Close ticket #59, change audio plugin during a conversation

disable the functionality

src/audio/alsalayer.cpp

@@ -59,6 +59,12 @@ AlsaLayer::closeLayer()
 AlsaLayer::openDevice (int indexIn, int indexOut, int sampleRate, int frameSize, int stream , std::string plugin) 
 {
 
+    // We don't accept that the audio plugin is changed during a conversation
+    if( _talk ){
+        _debug("can't switch audio plugin when talking\n. Please hang up and try again...\n");
+        return false;
+    }
+        
     if(deviceClosed == false)
     {
         if( stream == SFL_PCM_CAPTURE )
@@ -694,4 +700,4 @@ AlsaLayer::adjustVolume( void* buffer , int len, int stream )
     return src ; 
 }
 
-void AlsaLayer::setPlaybackVolume( double volume ){}
+void AlsaLayer::setPlaybackVolume( double volume UNUSED){}

src/managerimpl.cpp

@@ -1274,10 +1274,12 @@ ManagerImpl::setInputAudioPlugin(const std::string& audioPlugin)
   void
 ManagerImpl::setOutputAudioPlugin(const std::string& audioPlugin)
 {
-  //int layer = _audiodriver -> getLayerType();
+
+    int res;
+
   _debug("Set output audio plugin\n");
   _audiodriver -> setErrorMessage( -1 );
-  _audiodriver -> openDevice( _audiodriver -> getIndexIn(),
+  res = _audiodriver -> openDevice( _audiodriver -> getIndexIn(),
 			      _audiodriver -> getIndexOut(),
 			      _audiodriver -> getSampleRate(),
 			      _audiodriver -> getFrameSize(),
@@ -1286,7 +1288,7 @@ ManagerImpl::setOutputAudioPlugin(const std::string& audioPlugin)
   if( _audiodriver -> getErrorMessage() != -1)
     notifyErrClient( _audiodriver -> getErrorMessage() );
   // set config
-  setConfig( AUDIO , ALSA_PLUGIN , audioPlugin );
+  if(res)   setConfig( AUDIO , ALSA_PLUGIN , audioPlugin );
 }
 
 /**