Visualizzazione audio C#

Question

Vorrei creare un sistema di visualizzazione audio utilizzando il linguaggio C# e .NET Framework. Questo potrebbe apparire nell'applicazione Winamp. Forse esiste una biblioteca libera o alcuni articoli interessanti che descrivono come farlo? Esempio: alt text http://img44.imageshack.us/img44/9982/examplel.png

Answer 1

Si può provare questi collegamenti

OpenVP (è una piattaforma gratuita e open-source per lo sviluppo di visualizzazioni musica, scritto in C#), vedere il OpenVP Screenshots.

Sound visualizer in C#

Play and Visualize WAV Files using Managed Direct Sound

Bye.

Answer 2

Ecco uno script che calcola la FFT di qualsiasi suono riprodotto sul computer utilizzando l'API WASAPI. Esso utilizza CSCore e nei WinformsVisualization esempio:

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]; 
       } 
      } 
     } 

    } 
} 

Poi durante il recupero del barData da uno script diverso è consigliabile per bloccarla prima poiché questa viene modificata in un thread separato.

Non sono sicuro di dove trovo lo GetSpectrumPoints poiché non sembra essere nello Github Repo, ma eccolo qui. Basta incollarlo in quel file e il mio codice dovrebbe funzionare.

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; 
}