diff -ru swfmill-0.3.3_/src/swft/swft_import_jpeg.cpp swfmill-0.3.3/src/swft/swft_import_jpeg.cpp
--- swfmill-0.3.3_/src/swft/swft_import_jpeg.cpp	2016-10-25 14:28:36.560342480 +0000
+++ swfmill-0.3.3/src/swft/swft_import_jpeg.cpp	2016-10-25 14:27:42.640012522 +0000
@@ -10,7 +10,7 @@
 #include <zlib.h>
 
 #define TMP_STRLEN 0xff
-const char jpeg_header[] = { 0xff, 0xd9, 0xff, 0xd8, 0 };
+const char jpeg_header[] = { (char)0xff, (char)0xd9, (char)0xff, (char)0xd8, 0 };
 
 // defined in swft_import_png
 bool compress( unsigned char *inputBuffer, int inLength, unsigned char *outputBuffer, int *outLength );