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- /*
- * Common code between AC3 and E-AC3 decoder
- * 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 AC3 and E-AC3 decoder.
- */
-
- #ifndef FFMPEG_AC3DEC_H
- #define FFMPEG_AC3DEC_H
-
- #include "libavutil/random.h"
- #include "ac3tab.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 center_mix_level; ///< Center mix level index
- int surround_mix_level; ///< Surround mix level index
- ///@}
-
- ///@defgroup cpl standard coupling
- int cpl_in_use[MAX_BLOCKS]; ///< coupling in use (cplinu)
- 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)
- int cpl_band_struct[18]; ///< coupling band structure (cplbndstrc)
- int cpl_coords[AC3_MAX_CHANNELS][18]; ///< coupling coordinates (cplco)
- ///@}
-
- ///@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
- float downmix_coeff_adjust[2]; ///< adjustment needed for each output channel when downmixing
- 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 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)
- AVRandomState 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
- ///@}
-
- 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*2]); ///< temporary storage for output before windowing
- DECLARE_ALIGNED_16(float, tmp_imdct[AC3_BLOCK_SIZE]); ///< temporary storage for imdct transform
- DECLARE_ALIGNED_16(float, output[AC3_MAX_CHANNELS][AC3_BLOCK_SIZE]); ///< output after imdct transform and windowing
- DECLARE_ALIGNED_16(short, int_output[AC3_MAX_CHANNELS-1][AC3_BLOCK_SIZE]); ///< final 16-bit integer output
- ///@}
- } AC3DecodeContext;
-
- #endif /* FFMPEG_AC3DEC_H */
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