X-Git-Url: http://git.asbjorn.biz/?a=blobdiff_plain;f=lib%2Fpng.c;h=8578d2dbee85551bca002de752f55abe85312b2f;hb=6a529bfa890997a55fec9ae0e0d388cf9d5276c2;hp=e30587204e14ed8571b98ab6b84598ef06721cac;hpb=4513e3be4df534f961bdca64480631fe798c67fb;p=swftools.git

diff --git a/lib/png.c b/lib/png.c
index e305872..8578d2d 100644
--- a/lib/png.c
+++ b/lib/png.c
@@ -99,12 +99,12 @@ static int png_read_header(FILE*fi, struct png_header*header)
     unsigned char*data;
     fread(head2,8,1,fi);
     if(strncmp((const char*)head,(const char*)head2,4))
-	return 0;
+	return 0; // not a png file
     
     while(png_read_chunk(&id, &len, &data, fi))
     {
 	//printf("Chunk: %c%c%c%c (len:%d)\n", id[0],id[1],id[2],id[3], len);
-	if(!strncasecmp(id, "IHDR", 4)) {
+	if(!strncmp(id, "IHDR", 4)) {
 	    char a,b,c,f,i;
 	    if(len < 8) exit(1);
 	    header->width = data[0]<<24|data[1]<<16|data[2]<<8|data[3];
@@ -197,6 +197,7 @@ static void applyfilter1(int mode, unsigned char*src, unsigned char*old, unsigne
     else if(mode==3) {
 	for(x=0;x<width;x++) {
 	    *dest = *src+(*old+last)/2;
+	    last = *dest;
 	    dest++;
 	    old++;
 	    src++;
@@ -439,7 +440,7 @@ static void inline applyfilter4(int mode, unsigned char*src, unsigned char*old,
 }
 
 
-EXPORT int getPNGdimensions(char*sname, int*destwidth, int*destheight)
+EXPORT int getPNGdimensions(const char*sname, int*destwidth, int*destheight)
 {
     FILE*fi;
     struct png_header header;
@@ -448,7 +449,6 @@ EXPORT int getPNGdimensions(char*sname, int*destwidth, int*destheight)
 	return 0;
     }
     if(!png_read_header(fi, &header)) {
-	fprintf(stderr, "Error reading header from file %s\n", sname);
 	return 0;
     }
 
@@ -457,7 +457,7 @@ EXPORT int getPNGdimensions(char*sname, int*destwidth, int*destheight)
     return 1;
 }
 
-EXPORT int getPNG(char*sname, int*destwidth, int*destheight, unsigned char**destdata)
+EXPORT int getPNG(const char*sname, int*destwidth, int*destheight, unsigned char**destdata)
 {
     char tagid[4];
     int len;
@@ -485,7 +485,6 @@ EXPORT int getPNG(char*sname, int*destwidth, int*destheight, unsigned char**dest
     }
 
     if(!png_read_header(fi, &header)) {
-	printf("Error reading header from file %s\n", sname);
 	return 0;
     }
 
@@ -619,6 +618,9 @@ EXPORT int getPNG(char*sname, int*destwidth, int*destheight, unsigned char**dest
 	int x,y;
 	int pos=0;
 	*destdata = data2;
+	
+	unsigned char* firstline = malloc(header.width*4);
+	memset(firstline,0,header.width*4);
 	for(y=0;y<header.height;y++) {
 	    int mode = imagedata[pos++]; //filter mode
 	    unsigned char*src;
@@ -639,8 +641,7 @@ EXPORT int getPNG(char*sname, int*destwidth, int*destheight, unsigned char**dest
 	    }
 
 	    if(!y) {
-		memset(data2,0,header.width*4);
-		old = &data2[y*header.width*4];
+		old = firstline;
 	    } else {
 		old = &data2[(y-1)*header.width*4];
 	    }
@@ -661,6 +662,7 @@ EXPORT int getPNG(char*sname, int*destwidth, int*destheight, unsigned char**dest
 		}
 	    }
 	}
+	free(firstline);
         free(imagedata);
     } else if(header.mode == 0 || header.mode == 3) {
 	COL*rgba = 0;
@@ -1009,7 +1011,7 @@ static void filter_line(int filtermode, unsigned char*dest, unsigned char*src, i
     }
 }
 
-EXPORT void writePNG(char*filename, unsigned char*data, int width, int height)
+EXPORT void writePNG(const char*filename, unsigned char*data, int width, int height)
 {
     FILE*fi;
     int crc;
@@ -1074,7 +1076,7 @@ EXPORT void writePNG(char*filename, unsigned char*data, int width, int height)
     long idatpos = png_start_chunk(fi, "IDAT", 0);
     
     memset(&zs,0,sizeof(z_stream));
-    Bytef*writebuf = malloc(ZLIB_BUFFER_SIZE);
+    Bytef*writebuf = (Bytef*)malloc(ZLIB_BUFFER_SIZE);
     zs.zalloc = Z_NULL;
     zs.zfree  = Z_NULL;
     zs.opaque = Z_NULL;