lavfi: Add infrastructure for building OpenCL source into libavfilter

libavfilter/Makefile

@@ -405,3 +405,9 @@ TOOLS-$(CONFIG_LIBZMQ) += zmqsend
 
 clean::
 	$(RM) $(CLEANSUFFIXES:%=libavfilter/libmpcodecs/%)
+
+OPENCL = $(subst $(SRC_PATH)/,,$(wildcard $(SRC_PATH)/libavfilter/opencl/*.cl))
+.SECONDARY: $(OPENCL:.cl=.c)
+libavfilter/opencl/%.c: TAG = OPENCL
+libavfilter/opencl/%.c: $(SRC_PATH)/libavfilter/opencl/%.cl
+	$(M)$(SRC_PATH)/tools/cl2c $< $@

libavfilter/opencl_source.h

@@ -0,0 +1,22 @@
+/*
+ * 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
+ */
+
+#ifndef AVFILTER_OPENCL_SOURCE_H
+#define AVFILTER_OPENCL_SOURCE_H
+
+#endif /* AVFILTER_OPENCL_SOURCE_H */

tools/cl2c

@@ -0,0 +1,20 @@
+#!/bin/sh
+# Convert an OpenCL source file into a C source file containing the
+# OpenCL source as a C string.  Also adds a #line directive so that
+# compiler messages are useful.
+
+input="$1"
+output="$2"
+
+name=$(basename "$input" | sed 's/.cl$//')
+
+cat >$output <<EOF
+// Generated from $input
+const char *ff_opencl_source_$name =
+"#line 1 \"$input\"\n"
+EOF
+
+# Convert \ to \\ and " to \", then add " to the start and end of the line.
+cat "$input" | sed 's/\\/\\\\/g;s/\"/\\\"/g;s/^/\"/;s/$/\\n\"/' >>$output
+
+echo ";" >>$output