mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-11-26 19:01:44 +02:00
184 lines
9.1 KiB
C
184 lines
9.1 KiB
C
/*
|
|
* Common code between the AC-3 and E-AC-3 decoders
|
|
* Copyright (c) 2007 Bartlomiej Wolowiec <bartek.wolowiec@gmail.com>
|
|
*
|
|
* This file is part of FFmpeg.
|
|
*
|
|
* FFmpeg is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2.1 of the License, or (at your option) any later version.
|
|
*
|
|
* FFmpeg is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with FFmpeg; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
/**
|
|
* @file ac3.h
|
|
* Common code between the AC-3 and E-AC-3 decoders.
|
|
*/
|
|
|
|
#ifndef FFMPEG_AC3DEC_H
|
|
#define FFMPEG_AC3DEC_H
|
|
|
|
#include "libavutil/lfg.h"
|
|
#include "ac3.h"
|
|
#include "bitstream.h"
|
|
#include "dsputil.h"
|
|
|
|
/* override ac3.h to include coupling channel */
|
|
#undef AC3_MAX_CHANNELS
|
|
#define AC3_MAX_CHANNELS 7
|
|
#define CPL_CH 0
|
|
|
|
#define AC3_OUTPUT_LFEON 8
|
|
|
|
#define AC3_MAX_COEFS 256
|
|
#define AC3_BLOCK_SIZE 256
|
|
#define MAX_BLOCKS 6
|
|
|
|
typedef struct {
|
|
AVCodecContext *avctx; ///< parent context
|
|
GetBitContext gbc; ///< bitstream reader
|
|
uint8_t *input_buffer; ///< temp buffer to prevent overread
|
|
|
|
///@defgroup bsi bit stream information
|
|
///@{
|
|
int frame_type; ///< frame type (strmtyp)
|
|
int substreamid; ///< substream identification
|
|
int frame_size; ///< current frame size, in bytes
|
|
int bit_rate; ///< stream bit rate, in bits-per-second
|
|
int sample_rate; ///< sample frequency, in Hz
|
|
int num_blocks; ///< number of audio blocks
|
|
int channel_mode; ///< channel mode (acmod)
|
|
int lfe_on; ///< lfe channel in use
|
|
int channel_map; ///< custom channel map
|
|
int center_mix_level; ///< Center mix level index
|
|
int surround_mix_level; ///< Surround mix level index
|
|
int eac3; ///< indicates if current frame is E-AC-3
|
|
///@}
|
|
|
|
///@defgroup audfrm frame syntax parameters
|
|
int snr_offset_strategy; ///< SNR offset strategy (snroffststr)
|
|
int block_switch_syntax; ///< block switch syntax enabled (blkswe)
|
|
int dither_flag_syntax; ///< dither flag syntax enabled (dithflage)
|
|
int bit_allocation_syntax; ///< bit allocation model syntax enabled (bamode)
|
|
int fast_gain_syntax; ///< fast gain codes enabled (frmfgaincode)
|
|
int dba_syntax; ///< delta bit allocation syntax enabled (dbaflde)
|
|
int skip_syntax; ///< skip field syntax enabled (skipflde)
|
|
///@}
|
|
|
|
///@defgroup cpl standard coupling
|
|
int cpl_in_use[MAX_BLOCKS]; ///< coupling in use (cplinu)
|
|
int cpl_strategy_exists[MAX_BLOCKS]; ///< coupling strategy exists (cplstre)
|
|
int channel_in_cpl[AC3_MAX_CHANNELS]; ///< channel in coupling (chincpl)
|
|
int phase_flags_in_use; ///< phase flags in use (phsflginu)
|
|
int phase_flags[18]; ///< phase flags (phsflg)
|
|
int num_cpl_subbands; ///< number of coupling sub bands (ncplsubnd)
|
|
int num_cpl_bands; ///< number of coupling bands (ncplbnd)
|
|
uint8_t cpl_band_struct[18]; ///< coupling band structure (cplbndstrc)
|
|
int firstchincpl; ///< first channel in coupling
|
|
int first_cpl_coords[AC3_MAX_CHANNELS]; ///< first coupling coordinates states (firstcplcos)
|
|
int cpl_coords[AC3_MAX_CHANNELS][18]; ///< coupling coordinates (cplco)
|
|
///@}
|
|
|
|
///@defgroup aht adaptive hybrid transform
|
|
int channel_uses_aht[AC3_MAX_CHANNELS]; ///< channel AHT in use (chahtinu)
|
|
int pre_mantissa[AC3_MAX_CHANNELS][AC3_MAX_COEFS][MAX_BLOCKS]; ///< pre-IDCT mantissas
|
|
///@}
|
|
|
|
///@defgroup channel channel
|
|
int fbw_channels; ///< number of full-bandwidth channels
|
|
int channels; ///< number of total channels
|
|
int lfe_ch; ///< index of LFE channel
|
|
float downmix_coeffs[AC3_MAX_CHANNELS][2]; ///< stereo downmix coefficients
|
|
int downmixed; ///< indicates if coeffs are currently downmixed
|
|
int output_mode; ///< output channel configuration
|
|
int out_channels; ///< number of output channels
|
|
///@}
|
|
|
|
///@defgroup dynrng dynamic range
|
|
float dynamic_range[2]; ///< dynamic range
|
|
///@}
|
|
|
|
///@defgroup bandwidth bandwidth
|
|
int start_freq[AC3_MAX_CHANNELS]; ///< start frequency bin (strtmant)
|
|
int end_freq[AC3_MAX_CHANNELS]; ///< end frequency bin (endmant)
|
|
///@}
|
|
|
|
///@defgroup rematrixing rematrixing
|
|
int num_rematrixing_bands; ///< number of rematrixing bands (nrematbnd)
|
|
int rematrixing_flags[4]; ///< rematrixing flags (rematflg)
|
|
///@}
|
|
|
|
///@defgroup exponents exponents
|
|
int num_exp_groups[AC3_MAX_CHANNELS]; ///< Number of exponent groups (nexpgrp)
|
|
int8_t dexps[AC3_MAX_CHANNELS][AC3_MAX_COEFS]; ///< decoded exponents
|
|
int exp_strategy[MAX_BLOCKS][AC3_MAX_CHANNELS]; ///< exponent strategies (expstr)
|
|
///@}
|
|
|
|
///@defgroup bitalloc bit allocation
|
|
AC3BitAllocParameters bit_alloc_params; ///< bit allocation parameters
|
|
int first_cpl_leak; ///< first coupling leak state (firstcplleak)
|
|
int snr_offset[AC3_MAX_CHANNELS]; ///< signal-to-noise ratio offsets (snroffst)
|
|
int fast_gain[AC3_MAX_CHANNELS]; ///< fast gain values/SMR's (fgain)
|
|
uint8_t bap[AC3_MAX_CHANNELS][AC3_MAX_COEFS]; ///< bit allocation pointers
|
|
int16_t psd[AC3_MAX_CHANNELS][AC3_MAX_COEFS]; ///< scaled exponents
|
|
int16_t band_psd[AC3_MAX_CHANNELS][50]; ///< interpolated exponents
|
|
int16_t mask[AC3_MAX_CHANNELS][50]; ///< masking curve values
|
|
int dba_mode[AC3_MAX_CHANNELS]; ///< delta bit allocation mode
|
|
int dba_nsegs[AC3_MAX_CHANNELS]; ///< number of delta segments
|
|
uint8_t dba_offsets[AC3_MAX_CHANNELS][8]; ///< delta segment offsets
|
|
uint8_t dba_lengths[AC3_MAX_CHANNELS][8]; ///< delta segment lengths
|
|
uint8_t dba_values[AC3_MAX_CHANNELS][8]; ///< delta values for each segment
|
|
///@}
|
|
|
|
///@defgroup dithering zero-mantissa dithering
|
|
int dither_all; ///< true if all channels are dithered
|
|
int dither_flag[AC3_MAX_CHANNELS]; ///< dither flags (dithflg)
|
|
AVLFG dith_state; ///< for dither generation
|
|
///@}
|
|
|
|
///@defgroup imdct IMDCT
|
|
int block_switch[AC3_MAX_CHANNELS]; ///< block switch flags (blksw)
|
|
MDCTContext imdct_512; ///< for 512 sample IMDCT
|
|
MDCTContext imdct_256; ///< for 256 sample IMDCT
|
|
///@}
|
|
|
|
///@defgroup opt optimization
|
|
DSPContext dsp; ///< for optimization
|
|
float add_bias; ///< offset for float_to_int16 conversion
|
|
float mul_bias; ///< scaling for float_to_int16 conversion
|
|
///@}
|
|
|
|
DECLARE_ALIGNED_16(int, fixed_coeffs[AC3_MAX_CHANNELS][AC3_MAX_COEFS]); ///> fixed-point transform coefficients
|
|
|
|
///@defgroup arrays aligned arrays
|
|
DECLARE_ALIGNED_16(float, transform_coeffs[AC3_MAX_CHANNELS][AC3_MAX_COEFS]); ///< transform coefficients
|
|
DECLARE_ALIGNED_16(float, delay[AC3_MAX_CHANNELS][AC3_BLOCK_SIZE]); ///< delay - added to the next block
|
|
DECLARE_ALIGNED_16(float, window[AC3_BLOCK_SIZE]); ///< window coefficients
|
|
DECLARE_ALIGNED_16(float, tmp_output[AC3_BLOCK_SIZE]); ///< temporary storage for output before windowing
|
|
DECLARE_ALIGNED_16(float, output[AC3_MAX_CHANNELS][AC3_BLOCK_SIZE]); ///< output after imdct transform and windowing
|
|
///@}
|
|
} AC3DecodeContext;
|
|
|
|
/**
|
|
* Parse the E-AC-3 frame header.
|
|
* This parses both the bit stream info and audio frame header.
|
|
*/
|
|
int ff_eac3_parse_header(AC3DecodeContext *s);
|
|
|
|
/**
|
|
* Decode mantissas in a single channel for the entire frame.
|
|
* This is used when AHT mode is enabled.
|
|
*/
|
|
void ff_eac3_decode_transform_coeffs_aht_ch(AC3DecodeContext *s, int ch);
|
|
|
|
#endif /* FFMPEG_AC3DEC_H */
|