89 lines
2.5 KiB
C#
89 lines
2.5 KiB
C#
using Microsoft.Xna.Framework;
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using NAudio.Dsp;
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using NAudio.Wave;
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using System;
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namespace RecrownedAthenaeum.Audio
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{
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public class TransparentSampleProvider : ISampleProvider
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{
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private const int FFT_SIZE = 2048;
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private readonly int m;
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private ISampleProvider source;
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private Complex[] fftBuffer;
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private volatile bool updatedSpectrum;
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private readonly float[] currentSpectrum;
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private int channelCount;
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public bool performFFT;
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public TransparentSampleProvider(ISampleProvider sampleProvider)
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{
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m = (int)Math.Log(FFT_SIZE);
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source = sampleProvider;
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channelCount = sampleProvider.WaveFormat.Channels;
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fftBuffer = new Complex[FFT_SIZE];
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currentSpectrum = new float[FFT_SIZE];
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}
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public WaveFormat WaveFormat
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{
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get
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{
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return source.WaveFormat;
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}
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}
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public float[] GetCurrentSpectrum()
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{
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if (updatedSpectrum)
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{
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lock (fftBuffer)
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{
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for (int binID = 0; binID < currentSpectrum.Length; binID++)
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{
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currentSpectrum[binID] = fftBuffer[binID].X;
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}
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}
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}
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return currentSpectrum;
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}
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public int Read(float[] buffer, int offset, int count)
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{
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int sampleCount = source.Read(buffer, offset, count);
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if (performFFT)
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{
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int fftOffset = 0;
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for (int s = 0; s < sampleCount; s += channelCount)
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{
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if (s >= FFT_SIZE)
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{
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lock (fftBuffer)
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{
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FastFourierTransform.FFT(true, m, fftBuffer);
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}
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updatedSpectrum = true;
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fftOffset -= FFT_SIZE;
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}
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float greatestVal = 0;
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for (int c = 0; c < channelCount; c++)
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{
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greatestVal = MathHelper.Max(buffer[s + offset + c], greatestVal);
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}
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fftBuffer[s + fftOffset].X = (float)(buffer[s + offset] * FastFourierTransform.HammingWindow(s, FFT_SIZE));
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fftBuffer[s + fftOffset].Y = 0;
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}
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}
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return sampleCount;
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}
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}
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}
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