ATFX_WIDTH( )

Description | Example | Errors

Name:	long ATFX_WIDTH(dev)
Inputs:	int dev	fax channel device handle
Returns:	Width of transferred page if successful
	AT_FAILURE if error
Includes:	srllib.h
	dxxxlib.h
	faxlib.h
Category:	extended attribute
Mode:	synchronous

Description

The ATFX_WIDTH( ) function returns the decimal value of the negotiated width (in pixels per line) of the fax page transmitted. Valid values are:

1728	(pixels per line)
2048	(pixels per line)
2432	(pixels per line)

Parameter	Description
dev	Specifies the channel device handle for the fax channel obtained when the channel was opened.

The data provided by this function is updated each time the fax transfer completes Phase D of the T.30 protocol.

To monitor width, you must enable Phase D events and issue ATFX_WIDTH( ) when the TFX_PHASED event occurs. Note that since Phase D also occurs at the end of a send or receive when a Phase D event is not generated, you can also issue this function after a TFX_FAXSEND or TFX_FAXRECV event.

The width value returned by ATFX_WIDTH( ) at the end of a fax session remains available to the application until a new send or receive is initiated on that channel.

NOTE:

Between multiple Phase D completions during the same fax session, ATFX_WIDTH( ) returns the width information from the previously completed page.

If you have enabled generation of Phase D events, you can call ATFX_WIDTH( ) in the handler routine for the Phase D event to determine the width of the transferred page (see programming example).

Example

#include <stdio.h>  
#include <windows.h>  
#include <srllib.h>  
#include <dxxxlib.h>  
#include <faxlib.h>  
DF_IOTT iott[10];  
int dev;  
/* Handler for Phase D events. */  
int phd_hdlr( );  
main( )  
{  
   /*  
    * Open the channel using fx_open( ) and obtain the Dialogic  
    * FAX device handle in dev.  
    */  
   .  
   .  
   /*  
    * Install handler to service TFX_PHASED events.  
    */  
    if (sr_enbhdlr(dev, TFX_PHASED, phd_hdlr) == -1) {  
        printf("Failed to install Phase D handler \n");  
        return;  
}  
    
   /*  
    * Call fx_sendfax( ) in synchronous mode after setting  
    * up the DF_IOTT array. Set DF_PHASED bit in mode field  
    * to enable generation of Phase D events.  
    */  
   if (fx_sendfax(dev, iott, EV_SYNC|DF_PHASED) == -1) {  
      printf("Error - %s (error code %d)\n",  
         ATDV_ERRMSGP(dev), ATDV_LASTERR(dev));  
      if (ATDV_LASTERR(dev)==EDX_SYSTEM) {  
         /* Perform system error processing */  
      }  
   }  
   /*  
    * Width of the page just transferred is available at  
    * this point.  
    */  
   printf("Page width: %ld\n", ATFX_WIDTH(dev));  
   .  
   .  
}  
/*  
 * Handler registered with SRL to handle TFX_PHASED events.  
 */  
int phd_hdlr( )  
{  
   int dev = sr_getevtdev( );  
   /*  
    * Width of the page just transferred is available at  
    * this point.  
    */  
   printf("Page width: %ld\n", ATFX_WIDTH(dev));  
   .  
   .  
   return(0);  
}

Errors

If one of the following conditions is present, this function fails and returns AT_FAILURE:

• An invalid fax channel device handle is specified in dev.
• The function is called prior to the completion of the first Phase D event.

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