FFmpeg: libavcodec/vp56dsp.c Source File

00001 /*
00002  * Copyright (c) 2006 Aurelien Jacobs <aurel@gnuage.org>
00003  * Copyright (c) 2010 Mans Rullgard <mans@mansr.com>
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #include <stdint.h>
00023 #include "avcodec.h"
00024 #include "vp56dsp.h"
00025 #include "libavutil/common.h"
00026 
00027 /* Gives very similar result than the vp6 version except in a few cases */
00028 static int vp5_adjust(int v, int t)
00029 {
00030     int s2, s1 = v >> 31;
00031     v ^= s1;
00032     v -= s1;
00033     v *= v < 2*t;
00034     v -= t;
00035     s2 = v >> 31;
00036     v ^= s2;
00037     v -= s2;
00038     v = t - v;
00039     v += s1;
00040     v ^= s1;
00041     return v;
00042 }
00043 
00044 static int vp6_adjust(int v, int t)
00045 {
00046     int V = v, s = v >> 31;
00047     V ^= s;
00048     V -= s;
00049     if (V-t-1 >= (unsigned)(t-1))
00050         return v;
00051     V = 2*t - V;
00052     V += s;
00053     V ^= s;
00054     return V;
00055 }
00056 
00057 
00058 #define VP56_EDGE_FILTER(pfx, suf, pix_inc, line_inc)                   \
00059 static void pfx##_edge_filter_##suf(uint8_t *yuv, int stride, int t)    \
00060 {                                                                       \
00061     int pix2_inc = 2 * pix_inc;                                         \
00062     int i, v;                                                           \
00063                                                                         \
00064     for (i=0; i<12; i++) {                                              \
00065         v = (yuv[-pix2_inc] + 3*(yuv[0]-yuv[-pix_inc]) - yuv[pix_inc] + 4)>>3;\
00066         v = pfx##_adjust(v, t);                                         \
00067         yuv[-pix_inc] = av_clip_uint8(yuv[-pix_inc] + v);               \
00068         yuv[0] = av_clip_uint8(yuv[0] - v);                             \
00069         yuv += line_inc;                                                \
00070     }                                                                   \
00071 }
00072 
00073 VP56_EDGE_FILTER(vp5, hor, 1, stride)
00074 VP56_EDGE_FILTER(vp5, ver, stride, 1)
00075 VP56_EDGE_FILTER(vp6, hor, 1, stride)
00076 VP56_EDGE_FILTER(vp6, ver, stride, 1)
00077 
00078 void ff_vp56dsp_init(VP56DSPContext *s, enum AVCodecID codec)
00079 {
00080     if (codec == AV_CODEC_ID_VP5) {
00081         s->edge_filter_hor = vp5_edge_filter_hor;
00082         s->edge_filter_ver = vp5_edge_filter_ver;
00083     } else {
00084         s->edge_filter_hor = vp6_edge_filter_hor;
00085         s->edge_filter_ver = vp6_edge_filter_ver;
00086 
00087         if (CONFIG_VP6_DECODER) {
00088             s->vp6_filter_diag4 = ff_vp6_filter_diag4_c;
00089         }
00090     }
00091 
00092     if (ARCH_ARM) ff_vp56dsp_init_arm(s, codec);
00093     if (HAVE_MMX) ff_vp56dsp_init_x86(s, codec);
00094 }