| /* |
| * Common code between the AC-3 and E-AC-3 decoders |
| * Copyright (c) 2007 Bartlomiej Wolowiec <bartek.wolowiec@gmail.com> |
| * |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * FFmpeg is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| /** |
| * @file libavcodec/ac3.h |
| * Common code between the AC-3 and E-AC-3 decoders. |
| */ |
| |
| #ifndef AVCODEC_AC3DEC_H |
| #define AVCODEC_AC3DEC_H |
| |
| #include "libavutil/internal.h" |
| #include "libavutil/lfg.h" |
| #include "ac3.h" |
| #include "bitstream.h" |
| #include "dsputil.h" |
| |
| /* override ac3.h to include coupling channel */ |
| #undef AC3_MAX_CHANNELS |
| #define AC3_MAX_CHANNELS 7 |
| #define CPL_CH 0 |
| |
| #define AC3_OUTPUT_LFEON 8 |
| |
| #define AC3_MAX_COEFS 256 |
| #define AC3_BLOCK_SIZE 256 |
| #define MAX_BLOCKS 6 |
| |
| typedef struct { |
| AVCodecContext *avctx; ///< parent context |
| GetBitContext gbc; ///< bitstream reader |
| uint8_t *input_buffer; ///< temp buffer to prevent overread |
| |
| ///@defgroup bsi bit stream information |
| ///@{ |
| int frame_type; ///< frame type (strmtyp) |
| int substreamid; ///< substream identification |
| int frame_size; ///< current frame size, in bytes |
| int bit_rate; ///< stream bit rate, in bits-per-second |
| int sample_rate; ///< sample frequency, in Hz |
| int num_blocks; ///< number of audio blocks |
| int channel_mode; ///< channel mode (acmod) |
| int lfe_on; ///< lfe channel in use |
| int channel_map; ///< custom channel map |
| int center_mix_level; ///< Center mix level index |
| int surround_mix_level; ///< Surround mix level index |
| int eac3; ///< indicates if current frame is E-AC-3 |
| ///@} |
| |
| ///@defgroup audfrm frame syntax parameters |
| int snr_offset_strategy; ///< SNR offset strategy (snroffststr) |
| int block_switch_syntax; ///< block switch syntax enabled (blkswe) |
| int dither_flag_syntax; ///< dither flag syntax enabled (dithflage) |
| int bit_allocation_syntax; ///< bit allocation model syntax enabled (bamode) |
| int fast_gain_syntax; ///< fast gain codes enabled (frmfgaincode) |
| int dba_syntax; ///< delta bit allocation syntax enabled (dbaflde) |
| int skip_syntax; ///< skip field syntax enabled (skipflde) |
| ///@} |
| |
| ///@defgroup cpl standard coupling |
| int cpl_in_use[MAX_BLOCKS]; ///< coupling in use (cplinu) |
| int cpl_strategy_exists[MAX_BLOCKS]; ///< coupling strategy exists (cplstre) |
| int channel_in_cpl[AC3_MAX_CHANNELS]; ///< channel in coupling (chincpl) |
| int phase_flags_in_use; ///< phase flags in use (phsflginu) |
| int phase_flags[18]; ///< phase flags (phsflg) |
| int num_cpl_subbands; ///< number of coupling sub bands (ncplsubnd) |
| int num_cpl_bands; ///< number of coupling bands (ncplbnd) |
| uint8_t cpl_band_struct[18]; ///< coupling band structure (cplbndstrc) |
| int firstchincpl; ///< first channel in coupling |
| int first_cpl_coords[AC3_MAX_CHANNELS]; ///< first coupling coordinates states (firstcplcos) |
| int cpl_coords[AC3_MAX_CHANNELS][18]; ///< coupling coordinates (cplco) |
| ///@} |
| |
| ///@defgroup aht adaptive hybrid transform |
| int channel_uses_aht[AC3_MAX_CHANNELS]; ///< channel AHT in use (chahtinu) |
| int pre_mantissa[AC3_MAX_CHANNELS][AC3_MAX_COEFS][MAX_BLOCKS]; ///< pre-IDCT mantissas |
| ///@} |
| |
| ///@defgroup channel channel |
| int fbw_channels; ///< number of full-bandwidth channels |
| int channels; ///< number of total channels |
| int lfe_ch; ///< index of LFE channel |
| float downmix_coeffs[AC3_MAX_CHANNELS][2]; ///< stereo downmix coefficients |
| int downmixed; ///< indicates if coeffs are currently downmixed |
| int output_mode; ///< output channel configuration |
| int out_channels; ///< number of output channels |
| ///@} |
| |
| ///@defgroup dynrng dynamic range |
| float dynamic_range[2]; ///< dynamic range |
| ///@} |
| |
| ///@defgroup bandwidth bandwidth |
| int start_freq[AC3_MAX_CHANNELS]; ///< start frequency bin (strtmant) |
| int end_freq[AC3_MAX_CHANNELS]; ///< end frequency bin (endmant) |
| ///@} |
| |
| ///@defgroup rematrixing rematrixing |
| int num_rematrixing_bands; ///< number of rematrixing bands (nrematbnd) |
| int rematrixing_flags[4]; ///< rematrixing flags (rematflg) |
| ///@} |
| |
| ///@defgroup exponents exponents |
| int num_exp_groups[AC3_MAX_CHANNELS]; ///< Number of exponent groups (nexpgrp) |
| int8_t dexps[AC3_MAX_CHANNELS][AC3_MAX_COEFS]; ///< decoded exponents |
| int exp_strategy[MAX_BLOCKS][AC3_MAX_CHANNELS]; ///< exponent strategies (expstr) |
| ///@} |
| |
| ///@defgroup bitalloc bit allocation |
| AC3BitAllocParameters bit_alloc_params; ///< bit allocation parameters |
| int first_cpl_leak; ///< first coupling leak state (firstcplleak) |
| int snr_offset[AC3_MAX_CHANNELS]; ///< signal-to-noise ratio offsets (snroffst) |
| int fast_gain[AC3_MAX_CHANNELS]; ///< fast gain values/SMR's (fgain) |
| uint8_t bap[AC3_MAX_CHANNELS][AC3_MAX_COEFS]; ///< bit allocation pointers |
| int16_t psd[AC3_MAX_CHANNELS][AC3_MAX_COEFS]; ///< scaled exponents |
| int16_t band_psd[AC3_MAX_CHANNELS][50]; ///< interpolated exponents |
| int16_t mask[AC3_MAX_CHANNELS][50]; ///< masking curve values |
| int dba_mode[AC3_MAX_CHANNELS]; ///< delta bit allocation mode |
| int dba_nsegs[AC3_MAX_CHANNELS]; ///< number of delta segments |
| uint8_t dba_offsets[AC3_MAX_CHANNELS][8]; ///< delta segment offsets |
| uint8_t dba_lengths[AC3_MAX_CHANNELS][8]; ///< delta segment lengths |
| uint8_t dba_values[AC3_MAX_CHANNELS][8]; ///< delta values for each segment |
| ///@} |
| |
| ///@defgroup dithering zero-mantissa dithering |
| int dither_flag[AC3_MAX_CHANNELS]; ///< dither flags (dithflg) |
| AVLFG dith_state; ///< for dither generation |
| ///@} |
| |
| ///@defgroup imdct IMDCT |
| int block_switch[AC3_MAX_CHANNELS]; ///< block switch flags (blksw) |
| MDCTContext imdct_512; ///< for 512 sample IMDCT |
| MDCTContext imdct_256; ///< for 256 sample IMDCT |
| ///@} |
| |
| ///@defgroup opt optimization |
| DSPContext dsp; ///< for optimization |
| float add_bias; ///< offset for float_to_int16 conversion |
| float mul_bias; ///< scaling for float_to_int16 conversion |
| ///@} |
| |
| DECLARE_ALIGNED_16(int, fixed_coeffs[AC3_MAX_CHANNELS][AC3_MAX_COEFS]); ///> fixed-point transform coefficients |
| |
| ///@defgroup arrays aligned arrays |
| DECLARE_ALIGNED_16(float, transform_coeffs[AC3_MAX_CHANNELS][AC3_MAX_COEFS]); ///< transform coefficients |
| DECLARE_ALIGNED_16(float, delay[AC3_MAX_CHANNELS][AC3_BLOCK_SIZE]); ///< delay - added to the next block |
| DECLARE_ALIGNED_16(float, window[AC3_BLOCK_SIZE]); ///< window coefficients |
| DECLARE_ALIGNED_16(float, tmp_output[AC3_BLOCK_SIZE]); ///< temporary storage for output before windowing |
| DECLARE_ALIGNED_16(float, output[AC3_MAX_CHANNELS][AC3_BLOCK_SIZE]); ///< output after imdct transform and windowing |
| ///@} |
| } AC3DecodeContext; |
| |
| /** |
| * Parse the E-AC-3 frame header. |
| * This parses both the bit stream info and audio frame header. |
| */ |
| int ff_eac3_parse_header(AC3DecodeContext *s); |
| |
| /** |
| * Decode mantissas in a single channel for the entire frame. |
| * This is used when AHT mode is enabled. |
| */ |
| void ff_eac3_decode_transform_coeffs_aht_ch(AC3DecodeContext *s, int ch); |
| |
| #endif /* AVCODEC_AC3DEC_H */ |
