问题
I'm trying to use jpeglib to write a jpeg file to my own, without use the pre-build functions like jpeg_compress etc etc, but writing headers and tables individually... And here there are a lots of problem...
I'm using Windows and Visual Studio, so I tried to install the .exe file from gnuwin site and include in my code the 4 header files of the "include" folder, but when I try to call some functions like write_file_header, jpeg_stdio_dest etc etc, it says that there is a missing link, so I must include every .c file where those function are implemented...
I tried to include the src files too, but same result... every example I find includes only the header jpeglib.h and nothing else, but in this way I cannot use the functions I need, so my question is, how can I use those libraries properly? thank you
Edit: the error message is error C3861: identifier not found... simply, when i try to call some function situated in some .c file of the libjpeg, the compiler cannot found where those function are...
Edit n.2:here the start of function:
#include "jpeglib.h"
#include "jerror.h"
#include "Common.h"
void jpeg(unsigned int *Src, int srclen, unsigned int *cod, unsigned int *length){
struct jpeg_compress_struct cinfo;
write_file_header(&cinfo); <- here is the problem... how can i access that function?
回答1:
You should not include the .c files directly, you have to tell your compiler to link against the library like in this tutorial.
The jpeg library has to be built separately.
来源：https://stackoverflow.com/questions/11240447/how-to-use-jpeglib