1 files changed, 115 insertions, 0 deletions
diff --git a/converter/ppm/yuvtoppm.c b/converter/ppm/yuvtoppm.c
new file mode 100644
index 00000000..2b44c65f
--- /dev/null
+++ b/converter/ppm/yuvtoppm.c
@@ -0,0 +1,115 @@
+/* yuvtoppm.c - convert Abekas YUV bytes into a portable pixmap
+**
+** by Marc Boucher
+** Internet: marc@PostImage.COM
+** 
+** Based on Example Conversion Program, A60/A64 Digital Video Interface
+** Manual, page 69
+**
+** Uses integer arithmetic rather than floating point for better performance
+**
+** Copyright (C) 1991 by DHD PostImage Inc.
+** Copyright (C) 1987 by Abekas Video Systems Inc.
+** Copyright (C) 1991 by Jef Poskanzer.
+**
+** Permission to use, copy, modify, and distribute this software and its
+** documentation for any purpose and without fee is hereby granted, provided
+** that the above copyright notice appear in all copies and that both that
+** copyright notice and this permission notice appear in supporting
+** documentation.  This software is provided "as is" without express or
+** implied warranty.
+*/
+
+#include "ppm.h"
+#include "mallocvar.h"
+
+/* x must be signed for the following to work correctly */
+#define limit(x) ((((x)>0xffffff)?0xff0000:(((x)<=0xffff)?0:(x)&0xff0000))>>16)
+
+int
+main(argc, argv)
+	char          **argv;
+{
+	FILE           *ifp;
+	pixel          *pixrow;
+	int             argn, rows, cols, row;
+	const char     * const usage = "<width> <height> [yuvfile]";
+    struct yuv {
+        /* This is an element of a YUV file.  It describes two 
+           side-by-side pixels.
+        */
+        unsigned char u;
+        unsigned char y1;
+        unsigned char v;
+        unsigned char y2;
+    } *yuvbuf;
+
+	ppm_init(&argc, argv);
+
+	argn = 1;
+
+	if (argn + 2 > argc)
+		pm_usage(usage);
+
+	cols = atoi(argv[argn++]);
+	rows = atoi(argv[argn++]);
+	if (cols <= 0 || rows <= 0)
+		pm_usage(usage);
+
+	if (argn < argc) {
+		ifp = pm_openr(argv[argn]);
+		++argn;
+	} else
+		ifp = stdin;
+
+	if (argn != argc)
+		pm_usage(usage);
+
+    if (cols % 2 != 0) {
+        pm_error("Number of columns (%d) is odd.  A YUV image must have an "
+                 "even number of columns.", cols);
+    }
+
+	ppm_writeppminit(stdout, cols, rows, (pixval) 255, 0);
+	pixrow = ppm_allocrow(cols);
+    MALLOCARRAY(yuvbuf, (cols+1)/2);
+    if (yuvbuf == NULL)
+        pm_error("Unable to allocate YUV buffer for %d columns.", cols);
+
+	for (row = 0; row < rows; ++row) {
+		int    col;
+
+		fread(yuvbuf, cols * 2, 1, ifp);
+
+		for (col = 0; col < cols; col += 2) {
+            /* Produce two pixels in pixrow[] */
+            int y1, u, v, y2, r, g, b;
+
+			u = yuvbuf[col/2].u-128;
+
+            y1 = yuvbuf[col/2].y1 - 16;
+			if (y1 < 0) y1 = 0;
+
+            v = yuvbuf[col/2].v - 128;
+
+            y2 = yuvbuf[col/2].y2 - 16;
+			if (y2 < 0) y2 = 0;
+
+			r = 104635 * v;
+			g = -25690 * u + -53294 * v;
+			b = 132278 * u;
+
+			y1*=76310; y2*=76310;
+
+			PPM_ASSIGN(pixrow[col], limit(r+y1), limit(g+y1), limit(b+y1));
+			PPM_ASSIGN(pixrow[col+1], limit(r+y2), limit(g+y2), limit(b+y2));
+		}
+		ppm_writeppmrow(stdout, pixrow, cols, (pixval) 255, 0);
+	}
+    free(yuvbuf);
+    ppm_freerow(pixrow);
+	pm_close(ifp);
+	pm_close(stdout);
+
+	exit(0);
+}