Dialogic 6.2 Manuale Utente

Developing a Fax Application

November 2009

87

BT_ZERO(args_strip);

 

args_strip.fmt = DATA_G3;

 

args_strip.resolution = RES_200H_100V;

 

args_strip.width = WIDTH_A4;

 

BfvFaxStripParams(lp,&args_strip);

 

BT_ZERO(args_fax);

 

args_fax.fname = "g3_file";

 

args_fax.fmt = DATA_G3;

 

BfvFaxSendFile(lp, &args_fax);

 

BfvFaxEndOfDocument(lp, &args_fax);

Although applications can directly read and write TIFF-F files with 

a set of Bfv library functions, some knowledge of TIFF-F file format 

is useful.

The BfvTiffOpen and BfvTiffClose functions open and close 

TIFF-F files, respectively.

The BfvTiffReadIFD and BfvTiffReadImage functions read an 

opened TIFF file. BfvTiffReadIFD calls a user-supplied function 

repeatedly with IFD entry information stored in an IFD (Image File 

Directory) for a particular page. The application can use fseek to 

move to locations in the TIFF file as directed by the tags (using the 
TIFF_FP(tp)

 macro to get the file pointer) and BfvTiffReadRes to 

help determine the resolution, as is often needed. The 

BfvTiffReadImage function puts data into a user-supplied buffer 

until the end of the page is reached.

A sample program to read a TIFF-F file follows:

main()

 

{

 

    int my_ifd_func();

 

    TFILE *tp;

 

    unsigned char buf[1024];

 

    int n;

 

    struct args_tiff args_tiff;

 

    BT_ZERO(args_tiff);

 

    args_tiff.fname = "filename";

 

    args_tiff.fmode = "r";

 

    tp = BfvTiffOpen(&args_tiff);

 

    for (;;)

 

    {

 

    args_tiff.tp = tp;

 

    args_tiff.func = my_ifd_func;

 

    args_tiff.arg = NULL;

 

    if (BfvTiffReadIFD(&args_tiff) <= 0)

 

        break;

 

    args_tiff.buf = buf;

 

    args_tiff.size = sizeof(buf);