User:Robin Cornelius/OpenJPEG 1.3

Openjpeg 1.3 requires some patches in order to correctly work with SecondLife/Snowglobe

Patch 1 - Prevent random crash accessing meta data

--- openjpeg-1.3+dfsg.orig/libopenjpeg/image.c	2007-10-18 13:26:11.000000000 +0100
+++ openjpeg/libopenjpeg/image.c	2009-10-29 09:16:32.578125000 +0000
@@ -28,6 +28,7 @@
 
 opj_image_t* opj_image_create0(void) {
 	opj_image_t *image = (opj_image_t*)opj_malloc(sizeof(opj_image_t));
+	image->comps = NULL;
 	return image;
}

Patch 2 - Prevent transparent avatars

--- ./libopenjpeg/t1.c	2009-08-16 09:17:53.000000000 +0100
+++ ./libopenjpeg/t1.c	2009-08-16 09:21:42.000000000 +0100
@@ -738,14 +738,27 @@
 		double stepsize,
 		int numcomps)
 {
-	double w1, w2, wmsedec;
+	double w1 = 1, w2, wmsedec;
+	
+	// Prevent running an MCT on more than 3 components. NB openjpeg v2.0 will support this via
+	// custom MCT tables that can be passed as encode parameters, 1.3 cannot support this as it
+	// uses a static table of 3 entries and there for can only cope with 3 components with out an
+	// array overflow
+
+	if(numcomps==3) {
+	        if (qmfbid == 1) {
+			w1 = (numcomps > 1) ? mct_getnorm(compno) : 1.0;
+		} else {
+			w1 = (numcomps > 1) ? mct_getnorm_real(compno) : 1.0;	
+		}
+	}	
+
 	if (qmfbid == 1) {
-		w1 = (numcomps > 1) ? mct_getnorm(compno) : 1.0;
 		w2 = dwt_getnorm(level, orient);
 	} else {			/* if (qmfbid == 0) */
-		w1 = (numcomps > 1) ? mct_getnorm_real(compno) : 1.0;
 		w2 = dwt_getnorm_real(level, orient);
 	}
+
 	wmsedec = w1 * w2 * stepsize * (1 << bpno);
 	wmsedec *= wmsedec * nmsedec / 8192.0;