LIA_SpkDet/SimpleSpkDetSystem: Added accessors for the decision thres…

…hold.

The threshold is used in verifySpeaker() and identifySpeaker() to decide whether the tested voice is a match for the target model.
Previously, its value could only be set through the configuration file, and could not be retrieved directly (apart from parsing the configuration file). It can now be adjusted during the use of the system.

LIA_SpkDet/SimpleSpkDetSystem/include/SimpleSpkDetSystem.h

@@ -31,6 +31,8 @@ namespace alize
         bool isUBMLoaded();
         vector<String> speakerIDs();
 		void setOption(String opt, String optValue);
+	    double decisionThreshold();
+	    void setDecisionThreshold(double newValue);
 
 	    void addAudio(uint32_t sampleCount, int16_t *samples);  // for 16 bit linear PCM
 		void addAudio(uint32_t dataSize, void *data);           // for other formats (following the format specified in the configuration file)
@@ -63,6 +65,7 @@ namespace alize
 		StatServer* _ss;                        ///< stat server
         Config* _config;                        ///< configuration file
 	    String _workdirPath;                    ///< working directory (for model storage + temp files)
+	    double _decisionThreshold;              ///< for score comparison in verifySpeaker and identifySpeaker
 		XLine lstFeatureFile;                   ///< list of feature files loaded in the feature server
 		vector<unsigned long> featureCounts;    ///< size of each feature file in the feature server
         struct ScoreAcc;

LIA_SpkDet/SimpleSpkDetSystem/src/SimpleSpkDetSystem.cpp

@@ -577,6 +577,27 @@ void SimpleSpkDetSystem::setOption(String opt, String optValue) {
 	//		Probably not worth the trouble.
 }
 
+/*! \fn void SimpleSpkDetSystem::decisionThreshold()
+ *  \brief  Returns the theshold used in verifySpeaker() and identifySpeaker()
+ *          Only speakers with scores higher than the decision threshold will be
+ *          considered a match for the target speaker.
+ */
+double SimpleSpkDetSystem::decisionThreshold() {
+	return _decisionThreshold;
+}
+
+/*! \fn void SimpleSpkDetSystem::setDecisionThreshold(double newValue)
+ *  \brief  Sets the theshold used in verifySpeaker() and identifySpeaker()
+ *          Only speakers with scores higher than the decision threshold will be
+ *          considered a match for the target speaker.
+ *
+ *  \param[in]      newValue        the new decision threshold
+ */
+void SimpleSpkDetSystem::setDecisionThreshold(double newValue) {
+	_decisionThreshold = newValue;
+}
+
+
 
 
 /*! \fn void SimpleSpkDetSystem::resetAudio()
@@ -960,7 +981,6 @@ void SimpleSpkDetSystem::createSpeakerModel(String uId) {
  *  \return true if the features match the given speaker, otherwise false
  */
 bool SimpleSpkDetSystem::verifySpeaker(String targetSpeakerId, float &resultingScore, bool withScoreAccumulation) {
-	double threshold=0.0;
 	int idx = _ms->getMixtureIndex(targetSpeakerId);
 	if(idx==-1)
 		throw Exception("Mixture not found: "+targetSpeakerId, __FILE__, __LINE__);
@@ -993,9 +1013,7 @@ bool SimpleSpkDetSystem::verifySpeaker(String targetSpeakerId, float &resultingS
 		}
 	}
 
-	if (_config->existsParam("threshold"))
-		threshold=(_config->getParam("threshold")).toDouble();
-	return (resultingScore > threshold);
+	return (resultingScore > _decisionThreshold);
 }
 
 
@@ -1058,11 +1076,7 @@ bool SimpleSpkDetSystem::identifySpeaker(String &foundSpeakerId, float &resultin
 	foundSpeakerId = _ms->getMixture(bestScoreIndex).getId();
 	resultingScore = bestScore;
 
-	double threshold=0.0;
-	if (_config->existsParam("threshold"))
-		threshold=(_config->getParam("threshold")).toDouble();
-
-	return (bestScore > threshold);
+	return (bestScore > _decisionThreshold);
 }
 
 
@@ -1147,6 +1161,11 @@ SimpleSpkDetSystem::SimpleSpkDetSystem(Config &config, String workdirPath) {
 	} else {
 		verboseLevel = verbose ? 1 : 0;
 	}
+
+	if (_config->existsParam("threshold"))
+		_decisionThreshold = (_config->getParam("threshold")).toDouble();
+	else
+		_decisionThreshold = 0.0;
 
 	_fs=new FeatureServer(*_config);
 	_ms=new MixtureServer(*_config);