lavc: introduce VideoDSPContext

Move some functions from dsputil. The idea is that videodsp contains
functions that are useful for a large and varied set of video decoders.
Currently, it contains emulated_edge_mc() and prefetch().

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

libavcodec/arm/videodsp_init_arm.c

@@ -0,0 +1,29 @@
+/*
+ * Copyright (C) 2012 Ronald S. Bultje
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "libavutil/arm/cpu.h"
+#include "libavcodec/videodsp.h"
+#include "videodsp_arm.h"
+
+void ff_videodsp_init_arm(VideoDSPContext *ctx, int bpc)
+{
+    int cpu_flags = av_get_cpu_flags();
+    if (have_armv5te(cpu_flags)) ff_videodsp_init_armv5te(ctx, bpc);
+}