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vp56dsp.c
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1 /*
2  * Copyright (c) 2006 Aurelien Jacobs <aurel@gnuage.org>
3  * Copyright (c) 2010 Mans Rullgard <mans@mansr.com>
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include <stdint.h>
23 
24 #include "libavutil/attributes.h"
25 #include "avcodec.h"
26 #include "vp56dsp.h"
27 #include "libavutil/common.h"
28 
29 /* Gives very similar result than the vp6 version except in a few cases */
30 static int vp5_adjust(int v, int t)
31 {
32  int s2, s1 = v >> 31;
33  v ^= s1;
34  v -= s1;
35  v *= v < 2*t;
36  v -= t;
37  s2 = v >> 31;
38  v ^= s2;
39  v -= s2;
40  v = t - v;
41  v += s1;
42  v ^= s1;
43  return v;
44 }
45 
46 static int vp6_adjust(int v, int t)
47 {
48  int V = v, s = v >> 31;
49  V ^= s;
50  V -= s;
51  if (V-t-1 >= (unsigned)(t-1))
52  return v;
53  V = 2*t - V;
54  V += s;
55  V ^= s;
56  return V;
57 }
58 
59 
60 #define VP56_EDGE_FILTER(pfx, suf, pix_inc, line_inc) \
61 static void pfx##_edge_filter_##suf(uint8_t *yuv, int stride, int t) \
62 { \
63  int pix2_inc = 2 * pix_inc; \
64  int i, v; \
65  \
66  for (i=0; i<12; i++) { \
67  v = (yuv[-pix2_inc] + 3*(yuv[0]-yuv[-pix_inc]) - yuv[pix_inc] + 4)>>3;\
68  v = pfx##_adjust(v, t); \
69  yuv[-pix_inc] = av_clip_uint8(yuv[-pix_inc] + v); \
70  yuv[0] = av_clip_uint8(yuv[0] - v); \
71  yuv += line_inc; \
72  } \
73 }
74 
75 VP56_EDGE_FILTER(vp5, hor, 1, stride)
76 VP56_EDGE_FILTER(vp5, ver, stride, 1)
77 VP56_EDGE_FILTER(vp6, hor, 1, stride)
78 VP56_EDGE_FILTER(vp6, ver, stride, 1)
79 
81 {
82  if (codec == AV_CODEC_ID_VP5) {
83  s->edge_filter_hor = vp5_edge_filter_hor;
84  s->edge_filter_ver = vp5_edge_filter_ver;
85  } else {
86  s->edge_filter_hor = vp6_edge_filter_hor;
87  s->edge_filter_ver = vp6_edge_filter_ver;
88 
89  if (CONFIG_VP6_DECODER) {
90  s->vp6_filter_diag4 = ff_vp6_filter_diag4_c;
91 
92  if (ARCH_ARM)
93  ff_vp6dsp_init_arm(s, codec);
94  if (ARCH_X86)
95  ff_vp6dsp_init_x86(s, codec);
96  }
97  }
98 }