dcb_setcde( )

Description | Cautions | Example | Errors | See Also

Name:	int dcb_setcde(devh,confid,cdt)
Inputs:	int devh	DCB/SC DSP device handle
	int confid	conference identifier
	MS_CDT *cdt	pointer to conference descriptor table element
Returns:	0 on success
	-1 on failure
Includes:	srllib.h
	dtilib.h
	msilib.h
	dcblib.h
Category:	Conference Management
Mode:	synchronous

Description

The dcb_setcde( ) function changes the attributes of a conferee in an existing conference.

Parameter	Description
devh:	The DCB/SC DSP device handle.
confid:	The conference identifier number.
cdt:	Pointer to the conference descriptor table element.

The conference descriptor table is an array of the MS_CDT structure. The MS_CDT structure has the following format:

typedef struct {  
          int chan_num;      /* SCbus time slot number */  
          int chan_sel;      /* time slot selector */  
          int chan_attr;     /* attribute description */  
} MS_CDT;

The chan_num denotes the time slot number of the device to be included in the conference. The chan_sel defines the meaning of the chan_num. At present, chan_sel must be set to the following value:

• MSPN_TS SCbus time slot number

The chan_attr is a bitmask describing the conferee's properties within the conference. It can have one or more of the following values ORed together:

• MSPA_NULL No special attributes.
• MSPA_RO Conferee participates in conference in receive-only
  mode.
• MSPA_TARIFF Conferee receives periodic tone for duration of call.
• MSPA_COACH Conferee is a coach. Coach is heard by pupil only.
• MSPA_PUPIL Conferee is a pupil. Pupil hears everyone including
  coach.

NOTE:

If the conferee attributes of more than one conferee are to be set, this function must be called multiple times.

Table 6. Valid Attribute Combinations

Pupil	Coach	Periodic Tone	Receive-only mode
			X
		X
		X	X
	X
X
X		X

NOTES:

1. Only one coach and one pupil are allowed in a conference at any time.

2. The default MSPA_NULL must be used if channel attributes are not set.

3. Invalid attribute combinations may lead to unexpected results.

Cautions

This function fails when:

• The device handle specified is invalid.
• The conference ID is invalid.

Example

#include <windows.h>  
#include <stdio.h>  
#include "srllib.h"  
#include "dtilib.h"  
#include "msilib.h"  
#include "dcblib.h"  
#include "errno.h"  
#define   NUM_PARTIES   2  
main()   
{  
   int  dspdevh;               /* DCB/SC DSP device handle */  
   MS_CDT  cdt[NUM_PARTIES];   /* Conference descriptor table */  
   int  confid;                /* Conference ID */  
   int  tsdevh1, tsdevh2;      /* DTI time slot device handle */  
   long  scts;                 /* SCbus transmit time slot */  
   SC_TSINFO  tsinfo;          /* Time slot information structure */  
   /* Open DCB/SC board 1, DSP 3 device */  
   if ((dspdevh = dcb_open("dcbB1D3",0)) == -1) {  
      printf("Cannot open dcbB1D3 : errno = %d", errno);  
      exit(1);  
   }  
   /* Open DTI board 1, time slot 1 */  
   if ((tsdevh1 = dt_open("dtiB1T1",0)) == -1) {  
      printf( "Cannot open dtiB1T1: errno=%d", errno);    
      exit(1);  
   }  
   /* Prepare time slot information structure */  
   tsinfo.sc_numts = 1;  
   tsinfo.sc_tsarrayp = &scts;  
   /* get transmit time slot of DTI tsdevh1 */  
   if (dt_getxmitslot(tsdevh1, &tsinfo) == -1){  
      printf("Error Message : %s", ATDV_ERRMSGP(tsdevh1));  
      exit(1);  
   }  
   /* Set up CDT structure */  
   cdt[0].chan_num  = (int)scts;     /* SCbus time slot returned */  
   cdt[0].chan_sel  = MSPN_TS;       /* by dt_getxmitslot() */  
   cdt[0].chan_attr = MSPA_TARIFF;   /* Conferee will receive period tariff tones */ 
  
   /* Open DTI board 1, time slot 2 */  
   if ((tsdevh2 = dt_open("dtiB1T2",0)) == -1) {  
      printf( "Cannot open dtiB1T2 : errno = %d", errno);    
      exit(1);  
   }  
   /* Get transmit time slot of DTI tsdevh2 */  
   if (dt_getxmitslot(tsdevh2, &tsinfo) == -1){  
      printf("Error Message = %s", ATDV_ERRMSGP(tsdevh2));  
      exit(1);  
   }  
   /* Set up CDT structure */  
   cdt[1].chan_num  = (int)scts;    /* SCbus time slot returned */  
   cdt[1].chan_sel  = MSPN_TS;      /* returned from getxmitslot */  
   cdt[1].chan_attr = MSPA_PUPIL;   /* Conferee may be coached later */  
   /* Establish a 2 party conference */  
   if (dcb_estconf(dspdevh, cdt, NUM_PARTIES, MSCA_ND, &confid) == -1){  
      printf("Error Message = %s",ATDV_ERRMSGP(dspdevh));  
      exit(1);  
   }  
   /* Do a listen for tsdevh1 */  
   tsinfo.sc_numts = 1;  
   tsinfo.sc_tsarrayp = &cdt[0].chan_lts;  
   if (dt_listen(tsdevh1,&tsinfo) == -1){  
      printf("Error Message : %s", ATDV_ERRMSGP(tsdevh1));  
      exit(1);  
   }
  
   /* Do a listen for tsdevh2 */  
   tsinfo.sc_numts = 1;  
   tsinfo.sc_tsarrayp = &cdt[1].chan_lts;  
   if (dt_listen(tsdevh2,&tsinfo) == -1){  
      printf("Error Message : %s", ATDV_ERRMSGP(tsdevh2));  
      exit(1);  
   }  
   /* Now change the attribute of the last added conferee */  
   /* NOTE : scts still contains the transmit time slot of tsdevh2 */  
   cdt[0].chan_num = (int)scts;  
   cdt[0].chan_sel = MSPN_TS;  
   cdt[0].chan_attr = MSPA_TARIFF;  
   if((dcb_setcde(dspdevh, confid, &cdt[0])) == -1) {  
     printf("Error Message : %s", ATDV_ERRMSGP(dspdevh));  
     exit(1);  
   }  
   /* Perform 'unlistens' on the listening DTI time slots */  
   if (dt_unlisten(tsdevh1) == -1){  
      printf("Error Message : %s", ATDV_ERRMSGP(tsdevh1));  
      exit(1);  
   }  
   if (dt_unlisten(tsdevh2) == -1){  
      printf("Error Message : %s", ATDV_ERRMSGP(tsdevh2));  
      exit(1);  
   }  
   /* Delete the conference */  
   if(dcb_delconf(dspdevh, confid) == -1) {  
      printf("Cannot delete conference %d. Error Message = %s", confid,  
              ATDV_ERRMSGP(dspdevh));  
      exit(1);  
   }  
   /* Close all open devices */  
   if (dt_close(tsdevh1) == -1){  
      printf("Error closing tsdevh1\n");  
      exit(1);  
   }  
   if (dt_close(tsdevh2) == -1){  
      printf("Error closing tsdevh2\n");  
      exit(1);  
   }  
   if (dcb_close(dspdevh) == -1){  
      printf("Cannot close dcbB1D3 : errno = %d\n", errno);  
      exit(1);  
   }  
   
}

Errors

If the function does not complete successfully, it will return -1 to indicate an error. Use the Standard Attribute functions ATDV_LASTERR( ) to obtain the applicable error value, or ATDV_ERRMSGP( ) to obtain a more descriptive error message.

Refer to the error type tables found in Chapter 2 of this guide. Error defines can be found in dtilib.h, msilib.h or dcblib.h.

See Also

• dcb_addtoconf( )
• dcb_estconf( )
• dcb_getcde( )

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