blk]; 
524 
if (block>new_rematrixing_strategy)

525 
flags = block>rematrixing_flags; 
526 
for (bnd = 0; bnd < s>num_rematrixing_bands; bnd++) { 
527 
if (flags[bnd]) {

528 
start = ff_ac3_rematrix_band_tab[bnd]; 
529 
end = FFMIN(nb_coefs, ff_ac3_rematrix_band_tab[bnd+1]);

530 
for (i = start; i < end; i++) {

531 
int32_t lt = block>fixed_coef[0][i];

532 
int32_t rt = block>fixed_coef[1][i];

533 
block>fixed_coef[0][i] = (lt + rt) >> 1; 
534 
block>fixed_coef[1][i] = (lt  rt) >> 1; 
535 
} 
536 
} 
537 
} 
538 
} 
539 
} 
540  
541  
542 
/**

543 
* Initialize exponent tables.

544 
*/

545 
static av_cold void exponent_init(AC3EncodeContext *s) 
546 
{ 
547 
int i;

548 
for (i = 73; i < 256; i++) { 
549 
exponent_group_tab[0][i] = (i  1) / 3; 
550 
exponent_group_tab[1][i] = (i + 2) / 6; 
551 
exponent_group_tab[2][i] = (i + 8) / 12; 
552 
} 
553 
/* LFE */

554 
exponent_group_tab[0][7] = 2; 
555 
} 
556  
557  
558 
/**

559 
* Extract exponents from the MDCT coefficients.

560 
* This takes into account the normalization that was done to the input samples

561 
* by adjusting the exponents by the exponent shift values.

562 
*/

563 
static void extract_exponents(AC3EncodeContext *s) 
564 
{ 
565 
int blk, ch, i;

566  
567 
for (ch = 0; ch < s>channels; ch++) { 
568 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { 
569 
AC3Block *block = &s>blocks[blk]; 
570 
uint8_t *exp = block>exp[ch]; 
571 
int32_t *coef = block>fixed_coef[ch]; 
572 
for (i = 0; i < AC3_MAX_COEFS; i++) { 
573 
int e;

574 
int v = abs(coef[i]);

575 
if (v == 0) 
576 
e = 24;

577 
else {

578 
e = 23  av_log2(v);

579 
if (e >= 24) { 
580 
e = 24;

581 
coef[i] = 0;

582 
} 
583 
av_assert2(e >= 0);

584 
} 
585 
exp[i] = e; 
586 
} 
587 
} 
588 
} 
589 
} 
590  
591  
592 
/**

593 
* Exponent Difference Threshold.

594 
* New exponents are sent if their SAD exceed this number.

595 
*/

596 
#define EXP_DIFF_THRESHOLD 500 
597  
598  
599 
/**

600 
* Calculate exponent strategies for all blocks in a single channel.

601 
*/

602 
static void compute_exp_strategy_ch(AC3EncodeContext *s, uint8_t *exp_strategy, 
603 
uint8_t *exp) 
604 
{ 
605 
int blk, blk1;

606 
int exp_diff;

607  
608 
/* estimate if the exponent variation & decide if they should be

609 
reused in the next frame */

610 
exp_strategy[0] = EXP_NEW;

611 
exp += AC3_MAX_COEFS; 
612 
for (blk = 1; blk < AC3_MAX_BLOCKS; blk++) { 
613 
exp_diff = s>dsp.sad[0](NULL, exp, exp  AC3_MAX_COEFS, 16, 16); 
614 
if (exp_diff > EXP_DIFF_THRESHOLD)

615 
exp_strategy[blk] = EXP_NEW; 
616 
else

617 
exp_strategy[blk] = EXP_REUSE; 
618 
exp += AC3_MAX_COEFS; 
619 
} 
620  
621 
/* now select the encoding strategy type : if exponents are often

622 
recoded, we use a coarse encoding */

623 
blk = 0;

624 
while (blk < AC3_MAX_BLOCKS) {

625 
blk1 = blk + 1;

626 
while (blk1 < AC3_MAX_BLOCKS && exp_strategy[blk1] == EXP_REUSE)

627 
blk1++; 
628 
switch (blk1  blk) {

629 
case 1: exp_strategy[blk] = EXP_D45; break; 
630 
case 2: 
631 
case 3: exp_strategy[blk] = EXP_D25; break; 
632 
default: exp_strategy[blk] = EXP_D15; break; 
633 
} 
634 
blk = blk1; 
635 
} 
636 
} 
637  
638  
639 
/**

640 
* Calculate exponent strategies for all channels.

641 
* Array arrangement is reversed to simplify the perchannel calculation.

642 
*/

643 
static void compute_exp_strategy(AC3EncodeContext *s) 
644 
{ 
645 
int ch, blk;

646  
647 
for (ch = 0; ch < s>fbw_channels; ch++) { 
648 
compute_exp_strategy_ch(s, s>exp_strategy[ch], s>blocks[0].exp[ch]);

649 
} 
650 
if (s>lfe_on) {

651 
ch = s>lfe_channel; 
652 
s>exp_strategy[ch][0] = EXP_D15;

653 
for (blk = 1; blk < AC3_MAX_BLOCKS; blk++) 
654 
s>exp_strategy[ch][blk] = EXP_REUSE; 
655 
} 
656 
} 
657  
658  
659 
/**

660 
* Update the exponents so that they are the ones the decoder will decode.

661 
*/

662 
static void encode_exponents_blk_ch(uint8_t *exp, int nb_exps, int exp_strategy) 
663 
{ 
664 
int nb_groups, i, k;

665  
666 
nb_groups = exponent_group_tab[exp_strategy1][nb_exps] * 3; 
667  
668 
/* for each group, compute the minimum exponent */

669 
switch(exp_strategy) {

670 
case EXP_D25:

671 
for (i = 1, k = 1; i <= nb_groups; i++) { 
672 
uint8_t exp_min = exp[k]; 
673 
if (exp[k+1] < exp_min) 
674 
exp_min = exp[k+1];

675 
exp[i] = exp_min; 
676 
k += 2;

677 
} 
678 
break;

679 
case EXP_D45:

680 
for (i = 1, k = 1; i <= nb_groups; i++) { 
681 
uint8_t exp_min = exp[k]; 
682 
if (exp[k+1] < exp_min) 
683 
exp_min = exp[k+1];

684 
if (exp[k+2] < exp_min) 
685 
exp_min = exp[k+2];

686 
if (exp[k+3] < exp_min) 
687 
exp_min = exp[k+3];

688 
exp[i] = exp_min; 
689 
k += 4;

690 
} 
691 
break;

692 
} 
693  
694 
/* constraint for DC exponent */

695 
if (exp[0] > 15) 
696 
exp[0] = 15; 
697  
698 
/* decrease the delta between each groups to within 2 so that they can be

699 
differentially encoded */

700 
for (i = 1; i <= nb_groups; i++) 
701 
exp[i] = FFMIN(exp[i], exp[i1] + 2); 
702 
i; 
703 
while (i >= 0) 
704 
exp[i] = FFMIN(exp[i], exp[i+1] + 2); 
705  
706 
/* now we have the exponent values the decoder will see */

707 
switch (exp_strategy) {

708 
case EXP_D25:

709 
for (i = nb_groups, k = nb_groups * 2; i > 0; i) { 
710 
uint8_t exp1 = exp[i]; 
711 
exp[k] = exp1; 
712 
exp[k] = exp1; 
713 
} 
714 
break;

715 
case EXP_D45:

716 
for (i = nb_groups, k = nb_groups * 4; i > 0; i) { 
717 
exp[k] = exp[k1] = exp[k2] = exp[k3] = exp[i]; 
718 
k = 4;

719 
} 
720 
break;

721 
} 
722 
} 
723  
724  
725 
/**

726 
* Encode exponents from original extracted form to what the decoder will see.

727 
* This copies and groups exponents based on exponent strategy and reduces

728 
* deltas between adjacent exponent groups so that they can be differentially

729 
* encoded.

730 
*/

731 
static void encode_exponents(AC3EncodeContext *s) 
732 
{ 
733 
int blk, blk1, ch;

734 
uint8_t *exp, *exp_strategy; 
735 
int nb_coefs, num_reuse_blocks;

736  
737 
for (ch = 0; ch < s>channels; ch++) { 
738 
exp = s>blocks[0].exp[ch];

739 
exp_strategy = s>exp_strategy[ch]; 
740 
nb_coefs = s>nb_coefs[ch]; 
741  
742 
blk = 0;

743 
while (blk < AC3_MAX_BLOCKS) {

744 
blk1 = blk + 1;

745  
746 
/* count the number of EXP_REUSE blocks after the current block

747 
and set exponent reference block pointers */

748 
s>blocks[blk].exp_ref_block[ch] = &s>blocks[blk]; 
749 
while (blk1 < AC3_MAX_BLOCKS && exp_strategy[blk1] == EXP_REUSE) {

750 
s>blocks[blk1].exp_ref_block[ch] = &s>blocks[blk]; 
751 
blk1++; 
752 
} 
753 
num_reuse_blocks = blk1  blk  1;

754  
755 
/* for the EXP_REUSE case we select the min of the exponents */

756 
s>ac3dsp.ac3_exponent_min(exp, num_reuse_blocks, nb_coefs); 
757  
758 
encode_exponents_blk_ch(exp, nb_coefs, exp_strategy[blk]); 
759  
760 
exp += AC3_MAX_COEFS * (num_reuse_blocks + 1);

761 
blk = blk1; 
762 
} 
763 
} 
764 
} 
765  
766  
767 
/**

768 
* Group exponents.

769 
* 3 deltaencoded exponents are in each 7bit group. The number of groups

770 
* varies depending on exponent strategy and bandwidth.

771 
*/

772 
static void group_exponents(AC3EncodeContext *s) 
773 
{ 
774 
int blk, ch, i;

775 
int group_size, nb_groups, bit_count;

776 
uint8_t *p; 
777 
int delta0, delta1, delta2;

778 
int exp0, exp1;

779  
780 
bit_count = 0;

781 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { 
782 
AC3Block *block = &s>blocks[blk]; 
783 
for (ch = 0; ch < s>channels; ch++) { 
784 
int exp_strategy = s>exp_strategy[ch][blk];

785 
if (exp_strategy == EXP_REUSE)

786 
continue;

787 
group_size = exp_strategy + (exp_strategy == EXP_D45); 
788 
nb_groups = exponent_group_tab[exp_strategy1][s>nb_coefs[ch]];

789 
bit_count += 4 + (nb_groups * 7); 
790 
p = block>exp[ch]; 
791  
792 
/* DC exponent */

793 
exp1 = *p++; 
794 
block>grouped_exp[ch][0] = exp1;

795  
796 
/* remaining exponents are delta encoded */

797 
for (i = 1; i <= nb_groups; i++) { 
798 
/* merge three delta in one code */

799 
exp0 = exp1; 
800 
exp1 = p[0];

801 
p += group_size; 
802 
delta0 = exp1  exp0 + 2;

803 
av_assert2(delta0 >= 0 && delta0 <= 4); 
804  
805 
exp0 = exp1; 
806 
exp1 = p[0];

807 
p += group_size; 
808 
delta1 = exp1  exp0 + 2;

809 
av_assert2(delta1 >= 0 && delta1 <= 4); 
810  
811 
exp0 = exp1; 
812 
exp1 = p[0];

813 
p += group_size; 
814 
delta2 = exp1  exp0 + 2;

815 
av_assert2(delta2 >= 0 && delta2 <= 4); 
816  
817 
block>grouped_exp[ch][i] = ((delta0 * 5 + delta1) * 5) + delta2; 
818 
} 
819 
} 
820 
} 
821  
822 
s>exponent_bits = bit_count; 
823 
} 
824  
825  
826 
/**

827 
* Calculate final exponents from the supplied MDCT coefficients and exponent shift.

828 
* Extract exponents from MDCT coefficients, calculate exponent strategies,

829 
* and encode final exponents.

830 
*/

831 
static void process_exponents(AC3EncodeContext *s) 
832 
{ 
833 
extract_exponents(s); 
834  
835 
compute_exp_strategy(s); 
836  
837 
encode_exponents(s); 
838  
839 
group_exponents(s); 
840  
841 
emms_c(); 
842 
} 
843  
844  
845 
/**

846 
* Count frame bits that are based solely on fixed parameters.

847 
* This only has to be run once when the encoder is initialized.

848 
*/

849 
static void count_frame_bits_fixed(AC3EncodeContext *s) 
850 
{ 
851 
static const int frame_bits_inc[8] = { 0, 0, 2, 2, 2, 4, 2, 4 }; 
852 
int blk;

853 
int frame_bits;

854  
855 
/* assumptions:

856 
* no dynamic range codes

857 
* no channel coupling

858 
* bit allocation parameters do not change between blocks

859 
* SNR offsets do not change between blocks

860 
* no delta bit allocation

861 
* no skipped data

862 
* no auxilliary data

863 
*/

864  
865 
/* header size */

866 
frame_bits = 65;

867 
frame_bits += frame_bits_inc[s>channel_mode]; 
868  
869 
/* audio blocks */

870 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { 
871 
frame_bits += s>fbw_channels * 2 + 2; /* blksw * c, dithflag * c, dynrnge, cplstre */ 
872 
if (s>channel_mode == AC3_CHMODE_STEREO) {

873 
frame_bits++; /* rematstr */

874 
} 
875 
frame_bits += 2 * s>fbw_channels; /* chexpstr[2] * c */ 
876 
if (s>lfe_on)

877 
frame_bits++; /* lfeexpstr */

878 
frame_bits++; /* baie */

879 
frame_bits++; /* snr */

880 
frame_bits += 2; /* delta / skip */ 
881 
} 
882 
frame_bits++; /* cplinu for block 0 */

883 
/* bit alloc info */

884 
/* sdcycod[2], fdcycod[2], sgaincod[2], dbpbcod[2], floorcod[3] */

885 
/* csnroffset[6] */

886 
/* (fsnoffset[4] + fgaincod[4]) * c */

887 
frame_bits += 2*4 + 3 + 6 + s>channels * (4 + 3); 
888  
889 
/* auxdatae, crcrsv */

890 
frame_bits += 2;

891  
892 
/* CRC */

893 
frame_bits += 16;

894  
895 
s>frame_bits_fixed = frame_bits; 
896 
} 
897  
898  
899 
/**

900 
* Initialize bit allocation.

901 
* Set default parameter codes and calculate parameter values.

902 
*/

903 
static void bit_alloc_init(AC3EncodeContext *s) 
904 
{ 
905 
int ch;

906  
907 
/* init default parameters */

908 
s>slow_decay_code = 2;

909 
s>fast_decay_code = 1;

910 
s>slow_gain_code = 1;

911 
s>db_per_bit_code = 3;

912 
s>floor_code = 7;

913 
for (ch = 0; ch < s>channels; ch++) 
914 
s>fast_gain_code[ch] = 4;

915  
916 
/* initial snr offset */

917 
s>coarse_snr_offset = 40;

918  
919 
/* compute real values */

920 
/* currently none of these values change during encoding, so we can just

921 
set them once at initialization */

922 
s>bit_alloc.slow_decay = ff_ac3_slow_decay_tab[s>slow_decay_code] >> s>bit_alloc.sr_shift; 
923 
s>bit_alloc.fast_decay = ff_ac3_fast_decay_tab[s>fast_decay_code] >> s>bit_alloc.sr_shift; 
924 
s>bit_alloc.slow_gain = ff_ac3_slow_gain_tab[s>slow_gain_code]; 
925 
s>bit_alloc.db_per_bit = ff_ac3_db_per_bit_tab[s>db_per_bit_code]; 
926 
s>bit_alloc.floor = ff_ac3_floor_tab[s>floor_code]; 
927  
928 
count_frame_bits_fixed(s); 
929 
} 
930  
931  
932 
/**

933 
* Count the bits used to encode the frame, minus exponents and mantissas.

934 
* Bits based on fixed parameters have already been counted, so now we just

935 
* have to add the bits based on parameters that change during encoding.

936 
*/

937 
static void count_frame_bits(AC3EncodeContext *s) 
938 
{ 
939 
AC3EncOptions *opt = &s>options; 
940 
int blk, ch;

941 
int frame_bits = 0; 
942  
943 
if (opt>audio_production_info)

944 
frame_bits += 7;

945 
if (s>bitstream_id == 6) { 
946 
if (opt>extended_bsi_1)

947 
frame_bits += 14;

948 
if (opt>extended_bsi_2)

949 
frame_bits += 14;

950 
} 
951  
952 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { 
953 
/* stereo rematrixing */

954 
if (s>channel_mode == AC3_CHMODE_STEREO &&

955 
s>blocks[blk].new_rematrixing_strategy) { 
956 
frame_bits += s>num_rematrixing_bands; 
957 
} 
958  
959 
for (ch = 0; ch < s>fbw_channels; ch++) { 
960 
if (s>exp_strategy[ch][blk] != EXP_REUSE)

961 
frame_bits += 6 + 2; /* chbwcod[6], gainrng[2] */ 
962 
} 
963 
} 
964 
s>frame_bits = s>frame_bits_fixed + frame_bits; 
965 
} 
966  
967  
968 
/**

969 
* Finalize the mantissa bit count by adding in the grouped mantissas.

970 
*/

971 
static int compute_mantissa_size_final(int mant_cnt[5]) 
972 
{ 
973 
// bap=1 : 3 mantissas in 5 bits

974 
int bits = (mant_cnt[1] / 3) * 5; 
975 
// bap=2 : 3 mantissas in 7 bits

976 
// bap=4 : 2 mantissas in 7 bits

977 
bits += ((mant_cnt[2] / 3) + (mant_cnt[4] >> 1)) * 7; 
978 
// bap=3 : each mantissa is 3 bits

979 
bits += mant_cnt[3] * 3; 
980 
return bits;

981 
} 
982  
983  
984 
/**

985 
* Calculate masking curve based on the final exponents.

986 
* Also calculate the power spectral densities to use in future calculations.

987 
*/

988 
static void bit_alloc_masking(AC3EncodeContext *s) 
989 
{ 
990 
int blk, ch;

991  
992 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { 
993 
AC3Block *block = &s>blocks[blk]; 
994 
for (ch = 0; ch < s>channels; ch++) { 
995 
/* We only need psd and mask for calculating bap.

996 
Since we currently do not calculate bap when exponent

997 
strategy is EXP_REUSE we do not need to calculate psd or mask. */

998 
if (s>exp_strategy[ch][blk] != EXP_REUSE) {

999 
ff_ac3_bit_alloc_calc_psd(block>exp[ch], 0,

1000 
s>nb_coefs[ch], 
1001 
block>psd[ch], block>band_psd[ch]); 
1002 
ff_ac3_bit_alloc_calc_mask(&s>bit_alloc, block>band_psd[ch], 
1003 
0, s>nb_coefs[ch],

1004 
ff_ac3_fast_gain_tab[s>fast_gain_code[ch]], 
1005 
ch == s>lfe_channel, 
1006 
DBA_NONE, 0, NULL, NULL, NULL, 
1007 
block>mask[ch]); 
1008 
} 
1009 
} 
1010 
} 
1011 
} 
1012  
1013  
1014 
/**

1015 
* Ensure that bap for each block and channel point to the current bap_buffer.

1016 
* They may have been switched during the bit allocation search.

1017 
*/

1018 
static void reset_block_bap(AC3EncodeContext *s) 
1019 
{ 
1020 
int blk, ch;

1021 
if (s>blocks[0].bap[0] == s>bap_buffer) 
1022 
return;

1023 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { 
1024 
for (ch = 0; ch < s>channels; ch++) { 
1025 
s>blocks[blk].bap[ch] = &s>bap_buffer[AC3_MAX_COEFS * (blk * s>channels + ch)]; 
1026 
} 
1027 
} 
1028 
} 
1029  
1030  
1031 
/**

1032 
* Run the bit allocation with a given SNR offset.

1033 
* This calculates the bit allocation pointers that will be used to determine

1034 
* the quantization of each mantissa.

1035 
* @return the number of bits needed for mantissas if the given SNR offset is

1036 
* is used.

1037 
*/

1038 
static int bit_alloc(AC3EncodeContext *s, int snr_offset) 
1039 
{ 
1040 
int blk, ch;

1041 
int mantissa_bits;

1042 
int mant_cnt[5]; 
1043  
1044 
snr_offset = (snr_offset  240) << 2; 
1045  
1046 
reset_block_bap(s); 
1047 
mantissa_bits = 0;

1048 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { 
1049 
AC3Block *block; 
1050 
// initialize grouped mantissa counts. these are set so that they are

1051 
// padded to the next whole group size when bits are counted in

1052 
// compute_mantissa_size_final

1053 
mant_cnt[0] = mant_cnt[3] = 0; 
1054 
mant_cnt[1] = mant_cnt[2] = 2; 
1055 
mant_cnt[4] = 1; 
1056 
for (ch = 0; ch < s>channels; ch++) { 
1057 
/* Currently the only bit allocation parameters which vary across

1058 
blocks within a frame are the exponent values. We can take

1059 
advantage of that by reusing the bit allocation pointers

1060 
whenever we reuse exponents. */

1061 
block = s>blocks[blk].exp_ref_block[ch]; 
1062 
if (s>exp_strategy[ch][blk] != EXP_REUSE) {

1063 
s>ac3dsp.bit_alloc_calc_bap(block>mask[ch], block>psd[ch], 0,

1064 
s>nb_coefs[ch], snr_offset, 
1065 
s>bit_alloc.floor, ff_ac3_bap_tab, 
1066 
block>bap[ch]); 
1067 
} 
1068 
mantissa_bits += s>ac3dsp.compute_mantissa_size(mant_cnt, block>bap[ch], s>nb_coefs[ch]); 
1069 
} 
1070 
mantissa_bits += compute_mantissa_size_final(mant_cnt); 
1071 
} 
1072 
return mantissa_bits;

1073 
} 
1074  
1075  
1076 
/**

1077 
* Constant bitrate bit allocation search.

1078 
* Find the largest SNR offset that will allow data to fit in the frame.

1079 
*/

1080 
static int cbr_bit_allocation(AC3EncodeContext *s) 
1081 
{ 
1082 
int ch;

1083 
int bits_left;

1084 
int snr_offset, snr_incr;

1085  
1086 
bits_left = 8 * s>frame_size  (s>frame_bits + s>exponent_bits);

1087 
av_assert2(bits_left >= 0);

1088  
1089 
snr_offset = s>coarse_snr_offset << 4;

1090  
1091 
/* if previous frame SNR offset was 1023, check if current frame can also

1092 
use SNR offset of 1023. if so, skip the search. */

1093 
if ((snr_offset  s>fine_snr_offset[0]) == 1023) { 
1094 
if (bit_alloc(s, 1023) <= bits_left) 
1095 
return 0; 
1096 
} 
1097  
1098 
while (snr_offset >= 0 && 
1099 
bit_alloc(s, snr_offset) > bits_left) { 
1100 
snr_offset = 64;

1101 
} 
1102 
if (snr_offset < 0) 
1103 
return AVERROR(EINVAL);

1104  
1105 
FFSWAP(uint8_t *, s>bap_buffer, s>bap1_buffer); 
1106 
for (snr_incr = 64; snr_incr > 0; snr_incr >>= 2) { 
1107 
while (snr_offset + snr_incr <= 1023 && 
1108 
bit_alloc(s, snr_offset + snr_incr) <= bits_left) { 
1109 
snr_offset += snr_incr; 
1110 
FFSWAP(uint8_t *, s>bap_buffer, s>bap1_buffer); 
1111 
} 
1112 
} 
1113 
FFSWAP(uint8_t *, s>bap_buffer, s>bap1_buffer); 
1114 
reset_block_bap(s); 
1115  
1116 
s>coarse_snr_offset = snr_offset >> 4;

1117 
for (ch = 0; ch < s>channels; ch++) 
1118 
s>fine_snr_offset[ch] = snr_offset & 0xF;

1119  
1120 
return 0; 
1121 
} 
1122  
1123  
1124 
/**

1125 
* Downgrade exponent strategies to reduce the bits used by the exponents.

1126 
* This is a fallback for when bit allocation fails with the normal exponent

1127 
* strategies. Each time this function is run it only downgrades the

1128 
* strategy in 1 channel of 1 block.

1129 
* @return nonzero if downgrade was unsuccessful

1130 
*/

1131 
static int downgrade_exponents(AC3EncodeContext *s) 
1132 
{ 
1133 
int ch, blk;

1134  
1135 
for (ch = 0; ch < s>fbw_channels; ch++) { 
1136 
for (blk = AC3_MAX_BLOCKS1; blk >= 0; blk) { 
1137 
if (s>exp_strategy[ch][blk] == EXP_D15) {

1138 
s>exp_strategy[ch][blk] = EXP_D25; 
1139 
return 0; 
1140 
} 
1141 
} 
1142 
} 
1143 
for (ch = 0; ch < s>fbw_channels; ch++) { 
1144 
for (blk = AC3_MAX_BLOCKS1; blk >= 0; blk) { 
1145 
if (s>exp_strategy[ch][blk] == EXP_D25) {

1146 
s>exp_strategy[ch][blk] = EXP_D45; 
1147 
return 0; 
1148 
} 
1149 
} 
1150 
} 
1151 
for (ch = 0; ch < s>fbw_channels; ch++) { 
1152 
/* block 0 cannot reuse exponents, so only downgrade D45 to REUSE if

1153 
the block number > 0 */

1154 
for (blk = AC3_MAX_BLOCKS1; blk > 0; blk) { 
1155 
if (s>exp_strategy[ch][blk] > EXP_REUSE) {

1156 
s>exp_strategy[ch][blk] = EXP_REUSE; 
1157 
return 0; 
1158 
} 
1159 
} 
1160 
} 
1161 
return 1; 
1162 
} 
1163  
1164  
1165 
/**

1166 
* Reduce the bandwidth to reduce the number of bits used for a given SNR offset.

1167 
* This is a second fallback for when bit allocation still fails after exponents

1168 
* have been downgraded.

1169 
* @return nonzero if bandwidth reduction was unsuccessful

1170 
*/

1171 
static int reduce_bandwidth(AC3EncodeContext *s, int min_bw_code) 
1172 
{ 
1173 
int ch;

1174  
1175 
if (s>bandwidth_code[0] > min_bw_code) { 
1176 
for (ch = 0; ch < s>fbw_channels; ch++) { 
1177 
s>bandwidth_code[ch]; 
1178 
s>nb_coefs[ch] = s>bandwidth_code[ch] * 3 + 73; 
1179 
} 
1180 
return 0; 
1181 
} 
1182 
return 1; 
1183 
} 
1184  
1185  
1186 
/**

1187 
* Perform bit allocation search.

1188 
* Finds the SNR offset value that maximizes quality and fits in the specified

1189 
* frame size. Output is the SNR offset and a set of bit allocation pointers

1190 
* used to quantize the mantissas.

1191 
*/

1192 
static int compute_bit_allocation(AC3EncodeContext *s) 
1193 
{ 
1194 
int ret;

1195  
1196 
count_frame_bits(s); 
1197  
1198 
bit_alloc_masking(s); 
1199  
1200 
ret = cbr_bit_allocation(s); 
1201 
while (ret) {

1202 
/* fallback 1: downgrade exponents */

1203 
if (!downgrade_exponents(s)) {

1204 
extract_exponents(s); 
1205 
encode_exponents(s); 
1206 
group_exponents(s); 
1207 
ret = compute_bit_allocation(s); 
1208 
continue;

1209 
} 
1210  
1211 
/* fallback 2: reduce bandwidth */

1212 
/* only do this if the user has not specified a specific cutoff

1213 
frequency */

1214 
if (!s>cutoff && !reduce_bandwidth(s, 0)) { 
1215 
process_exponents(s); 
1216 
ret = compute_bit_allocation(s); 
1217 
continue;

1218 
} 
1219  
1220 
/* fallbacks were not enough... */

1221 
break;

1222 
} 
1223  
1224 
return ret;

1225 
} 
1226  
1227  
1228 
/**

1229 
* Symmetric quantization on 'levels' levels.

1230 
*/

1231 
static inline int sym_quant(int c, int e, int levels) 
1232 
{ 
1233 
int v = (((levels * c) >> (24  e)) + levels) >> 1; 
1234 
av_assert2(v >= 0 && v < levels);

1235 
return v;

1236 
} 
1237  
1238  
1239 
/**

1240 
* Asymmetric quantization on 2^qbits levels.

1241 
*/

1242 
static inline int asym_quant(int c, int e, int qbits) 
1243 
{ 
1244 
int lshift, m, v;

1245  
1246 
lshift = e + qbits  24;

1247 
if (lshift >= 0) 
1248 
v = c << lshift; 
1249 
else

1250 
v = c >> (lshift); 
1251 
/* rounding */

1252 
v = (v + 1) >> 1; 
1253 
m = (1 << (qbits1)); 
1254 
if (v >= m)

1255 
v = m  1;

1256 
av_assert2(v >= m); 
1257 
return v & ((1 << qbits)1); 
1258 
} 
1259  
1260  
1261 
/**

1262 
* Quantize a set of mantissas for a single channel in a single block.

1263 
*/

1264 
static void quantize_mantissas_blk_ch(AC3Mant *s, int32_t *fixed_coef, 
1265 
uint8_t *exp, 
1266 
uint8_t *bap, uint16_t *qmant, int n)

1267 
{ 
1268 
int i;

1269  
1270 
for (i = 0; i < n; i++) { 
1271 
int v;

1272 
int c = fixed_coef[i];

1273 
int e = exp[i];

1274 
int b = bap[i];

1275 
switch (b) {

1276 
case 0: 
1277 
v = 0;

1278 
break;

1279 
case 1: 
1280 
v = sym_quant(c, e, 3);

1281 
switch (s>mant1_cnt) {

1282 
case 0: 
1283 
s>qmant1_ptr = &qmant[i]; 
1284 
v = 9 * v;

1285 
s>mant1_cnt = 1;

1286 
break;

1287 
case 1: 
1288 
*s>qmant1_ptr += 3 * v;

1289 
s>mant1_cnt = 2;

1290 
v = 128;

1291 
break;

1292 
default:

1293 
*s>qmant1_ptr += v; 
1294 
s>mant1_cnt = 0;

1295 
v = 128;

1296 
break;

1297 
} 
1298 
break;

1299 
case 2: 
1300 
v = sym_quant(c, e, 5);

1301 
switch (s>mant2_cnt) {

1302 
case 0: 
1303 
s>qmant2_ptr = &qmant[i]; 
1304 
v = 25 * v;

1305 
s>mant2_cnt = 1;

1306 
break;

1307 
case 1: 
1308 
*s>qmant2_ptr += 5 * v;

1309 
s>mant2_cnt = 2;

1310 
v = 128;

1311 
break;

1312 
default:

1313 
*s>qmant2_ptr += v; 
1314 
s>mant2_cnt = 0;

1315 
v = 128;

1316 
break;

1317 
} 
1318 
break;

1319 
case 3: 
1320 
v = sym_quant(c, e, 7);

1321 
break;

1322 
case 4: 
1323 
v = sym_quant(c, e, 11);

1324 
switch (s>mant4_cnt) {

1325 
case 0: 
1326 
s>qmant4_ptr = &qmant[i]; 
1327 
v = 11 * v;

1328 
s>mant4_cnt = 1;

1329 
break;

1330 
default:

1331 
*s>qmant4_ptr += v; 
1332 
s>mant4_cnt = 0;

1333 
v = 128;

1334 
break;

1335 
} 
1336 
break;

1337 
case 5: 
1338 
v = sym_quant(c, e, 15);

1339 
break;

1340 
case 14: 
1341 
v = asym_quant(c, e, 14);

1342 
break;

1343 
case 15: 
1344 
v = asym_quant(c, e, 16);

1345 
break;

1346 
default:

1347 
v = asym_quant(c, e, b  1);

1348 
break;

1349 
} 
1350 
qmant[i] = v; 
1351 
} 
1352 
} 
1353  
1354  
1355 
/**

1356 
* Quantize mantissas using coefficients, exponents, and bit allocation pointers.

1357 
*/

1358 
static void quantize_mantissas(AC3EncodeContext *s) 
1359 
{ 
1360 
int blk, ch;

1361  
1362  
1363 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { 
1364 
AC3Block *block = &s>blocks[blk]; 
1365 
AC3Block *ref_block; 
1366 
AC3Mant m = { 0 };

1367  
1368 
for (ch = 0; ch < s>channels; ch++) { 
1369 
ref_block = block>exp_ref_block[ch]; 
1370 
quantize_mantissas_blk_ch(&m, block>fixed_coef[ch], 
1371 
ref_block>exp[ch], ref_block>bap[ch], 
1372 
block>qmant[ch], s>nb_coefs[ch]); 
1373 
} 
1374 
} 
1375 
} 
1376  
1377  
1378 
/**

1379 
* Write the AC3 frame header to the output bitstream.

1380 
*/

1381 
static void output_frame_header(AC3EncodeContext *s) 
1382 
{ 
1383 
AC3EncOptions *opt = &s>options; 
1384  
1385 
put_bits(&s>pb, 16, 0x0b77); /* frame header */ 
1386 
put_bits(&s>pb, 16, 0); /* crc1: will be filled later */ 
1387 
put_bits(&s>pb, 2, s>bit_alloc.sr_code);

1388 
put_bits(&s>pb, 6, s>frame_size_code + (s>frame_size  s>frame_size_min) / 2); 
1389 
put_bits(&s>pb, 5, s>bitstream_id);

1390 
put_bits(&s>pb, 3, s>bitstream_mode);

1391 
put_bits(&s>pb, 3, s>channel_mode);

1392 
if ((s>channel_mode & 0x01) && s>channel_mode != AC3_CHMODE_MONO) 
1393 
put_bits(&s>pb, 2, s>center_mix_level);

1394 
if (s>channel_mode & 0x04) 
1395 
put_bits(&s>pb, 2, s>surround_mix_level);

1396 
if (s>channel_mode == AC3_CHMODE_STEREO)

1397 
put_bits(&s>pb, 2, opt>dolby_surround_mode);

1398 
put_bits(&s>pb, 1, s>lfe_on); /* LFE */ 
1399 
put_bits(&s>pb, 5, opt>dialogue_level);

1400 
put_bits(&s>pb, 1, 0); /* no compression control word */ 
1401 
put_bits(&s>pb, 1, 0); /* no lang code */ 
1402 
put_bits(&s>pb, 1, opt>audio_production_info);

1403 
if (opt>audio_production_info) {

1404 
put_bits(&s>pb, 5, opt>mixing_level  80); 
1405 
put_bits(&s>pb, 2, opt>room_type);

1406 
} 
1407 
put_bits(&s>pb, 1, opt>copyright);

1408 
put_bits(&s>pb, 1, opt>original);

1409 
if (s>bitstream_id == 6) { 
1410 
/* alternate bit stream syntax */

1411 
put_bits(&s>pb, 1, opt>extended_bsi_1);

1412 
if (opt>extended_bsi_1) {

1413 
put_bits(&s>pb, 2, opt>preferred_stereo_downmix);

1414 
put_bits(&s>pb, 3, s>ltrt_center_mix_level);

1415 
put_bits(&s>pb, 3, s>ltrt_surround_mix_level);

1416 
put_bits(&s>pb, 3, s>loro_center_mix_level);

1417 
put_bits(&s>pb, 3, s>loro_surround_mix_level);

1418 
} 
1419 
put_bits(&s>pb, 1, opt>extended_bsi_2);

1420 
if (opt>extended_bsi_2) {

1421 
put_bits(&s>pb, 2, opt>dolby_surround_ex_mode);

1422 
put_bits(&s>pb, 2, opt>dolby_headphone_mode);

1423 
put_bits(&s>pb, 1, opt>ad_converter_type);

1424 
put_bits(&s>pb, 9, 0); /* xbsi2 and encinfo : reserved */ 
1425 
} 
1426 
} else {

1427 
put_bits(&s>pb, 1, 0); /* no time code 1 */ 
1428 
put_bits(&s>pb, 1, 0); /* no time code 2 */ 
1429 
} 
1430 
put_bits(&s>pb, 1, 0); /* no additional bit stream info */ 
1431 
} 
1432  
1433  
1434 
/**

1435 
* Write one audio block to the output bitstream.

1436 
*/

1437 
static void output_audio_block(AC3EncodeContext *s, int blk) 
1438 
{ 
1439 
int ch, i, baie, rbnd;

1440 
AC3Block *block = &s>blocks[blk]; 
1441  
1442 
/* block switching */

1443 
for (ch = 0; ch < s>fbw_channels; ch++) 
1444 
put_bits(&s>pb, 1, 0); 
1445  
1446 
/* dither flags */

1447 
for (ch = 0; ch < s>fbw_channels; ch++) 
1448 
put_bits(&s>pb, 1, 1); 
1449  
1450 
/* dynamic range codes */

1451 
put_bits(&s>pb, 1, 0); 
1452  
1453 
/* channel coupling */

1454 
if (!blk) {

1455 
put_bits(&s>pb, 1, 1); /* coupling strategy present */ 
1456 
put_bits(&s>pb, 1, 0); /* no coupling strategy */ 
1457 
} else {

1458 
put_bits(&s>pb, 1, 0); /* no new coupling strategy */ 
1459 
} 
1460  
1461 
/* stereo rematrixing */

1462 
if (s>channel_mode == AC3_CHMODE_STEREO) {

1463 
put_bits(&s>pb, 1, block>new_rematrixing_strategy);

1464 
if (block>new_rematrixing_strategy) {

1465 
/* rematrixing flags */

1466 
for (rbnd = 0; rbnd < s>num_rematrixing_bands; rbnd++) 
1467 
put_bits(&s>pb, 1, block>rematrixing_flags[rbnd]);

1468 
} 
1469 
} 
1470  
1471 
/* exponent strategy */

1472 
for (ch = 0; ch < s>fbw_channels; ch++) 
1473 
put_bits(&s>pb, 2, s>exp_strategy[ch][blk]);

1474 
if (s>lfe_on)

1475 
put_bits(&s>pb, 1, s>exp_strategy[s>lfe_channel][blk]);

1476  
1477 
/* bandwidth */

1478 
for (ch = 0; ch < s>fbw_channels; ch++) { 
1479 
if (s>exp_strategy[ch][blk] != EXP_REUSE)

1480 
put_bits(&s>pb, 6, s>bandwidth_code[ch]);

1481 
} 
1482  
1483 
/* exponents */

1484 
for (ch = 0; ch < s>channels; ch++) { 
1485 
int nb_groups;

1486  
1487 
if (s>exp_strategy[ch][blk] == EXP_REUSE)

1488 
continue;

1489  
1490 
/* DC exponent */

1491 
put_bits(&s>pb, 4, block>grouped_exp[ch][0]); 
1492  
1493 
/* exponent groups */

1494 
nb_groups = exponent_group_tab[s>exp_strategy[ch][blk]1][s>nb_coefs[ch]];

1495 
for (i = 1; i <= nb_groups; i++) 
1496 
put_bits(&s>pb, 7, block>grouped_exp[ch][i]);

1497  
1498 
/* gain range info */

1499 
if (ch != s>lfe_channel)

1500 
put_bits(&s>pb, 2, 0); 
1501 
} 
1502  
1503 
/* bit allocation info */

1504 
baie = (blk == 0);

1505 
put_bits(&s>pb, 1, baie);

1506 
if (baie) {

1507 
put_bits(&s>pb, 2, s>slow_decay_code);

1508 
put_bits(&s>pb, 2, s>fast_decay_code);

1509 
put_bits(&s>pb, 2, s>slow_gain_code);

1510 
put_bits(&s>pb, 2, s>db_per_bit_code);

1511 
put_bits(&s>pb, 3, s>floor_code);

1512 
} 
1513  
1514 
/* snr offset */

1515 
put_bits(&s>pb, 1, baie);

1516 
if (baie) {

1517 
put_bits(&s>pb, 6, s>coarse_snr_offset);

1518 
for (ch = 0; ch < s>channels; ch++) { 
1519 
put_bits(&s>pb, 4, s>fine_snr_offset[ch]);

1520 
put_bits(&s>pb, 3, s>fast_gain_code[ch]);

1521 
} 
1522 
} 
1523  
1524 
put_bits(&s>pb, 1, 0); /* no delta bit allocation */ 
1525 
put_bits(&s>pb, 1, 0); /* no data to skip */ 
1526  
1527 
/* mantissas */

1528 
for (ch = 0; ch < s>channels; ch++) { 
1529 
int b, q;

1530 
AC3Block *ref_block = block>exp_ref_block[ch]; 
1531 
for (i = 0; i < s>nb_coefs[ch]; i++) { 
1532 
q = block>qmant[ch][i]; 
1533 
b = ref_block>bap[ch][i]; 
1534 
switch (b) {

1535 
case 0: break; 
1536 
case 1: if (q != 128) put_bits(&s>pb, 5, q); break; 
1537 
case 2: if (q != 128) put_bits(&s>pb, 7, q); break; 
1538 
case 3: put_bits(&s>pb, 3, q); break; 
1539 
case 4: if (q != 128) put_bits(&s>pb, 7, q); break; 
1540 
case 14: put_bits(&s>pb, 14, q); break; 
1541 
case 15: put_bits(&s>pb, 16, q); break; 
1542 
default: put_bits(&s>pb, b1, q); break; 
1543 
} 
1544 
} 
1545 
} 
1546 
} 
1547  
1548  
1549 
/** CRC16 Polynomial */

1550 
#define CRC16_POLY ((1 << 0)  (1 << 2)  (1 << 15)  (1 << 16)) 
1551  
1552  
1553 
static unsigned int mul_poly(unsigned int a, unsigned int b, unsigned int poly) 
1554 
{ 
1555 
unsigned int c; 
1556  
1557 
c = 0;

1558 
while (a) {

1559 
if (a & 1) 
1560 
c ^= b; 
1561 
a = a >> 1;

1562 
b = b << 1;

1563 
if (b & (1 << 16)) 
1564 
b ^= poly; 
1565 
} 
1566 
return c;

1567 
} 
1568  
1569  
1570 
static unsigned int pow_poly(unsigned int a, unsigned int n, unsigned int poly) 
1571 
{ 
1572 
unsigned int r; 
1573 
r = 1;

1574 
while (n) {

1575 
if (n & 1) 
1576 
r = mul_poly(r, a, poly); 
1577 
a = mul_poly(a, a, poly); 
1578 
n >>= 1;

1579 
} 
1580 
return r;

1581 
} 
1582  
1583  
1584 
/**

1585 
* Fill the end of the frame with 0's and compute the two CRCs.

1586 
*/

1587 
static void output_frame_end(AC3EncodeContext *s) 
1588 
{ 
1589 
const AVCRC *crc_ctx = av_crc_get_table(AV_CRC_16_ANSI);

1590 
int frame_size_58, pad_bytes, crc1, crc2_partial, crc2, crc_inv;

1591 
uint8_t *frame; 
1592  
1593 
frame_size_58 = ((s>frame_size >> 2) + (s>frame_size >> 4)) << 1; 
1594  
1595 
/* pad the remainder of the frame with zeros */

1596 
av_assert2(s>frame_size * 8  put_bits_count(&s>pb) >= 18); 
1597 
flush_put_bits(&s>pb); 
1598 
frame = s>pb.buf; 
1599 
pad_bytes = s>frame_size  (put_bits_ptr(&s>pb)  frame)  2;

1600 
av_assert2(pad_bytes >= 0);

1601 
if (pad_bytes > 0) 
1602 
memset(put_bits_ptr(&s>pb), 0, pad_bytes);

1603  
1604 
/* compute crc1 */

1605 
/* this is not so easy because it is at the beginning of the data... */

1606 
crc1 = av_bswap16(av_crc(crc_ctx, 0, frame + 4, frame_size_58  4)); 
1607 
crc_inv = s>crc_inv[s>frame_size > s>frame_size_min]; 
1608 
crc1 = mul_poly(crc_inv, crc1, CRC16_POLY); 
1609 
AV_WB16(frame + 2, crc1);

1610  
1611 
/* compute crc2 */

1612 
crc2_partial = av_crc(crc_ctx, 0, frame + frame_size_58,

1613 
s>frame_size  frame_size_58  3);

1614 
crc2 = av_crc(crc_ctx, crc2_partial, frame + s>frame_size  3, 1); 
1615 
/* ensure crc2 does not match sync word by flipping crcrsv bit if needed */

1616 
if (crc2 == 0x770B) { 
1617 
frame[s>frame_size  3] ^= 0x1; 
1618 
crc2 = av_crc(crc_ctx, crc2_partial, frame + s>frame_size  3, 1); 
1619 
} 
1620 
crc2 = av_bswap16(crc2); 
1621 
AV_WB16(frame + s>frame_size  2, crc2);

1622 
} 
1623  
1624  
1625 
/**

1626 
* Write the frame to the output bitstream.

1627 
*/

1628 
static void output_frame(AC3EncodeContext *s, unsigned char *frame) 
1629 
{ 
1630 
int blk;

1631  
1632 
init_put_bits(&s>pb, frame, AC3_MAX_CODED_FRAME_SIZE); 
1633  
1634 
output_frame_header(s); 
1635  
1636 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) 
1637 
output_audio_block(s, blk); 
1638  
1639 
output_frame_end(s); 
1640 
} 
1641  
1642  
1643 
static void dprint_options(AVCodecContext *avctx) 
1644 
{ 
1645 
#ifdef DEBUG

1646 
AC3EncodeContext *s = avctx>priv_data; 
1647 
AC3EncOptions *opt = &s>options; 
1648 
char strbuf[32]; 
1649  
1650 
switch (s>bitstream_id) {

1651 
case 6: strncpy(strbuf, "AC3 (alt syntax)", 32); break; 
1652 
case 8: strncpy(strbuf, "AC3 (standard)", 32); break; 
1653 
case 9: strncpy(strbuf, "AC3 (dnet halfrate)", 32); break; 
1654 
case 10: strncpy(strbuf, "AC3 (dnet quaterrate", 32); break; 
1655 
default: snprintf(strbuf, 32, "ERROR"); 
1656 
} 
1657 
av_dlog(avctx, "bitstream_id: %s (%d)\n", strbuf, s>bitstream_id);

1658 
av_dlog(avctx, "sample_fmt: %s\n", av_get_sample_fmt_name(avctx>sample_fmt));

1659 
av_get_channel_layout_string(strbuf, 32, s>channels, avctx>channel_layout);

1660 
av_dlog(avctx, "channel_layout: %s\n", strbuf);

1661 
av_dlog(avctx, "sample_rate: %d\n", s>sample_rate);

1662 
av_dlog(avctx, "bit_rate: %d\n", s>bit_rate);

1663 
if (s>cutoff)

1664 
av_dlog(avctx, "cutoff: %d\n", s>cutoff);

1665  
1666 
av_dlog(avctx, "per_frame_metadata: %s\n",

1667 
opt>allow_per_frame_metadata?"on":"off"); 
1668 
if (s>has_center)

1669 
av_dlog(avctx, "center_mixlev: %0.3f (%d)\n", opt>center_mix_level,

1670 
s>center_mix_level); 
1671 
else

1672 
av_dlog(avctx, "center_mixlev: {not written}\n");

1673 
if (s>has_surround)

1674 
av_dlog(avctx, "surround_mixlev: %0.3f (%d)\n", opt>surround_mix_level,

1675 
s>surround_mix_level); 
1676 
else

1677 
av_dlog(avctx, "surround_mixlev: {not written}\n");

1678 
if (opt>audio_production_info) {

1679 
av_dlog(avctx, "mixing_level: %ddB\n", opt>mixing_level);

1680 
switch (opt>room_type) {

1681 
case 0: strncpy(strbuf, "notindicated", 32); break; 
1682 
case 1: strncpy(strbuf, "large", 32); break; 
1683 
case 2: strncpy(strbuf, "small", 32); break; 
1684 
default: snprintf(strbuf, 32, "ERROR (%d)", opt>room_type); 
1685 
} 
1686 
av_dlog(avctx, "room_type: %s\n", strbuf);

1687 
} else {

1688 
av_dlog(avctx, "mixing_level: {not written}\n");

1689 
av_dlog(avctx, "room_type: {not written}\n");

1690 
} 
1691 
av_dlog(avctx, "copyright: %s\n", opt>copyright?"on":"off"); 
1692 
av_dlog(avctx, "dialnorm: %ddB\n", opt>dialogue_level);

1693 
if (s>channel_mode == AC3_CHMODE_STEREO) {

1694 
switch (opt>dolby_surround_mode) {

1695 
case 0: strncpy(strbuf, "notindicated", 32); break; 
1696 
case 1: strncpy(strbuf, "on", 32); break; 
1697 
case 2: strncpy(strbuf, "off", 32); break; 
1698 
default: snprintf(strbuf, 32, "ERROR (%d)", opt>dolby_surround_mode); 
1699 
} 
1700 
av_dlog(avctx, "dsur_mode: %s\n", strbuf);

1701 
} else {

1702 
av_dlog(avctx, "dsur_mode: {not written}\n");

1703 
} 
1704 
av_dlog(avctx, "original: %s\n", opt>original?"on":"off"); 
1705  
1706 
if (s>bitstream_id == 6) { 
1707 
if (opt>extended_bsi_1) {

1708 
switch (opt>preferred_stereo_downmix) {

1709 
case 0: strncpy(strbuf, "notindicated", 32); break; 
1710 
case 1: strncpy(strbuf, "ltrt", 32); break; 
1711 
case 2: strncpy(strbuf, "loro", 32); break; 
1712 
default: snprintf(strbuf, 32, "ERROR (%d)", opt>preferred_stereo_downmix); 
1713 
} 
1714 
av_dlog(avctx, "dmix_mode: %s\n", strbuf);

1715 
av_dlog(avctx, "ltrt_cmixlev: %0.3f (%d)\n",

1716 
opt>ltrt_center_mix_level, s>ltrt_center_mix_level); 
1717 
av_dlog(avctx, "ltrt_surmixlev: %0.3f (%d)\n",

1718 
opt>ltrt_surround_mix_level, s>ltrt_surround_mix_level); 
1719 
av_dlog(avctx, "loro_cmixlev: %0.3f (%d)\n",

1720 
opt>loro_center_mix_level, s>loro_center_mix_level); 
1721 
av_dlog(avctx, "loro_surmixlev: %0.3f (%d)\n",

1722 
opt>loro_surround_mix_level, s>loro_surround_mix_level); 
1723 
} else {

1724 
av_dlog(avctx, "extended bitstream info 1: {not written}\n");

1725 
} 
1726 
if (opt>extended_bsi_2) {

1727 
switch (opt>dolby_surround_ex_mode) {

1728 
case 0: strncpy(strbuf, "notindicated", 32); break; 
1729 
case 1: strncpy(strbuf, "on", 32); break; 
1730 
case 2: strncpy(strbuf, "off", 32); break; 
1731 
default: snprintf(strbuf, 32, "ERROR (%d)", opt>dolby_surround_ex_mode); 
1732 
} 
1733 
av_dlog(avctx, "dsurex_mode: %s\n", strbuf);

1734 
switch (opt>dolby_headphone_mode) {

1735 
case 0: strncpy(strbuf, "notindicated", 32); break; 
1736 
case 1: strncpy(strbuf, "on", 32); break; 
1737 
case 2: strncpy(strbuf, "off", 32); break; 
1738 
default: snprintf(strbuf, 32, "ERROR (%d)", opt>dolby_headphone_mode); 
1739 
} 
1740 
av_dlog(avctx, "dheadphone_mode: %s\n", strbuf);

1741  
1742 
switch (opt>ad_converter_type) {

1743 
case 0: strncpy(strbuf, "standard", 32); break; 
1744 
case 1: strncpy(strbuf, "hdcd", 32); break; 
1745 
default: snprintf(strbuf, 32, "ERROR (%d)", opt>ad_converter_type); 
1746 
} 
1747 
av_dlog(avctx, "ad_conv_type: %s\n", strbuf);

1748 
} else {

1749 
av_dlog(avctx, "extended bitstream info 2: {not written}\n");

1750 
} 
1751 
} 
1752 
#endif

1753 
} 
1754  
1755  
1756 
#define FLT_OPTION_THRESHOLD 0.01 
1757  
1758 
static int validate_float_option(float v, const float *v_list, int v_list_size) 
1759 
{ 
1760 
int i;

1761  
1762 
for (i = 0; i < v_list_size; i++) { 
1763 
if (v < (v_list[i] + FLT_OPTION_THRESHOLD) &&

1764 
v > (v_list[i]  FLT_OPTION_THRESHOLD)) 
1765 
break;

1766 
} 
1767 
if (i == v_list_size)

1768 
return 1; 
1769  
1770 
return i;

1771 
} 
1772  
1773  
1774 
static void validate_mix_level(void *log_ctx, const char *opt_name, 
1775 
float *opt_param, const float *list, 
1776 
int list_size, int default_value, int min_value, 
1777 
int *ctx_param)

1778 
{ 
1779 
int mixlev = validate_float_option(*opt_param, list, list_size);

1780 
if (mixlev < min_value) {

1781 
mixlev = default_value; 
1782 
if (*opt_param >= 0.0) { 
1783 
av_log(log_ctx, AV_LOG_WARNING, "requested %s is not valid. using "

1784 
"default value: %0.3f\n", opt_name, list[mixlev]);

1785 
} 
1786 
} 
1787 
*opt_param = list[mixlev]; 
1788 
*ctx_param = mixlev; 
1789 
} 
1790  
1791  
1792 
/**

1793 
* Validate metadata options as set by AVOption system.

1794 
* These values can optionally be changed perframe.

1795 
*/

1796 
static int validate_metadata(AVCodecContext *avctx) 
1797 
{ 
1798 
AC3EncodeContext *s = avctx>priv_data; 
1799 
AC3EncOptions *opt = &s>options; 
1800  
1801 
/* validate mixing levels */

1802 
if (s>has_center) {

1803 
validate_mix_level(avctx, "center_mix_level", &opt>center_mix_level,

1804 
cmixlev_options, CMIXLEV_NUM_OPTIONS, 1, 0, 
1805 
&s>center_mix_level); 
1806 
} 
1807 
if (s>has_surround) {

1808 
validate_mix_level(avctx, "surround_mix_level", &opt>surround_mix_level,

1809 
surmixlev_options, SURMIXLEV_NUM_OPTIONS, 1, 0, 
1810 
&s>surround_mix_level); 
1811 
} 
1812  
1813 
/* set audio production info flag */

1814 
if (opt>mixing_level >= 0  opt>room_type >= 0) { 
1815 
if (opt>mixing_level < 0) { 
1816 
av_log(avctx, AV_LOG_ERROR, "mixing_level must be set if "

1817 
"room_type is set\n");

1818 
return AVERROR(EINVAL);

1819 
} 
1820 
if (opt>mixing_level < 80) { 
1821 
av_log(avctx, AV_LOG_ERROR, "invalid mixing level. must be between "

1822 
"80dB and 111dB\n");

1823 
return AVERROR(EINVAL);

1824 
} 
1825 
/* default room type */

1826 
if (opt>room_type < 0) 
1827 
opt>room_type = 0;

1828 
opt>audio_production_info = 1;

1829 
} else {

1830 
opt>audio_production_info = 0;

1831 
} 
1832  
1833 
/* set extended bsi 1 flag */

1834 
if ((s>has_center  s>has_surround) &&

1835 
(opt>preferred_stereo_downmix >= 0 

1836 
opt>ltrt_center_mix_level >= 0 

1837 
opt>ltrt_surround_mix_level >= 0 

1838 
opt>loro_center_mix_level >= 0 

1839 
opt>loro_surround_mix_level >= 0)) {

1840 
/* default preferred stereo downmix */

1841 
if (opt>preferred_stereo_downmix < 0) 
1842 
opt>preferred_stereo_downmix = 0;

1843 
/* validate Lt/Rt center mix level */

1844 
validate_mix_level(avctx, "ltrt_center_mix_level",

1845 
&opt>ltrt_center_mix_level, extmixlev_options, 
1846 
EXTMIXLEV_NUM_OPTIONS, 5, 0, 
1847 
&s>ltrt_center_mix_level); 
1848 
/* validate Lt/Rt surround mix level */

1849 
validate_mix_level(avctx, "ltrt_surround_mix_level",

1850 
&opt>ltrt_surround_mix_level, extmixlev_options, 
1851 
EXTMIXLEV_NUM_OPTIONS, 6, 3, 
1852 
&s>ltrt_surround_mix_level); 
1853 
/* validate Lo/Ro center mix level */

1854 
validate_mix_level(avctx, "loro_center_mix_level",

1855 
&opt>loro_center_mix_level, extmixlev_options, 
1856 
EXTMIXLEV_NUM_OPTIONS, 5, 0, 
1857 
&s>loro_center_mix_level); 
1858 
/* validate Lo/Ro surround mix level */

1859 
validate_mix_level(avctx, "loro_surround_mix_level",

1860 
&opt>loro_surround_mix_level, extmixlev_options, 
1861 
EXTMIXLEV_NUM_OPTIONS, 6, 3, 
1862 
&s>loro_surround_mix_level); 
1863 
opt>extended_bsi_1 = 1;

1864 
} else {

1865 
opt>extended_bsi_1 = 0;

1866 
} 
1867  
1868 
/* set extended bsi 2 flag */

1869 
if (opt>dolby_surround_ex_mode >= 0  
1870 
opt>dolby_headphone_mode >= 0 

1871 
opt>ad_converter_type >= 0) {

1872 
/* default dolby surround ex mode */

1873 
if (opt>dolby_surround_ex_mode < 0) 
1874 
opt>dolby_surround_ex_mode = 0;

1875 
/* default dolby headphone mode */

1876 
if (opt>dolby_headphone_mode < 0) 
1877 
opt>dolby_headphone_mode = 0;

1878 
/* default A/D converter type */

1879 
if (opt>ad_converter_type < 0) 
1880 
opt>ad_converter_type = 0;

1881 
opt>extended_bsi_2 = 1;

1882 
} else {

1883 
opt>extended_bsi_2 = 0;

1884 
} 
1885  
1886 
/* set bitstream id for alternate bitstream syntax */

1887 
if (opt>extended_bsi_1  opt>extended_bsi_2) {

1888 
if (s>bitstream_id > 8 && s>bitstream_id < 11) { 
1889 
static int warn_once = 1; 
1890 
if (warn_once) {

1891 
av_log(avctx, AV_LOG_WARNING, "alternate bitstream syntax is "

1892 
"not compatible with reduced samplerates. writing of "

1893 
"extended bitstream information will be disabled.\n");

1894 
warn_once = 0;

1895 
} 
1896 
} else {

1897 
s>bitstream_id = 6;

1898 
} 
1899 
} 
1900  
1901 
return 0; 
1902 
} 
1903  
1904  
1905 
/**

1906 
* Encode a single AC3 frame.

1907 
*/

1908 
static int ac3_encode_frame(AVCodecContext *avctx, unsigned char *frame, 
1909 
int buf_size, void *data) 
1910 
{ 
1911 
AC3EncodeContext *s = avctx>priv_data; 
1912 
const SampleType *samples = data;

1913 
int ret;

1914  
1915 
if (s>options.allow_per_frame_metadata) {

1916 
ret = validate_metadata(avctx); 
1917 
if (ret)

1918 
return ret;

1919 
} 
1920  
1921 
if (s>bit_alloc.sr_code == 1) 
1922 
adjust_frame_size(s); 
1923  
1924 
deinterleave_input_samples(s, samples); 
1925  
1926 
apply_mdct(s); 
1927  
1928 
scale_coefficients(s); 
1929  
1930 
compute_rematrixing_strategy(s); 
1931  
1932 
apply_rematrixing(s); 
1933  
1934 
process_exponents(s); 
1935  
1936 
ret = compute_bit_allocation(s); 
1937 
if (ret) {

1938 
av_log(avctx, AV_LOG_ERROR, "Bit allocation failed. Try increasing the bitrate.\n");

1939 
return ret;

1940 
} 
1941  
1942 
quantize_mantissas(s); 
1943  
1944 
output_frame(s, frame); 
1945  
1946 
return s>frame_size;

1947 
} 
1948  
1949  
1950 
/**

1951 
* Finalize encoding and free any memory allocated by the encoder.

1952 
*/

1953 
static av_cold int ac3_encode_close(AVCodecContext *avctx) 
1954 
{ 
1955 
int blk, ch;

1956 
AC3EncodeContext *s = avctx>priv_data; 
1957  
1958 
for (ch = 0; ch < s>channels; ch++) 
1959 
av_freep(&s>planar_samples[ch]); 
1960 
av_freep(&s>planar_samples); 
1961 
av_freep(&s>bap_buffer); 
1962 
av_freep(&s>bap1_buffer); 
1963 
av_freep(&s>mdct_coef_buffer); 
1964 
av_freep(&s>fixed_coef_buffer); 
1965 
av_freep(&s>exp_buffer); 
1966 
av_freep(&s>grouped_exp_buffer); 
1967 
av_freep(&s>psd_buffer); 
1968 
av_freep(&s>band_psd_buffer); 
1969 
av_freep(&s>mask_buffer); 
1970 
av_freep(&s>qmant_buffer); 
1971 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { 
1972 
AC3Block *block = &s>blocks[blk]; 
1973 
av_freep(&block>bap); 
1974 
av_freep(&block>mdct_coef); 
1975 
av_freep(&block>fixed_coef); 
1976 
av_freep(&block>exp); 
1977 
av_freep(&block>grouped_exp); 
1978 
av_freep(&block>psd); 
1979 
av_freep(&block>band_psd); 
1980 
av_freep(&block>mask); 
1981 
av_freep(&block>qmant); 
1982 
} 
1983  
1984 
mdct_end(&s>mdct); 
1985  
1986 
av_freep(&avctx>coded_frame); 
1987 
return 0; 
1988 
} 
1989  
1990  
1991 
/**

1992 
* Set channel information during initialization.

1993 
*/

1994 
static av_cold int set_channel_info(AC3EncodeContext *s, int channels, 
1995 
int64_t *channel_layout) 
1996 
{ 
1997 
int ch_layout;

1998  
1999 
if (channels < 1  channels > AC3_MAX_CHANNELS) 
2000 
return AVERROR(EINVAL);

2001 
if ((uint64_t)*channel_layout > 0x7FF) 
2002 
return AVERROR(EINVAL);

2003 
ch_layout = *channel_layout; 
2004 
if (!ch_layout)

2005 
ch_layout = avcodec_guess_channel_layout(channels, CODEC_ID_AC3, NULL);

2006 
if (av_get_channel_layout_nb_channels(ch_layout) != channels)

2007 
return AVERROR(EINVAL);

2008  
2009 
s>lfe_on = !!(ch_layout & AV_CH_LOW_FREQUENCY); 
2010 
s>channels = channels; 
2011 
s>fbw_channels = channels  s>lfe_on; 
2012 
s>lfe_channel = s>lfe_on ? s>fbw_channels : 1;

2013 
if (s>lfe_on)

2014 
ch_layout = AV_CH_LOW_FREQUENCY; 
2015  
2016 
switch (ch_layout) {

2017 
case AV_CH_LAYOUT_MONO: s>channel_mode = AC3_CHMODE_MONO; break; 
2018 
case AV_CH_LAYOUT_STEREO: s>channel_mode = AC3_CHMODE_STEREO; break; 
2019 
case AV_CH_LAYOUT_SURROUND: s>channel_mode = AC3_CHMODE_3F; break; 
2020 
case AV_CH_LAYOUT_2_1: s>channel_mode = AC3_CHMODE_2F1R; break; 
2021 
case AV_CH_LAYOUT_4POINT0: s>channel_mode = AC3_CHMODE_3F1R; break; 
2022 
case AV_CH_LAYOUT_QUAD:

2023 
case AV_CH_LAYOUT_2_2: s>channel_mode = AC3_CHMODE_2F2R; break; 
2024 
case AV_CH_LAYOUT_5POINT0:

2025 
case AV_CH_LAYOUT_5POINT0_BACK: s>channel_mode = AC3_CHMODE_3F2R; break; 
2026 
default:

2027 
return AVERROR(EINVAL);

2028 
} 
2029 
s>has_center = (s>channel_mode & 0x01) && s>channel_mode != AC3_CHMODE_MONO;

2030 
s>has_surround = s>channel_mode & 0x04;

2031  
2032 
s>channel_map = ff_ac3_enc_channel_map[s>channel_mode][s>lfe_on]; 
2033 
*channel_layout = ch_layout; 
2034 
if (s>lfe_on)

2035 
*channel_layout = AV_CH_LOW_FREQUENCY; 
2036  
2037 
return 0; 
2038 
} 
2039  
2040  
2041 
static av_cold int validate_options(AVCodecContext *avctx, AC3EncodeContext *s) 
2042 
{ 
2043 
int i, ret;

2044  
2045 
/* validate channel layout */

2046 
if (!avctx>channel_layout) {

2047 
av_log(avctx, AV_LOG_WARNING, "No channel layout specified. The "

2048 
"encoder will guess the layout, but it "

2049 
"might be incorrect.\n");

2050 
} 
2051 
ret = set_channel_info(s, avctx>channels, &avctx>channel_layout); 
2052 
if (ret) {

2053 
av_log(avctx, AV_LOG_ERROR, "invalid channel layout\n");

2054 
return ret;

2055 
} 
2056  
2057 
/* validate sample rate */

2058 
for (i = 0; i < 9; i++) { 
2059 
if ((ff_ac3_sample_rate_tab[i / 3] >> (i % 3)) == avctx>sample_rate) 
2060 
break;

2061 
} 
2062 
if (i == 9) { 
2063 
av_log(avctx, AV_LOG_ERROR, "invalid sample rate\n");

2064 
return AVERROR(EINVAL);

2065 
} 
2066 
s>sample_rate = avctx>sample_rate; 
2067 
s>bit_alloc.sr_shift = i % 3;

2068 
s>bit_alloc.sr_code = i / 3;

2069 
s>bitstream_id = 8 + s>bit_alloc.sr_shift;

2070  
2071 
/* validate bit rate */

2072 
for (i = 0; i < 19; i++) { 
2073 
if ((ff_ac3_bitrate_tab[i] >> s>bit_alloc.sr_shift)*1000 == avctx>bit_rate) 
2074 
break;

2075 
} 
2076 
if (i == 19) { 
2077 
av_log(avctx, AV_LOG_ERROR, "invalid bit rate\n");

2078 
return AVERROR(EINVAL);

2079 
} 
2080 
s>bit_rate = avctx>bit_rate; 
2081 
s>frame_size_code = i << 1;

2082  
2083 
/* validate cutoff */

2084 
if (avctx>cutoff < 0) { 
2085 
av_log(avctx, AV_LOG_ERROR, "invalid cutoff frequency\n");

2086 
return AVERROR(EINVAL);

2087 
} 
2088 
s>cutoff = avctx>cutoff; 
2089 
if (s>cutoff > (s>sample_rate >> 1)) 
2090 
s>cutoff = s>sample_rate >> 1;

2091  
2092 
/* validate audio service type / channels combination */

2093 
if ((avctx>audio_service_type == AV_AUDIO_SERVICE_TYPE_KARAOKE &&

2094 
avctx>channels == 1) 

2095 
((avctx>audio_service_type == AV_AUDIO_SERVICE_TYPE_COMMENTARY  
2096 
avctx>audio_service_type == AV_AUDIO_SERVICE_TYPE_EMERGENCY  
2097 
avctx>audio_service_type == AV_AUDIO_SERVICE_TYPE_VOICE_OVER) 
2098 
&& avctx>channels > 1)) {

2099 
av_log(avctx, AV_LOG_ERROR, "invalid audio service type for the "

2100 
"specified number of channels\n");

2101 
return AVERROR(EINVAL);

2102 
} 
2103  
2104 
ret = validate_metadata(avctx); 
2105 
if (ret)

2106 
return ret;

2107  
2108 
return 0; 
2109 
} 
2110  
2111  
2112 
/**

2113 
* Set bandwidth for all channels.

2114 
* The user can optionally supply a cutoff frequency. Otherwise an appropriate

2115 
* default value will be used.

2116 
*/

2117 
static av_cold void set_bandwidth(AC3EncodeContext *s) 
2118 
{ 
2119 
int ch, bw_code;

2120  
2121 
if (s>cutoff) {

2122 
/* calculate bandwidth based on userspecified cutoff frequency */

2123 
int fbw_coeffs;

2124 
fbw_coeffs = s>cutoff * 2 * AC3_MAX_COEFS / s>sample_rate;

2125 
bw_code = av_clip((fbw_coeffs  73) / 3, 0, 60); 
2126 
} else {

2127 
/* use default bandwidth setting */

2128 
bw_code = ac3_bandwidth_tab[s>fbw_channels1][s>bit_alloc.sr_code][s>frame_size_code/2]; 
2129 
} 
2130  
2131 
/* set number of coefficients for each channel */

2132 
for (ch = 0; ch < s>fbw_channels; ch++) { 
2133 
s>bandwidth_code[ch] = bw_code; 
2134 
s>nb_coefs[ch] = bw_code * 3 + 73; 
2135 
} 
2136 
if (s>lfe_on)

2137 
s>nb_coefs[s>lfe_channel] = 7; /* LFE channel always has 7 coefs */ 
2138 
} 
2139  
2140  
2141 
static av_cold int allocate_buffers(AVCodecContext *avctx) 
2142 
{ 
2143 
int blk, ch;

2144 
AC3EncodeContext *s = avctx>priv_data; 
2145  
2146 
FF_ALLOC_OR_GOTO(avctx, s>planar_samples, s>channels * sizeof(*s>planar_samples),

2147 
alloc_fail); 
2148 
for (ch = 0; ch < s>channels; ch++) { 
2149 
FF_ALLOCZ_OR_GOTO(avctx, s>planar_samples[ch], 
2150 
(AC3_FRAME_SIZE+AC3_BLOCK_SIZE) * sizeof(**s>planar_samples),

2151 
alloc_fail); 
2152 
} 
2153 
FF_ALLOC_OR_GOTO(avctx, s>bap_buffer, AC3_MAX_BLOCKS * s>channels * 
2154 
AC3_MAX_COEFS * sizeof(*s>bap_buffer), alloc_fail);

2155 
FF_ALLOC_OR_GOTO(avctx, s>bap1_buffer, AC3_MAX_BLOCKS * s>channels * 
2156 
AC3_MAX_COEFS * sizeof(*s>bap1_buffer), alloc_fail);

2157 
FF_ALLOC_OR_GOTO(avctx, s>mdct_coef_buffer, AC3_MAX_BLOCKS * s>channels * 
2158 
AC3_MAX_COEFS * sizeof(*s>mdct_coef_buffer), alloc_fail);

2159 
FF_ALLOC_OR_GOTO(avctx, s>exp_buffer, AC3_MAX_BLOCKS * s>channels * 
2160 
AC3_MAX_COEFS * sizeof(*s>exp_buffer), alloc_fail);

2161 
FF_ALLOC_OR_GOTO(avctx, s>grouped_exp_buffer, AC3_MAX_BLOCKS * s>channels * 
2162 
128 * sizeof(*s>grouped_exp_buffer), alloc_fail); 
2163 
FF_ALLOC_OR_GOTO(avctx, s>psd_buffer, AC3_MAX_BLOCKS * s>channels * 
2164 
AC3_MAX_COEFS * sizeof(*s>psd_buffer), alloc_fail);

2165 
FF_ALLOC_OR_GOTO(avctx, s>band_psd_buffer, AC3_MAX_BLOCKS * s>channels * 
2166 
64 * sizeof(*s>band_psd_buffer), alloc_fail); 
2167 
FF_ALLOC_OR_GOTO(avctx, s>mask_buffer, AC3_MAX_BLOCKS * s>channels * 
2168 
64 * sizeof(*s>mask_buffer), alloc_fail); 
2169 
FF_ALLOC_OR_GOTO(avctx, s>qmant_buffer, AC3_MAX_BLOCKS * s>channels * 
2170 
AC3_MAX_COEFS * sizeof(*s>qmant_buffer), alloc_fail);

2171 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { 
2172 
AC3Block *block = &s>blocks[blk]; 
2173 
FF_ALLOC_OR_GOTO(avctx, block>bap, s>channels * sizeof(*block>bap),

2174 
alloc_fail); 
2175 
FF_ALLOCZ_OR_GOTO(avctx, block>mdct_coef, s>channels * sizeof(*block>mdct_coef),

2176 
alloc_fail); 
2177 
FF_ALLOCZ_OR_GOTO(avctx, block>exp, s>channels * sizeof(*block>exp),

2178 
alloc_fail); 
2179 
FF_ALLOCZ_OR_GOTO(avctx, block>grouped_exp, s>channels * sizeof(*block>grouped_exp),

2180 
alloc_fail); 
2181 
FF_ALLOCZ_OR_GOTO(avctx, block>psd, s>channels * sizeof(*block>psd),

2182 
alloc_fail); 
2183 
FF_ALLOCZ_OR_GOTO(avctx, block>band_psd, s>channels * sizeof(*block>band_psd),

2184 
alloc_fail); 
2185 
FF_ALLOCZ_OR_GOTO(avctx, block>mask, s>channels * sizeof(*block>mask),

2186 
alloc_fail); 
2187 
FF_ALLOCZ_OR_GOTO(avctx, block>qmant, s>channels * sizeof(*block>qmant),

2188 
alloc_fail); 
2189  
2190 
for (ch = 0; ch < s>channels; ch++) { 
2191 
/* arrangement: block, channel, coeff */

2192 
block>bap[ch] = &s>bap_buffer [AC3_MAX_COEFS * (blk * s>channels + ch)]; 
2193 
block>mdct_coef[ch] = &s>mdct_coef_buffer [AC3_MAX_COEFS * (blk * s>channels + ch)]; 
2194 
block>grouped_exp[ch] = &s>grouped_exp_buffer[128 * (blk * s>channels + ch)];

2195 
block>psd[ch] = &s>psd_buffer [AC3_MAX_COEFS * (blk * s>channels + ch)]; 
2196 
block>band_psd[ch] = &s>band_psd_buffer [64 * (blk * s>channels + ch)];

2197 
block>mask[ch] = &s>mask_buffer [64 * (blk * s>channels + ch)];

2198 
block>qmant[ch] = &s>qmant_buffer [AC3_MAX_COEFS * (blk * s>channels + ch)]; 
2199  
2200 
/* arrangement: channel, block, coeff */

2201 
block>exp[ch] = &s>exp_buffer [AC3_MAX_COEFS * (AC3_MAX_BLOCKS * ch + blk)]; 
2202 
} 
2203 
} 
2204  
2205 
if (CONFIG_AC3ENC_FLOAT) {

2206 
FF_ALLOC_OR_GOTO(avctx, s>fixed_coef_buffer, AC3_MAX_BLOCKS * s>channels * 
2207 
AC3_MAX_COEFS * sizeof(*s>fixed_coef_buffer), alloc_fail);

2208 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { 
2209 
AC3Block *block = &s>blocks[blk]; 
2210 
FF_ALLOCZ_OR_GOTO(avctx, block>fixed_coef, s>channels * 
2211 
sizeof(*block>fixed_coef), alloc_fail);

2212 
for (ch = 0; ch < s>channels; ch++) 
2213 
block>fixed_coef[ch] = &s>fixed_coef_buffer[AC3_MAX_COEFS * (blk * s>channels + ch)]; 
2214 
} 
2215 
} else {

2216 
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { 
2217 
AC3Block *block = &s>blocks[blk]; 
2218 
FF_ALLOCZ_OR_GOTO(avctx, block>fixed_coef, s>channels * 
2219 
sizeof(*block>fixed_coef), alloc_fail);

2220 
for (ch = 0; ch < s>channels; ch++) 
2221 
block>fixed_coef[ch] = (int32_t *)block>mdct_coef[ch]; 
2222 
} 
2223 
} 
2224  
2225 
return 0; 
2226 
alloc_fail:

2227 
return AVERROR(ENOMEM);

2228 
} 
2229  
2230  
2231 
/**

2232 
* Initialize the encoder.

2233 
*/

2234 
static av_cold int ac3_encode_init(AVCodecContext *avctx) 
2235 
{ 
2236 
AC3EncodeContext *s = avctx>priv_data; 
2237 
int ret, frame_size_58;

2238  
2239 
avctx>frame_size = AC3_FRAME_SIZE; 
2240  
2241 
ff_ac3_common_init(); 
2242  
2243 
ret = validate_options(avctx, s); 
2244 
if (ret)

2245 
return ret;

2246  
2247 
s>bitstream_mode = avctx>audio_service_type; 
2248 
if (s>bitstream_mode == AV_AUDIO_SERVICE_TYPE_KARAOKE)

2249 
s>bitstream_mode = 0x7;

2250  
2251 
s>frame_size_min = 2 * ff_ac3_frame_size_tab[s>frame_size_code][s>bit_alloc.sr_code];

2252 
s>bits_written = 0;

2253 
s>samples_written = 0;

2254 
s>frame_size = s>frame_size_min; 
2255  
2256 
/* calculate crc_inv for both possible frame sizes */

2257 
frame_size_58 = (( s>frame_size >> 2) + ( s>frame_size >> 4)) << 1; 
2258 
s>crc_inv[0] = pow_poly((CRC16_POLY >> 1), (8 * frame_size_58)  16, CRC16_POLY); 
2259 
if (s>bit_alloc.sr_code == 1) { 
2260 
frame_size_58 = (((s>frame_size+2) >> 2) + ((s>frame_size+2) >> 4)) << 1; 
2261 
s>crc_inv[1] = pow_poly((CRC16_POLY >> 1), (8 * frame_size_58)  16, CRC16_POLY); 
2262 
} 
2263  
2264 
set_bandwidth(s); 
2265  
2266 
rematrixing_init(s); 
2267  
2268 
exponent_init(s); 
2269  
2270 
bit_alloc_init(s); 
2271  
2272 
ret = mdct_init(avctx, &s>mdct, 9);

2273 
if (ret)

2274 
goto init_fail;

2275  
2276 
ret = allocate_buffers(avctx); 
2277 
if (ret)

2278 
goto init_fail;

2279  
2280 
avctx>coded_frame= avcodec_alloc_frame(); 
2281  
2282 
dsputil_init(&s>dsp, avctx); 
2283 
ff_ac3dsp_init(&s>ac3dsp, avctx>flags & CODEC_FLAG_BITEXACT); 
2284  
2285 
dprint_options(avctx); 
2286  
2287 
return 0; 
2288 
init_fail:

2289 
ac3_encode_close(avctx); 
2290 
return ret;

2291 
} 