diff --git a/src/main.cpp b/src/main.cpp
index 4de916e..ec9e1fe 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -166,7 +166,7 @@ void CVisualizationShadertoy::Render()
   }
 }
 
-bool CVisualizationShadertoy::Start(int iChannels, int iSamplesPerSec, int iBitsPerSample, std::string szSongName)
+bool CVisualizationShadertoy::Start(int iChannels, int iSamplesPerSec, int iBitsPerSample, const std::string& szSongName)
 {
 #ifdef DEBUG_PRINT
   printf("Start %i %i %i %s\n", iChannels, iSamplesPerSec, iBitsPerSample, szSongName.c_str());
@@ -206,7 +206,7 @@ void CVisualizationShadertoy::Stop()
 }
 
 
-void CVisualizationShadertoy::AudioData(const float* pAudioData, int iAudioDataLength, float* pFreqData, int iFreqDataLength)
+void CVisualizationShadertoy::AudioData(const float* pAudioData, size_t iAudioDataLength)
 {
   WriteToBuffer(pAudioData, iAudioDataLength, 2);
 
diff --git a/src/main.h b/src/main.h
index 2f71574..61a0db9 100644
--- a/src/main.h
+++ b/src/main.h
@@ -25,9 +25,9 @@ class ATTR_DLL_LOCAL CVisualizationShadertoy
   CVisualizationShadertoy();
   ~CVisualizationShadertoy() override;
 
-  bool Start(int channels, int samplesPerSec, int bitsPerSample, std::string songName) override;
+  bool Start(int channels, int samplesPerSec, int bitsPerSample, const std::string& songName) override;
   void Stop() override;
-  void AudioData(const float* audioData, int audioDataLength, float* freqData, int freqDataLength) override;
+  void AudioData(const float* audioData, size_t audioDataLength) override;
   void Render() override;
   bool GetPresets(std::vector<std::string>& presets) override;
   int GetActivePreset() override;