FFmpeg/libavcodec/hpeldsp.h
Clément Bœsch 6426c58b1c Merge commit '48b80f8393d418ad35d73f5a36f5011de1928f3c'
* commit '48b80f8393d418ad35d73f5a36f5011de1928f3c':
  hpeldsp: Explain why put_no_rnd_pixels_tab is larger than necessary

Merged-by: Clément Bœsch <cboesch@gopro.com>
2017-03-15 12:34:51 +01:00

107 lines
4.0 KiB
C

/*
* Half-pel DSP functions.
* Copyright (c) 2000, 2001, 2002 Fabrice Bellard
* Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
*
* 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
* Half-pel DSP functions.
*/
#ifndef AVCODEC_HPELDSP_H
#define AVCODEC_HPELDSP_H
#include <stdint.h>
#include <stddef.h>
/* add and put pixel (decoding) */
// blocksizes for hpel_pixels_func are 8x4,8x8 16x8 16x16
// h for hpel_pixels_func is limited to {width/2, width} but never larger
// than 16 and never smaller than 4
typedef void (*op_pixels_func)(uint8_t *block /*align width (8 or 16)*/,
const uint8_t *pixels /*align 1*/,
ptrdiff_t line_size, int h);
/**
* Half-pel DSP context.
*/
typedef struct HpelDSPContext {
/**
* Halfpel motion compensation with rounding (a+b+1)>>1.
* this is an array[4][4] of motion compensation functions for 4
* horizontal blocksizes (8,16) and the 4 halfpel positions<br>
* *pixels_tab[ 0->16xH 1->8xH ][ xhalfpel + 2*yhalfpel ]
* @param block destination where the result is stored
* @param pixels source
* @param line_size number of bytes in a horizontal line of block
* @param h height
*/
op_pixels_func put_pixels_tab[4][4];
/**
* Halfpel motion compensation with rounding (a+b+1)>>1.
* This is an array[4][4] of motion compensation functions for 4
* horizontal blocksizes (8,16) and the 4 halfpel positions<br>
* *pixels_tab[ 0->16xH 1->8xH ][ xhalfpel + 2*yhalfpel ]
* @param block destination into which the result is averaged (a+b+1)>>1
* @param pixels source
* @param line_size number of bytes in a horizontal line of block
* @param h height
*/
op_pixels_func avg_pixels_tab[4][4];
/**
* Halfpel motion compensation with no rounding (a+b)>>1.
* this is an array[4][4] of motion compensation functions for 2
* horizontal blocksizes (8,16) and the 4 halfpel positions<br>
* *pixels_tab[ 0->16xH 1->8xH ][ xhalfpel + 2*yhalfpel ]
* @param block destination where the result is stored
* @param pixels source
* @param line_size number of bytes in a horizontal line of block
* @param h height
* @note The size is kept at [4][4] to match the above pixel_tabs and avoid
* out of bounds reads in the motion estimation code.
*/
op_pixels_func put_no_rnd_pixels_tab[4][4];
/**
* Halfpel motion compensation with no rounding (a+b)>>1.
* this is an array[4] of motion compensation functions for 1
* horizontal blocksize (16) and the 4 halfpel positions<br>
* *pixels_tab[0][ xhalfpel + 2*yhalfpel ]
* @param block destination into which the result is averaged (a+b)>>1
* @param pixels source
* @param line_size number of bytes in a horizontal line of block
* @param h height
*/
op_pixels_func avg_no_rnd_pixels_tab[4];
} HpelDSPContext;
void ff_hpeldsp_init(HpelDSPContext *c, int flags);
void ff_hpeldsp_init_aarch64(HpelDSPContext *c, int flags);
void ff_hpeldsp_init_alpha(HpelDSPContext *c, int flags);
void ff_hpeldsp_init_arm(HpelDSPContext *c, int flags);
void ff_hpeldsp_init_ppc(HpelDSPContext *c, int flags);
void ff_hpeldsp_init_x86(HpelDSPContext *c, int flags);
void ff_hpeldsp_init_mips(HpelDSPContext *c, int flags);
#endif /* AVCODEC_HPELDSP_H */