VP56: move vp56_edge_filter to new VP56DSPContext

Using macro templates allows the vp[56]_adjust functions to be
inlined instead of called through function pointers.  The new
function pointers enable optimised implementations of the filters.

4% faster VP6 decoding on Cortex-A8.

Originally committed as revision 22992 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 86 insertions, 0 deletions

diff --git a/libavcodec/vp56dsp.c b/libavcodec/vp56dsp.c
new file mode 100644
index 0000000000..f9da3d78dd
--- /dev/null
+++ b/libavcodec/vp56dsp.c
@@ -0,0 +1,86 @@
+/*
+ * Copyright (c) 2006 Aurelien Jacobs <aurel@gnuage.org>
+ * Copyright (c) 2010 Mans Rullgard <mans@mansr.com>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <stdint.h>
+#include "avcodec.h"
+#include "vp56dsp.h"
+
+/* Gives very similar result than the vp6 version except in a few cases */
+static int vp5_adjust(int v, int t)
+{
+    int s2, s1 = v >> 31;
+    v ^= s1;
+    v -= s1;
+    v *= v < 2*t;
+    v -= t;
+    s2 = v >> 31;
+    v ^= s2;
+    v -= s2;
+    v = t - v;
+    v += s1;
+    v ^= s1;
+    return v;
+}
+
+static int vp6_adjust(int v, int t)
+{
+    int V = v, s = v >> 31;
+    V ^= s;
+    V -= s;
+    if (V-t-1 >= (unsigned)(t-1))
+        return v;
+    V = 2*t - V;
+    V += s;
+    V ^= s;
+    return V;
+}
+
+
+#define VP56_EDGE_FILTER(pfx, suf, pix_inc, line_inc)                   \
+static void pfx##_edge_filter_##suf(uint8_t *yuv, int stride, int t)    \
+{                                                                       \
+    int pix2_inc = 2 * pix_inc;                                         \
+    int i, v;                                                           \
+                                                                        \
+    for (i=0; i<12; i++) {                                              \
+        v = (yuv[-pix2_inc] + 3*(yuv[0]-yuv[-pix_inc]) - yuv[pix_inc] + 4)>>3;\
+        v = pfx##_adjust(v, t);                                         \
+        yuv[-pix_inc] = av_clip_uint8(yuv[-pix_inc] + v);               \
+        yuv[0] = av_clip_uint8(yuv[0] - v);                             \
+        yuv += line_inc;                                                \
+    }                                                                   \
+}
+
+VP56_EDGE_FILTER(vp5, hor, 1, stride)
+VP56_EDGE_FILTER(vp5, ver, stride, 1)
+VP56_EDGE_FILTER(vp6, hor, 1, stride)
+VP56_EDGE_FILTER(vp6, ver, stride, 1)
+
+void ff_vp56dsp_init(VP56DSPContext *s, enum CodecID codec)
+{
+    if (codec == CODEC_ID_VP5) {
+        s->edge_filter_hor = vp5_edge_filter_hor;
+        s->edge_filter_ver = vp5_edge_filter_ver;
+    } else {
+        s->edge_filter_hor = vp6_edge_filter_hor;
+        s->edge_filter_ver = vp6_edge_filter_ver;
+    }
+}