- png_uint_32 s0=*(rp )<<8 | *(rp+1);
- png_uint_32 s1=*(rp+2)<<8 | *(rp+3);
- png_uint_32 s2=*(rp+4)<<8 | *(rp+5);
- png_uint_32 red=(s0-s1)&0xffff;
- png_uint_32 blue=(s2-s1)&0xffff;
- *(rp ) = (png_byte)((red>>8)&0xff);
- *(rp+1) = (png_byte)(red&0xff);
- *(rp+4) = (png_byte)((blue>>8)&0xff);
- *(rp+5) = (png_byte)(blue&0xff);
+ png_uint_32 s0 = (*(rp ) << 8) | *(rp+1);
+ png_uint_32 s1 = (*(rp+2) << 8) | *(rp+3);
+ png_uint_32 s2 = (*(rp+4) << 8) | *(rp+5);
+ png_uint_32 red = (png_uint_32)((s0 - s1) & 0xffffL);
+ png_uint_32 blue = (png_uint_32)((s2 - s1) & 0xffffL);
+ *(rp ) = (png_byte)((red >> 8) & 0xff);
+ *(rp+1) = (png_byte)(red & 0xff);
+ *(rp+4) = (png_byte)((blue >> 8) & 0xff);
+ *(rp+5) = (png_byte)(blue & 0xff);