Signed-off-by: Geoff Hill <geoff@geoffhill.org> Signed-off-by: Martin Storsjö <martin@martin.st>
		
			
				
	
	
		
			124 lines
		
	
	
		
			4.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			124 lines
		
	
	
		
			4.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * AC-3 DSP functions
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 * Copyright (c) 2011 Justin Ruggles
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg 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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 * FFmpeg 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 FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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#ifndef AVCODEC_AC3DSP_H
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#define AVCODEC_AC3DSP_H
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#include <stddef.h>
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#include <stdint.h>
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/**
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 * Number of mantissa bits written for each bap value.
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 * bap values with fractional bits are set to 0 and are calculated separately.
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 */
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extern const uint16_t ff_ac3_bap_bits[16];
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typedef struct AC3DSPContext {
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    /**
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     * Set each encoded exponent in a block to the minimum of itself and the
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     * exponents in the same frequency bin of up to 5 following blocks.
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     * @param exp   pointer to the start of the current block of exponents.
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     *              constraints: align 16
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     * @param num_reuse_blocks  number of blocks that will reuse exponents from the current block.
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     *                          constraints: range 0 to 5
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     * @param nb_coefs  number of frequency coefficients.
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     */
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    void (*ac3_exponent_min)(uint8_t *exp, int num_reuse_blocks, int nb_coefs);
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    /**
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     * Convert an array of float in range [-1.0,1.0] to int32_t with range
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     * [-(1<<24),(1<<24)]
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     *
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     * @param dst destination array of int32_t.
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     *            constraints: 32-byte aligned
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     * @param src source array of float.
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     *            constraints: 32-byte aligned
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     * @param len number of elements to convert.
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     *            constraints: multiple of 32 greater than zero
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     */
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    void (*float_to_fixed24)(int32_t *dst, const float *src, size_t len);
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    /**
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     * Calculate bit allocation pointers.
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     * The SNR is the difference between the masking curve and the signal.  AC-3
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     * uses this value for each frequency bin to allocate bits.  The snroffset
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     * parameter is a global adjustment to the SNR for all bins.
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     *
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     * @param[in]  mask       masking curve
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     * @param[in]  psd        signal power for each frequency bin
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     * @param[in]  start      starting bin location
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     * @param[in]  end        ending bin location
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     * @param[in]  snr_offset SNR adjustment
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     * @param[in]  floor      noise floor
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     * @param[in]  bap_tab    look-up table for bit allocation pointers
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     * @param[out] bap        bit allocation pointers
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     */
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    void (*bit_alloc_calc_bap)(int16_t *mask, int16_t *psd, int start, int end,
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                               int snr_offset, int floor,
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                               const uint8_t *bap_tab, uint8_t *bap);
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    /**
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     * Update bap counts using the supplied array of bap.
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     *
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     * @param[out] mant_cnt   bap counts for 1 block
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     * @param[in]  bap        array of bap, pointing to start coef bin
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     * @param[in]  len        number of elements to process
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     */
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    void (*update_bap_counts)(uint16_t mant_cnt[16], uint8_t *bap, int len);
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    /**
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     * Calculate the number of bits needed to encode a set of mantissas.
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     *
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     * @param[in] mant_cnt    bap counts for all blocks
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     * @return                mantissa bit count
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     */
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    int (*compute_mantissa_size)(uint16_t mant_cnt[6][16]);
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    void (*extract_exponents)(uint8_t *exp, int32_t *coef, int nb_coefs);
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    void (*sum_square_butterfly_int32)(int64_t sum[4], const int32_t *coef0,
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                                       const int32_t *coef1, int len);
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    void (*sum_square_butterfly_float)(float sum[4], const float *coef0,
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                                       const float *coef1, int len);
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    int out_channels;
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    int in_channels;
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    void (*downmix)(float **samples, float **matrix, int len);
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    void (*downmix_fixed)(int32_t **samples, int16_t **matrix, int len);
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} AC3DSPContext;
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void ff_ac3dsp_init(AC3DSPContext *c);
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void ff_ac3dsp_init_aarch64(AC3DSPContext *c);
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void ff_ac3dsp_init_arm(AC3DSPContext *c);
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void ff_ac3dsp_init_x86(AC3DSPContext *c);
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void ff_ac3dsp_init_mips(AC3DSPContext *c);
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void ff_ac3dsp_init_riscv(AC3DSPContext *c);
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void ff_ac3dsp_downmix(AC3DSPContext *c, float **samples, float **matrix,
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                       int out_ch, int in_ch, int len);
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void ff_ac3dsp_downmix_fixed(AC3DSPContext *c, int32_t **samples, int16_t **matrix,
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                             int out_ch, int in_ch, int len);
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void ff_ac3dsp_set_downmix_x86(AC3DSPContext *c);
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#endif /* AVCODEC_AC3DSP_H */
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