2009-08-30 8 views

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2

Voici un script qui calcule la FFT de tout son lu sur l'ordinateur à l'aide de l'API WASAPI. Il utilise CScore et son WinformsVisualization exemple:

using CSCore; 
using CSCore.SoundIn; 
using CSCore.Codecs.WAV; 
using WinformsVisualization.Visualization; 
using CSCore.DSP; 
using CSCore.Streams; 
using System; 

public class SoundCapture 
{ 

    public int numBars = 30; 

    public int minFreq = 5; 
    public int maxFreq = 4500; 
    public int barSpacing = 0; 
    public bool logScale = true; 
    public bool isAverage = false; 

    public float highScaleAverage = 2.0f; 
    public float highScaleNotAverage = 3.0f; 



    LineSpectrum lineSpectrum; 

    WasapiCapture capture; 
    WaveWriter writer; 
    FftSize fftSize; 
    float[] fftBuffer; 

    SingleBlockNotificationStream notificationSource; 

    BasicSpectrumProvider spectrumProvider; 

    IWaveSource finalSource; 

    public SoundCapture() 
    { 

     // This uses the wasapi api to get any sound data played by the computer 
     capture = new WasapiLoopbackCapture(); 

     capture.Initialize(); 

     // Get our capture as a source 
     IWaveSource source = new SoundInSource(capture); 


     // From https://github.com/filoe/cscore/blob/master/Samples/WinformsVisualization/Form1.cs 

     // This is the typical size, you can change this for higher detail as needed 
     fftSize = FftSize.Fft4096; 

     // Actual fft data 
     fftBuffer = new float[(int)fftSize]; 

     // These are the actual classes that give you spectrum data 
     // The specific vars of lineSpectrum here aren't that important because they can be changed by the user 
     spectrumProvider = new BasicSpectrumProvider(capture.WaveFormat.Channels, 
        capture.WaveFormat.SampleRate, fftSize); 

     lineSpectrum = new LineSpectrum(fftSize) 
     { 
      SpectrumProvider = spectrumProvider, 
      UseAverage = true, 
      BarCount = numBars, 
      BarSpacing = 2, 
      IsXLogScale = false, 
      ScalingStrategy = ScalingStrategy.Linear 
     }; 

     // Tells us when data is available to send to our spectrum 
     var notificationSource = new SingleBlockNotificationStream(source.ToSampleSource()); 

     notificationSource.SingleBlockRead += NotificationSource_SingleBlockRead; 

     // We use this to request data so it actualy flows through (figuring this out took forever...) 
     finalSource = notificationSource.ToWaveSource(); 

     capture.DataAvailable += Capture_DataAvailable; 
     capture.Start(); 
    } 

    private void Capture_DataAvailable(object sender, DataAvailableEventArgs e) 
    { 
     finalSource.Read(e.Data, e.Offset, e.ByteCount); 
    } 

    private void NotificationSource_SingleBlockRead(object sender, SingleBlockReadEventArgs e) 
    { 
     spectrumProvider.Add(e.Left, e.Right); 
    } 

    ~SoundCapture() 
    { 
     capture.Stop(); 
     capture.Dispose(); 
    } 

    public float[] barData = new float[20]; 

    public float[] GetFFtData() 
    { 
     lock (barData) 
     { 
      lineSpectrum.BarCount = numBars; 
      if (numBars != barData.Length) 
      { 
       barData = new float[numBars]; 
      } 
     } 

     if (spectrumProvider.IsNewDataAvailable) 
     { 
      lineSpectrum.MinimumFrequency = minFreq; 
      lineSpectrum.MaximumFrequency = maxFreq; 
      lineSpectrum.IsXLogScale = logScale; 
      lineSpectrum.BarSpacing = barSpacing; 
      lineSpectrum.SpectrumProvider.GetFftData(fftBuffer, this); 
      return lineSpectrum.GetSpectrumPoints(100.0f, fftBuffer); 
     } 
     else 
     { 
      return null; 
     } 
    } 

    public void ComputeData() 
    { 


     float[] resData = GetFFtData(); 

     int numBars = barData.Length; 

     if (resData == null) 
     { 
      return; 
     } 

     lock (barData) 
     { 
      for (int i = 0; i < numBars && i < resData.Length; i++) 
      { 
       // Make the data between 0.0 and 1.0 
       barData[i] = resData[i]/100.0f; 
      } 

      for (int i = 0; i < numBars && i < resData.Length; i++) 
      { 
       if (lineSpectrum.UseAverage) 
       { 
        // Scale the data because for some reason bass is always loud and treble is soft 
        barData[i] = barData[i] + highScaleAverage * (float)Math.Sqrt(i/(numBars + 0.0f)) * barData[i]; 
       } 
       else 
       { 
        barData[i] = barData[i] + highScaleNotAverage * (float)Math.Sqrt(i/(numBars + 0.0f)) * barData[i]; 
       } 
      } 
     } 

    } 
} 

Ensuite, lors de la récupération du barData à partir d'un autre script, il est recommandé de verrouiller la première car cela est modifié sur un thread séparé.

Je ne sais pas où j'ai obtenu GetSpectrumPoints car il ne semble pas être dans le Github Repo, mais le voici. Il suffit de coller cela dans ce fichier et mon code devrait fonctionner.

public float[] GetSpectrumPoints(float height, float[] fftBuffer) 
{ 
    SpectrumPointData[] dats = CalculateSpectrumPoints(height, fftBuffer); 
    float[] res = new float[dats.Length]; 
    for (int i = 0; i < dats.Length; i++) 
    { 
     res[i] = (float)dats[i].Value; 
    } 

    return res; 
} 
+0

J'ai essayé d'utiliser votre exemple de code, mais il ne semble pas que ['GetSpectrumPoints()' soit une fonction plus] (https://github.com/filoe/cscore/blob/29410b12ae35321c4556b072c0711a8f289c0544/Samples/ WinformsVisualization/Visualization/LineSpectrum.cs # L10), et la vérification de l'historique du dépôt git ne le montre pas non plus. Pourriez-vous clarifier/mettre à jour votre réponse? (* J'essaie d'intégrer la capture/le traitement audio sous Windows avec une application de console multiplateforme qui pilote les lumières LED, les valeurs de données de fréquence de 0,0 à 1,0 bar sont tout ce dont elle a besoin *) – Shane

+1

@Shane Désolé! J'ai ajouté ce code maintenant, espérons que cela aide – Phylliida

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