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FFmpeg/libavcodec/ac3dsp.h
Michael Niedermayer 797ef671dd Merge remote-tracking branch 'newdev/master'
* newdev/master:
  matroskadec: set default duration for simple block
  When building for MinGW32 disable strict ANSI compliancy.
  ARM: fix ff_apply_window_int16_neon() prototype
  configure: check for --as-needed support early
  ARM: NEON optimised apply_window_int16()
  ac3enc: NEON optimised shift functions
  ac3enc: NEON optimised ac3_max_msb_abs_int16 and ac3_exponent_min
  mpeg12.c: fix slice threading for mpeg2 field picture mode.
  ffmetadec.c: fix compiler warnings.
  configure: Don't explicitly disable ffplay or in/outdevices on dos
  configure: Remove the explicit disabling of ffserver
  configure: Add fork as a dependency to ffserver

Merged-by: Michael Niedermayer <michaelni@gmx.at>
2011-03-25 02:57:41 +01:00

91 lines
3.5 KiB
C

/*
* AC-3 DSP utils
* Copyright (c) 2011 Justin Ruggles
*
* 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
*/
#ifndef AVCODEC_AC3DSP_H
#define AVCODEC_AC3DSP_H
#include <stdint.h>
typedef struct AC3DSPContext {
/**
* Set each encoded exponent in a block to the minimum of itself and the
* exponents in the same frequency bin of up to 5 following blocks.
* @param exp pointer to the start of the current block of exponents.
* constraints: align 16
* @param num_reuse_blocks number of blocks that will reuse exponents from the current block.
* constraints: range 0 to 5
* @param nb_coefs number of frequency coefficients.
*/
void (*ac3_exponent_min)(uint8_t *exp, int num_reuse_blocks, int nb_coefs);
/**
* Calculate the maximum MSB of the absolute value of each element in an
* array of int16_t.
* @param src input array
* constraints: align 16. values must be in range [-32767,32767]
* @param len number of values in the array
* constraints: multiple of 16 greater than 0
* @return a value with the same MSB as max(abs(src[]))
*/
int (*ac3_max_msb_abs_int16)(const int16_t *src, int len);
/**
* Left-shift each value in an array of int16_t by a specified amount.
* @param src input array
* constraints: align 16
* @param len number of values in the array
* constraints: multiple of 32 greater than 0
* @param shift left shift amount
* constraints: range [0,15]
*/
void (*ac3_lshift_int16)(int16_t *src, unsigned int len, unsigned int shift);
/**
* Right-shift each value in an array of int32_t by a specified amount.
* @param src input array
* constraints: align 16
* @param len number of values in the array
* constraints: multiple of 16 greater than 0
* @param shift right shift amount
* constraints: range [0,31]
*/
void (*ac3_rshift_int32)(int32_t *src, unsigned int len, unsigned int shift);
/**
* Convert an array of float in range [-1.0,1.0] to int32_t with range
* [-(1<<24),(1<<24)]
*
* @param dst destination array of int32_t.
* constraints: 16-byte aligned
* @param src source array of float.
* constraints: 16-byte aligned
* @param len number of elements to convert.
* constraints: multiple of 32 greater than zero
*/
void (*float_to_fixed24)(int32_t *dst, const float *src, unsigned int len);
} AC3DSPContext;
void ff_ac3dsp_init (AC3DSPContext *c, int bit_exact);
void ff_ac3dsp_init_arm(AC3DSPContext *c, int bit_exact);
void ff_ac3dsp_init_x86(AC3DSPContext *c, int bit_exact);
#endif /* AVCODEC_AC3DSP_H */