This is the appendix P preprocessor contributed by Mark Brand.It takes a stdin stream of input data and converts it into a formthat can be used by pdf417.  You can use this as a preprocessor.   Also, this code has beenincorporated into the pdf417 library as well in the form ofthe pdf417_prep_to_raw routine.   You can use a stream and theannex P algorith to generate the inputs to pdf417.   first call     pdf417_init_arrays();  the    pdf417_prep_to_raw( buffer, buffer_len ); then   pdf417_en( ...   );    // to create the symbol  or   pdf417_en_new(  );   to create a symbol