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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 #include "avcodec.h"
24 #include "vp56dsp.h"
25 #include "libavutil/common.h"
26 
27 /* Gives very similar result than the vp6 version except in a few cases */
28 static int vp5_adjust(int v, int t)
29 {
30  int s2, s1 = v >> 31;
31  v ^= s1;
32  v -= s1;
33  v *= v < 2*t;
34  v -= t;
35  s2 = v >> 31;
36  v ^= s2;
37  v -= s2;
38  v = t - v;
39  v += s1;
40  v ^= s1;
41  return v;
42 }
43 
44 static int vp6_adjust(int v, int t)
45 {
46  int V = v, s = v >> 31;
47  V ^= s;
48  V -= s;
49  if (V-t-1 >= (unsigned)(t-1))
50  return v;
51  V = 2*t - V;
52  V += s;
53  V ^= s;
54  return V;
55 }
56 
57 
58 #define VP56_EDGE_FILTER(pfx, suf, pix_inc, line_inc) \
59 static void pfx##_edge_filter_##suf(uint8_t *yuv, int stride, int t) \
60 { \
61  int pix2_inc = 2 * pix_inc; \
62  int i, v; \
63  \
64  for (i=0; i<12; i++) { \
65  v = (yuv[-pix2_inc] + 3*(yuv[0]-yuv[-pix_inc]) - yuv[pix_inc] + 4)>>3;\
66  v = pfx##_adjust(v, t); \
67  yuv[-pix_inc] = av_clip_uint8(yuv[-pix_inc] + v); \
68  yuv[0] = av_clip_uint8(yuv[0] - v); \
69  yuv += line_inc; \
70  } \
71 }
72 
73 VP56_EDGE_FILTER(vp5, hor, 1, stride)
74 VP56_EDGE_FILTER(vp5, ver, stride, 1)
75 VP56_EDGE_FILTER(vp6, hor, 1, stride)
76 VP56_EDGE_FILTER(vp6, ver, stride, 1)
77 
79 {
80  if (codec == AV_CODEC_ID_VP5) {
81  s->edge_filter_hor = vp5_edge_filter_hor;
82  s->edge_filter_ver = vp5_edge_filter_ver;
83  } else {
84  s->edge_filter_hor = vp6_edge_filter_hor;
85  s->edge_filter_ver = vp6_edge_filter_ver;
86 
87  if (CONFIG_VP6_DECODER) {
88  s->vp6_filter_diag4 = ff_vp6_filter_diag4_c;
89  }
90  }
91 
92  if (ARCH_ARM) ff_vp56dsp_init_arm(s, codec);
93  if (ARCH_X86) ff_vp56dsp_init_x86(s, codec);
94 }