adiModifyPlayGain

Sets the play gain for the duration of the active play operation.

Supported board types

Prototype

DWORD adiModifyPlayGain ( CTAHD ctahd, int gain)

Argument	Description
ctahd	Context handle returned by ctaCreateContext or ctaAttachContext.
gain	The gain (dB) applied to the data as it is playing. The valid range is -54 through +24.

Return values

Return value	Description
SUCCESS
CTAERR_FUNCTION_NOT_ACTIVE	Play operation is not currently active.
CTAERR_INVALID_CTAHD	Context handle is invalid.
CTAERR_INVALID_STATE	Function not valid in the current port state.
CTAERR_SVR_COMM	Server communication error.

Details

Use adiModifyPlayGain to alter the gain applied to voice data as it is being transmitted. The gain remains set only for the current play operation instance. Values specified out of range are limited by the range.

Example

int myPlaySmartly( CTAHD ctahd, unsigned encoding,
                 void *buffer, unsigned bufsize )
{
  ADI_PLAY_PARMS playparms;
    CTA_EVENT event;
  int currentgain = 0;
  int currentspeed = 100;

  ctaGetParms( ADI_COLLECT_PARMID, &playparms, sizeof playparms );
  playparms.DTMFabort = 0x0; /* Don't abort on any DTMF */

  if( adiPlayFromMemory( ctahd, encoding,
                         buffer, bufsize, &playparms ) != SUCCESS )
      return MYFAILURE;

  do
  {
      myGetEvent( &event ); /* see ctaWaitEvent example */

      switch( event.id )
      {
          case ADIEVN_DIGIT_BEGIN:
              switch( (char)event.value )
              {
                    case '1': /* slower */
                        currentspeed -= 20;
                        adiModifyPlaySpeed( ctahd, currentspeed );
                        break;

                    case '3': /* faster */
                        currentspeed += 20;
                        adiModifyPlaySpeed( ctahd, currentspeed );
                        break;

                    case '4': /* softer */
                        currentgain -= 3; /* decrement 3 dB */
                        adiModifyPlayGain( ctahd, currentgain );
                        break;

                    case '6': /* louder */
                        currentgain += 3; /* increment 3 dB */
                        adiModifyPlayGain( ctahd, currentgain );
                        break;

                    default: /* ignore others */
                        break;
              }
                break;

          case ADIEVN_DIGIT_END: /* ignore end of dtmf */
          case 0: /* no event */
          default:
              break;
      }
  } while( event.id != ADIEVN_PLAY_DONE );

  if( event.value != CTA_REASON_FINISHED )
      return MYFAILURE;

  return SUCCESS;
}