Create Subversion repository

git-svn-id: http://svn.code.sf.net/p/netpbm/code/trunk@1 9d0c8265-081b-0410-96cb-a4ca84ce46f8

1 files changed, 97 insertions, 0 deletions

diff --git a/converter/ppm/ppmtoyuv.c b/converter/ppm/ppmtoyuv.c
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+/* ppmtoyuv.c - convert a portable pixmap into an Abekas YUV file
+**
+** by Marc Boucher
+** Internet: marc@PostImage.COM
+** 
+** Based on Example Conversion Program, A60/A64 Digital Video Interface
+** Manual, page 69.
+**
+** Copyright (C) 1991 by DHD PostImage Inc.
+** Copyright (C) 1987 by Abekas Video Systems Inc.
+**
+** 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"
+
+int
+main(argc, argv)
+char **argv;
+{
+	FILE *ifp;
+	pixel          *pixelrow;
+	register pixel *pP;
+	int             rows, cols, format, row;
+	register int    col;
+	pixval          maxval;
+	unsigned long   y1, y2=0, u=0, v=0, u0=0, u1, u2, v0=0, v1, v2;
+	unsigned char  *yuvbuf;
+
+
+	ppm_init(&argc, argv);
+
+	if (argc > 2) pm_usage("[ppmfile]");
+
+	if (argc == 2) ifp = pm_openr(argv[1]);
+	else ifp = stdin;
+
+	ppm_readppminit(ifp, &cols, &rows, &maxval, &format);
+
+    if (cols % 2 != 0)
+        pm_error("Image must have even number of columns.\n"
+                 "This image is %d columns wide.  Try Pnmcut.", cols);
+
+	pixelrow = ((pixel*) pm_allocrow( cols, sizeof(pixel) ));
+	yuvbuf = (unsigned char *) pm_allocrow( cols, 2 );
+
+	for (row = 0; row < rows; ++row) {
+		unsigned char *yuvptr;
+
+		ppm_readppmrow(ifp, pixelrow, cols, maxval, format);
+
+		for (col = 0, pP = pixelrow, yuvptr=yuvbuf; col < cols; col += 2, ++pP) {
+			pixval r, g, b;
+
+			/* first pixel gives Y and 0.5 of chroma */
+			r = PPM_GETR(*pP);
+			g = PPM_GETG(*pP);
+			b = PPM_GETB(*pP);
+
+			y1 = 16829 * r + 33039 * g + 6416 * b + (0xffff & y2);
+			u1 = -4853 * r - 9530 * g + 14383 * b;
+			v1 = 14386 * r - 12046 * g - 2340 * b;
+
+			pP++;
+			/* second pixel just yields a Y and 0.25 U, 0.25 V */
+			r = PPM_GETR(*pP);
+			g = PPM_GETG(*pP);
+			b = PPM_GETB(*pP);
+
+			y2 = 16829 * r + 33039 * g + 6416 * b + (0xffff & y1);
+			u2 = -2426 * r - 4765 * g + 7191 * b;
+			v2 = 7193 * r - 6023 * g - 1170 * b;
+
+			/* filter the chroma */
+			u = u0 + u1 + u2 + (0xffff & u);
+			v = v0 + v1 + v2 + (0xffff & v);
+
+			u0 = u2;
+			v0 = v2;
+
+			*yuvptr++ = (u >> 16) + 128;
+			*yuvptr++ = (y1 >> 16) + 16;
+			*yuvptr++ = (v >> 16) + 128;
+			*yuvptr++ = (y2 >> 16) + 16;
+		}
+		fwrite(yuvbuf, cols*2, 1, stdout);
+	}
+
+	pm_close(ifp);
+
+	exit(0);
+}