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7539a1fee2
AC3DSPContext.ac3_max_msb_abs_int16() finds the maximum MSB of the absolute
value of each element in an array of int16_t.
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>
(cherry picked from commit fbb6b49dab)
55 lines
2.1 KiB
C
55 lines
2.1 KiB
C
/*
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* AC-3 DSP utils
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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 <stdint.h>
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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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* Calculate the maximum MSB of the absolute value of each element in an
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* array of int16_t.
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* @param src input array
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* constraints: align 16. values must be in range [-32767,32767]
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* @param len number of values in the array
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* constraints: multiple of 16 greater than 0
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* @return a value with the same MSB as max(abs(src[]))
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*/
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int (*ac3_max_msb_abs_int16)(const int16_t *src, 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_x86(AC3DSPContext *c);
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#endif /* AVCODEC_AC3DSP_H */
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