/* * Common code between AC3 and E-AC3 decoder * Copyright (c) 2007 Bartlomiej Wolowiec * * 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 typedef struct { int num_blocks; ///< number of audio blocks int channel_mode; ///< channel mode (acmod) int block_switch[AC3_MAX_CHANNELS]; ///< block switch flags int dither_flag[AC3_MAX_CHANNELS]; ///< dither flags int dither_all; ///< true if all channels are dithered int cpl_in_use; ///< coupling in use int channel_in_cpl[AC3_MAX_CHANNELS]; ///< channel in coupling int phase_flags_in_use; ///< phase flags in use int phase_flags[18]; ///< phase flags int cpl_band_struct[18]; ///< coupling band structure int num_rematrixing_bands; ///< number of rematrixing bands int rematrixing_flags[4]; ///< rematrixing flags int exp_strategy[AC3_MAX_CHANNELS]; ///< exponent strategies int snr_offset[AC3_MAX_CHANNELS]; ///< signal-to-noise ratio offsets int fast_gain[AC3_MAX_CHANNELS]; ///< fast gain values (signal-to-mask ratio) 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 int sample_rate; ///< sample frequency, in Hz int bit_rate; ///< stream bit rate, in bits-per-second int frame_type; ///< frame type (strmtyp) int substreamid; ///< substream identification int frame_size; ///< current frame size, in bytes int channels; ///< number of total channels int fbw_channels; ///< number of full-bandwidth channels int lfe_on; ///< lfe channel in use int lfe_ch; ///< index of LFE channel int output_mode; ///< output channel configuration int out_channels; ///< number of output channels int center_mix_level; ///< Center mix level index int surround_mix_level; ///< Surround mix level index float downmix_coeffs[AC3_MAX_CHANNELS][2]; ///< stereo downmix coefficients float downmix_coeff_adjust[2]; ///< adjustment needed for each output channel when downmixing float dynamic_range[2]; ///< dynamic range int cpl_coords[AC3_MAX_CHANNELS][18]; ///< coupling coordinates int num_cpl_bands; ///< number of coupling bands int num_cpl_subbands; ///< number of coupling sub bands int start_freq[AC3_MAX_CHANNELS]; ///< start frequency bin int end_freq[AC3_MAX_CHANNELS]; ///< end frequency bin AC3BitAllocParameters bit_alloc_params; ///< bit allocation parameters int num_exp_groups[AC3_MAX_CHANNELS]; ///< Number of exponent groups int8_t dexps[AC3_MAX_CHANNELS][256]; ///< decoded exponents uint8_t bap[AC3_MAX_CHANNELS][256]; ///< bit allocation pointers int16_t psd[AC3_MAX_CHANNELS][256]; ///< scaled exponents int16_t band_psd[AC3_MAX_CHANNELS][50]; ///< interpolated exponents int16_t mask[AC3_MAX_CHANNELS][50]; ///< masking curve values int fixed_coeffs[AC3_MAX_CHANNELS][256]; ///> fixed-point transform coefficients DECLARE_ALIGNED_16(float, transform_coeffs[AC3_MAX_CHANNELS][256]); ///< transform coefficients int downmixed; ///< indicates if coeffs are currently downmixed /* For IMDCT. */ MDCTContext imdct_512; ///< for 512 sample IMDCT MDCTContext imdct_256; ///< for 256 sample IMDCT 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(float, output[AC3_MAX_CHANNELS][256]); ///< output after imdct transform and windowing DECLARE_ALIGNED_16(short, int_output[AC3_MAX_CHANNELS-1][256]); ///< final 16-bit integer output DECLARE_ALIGNED_16(float, delay[AC3_MAX_CHANNELS][256]); ///< delay - added to the next block DECLARE_ALIGNED_16(float, tmp_imdct[256]); ///< temporary storage for imdct transform DECLARE_ALIGNED_16(float, tmp_output[512]); ///< temporary storage for output before windowing DECLARE_ALIGNED_16(float, window[256]); ///< window coefficients /* Miscellaneous. */ GetBitContext gbc; ///< bitstream reader AVRandomState dith_state; ///< for dither generation AVCodecContext *avctx; ///< parent context uint8_t *input_buffer; ///< temp buffer to prevent overread } AC3DecodeContext; #endif /* FFMPEG_AC3DEC_H */