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hpeldsp.h
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1 /*
2  * Half-pel DSP functions.
3  * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
4  * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 /**
24  * @file
25  * Half-pel DSP functions.
26  */
27 
28 #ifndef AVCODEC_HPELDSP_H
29 #define AVCODEC_HPELDSP_H
30 
31 #include <stdint.h>
32 #include <stddef.h>
33 
34 /* add and put pixel (decoding) */
35 // blocksizes for hpel_pixels_func are 8x4,8x8 16x8 16x16
36 // h for hpel_pixels_func is limited to {width/2, width} but never larger
37 // than 16 and never smaller than 4
38 typedef void (*op_pixels_func)(uint8_t *block /*align width (8 or 16)*/,
39  const uint8_t *pixels /*align 1*/,
40  ptrdiff_t line_size, int h);
41 
42 /**
43  * Half-pel DSP context.
44  */
45 typedef struct HpelDSPContext {
46  /**
47  * Halfpel motion compensation with rounding (a+b+1)>>1.
48  * this is an array[4][4] of motion compensation functions for 4
49  * horizontal blocksizes (8,16) and the 4 halfpel positions<br>
50  * *pixels_tab[ 0->16xH 1->8xH ][ xhalfpel + 2*yhalfpel ]
51  * @param block destination where the result is stored
52  * @param pixels source
53  * @param line_size number of bytes in a horizontal line of block
54  * @param h height
55  */
57 
58  /**
59  * Halfpel motion compensation with rounding (a+b+1)>>1.
60  * This is an array[4][4] of motion compensation functions for 4
61  * horizontal blocksizes (8,16) and the 4 halfpel positions<br>
62  * *pixels_tab[ 0->16xH 1->8xH ][ xhalfpel + 2*yhalfpel ]
63  * @param block destination into which the result is averaged (a+b+1)>>1
64  * @param pixels source
65  * @param line_size number of bytes in a horizontal line of block
66  * @param h height
67  */
69 
70  /**
71  * Halfpel motion compensation with no rounding (a+b)>>1.
72  * this is an array[4][4] of motion compensation functions for 2
73  * horizontal blocksizes (8,16) and the 4 halfpel positions<br>
74  * *pixels_tab[ 0->16xH 1->8xH ][ xhalfpel + 2*yhalfpel ]
75  * @param block destination where the result is stored
76  * @param pixels source
77  * @param line_size number of bytes in a horizontal line of block
78  * @param h height
79  */
81 
82  /**
83  * Halfpel motion compensation with no rounding (a+b)>>1.
84  * this is an array[4] of motion compensation functions for 1
85  * horizontal blocksize (16) and the 4 halfpel positions<br>
86  * *pixels_tab[0][ xhalfpel + 2*yhalfpel ]
87  * @param block destination into which the result is averaged (a+b)>>1
88  * @param pixels source
89  * @param line_size number of bytes in a horizontal line of block
90  * @param h height
91  */
94 
96 
103 
104 #endif /* AVCODEC_HPELDSP_H */