From a6873099d06546003d4b2f738e418ca05e5f289b Mon Sep 17 00:00:00 2001
From: Frank Warmerdam <warmerdam@pobox.com>
Date: Wed, 31 Jul 2002 21:05:57 +0000
Subject: [PATCH] call TIFFGetField() on YCBCRSUBSAMPLING for tif_jpeg hack

---
 libtiff/tif_print.c | 15 +++++++++++++--
 libtiff/tif_strip.c | 19 ++++++++++++-------
 2 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/libtiff/tif_print.c b/libtiff/tif_print.c
index 5ceafbf4..2fe9acc9 100644
--- a/libtiff/tif_print.c
+++ b/libtiff/tif_print.c
@@ -1,4 +1,4 @@
-/* $Header: /cvs/maptools/cvsroot/libtiff/libtiff/tif_print.c,v 1.7 2002-03-27 06:31:29 warmerda Exp $ */
+/* $Header: /cvs/maptools/cvsroot/libtiff/libtiff/tif_print.c,v 1.8 2002-07-31 21:05:57 warmerda Exp $ */
 
 /*
  * Copyright (c) 1988-1997 Sam Leffler
@@ -319,8 +319,19 @@ TIFFPrintDirectory(TIFF* tif, FILE* fd, long flags)
 	}
 #ifdef YCBCR_SUPPORT
 	if (TIFFFieldSet(tif,FIELD_YCBCRSUBSAMPLING))
+        {
+            /*
+             * For hacky reasons (see tif_jpeg.c - JPEGFixupTestSubsampling),
+             * we need to fetch this rather than trust what is in our
+             * structures.
+             */
+            uint16 subsampling[2];
+
+            TIFFGetField( tif, TIFFTAG_YCBCRSUBSAMPLING, 
+                          subsampling + 0, subsampling + 1 );
 		fprintf(fd, "  YCbCr Subsampling: %u, %u\n",
-		    td->td_ycbcrsubsampling[0], td->td_ycbcrsubsampling[1]);
+                        subsampling[0], subsampling[1] );
+        }
 	if (TIFFFieldSet(tif,FIELD_YCBCRPOSITIONING)) {
 		fprintf(fd, "  YCbCr Positioning: ");
 		switch (td->td_ycbcrpositioning) {
diff --git a/libtiff/tif_strip.c b/libtiff/tif_strip.c
index c7c018a7..aecbb139 100644
--- a/libtiff/tif_strip.c
+++ b/libtiff/tif_strip.c
@@ -1,4 +1,4 @@
-/* $Header: /cvs/maptools/cvsroot/libtiff/libtiff/tif_strip.c,v 1.1 1999-07-27 21:50:27 mike Exp $ */
+/* $Header: /cvs/maptools/cvsroot/libtiff/libtiff/tif_strip.c,v 1.2 2002-07-31 21:05:57 warmerda Exp $ */
 
 /*
  * Copyright (c) 1991-1997 Sam Leffler
@@ -92,12 +92,17 @@ TIFFVStripSize(TIFF* tif, uint32 nrows)
 		 * horizontal/vertical subsampling area include
 		 * YCbCr data for the extended image.
 		 */
-		tsize_t w =
-		    TIFFroundup(td->td_imagewidth, td->td_ycbcrsubsampling[0]);
-		tsize_t scanline = TIFFhowmany(w*td->td_bitspersample, 8);
-		tsize_t samplingarea =
-		    td->td_ycbcrsubsampling[0]*td->td_ycbcrsubsampling[1];
-		nrows = TIFFroundup(nrows, td->td_ycbcrsubsampling[1]);
+                uint16 ycbcrsubsampling[2];
+                tsize_t w, scanline, samplingarea;
+
+                TIFFGetField( tif, TIFFTAG_YCBCRSUBSAMPLING, 
+                              ycbcrsubsampling + 0, 
+                              ycbcrsubsampling + 1 );
+
+		w = TIFFroundup(td->td_imagewidth, ycbcrsubsampling[0]);
+		scanline = TIFFhowmany(w*td->td_bitspersample, 8);
+		samplingarea = ycbcrsubsampling[0]*ycbcrsubsampling[1];
+		nrows = TIFFroundup(nrows, ycbcrsubsampling[1]);
 		/* NB: don't need TIFFhowmany here 'cuz everything is rounded */
 		return ((tsize_t)
 		    (nrows*scanline + 2*(nrows*scanline / samplingarea)));