[CLAM] how to use the SpectrumAnalysis object in pitch detection?

[Martijn Bosma]

Hello,

I have some problems with finding the fundamental frequency of an audio 
object.
The code of my function can be found below.
As its input it uses an audio object called chunk.
chunk contains one note of a melody.  (more or less one second in length)
My main problem is to go from an audio object to its spectrum

- Is it possible for the SpectrumAnalysis object to analyse the spectrum 
  of this chunk at once?

- How do I configure the spectrum analysis object for this task?
  (zeropadding, hopsize, windowsize, windowtype and circularshift?)

- when I run the program and the program reaches the do method of the
  SpectralAnalysis object in my code, I get the following exception 
  breakpoint:
	ASSERTION FAILED
	spectrum.cxx line 647:
	Spectrum::GetSize(): Complex size and Size mismatch.
  this is probably because of a wrong configuration of the 
  spectralAnalysis object or because of the size of the audio chunk.


- for the configuration of the FundFreqDetect and the SpectralPeakDetect 
  objects I use the default values of their configuration classes.
  (e.g. ffdConfig.DefaultValues();)
  is this correct, or necessary?


I have sent this problem before to the clamlist, but then I 
was not clear about what I would like to know.
I think now I have sent the code as well it is easier for people to see
where I go wrong here.

Thanks in advance for helping
Martijn

*************************************************************
//THE CODE:

// chunk is an audio object containing one note of the melody
// this method gets the  fundamental frequency of chunk. 
// It stores the resulting fundamental object in 
// the "vector<Fundamental> pitches"
void MyCLAMApp::DoFunfreq(Audio chunk)
{

	// make spectrum object
	SpectrumConfig cfg;
	cfg.SetSize(chunk_size / 2  + 1);

	Spectrum spec;
	spec.Configure(cfg);
	spec.ToDB();


	// spectrum analyzer
	// sampleRate = samplerate of the audio object chunk
	SpectralAnalysisConfig sac;
	sac.AddAll();
	sac.UpdateData();
    	sac.SetSamplingRate(sampleRate);
	sac.SetZeroPadding(0);
	sac.SetHopSize(0);
	sac.SetWindowSize(513);   
	sac.SetWindowType(EWindowType::eHamming);
    	sac.SetHopSize((sac.GetWindowSize()-1)/2);
	sac.GetCircularShift().SetAmount(-256);

	SpectralAnalysis sa;
	sa.Configure(sac);
	sa.Start();
	sa.Do(chunk, spec);	// this line of code causes the exception 
breakpoint
	sa.Stop();

	
	// get the spectralpeak array from spectrum
	SpectralPeakDetectConfig detectPeaksConfig;
	detectPeaksConfig.DefaultValues();

	SpectralPeakDetect	detectPeaks;
	detectPeaks.Configure(detectPeaksConfig);

	SpectralPeakArray peaks;
	peaks.SetScale(EScale(EScale::eLog));

	detectPeaks.Start();
	detectPeaks.Do(spec, peaks);
	detectPeaks.Stop();


	// fundamental frequency detection
	Fundamental fund;
	fund.AddCandidatesFreq();
    	fund.AddCandidatesErr();
    	fund.UpdateData();
	fund.SetnCandidates(0);
	fund.SetnMaxCandidates(60);

	FundFreqDetectConfig ffdConfig;
	ffdConfig.DefaultValues();

	FundFreqDetect ffd;
	ffd.Configure(ffdConfig);
	
	ffd.Start();
	ffd.Do(peaks, fund);
	ffd.Stop();


	// store the fundamental object
	pitches.push_back(fund);

}