dtmf.cpp

sip 开源代码 源于novell sip 开源代码 源于novell

/*
 *  Copyright (C) 2004-2006 Savoir-Faire Linux inc.
 *  Author : Yan Morin <[e-mail]>
 *  Author : Laurielle Lea <[e-mail]> 
 *
 * 	Portions Copyright (c) 2000 Billy Biggs <[e-mail]>
 *  Portions Copyright (c) 2004 Wirlab <[e-mail]>
 *                                                                              
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *                                                                              
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *                                                                              
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include "dtmf.h"

DTMF::DTMF (unsigned int sampleRate) 
: dtmfgenerator(sampleRate) 
{
  currentTone = 0;
  newTone = 0;
}

DTMF::~DTMF (void) 
{
}

void 
DTMF::startTone (char code) 
{
  newTone = code;
}

bool 
DTMF::generateDTMF (SFLDataFormat* buffer, size_t n) 
{
  if (!buffer) return false;

  try {
    if (currentTone != 0) {
      // Currently generating a DTMF tone
      if (currentTone == newTone) {
        // Continue generating the same tone
        dtmfgenerator.getNextSamples(buffer, n);
        return true;
      } else if (newTone != 0) {
        // New tone requested
        dtmfgenerator.getSamples(buffer, n, newTone);
        currentTone = newTone;
        return true;
      } else {
        // Stop requested
        currentTone = newTone;
        return false;
      }
    } else {
      // Not generating any DTMF tone
      if (newTone) {
        // Requested to generate a DTMF tone
        dtmfgenerator.getSamples(buffer, n, newTone);
        currentTone = newTone;
        return true;
      }
      return false;
    }
  } catch(DTMFException e) {
    // invalid key
    return false;
  }
}