Fixing samplerate conversion test and added some more useful methods for CITAAudioSample

include/ITAAudioSample.h

@@ -37,6 +37,12 @@ public:
 	  * Requires initialization or load to be used, otherwise methods will throw ITAException.
 	  */
 	CITAAudioSample( const float fSampleRate = 44100.0f );
+	
+	//! Create audio sample from file
+	/**
+	  * Requires initialization or load to be used, otherwise methods will throw ITAException.
+	  */
+	CITAAudioSample( const std::string& sFilePath );
 
 	//! Create (empty) audio sample with given parameters
 	/**
@@ -87,6 +93,9 @@ public:
 	//! Load audio sample from file and convert sample rate, if necessary
 	void LoadWithSampleTypeConversion( const std::string& sFilePath );
 
+	//! Load audio sample from file and convert sample rate, if necessary
+	void LoadWithSampleTypeConversion( const CITAAudioSample& asSource );
+
 private:
 
 	//! Disable this Init method from sample buffer

src/ITAAudioSample.cpp

 #include <ITAAudioSample.h>
 #include <ITAException.h>
 
+#include <cassert>
 #include <samplerate.h>
 
 CITAAudioSample::CITAAudioSample( const float fSampleRate )
@@ -26,6 +27,12 @@ CITAAudioSample::CITAAudioSample( const CITAAudioSample& sfSource )
 	ITASampleFrame::write( sfSource, sfSource.GetLength() );
 }
 
+CITAAudioSample::CITAAudioSample( const std::string& sFilePath )
+	:CITAAudioSample()
+{
+	Load( sFilePath );
+}
+
 void CITAAudioSample::Init( const int iNumChannels, const int iLength, const float fSampleRate, const bool bZeroInit /*= true */ )
 {
 	m_fSampleRate = fSampleRate;
@@ -45,12 +52,25 @@ void CITAAudioSample::LoadWithSampleTypeConversion( const std::string& sFilePath
 		Load( sfRaw, GetSampleRate() );
 }
 
+void CITAAudioSample::LoadWithSampleTypeConversion( const CITAAudioSample& asSource )
+{
+	ITASampleFrame* psfSource = ( ITASampleFrame* ) &asSource;
+	Load( *psfSource, asSource.GetSampleRate() );
+}
+
 void CITAAudioSample::Load( const CITAAudioSample& oSource )
 {
 	Load( oSource, oSource.GetSampleRate() );
 }
 
 
+void CITAAudioSample::Load( const std::string& sFilePath )
+{
+	double dSampleRate;
+	ITASampleFrame::Load( sFilePath, dSampleRate );
+	m_fSampleRate = float( dSampleRate );
+}
+
 float CITAAudioSample::GetSampleRate() const
 {
 	return m_fSampleRate;
@@ -70,26 +90,33 @@ void CITAAudioSample::Load( const ITASampleFrame& sfSource, const float fSourceS
 	}
 
 	const float fSRCRation = GetSampleRate() / fSourceSampleRate;
-	const int iTargetLength = (int) ceil( sfSource.GetLength() * fSRCRation ); // @tbd test!
-	Init( sfSource.GetNumChannels(), iTargetLength, m_fSampleRate );
+	const float fTargetLengthSamples = sfSource.GetLength() * fSRCRation;
+	int iTargetLengthSamples = ( int ) floor( fTargetLengthSamples );
+	const float fTargetLengthSubsampleFraction = fTargetLengthSamples - float( iTargetLengthSamples );
+	// Account for exact match, then the "last" sample is not resampled anymore and can be skipped
+	if( fTargetLengthSubsampleFraction == 0.0f )
+		iTargetLengthSamples--;
+	Init( sfSource.GetNumChannels(), iTargetLengthSamples, m_fSampleRate );
 
 	const int iConverter = SRC_SINC_MEDIUM_QUALITY;
 	for( int i = 0; i < sfSource.GetNumChannels(); i++ )
 	{
 		int iSRCError;
-		SRC_STATE* pSRCStace = src_new( iConverter, sfSource.GetNumChannels(), &iSRCError );
+		SRC_STATE* pSRCStace = src_new( iConverter, 1, &iSRCError ); // single channel conversion, samplerate expets interleaved. this is not compatible with ITASampleBuffer/Frame
 		if( pSRCStace == nullptr )
 			ITA_EXCEPT_INVALID_PARAMETER( "Could not create sample rate converter, samplerate error was: " + std::string( src_strerror( iSRCError ) ) );
-		
+
 		SRC_DATA oSRCData;
 		oSRCData.data_in = sfSource[ i ].GetData();
 		oSRCData.data_out = ( *this )[ i ].GetData();
-		oSRCData.input_frames = 1;
-		oSRCData.output_frames = 1;
+		oSRCData.input_frames = sfSource.GetLength(); // In samplerate, one frame is "one sample" of multi channel audio
+		oSRCData.output_frames = iTargetLengthSamples;
 		oSRCData.src_ratio = fSRCRation;
 		if( ( iSRCError = src_process( pSRCStace, &oSRCData ) ) != 0 )
 			ITA_EXCEPT_INVALID_PARAMETER( "Could not convert sample rate: " + std::string( src_strerror( iSRCError ) ) );
 
+		assert( oSRCData.output_frames_gen == iTargetLengthSamples );
+
 		src_delete( pSRCStace );
 	}
-}
+}
\ No newline at end of file

tests/ITABaseAudioSampleTest.cpp

@@ -7,6 +7,20 @@ using namespace std;
 
 int main( int, char** )
 {
+	try
+	{
+		CITAAudioSample asTTS48kHz( "tts.wav" );
+		CITAAudioSample asTTS44kHz;
+		asTTS44kHz.LoadWithSampleTypeConversion( asTTS48kHz );
+		asTTS44kHz.Store( "tts_44khz.wav" );
+
+		cout << "Converted files." << endl;
+	}
+	catch( ITAException& err )
+	{
+		cerr << "File test error: " << err << endl;
+	}
+
 	try
 	{
 		CITAAudioSample as44kfs;
@@ -18,13 +32,15 @@ int main( int, char** )
 		as44kfs[ 0 ][ 0 ] = 1.0f;
 		as44kfs[ 0 ][ as44kfs.GetLength() - 1 ] = -1.0f;
 
-		as48kfs.Load( as44kfs );
-		as96kfs.Load( as48kfs );
-		as128kfs.Load( as96kfs );
+		as48kfs.LoadWithSampleTypeConversion( as44kfs );
+		as96kfs.LoadWithSampleTypeConversion( as48kfs );
+		as128kfs.LoadWithSampleTypeConversion( as96kfs );
+
+		cout << "Converted." << endl;
 	}
 	catch( ITAException& err )
 	{
-		cerr << "Error: " << err << endl;
+		cerr << "Generic test error: " << err << endl;
 	}
 
 	return 0;