1 files changed, 94 insertions, 0 deletions
diff --git a/src/blind-temporal-arithm.c b/src/blind-temporal-arithm.c
new file mode 100644
index 0000000..f9f7b51
--- /dev/null
+++ b/src/blind-temporal-arithm.c
@@ -0,0 +1,94 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+USAGE("operation")
+
+/* Because the syntax for a function returning a function pointer is disgusting. */
+typedef void (*process_func)(struct stream *stream, void *image);
+
+#define LIST_OPERATORS(PIXFMT, TYPE)\
+	X(add, *img + *buf,     PIXFMT, TYPE)\
+	X(mul, *img * *buf,     PIXFMT, TYPE)\
+	X(min, MIN(*img, *buf), PIXFMT, TYPE)\
+	X(max, MAX(*img, *buf), PIXFMT, TYPE)
+
+#define X(NAME, ALGO, PIXFMT, TYPE)\
+	static void\
+	process_##PIXFMT##_##NAME(struct stream *stream, void *image)\
+	{\
+		TYPE *buf, *img = image;\
+		size_t i, n, j = 0, m = stream->frame_size / sizeof(TYPE);\
+		do {\
+			n = stream->ptr / sizeof(TYPE);\
+			buf = (TYPE *)(stream->buf);\
+			for (i = 0; i < n; i++, buf++) {\
+				*img = ALGO;\
+				if (++j == m) {\
+					j = 0;\
+					img = image;\
+				} else {\
+					img++;\
+				}\
+			}\
+			n *= sizeof(TYPE);\
+			memmove(stream->buf, stream->buf + n, stream->ptr -= n);\
+		} while (eread_stream(stream, SIZE_MAX));\
+	}
+LIST_OPERATORS(lf, double)
+LIST_OPERATORS(f, float)
+#undef X
+
+static process_func
+get_process_lf(const char *operation)
+{
+#define X(NAME, _ALGO, PIXFMT, TYPE)\
+	if (!strcmp(operation, #NAME)) return process_##PIXFMT##_##NAME;
+	LIST_OPERATORS(lf, double)
+#undef X
+	eprintf("algorithm not recognised: %s\n", operation);
+	return NULL;
+}
+
+static process_func
+get_process_f(const char *operation)
+{
+#define X(NAME, _ALGO, PIXFMT, TYPE)\
+	if (!strcmp(operation, #NAME)) return process_##PIXFMT##_##NAME;
+	LIST_OPERATORS(f, float)
+#undef X
+	eprintf("algorithm not recognised: %s\n", operation);
+	return NULL;
+}
+
+int
+main(int argc, char *argv[])
+{
+	struct stream stream;
+	process_func process;
+	char *img;
+
+	UNOFLAGS(argc != 1);
+
+	eopen_stream(&stream, NULL);
+
+	if (stream.encoding == DOUBLE)
+		process = get_process_lf(argv[0]);
+	else
+		process = get_process_f(argv[0]);
+
+	echeck_dimensions(&stream, WIDTH | HEIGHT, NULL);
+	img = emalloc(stream.frame_size);
+	if (!eread_frame(&stream, img))
+		eprintf("video has no frames\n");
+
+	process(&stream, img);
+	if (stream.ptr)
+		eprintf("%s: incomplete frame\n", stream.file);
+
+	stream.frames = 1;
+	fprint_stream_head(stdout, &stream);
+	efflush(stdout, "<stdout>");
+	ewriteall(STDOUT_FILENO, img, stream.frame_size, "<stdout>");
+	free(img);
+	return 0;
+}