Add blind-apply-kernel

Signed-off-by: Mattias Andrée <maandree@kth.se>

1 files changed, 159 insertions, 0 deletions

diff --git a/src/blind-apply-kernel.c b/src/blind-apply-kernel.c
new file mode 100644
index 0000000..6c00ab7
--- /dev/null
+++ b/src/blind-apply-kernel.c
@@ -0,0 +1,159 @@
+/* See LICENSE file for copyright and license details. */
+#ifndef TYPE
+#include "common.h"
+
+USAGE("[-apPxy] kernel-stream")
+
+static int no_alpha = 0;
+static int dont_premultiply = 0;
+static int per_pixel = 0;
+static int wrap_x = 0;
+static int wrap_y = 0;
+static size_t kern_w;
+static size_t kern_h;
+
+#define FILE "blind-apply-kernel.c"
+#include "define-functions.h"
+
+int
+main(int argc, char *argv[])
+{
+	struct stream colour, kernel;
+	void (*process)(struct stream *colour, struct stream *kernel);
+	size_t tmp;
+
+	ARGBEGIN {
+	case 'a':
+		no_alpha = 1;
+		break;
+	case 'p':
+		per_pixel = 1;
+		break;
+	case 'P':
+		dont_premultiply = 1;
+		break;
+	case 'x':
+		wrap_x = 1;
+		break;
+	case 'y':
+		wrap_y = 1;
+		break;
+	default:
+		usage();
+	} ARGEND;
+
+	if (argc != 1)
+		usage();
+
+	eopen_stream(&colour, NULL);
+	eopen_stream(&kernel, argv[0]);
+
+	SELECT_PROCESS_FUNCTION(&colour);
+	if (colour.encoding != kernel.encoding || colour.n_chan != kernel.n_chan)
+		eprintf("videos use incompatible pixel formats");
+	if (per_pixel && !(kernel.width % colour.width || kernel.height % colour.height))
+		eprintf("-p is specified but the dimensions of kernel-stream "
+		        "are not multiples of the dimensions of stdin.");
+
+	kern_w = per_pixel ? kernel.width  / colour.width  : kernel.width;
+	kern_h = per_pixel ? kernel.height / colour.height : kernel.height;
+
+	tmp = kernel.height, kernel.height = kern_h;
+	echeck_dimensions(&colour, WIDTH | HEIGHT, NULL);
+	echeck_dimensions(&kernel, WIDTH | HEIGHT, NULL);
+	kernel.height = tmp;
+
+	fprint_stream_head(stdout, &colour);
+	efflush(stdout, "<stdout>");
+	process(&colour, &kernel);
+	return 0;
+}
+
+#else
+
+static void
+PROCESS(struct stream *colour, struct stream *kernel)
+{
+	TYPE *out, *clr, *krn, *kern, *pix;
+	size_t i, x, y, n, x2, y2;
+	ssize_t cx, cy, xoff, yoff;
+
+	out = emalloc(colour->frame_size);
+	clr = emalloc(colour->frame_size);
+	krn = emalloc2(kern_h, kernel->row_size);
+
+	xoff = (ssize_t)(kern_w / 2);
+	yoff = (ssize_t)(kern_h / 2);
+
+	n = colour->width * colour->height * colour->n_chan;
+	while (eread_frame(colour, clr)) {
+		/* premultiply */
+		if (!no_alpha && !dont_premultiply) {
+			for (i = 0; i < n; i += 4) {
+				clr[i + 0] *= clr[i + 3];
+				clr[i + 1] *= clr[i + 3];
+				clr[i + 2] *= clr[i + 3];
+			}
+		}
+
+		/* apply kernel */
+		memset(out, 0, colour->frame_size);
+		pix = out;
+		for (y = 0; y < colour->height; y++) {
+			if ((!y || per_pixel) && !eread_segment(kernel, krn, kern_h * kernel->row_size))
+				goto done;
+			for (x = 0; x < colour->width; x++, pix += colour->n_chan) {
+				kern = per_pixel ? (krn + x * kern_w * kernel->n_chan) : krn;
+				for (y2 = 0; y2 < kern_h; y2++, kern += kernel->width * kernel->n_chan) {
+					cy = (ssize_t)(y + y2) - yoff;
+					if (cy < 0 || (size_t)cy >= colour->height) {
+						if (!wrap_y)
+							continue;
+						cy %= (ssize_t)(colour->height);
+						if (cy < 0)
+							cy += (ssize_t)(colour->height);
+					}
+					for (x2 = 0; x2 < kern_w; x2++) {
+						cx = (ssize_t)(x + x2) - xoff;
+						if (cx < 0 || (size_t)cx >= colour->width) {
+							if (!wrap_x)
+								continue;
+							cx %= (ssize_t)(colour->width);
+							if (cx < 0)
+								cx += (ssize_t)(colour->width);
+						}
+						for (i = 0; i < colour->n_chan; i++)
+							pix[i] += kern[x2 * kernel->n_chan + i] *
+							          clr[((size_t)cy * colour->width + (size_t)cx) * colour->n_chan + i];
+					}
+				}
+			}
+		}
+
+		/* unpremultiply */
+		if (!dont_premultiply) {
+			for (i = 0; i < n; i += 4) {
+				if (out[i + 3]) {
+					out[i + 0] /= out[i + 3];
+					out[i + 1] /= out[i + 3];
+					out[i + 2] /= out[i + 3];
+				}
+			}
+		}
+
+		/* ensure video is opaque if -a was used */
+		if (no_alpha)
+			for (i = 0; i < n; i += 4)
+				out[i + 3] = 1;
+
+		/* output video */
+		ewriteall(STDOUT_FILENO, out, colour->frame_size, "<stdout>");
+	}
+done:
+
+	free(out);
+	free(clr);
+	free(krn);
+}
+
+#endif