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 Libav.
6  *
7  * Libav 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  * Libav 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 Libav; 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 
26 /* Gives very similar result than the vp6 version except in a few cases */
27 static int vp5_adjust(int v, int t)
28 {
29  int s2, s1 = v >> 31;
30  v ^= s1;
31  v -= s1;
32  v *= v < 2*t;
33  v -= t;
34  s2 = v >> 31;
35  v ^= s2;
36  v -= s2;
37  v = t - v;
38  v += s1;
39  v ^= s1;
40  return v;
41 }
42 
43 static int vp6_adjust(int v, int t)
44 {
45  int V = v, s = v >> 31;
46  V ^= s;
47  V -= s;
48  if (V-t-1 >= (unsigned)(t-1))
49  return v;
50  V = 2*t - V;
51  V += s;
52  V ^= s;
53  return V;
54 }
55 
56 
57 #define VP56_EDGE_FILTER(pfx, suf, pix_inc, line_inc) \
58 static void pfx##_edge_filter_##suf(uint8_t *yuv, int stride, int t) \
59 { \
60  int pix2_inc = 2 * pix_inc; \
61  int i, v; \
62  \
63  for (i=0; i<12; i++) { \
64  v = (yuv[-pix2_inc] + 3*(yuv[0]-yuv[-pix_inc]) - yuv[pix_inc] + 4)>>3;\
65  v = pfx##_adjust(v, t); \
66  yuv[-pix_inc] = av_clip_uint8(yuv[-pix_inc] + v); \
67  yuv[0] = av_clip_uint8(yuv[0] - v); \
68  yuv += line_inc; \
69  } \
70 }
71 
72 VP56_EDGE_FILTER(vp5, hor, 1, stride)
73 VP56_EDGE_FILTER(vp5, ver, stride, 1)
74 VP56_EDGE_FILTER(vp6, hor, 1, stride)
75 VP56_EDGE_FILTER(vp6, ver, stride, 1)
76 
78 {
79  if (codec == CODEC_ID_VP5) {
80  s->edge_filter_hor = vp5_edge_filter_hor;
81  s->edge_filter_ver = vp5_edge_filter_ver;
82  } else {
83  s->edge_filter_hor = vp6_edge_filter_hor;
84  s->edge_filter_ver = vp6_edge_filter_ver;
85 
86  if (CONFIG_VP6_DECODER) {
87  s->vp6_filter_diag4 = ff_vp6_filter_diag4_c;
88  }
89  }
90 
91  if (ARCH_ARM) ff_vp56dsp_init_arm(s, codec);
92  if (HAVE_MMX) ff_vp56dsp_init_x86(s, codec);
93 }