コード例 #1
0
        public void ComputeMatrixUsingLomontRealFFT(ref Matrix m, int column, float[] audiodata, int pos)
        {
            // apply the window method (e.g HammingWindow, HannWindow etc)
            win.Apply(ref data, audiodata, pos);

            var fft = new double[data.Length / 2];

            Array.Copy(data, fft, data.Length / 2);
            lomonFFT.RealFFT(fft, true);

            // fft input will now contain the FFT values
            // r0, r(n/2), r1, i1, r2, i2 ...
            m.MatrixData[0][column] = Math.Sqrt(fft[0] * fft[0] * winSize);
            m.MatrixData[winSize / 2 - 1][column] = Math.Sqrt(fft[1] * fft[1] * winSize);
            for (int row = 1; row < winSize / 2; row++)
            {
                // amplitude (or magnitude) is the square root of the power spectrum
                // the magnitude spectrum is abs(fft), i.e. Math.Sqrt(re*re + img*img)
                // use 20*log10(Y) to get dB from amplitude
                // the power spectrum is the magnitude spectrum squared
                // use 10*log10(Y) to get dB from power spectrum
                m.MatrixData[row][column] = Math.Sqrt((fft[2 * row] * fft[2 * row] +
                                                       fft[2 * row + 1] * fft[2 * row + 1]) * winSize);
            }
        }
コード例 #2
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        public void SineWaveTest()
        {
            var sineWave = new[] { 0, 0.707f, 1, 0.707f, 0, -0.707f, -1, -0.707f };

            lomontFFT.RealFFT(sineWave, true);
            lomontFFT.RealFFT(sineWave, false);

            CollectionAssert.AreEqual(new float[] { 0, 0.707f, 1, 0.707f, 0, -0.707f, -1, -0.707f }, sineWave, floatComparer);
        }
コード例 #3
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        public double[] Spectrum(double[] input, bool scale)
        {
            var fft = new LomontFFT();

            fft.RealFFT(input, true);

            var spectrum = Helper.ComputeSpectrum(input);

            fft.RealFFT(input, false);

            return(spectrum);
        }
コード例 #4
0
ファイル: Fourier.cs プロジェクト: jarodz/ScopeLib
        /// <summary>
        /// Transforms time domain samples to the frequency domain.
        /// </summary>
        /// <param name="timeDomainSamples">The time domain samples.</param>
        /// <returns>The frequency domain samples.</returns>
        public SampleSequence TransformForward(SampleSequence timeDomainSamples)
        {
            var fftValues  = timeDomainSamples.Values.ToArray();
            var sampleRate = timeDomainSamples.SampleRate;

            // FFT frequency resolution is (sample rate) / (FFT window size).
            var frequencyResolution = sampleRate / fftValues.Length;

            _fft.RealFFT(fftValues, true); // fftValues is modified in place
            var amplitudes = ComputeAmplitudes(fftValues).ToArray();

            return(new SampleSequence(frequencyResolution, amplitudes));
        }
コード例 #5
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        public void SineWaveTest()
        {
            var sineWave = new[] { 0, 0.707f, 1, 0.707f, 0, -0.707f, -1, -0.707f };

            unsafe
            {
                float *input = stackalloc float[sineWave.Length];
                for (int i = 0; i < sineWave.Length; ++i)
                {
                    input[i] = sineWave[i];
                }

                lomontFFT.RealFFT(input, true, sineWave.Length);
                lomontFFT.RealFFT(input, false, sineWave.Length);

                for (int i = 0; i < sineWave.Length; ++i)
                {
                    sineWave[i] = input[i];
                }
            }

            CollectionAssert.AreEqual(new float[] { 0, 0.707f, 1, 0.707f, 0, -0.707f, -1, -0.707f }, sineWave, floatComparer);
        }
コード例 #6
0
ファイル: IFFTSignal.cs プロジェクト: nnikos123/VVVV.Audio
        public override void Pull(int count)
        {
            var real      = FFFTDataReal.Value;
            var imag      = FFFTDataImag.Value;
            var copyCount = Math.Min(count / 2, Math.Max(real.Length, imag.Length));
            var j         = 0;

            if (real.Length > imag.Length)
            {
                for (int i = 0; i < copyCount; i++)
                {
                    RealImagData[j++] = real[i];
                    RealImagData[j++] = imag[AudioUtils.Zmod(i, imag.Length)];
                }
            }
            else if (real.Length == imag.Length)
            {
                for (int i = 0; i < copyCount; i++)
                {
                    RealImagData[j++] = real[i];
                    RealImagData[j++] = imag[i];
                }
            }
            else
            {
                for (int i = 0; i < copyCount; i++)
                {
                    RealImagData[j++] = real[AudioUtils.Zmod(i, real.Length)];
                    RealImagData[j++] = imag[i];
                }
            }

            if (copyCount < count / 2)
            {
                for (int i = copyCount; i < count / 2; i++)
                {
                    RealImagData[j++] = 0;
                    RealImagData[j++] = 0;
                }
            }

            FFFT.RealFFT(RealImagData, false);

            //RealImagData[0] = RealImagData[1];

            TimeDomain.WriteDoubleWindowed(RealImagData, Window, 0, count, Gain);

            Write(TimeDomain, 0, count);
        }
コード例 #7
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    public static float[] GetSpectrum(float[] samples)
    {
        if (mono.Length != samples.Length / 2)
        {
            mono = new float[samples.Length / 2];
        }

        for (int i = 0; i < mono.Length; i++)
        {
            float monoSample = (samples[i * 2] + samples[i * 2 + 1]) * .5f;
            mono[i] = monoSample * 1.4f;
        }

        fft.RealFFT(mono, true);

        return(SpectrumMagnitude(mono));
    }
コード例 #8
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            public void PerformTask()
            {
                // perform the fft for each of the chosen window sizes
                // m_maxwid = 2048 (8192)
                // m_w = 512, 1024, 2048 (1024, 2048, 4096, 8192)
                for (int i = 0; i < m_maxwid / m_w; ++i)
                {
                    int origin = m_maxwid / 4 - m_w / 4;                 // for 50% overlap
                    for (int j = 0; j < m_w; ++j)
                    {
                        int index = origin + i * m_w / 2 + j;
                        if (index > m_in.Length - 1)
                        {
                            break;
                        }
                        m_rin[j] = m_in[index];
                    }

                    // perform windowing
                    m_window.Apply(m_rin);

                    var fft = new double[m_rin.Length];
                    Array.Copy(m_rin, fft, m_rin.Length);
                    m_fft.RealFFT(fft, true);

                    // fft input will now contain the FFT values
                    // r0, r(n/2), r1, i1, r2, i2 ...

                    // Include Nyquist but not DC
                    //m_s.spectrograms[m_res].data[i][0] = Math.Sqrt(fft[0] * fft[0]) / (m_w/2); // DC
                    m_s.spectrograms[m_res].data[i][m_w / 2 - 1] = Math.Sqrt(fft[1] * fft[1]) / (m_w / 2);               // Nyquist
                    for (int j = 1; j < m_w / 2; ++j)
                    {
                        double mag = Math.Sqrt(fft[2 * j] * fft[2 * j]
                                               + fft[2 * j + 1] * fft[2 * j + 1]);
                        double scaled = mag / (m_w / 2);
                        m_s.spectrograms[m_res].data[i][j] = scaled;
                    }
                }
            }
コード例 #9
0
ファイル: FourierDataProvider.cs プロジェクト: tdav/emocije
        private void CalculateFourierTransform()
        {
            PowerSpectra = new List <double>();
            int len = Data.Count();

            len = (int)Math.Pow(2, Math.Floor(Math.Log((double)len, 2)) + 1);
            List <double> D = Data.ToList();

            while (D.Count() < len)
            {
                D.Add(0);
            }

            double[] dat = D.ToArray();
            fft.RealFFT(dat, true);
            PowerSpectra.Add(dat[0] * dat[0]);
            for (int i = 2; i < dat.Length; i += 2)
            {
                PowerSpectra.Add(dat[i] * dat[i] + dat[i + 1] * dat[i + 1]);
            }
            PowerSpectra.Add(dat[1] * dat[1]);
        }
コード例 #10
0
    public void TimetoFreq(ref double[] audioSamples, int fftType = 0)
    {
        switch (fftType)
        {
        case 0:
        {
            _fft.FFT(audioSamples, true);
        }
        break;

        case 1:
        {
            _fft.RealFFT(ref audioSamples, true);
        }
        break;

        case 2:
        {
            _fft.TableFFT(audioSamples, true);
        }
        break;
        }
    }
コード例 #11
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        protected override void FillBuffer(float[] buffer, int offset, int count)
        {
            if (InputSignal.Value != null)
            {
                InputSignal.Read(buffer, offset, count);

                //write to buffer
                FRingBuffer.Write(buffer, offset, count);

                //calc fft
                var fftSize = FRingBuffer.Size;

                if (FFFTBuffer.Length != fftSize)
                {
                    FFFTBuffer = new double[fftSize];
                    FFTOut     = new double[fftSize];
                    FWindow    = AudioUtils.CreateWindowDouble(fftSize, WindowFunc);
                }

                FRingBuffer.ReadDoubleWindowed(FFFTBuffer, FWindow, 0, fftSize);
                FFFT.RealFFT(FFFTBuffer, true);
                Array.Copy(FFFTBuffer, FFTOut, fftSize);
            }
        }
コード例 #12
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        /// <summary>
        /// Performs the FFT on the provided samples.
        /// Will bin channels internally
        /// </summary>
        /// <returns>The FF.</returns>
        /// <param name="dAudioSamples">D audio samples.</param>
        /// <param name="fftType">Fft type.</param>
        /// <param name="forwardFFT">If set to <c>true</c> forward FF.</param>
        public double[] GetFFTOutputBins(ref double[] dAudioSamples, int fftType = 1, bool forwardFFT = true, bool applyHannWindowing = true)
        {
            if (!IsInitialized)
            {
                return(null);
            }

            if (_fftScript == null)
            {
                _fftScript   = new LomontFFT();
                _fftScript.A = 1;
                _fftScript.B = -1;
            }

            if (_fftBinsOutput == null || _fftBinsOutput.Length != FFTBinCount)
            {
                _fftBinsOutput = new double[FFTBinCount];
                _fftBinsActual = new double[_fftBinsOutput.Length / ChannelCount];
            }

            System.Array.Clear(_fftBinsOutput, 0, _fftBinsOutput.Length);

            for (int sampleIndex = 0; sampleIndex < _dAudioSamples.Length; sampleIndex += ChannelCount)
            {
                for (int channelIndex = 0; channelIndex < ChannelCount; ++channelIndex)
                {
                    int    binIndex = sampleIndex == 0 ? 0 : sampleIndex / ChannelCount;
                    double valToAdd = Mathf.Pow((float)_dAudioSamples [sampleIndex + channelIndex], 4);
                    //double valToAdd = _dAudioSamples [sampleIndex + channelIndex];
                    _fftBinsOutput [binIndex] += _dAudioSamples [sampleIndex + channelIndex];
                }
            }

            for (int i = 0; i < _fftBinsOutput.Length; ++i)
            {
                _fftBinsOutput [i] /= ChannelCount;
            }


            //apply hanning window
            if (applyHannWindowing)
            {
                Utilities.Hann(ref _fftBinsOutput);
            }

            switch (fftType)
            {
            case 0:
            {
                Debug.LogWarning("COMPLEXFFT NOT SUPPORTED YET");
                //_fftScript.FFT (_fftBinsOutput, forwardFFT);
            }
            break;

            case 1:
            {
                _fftScript.RealFFT(ref _fftBinsOutput, forwardFFT);
                _fftBinsOutput [0] = 0;
                _fftBinsOutput [1] = 0;
                for (int i = 2; i < _fftBinsOutput.Length; i += 2)
                {
                    float real = (float)_fftBinsOutput [i];
                    float im   = (float)_fftBinsOutput [i + 1];
                    float val  = Mathf.Sqrt(Mathf.Pow(real, 2) + Mathf.Pow(im, 2));
                    if (i == 2)
                    {
                        _fftBinsActual [0] = val;
                    }
                    else
                    {
                        _fftBinsActual [(i / 2) - 1] = val;
                    }
                }
            }
            break;

            case 2:
            {
                Debug.LogWarning("TABLEFFT NOT SUPPORTED YET");
                //_fftScript.TableFFT (_fftBinsOutput, forwardFFT);
            }
            break;
            }

            return(_fftBinsActual);
        }
コード例 #13
0
ファイル: Util.cs プロジェクト: AmiralBl3ndic/Zombeat-Office
 public static void GetSpectrum(float[] samples)
 {
     fft.RealFFT(samples, true);
 }
コード例 #14
0
ファイル: streamAudio.cs プロジェクト: imclab/synescape
    void saveFile()
    {
        float[] samples = new float[4096];
        //aud.GetOutputData (samples, 0);
        aud.clip.GetData(samples, Microphone.GetPosition(Microphone.devices[0]) - 4096);
        float maxAmp = (float)samples.Max() * 2;


        if (maxAmp > 0.001f)
        {
            LomontFFT fftMe     = new LomontFFT();
            double[]  sampleFFT = Array.ConvertAll(samples, x => (double)x);
            fftMe.RealFFT(sampleFFT, true);

            float[] frequences = new float[5];
            frequences[0] = (float)sampleFFT.Take(25).Max();
            frequences[1] = (float)sampleFFT.Skip(25).Take(50).Max();
            frequences[2] = (float)sampleFFT.Skip(75).Take(75).Max();
            frequences[3] = (float)sampleFFT.Skip(150).Take(100).Max();
            frequences[4] = (float)sampleFFT.Skip(250).Take(125).Max();
            float maxFreq      = frequences.Max();
            int   maxFreqIndex = frequences.ToList().IndexOf(maxFreq);


            if (maxFreqIndex == 0)
            {
                //float noise = (UnityEngine.Random.value - 0.5f) / 5f;
                float noise = 0f;
                makeOrb(maxFreq, new Vector3(22 + noise, -5, 20));
                makeOrb(maxFreq, new Vector3(-22 + noise, -5, 20));
            }
            if (maxFreqIndex == 1)
            {
                //float noise = (UnityEngine.Random.value - 0.5f) / 5f;
                float noise = 0f;
                makeOrb(maxFreq, new Vector3(20 + noise, -2, 20));
                makeOrb(maxFreq, new Vector3(-20 + noise, -2, 20));
                //makeOrb (maxFreq, new Vector3 (-35+ noise, -1, -15));
                //makeOrb (maxFreq, new Vector3 (35+ noise, -1, -15));
            }
            if (maxFreqIndex == 2)
            {
                //float noise = (UnityEngine.Random.value - 0.5f) / 5f;
                float noise = 0f;
                makeOrb(maxFreq, new Vector3(15 + noise, 3, 20));
                makeOrb(maxFreq, new Vector3(-15 + noise, 3, 20));
                //makeOrb(maxFreq,new Vector3(-25+ noise,0,-25));
                //makeOrb(maxFreq,new Vector3(25+ noise,0,-25));
            }
            if (maxFreqIndex == 3)
            {
                //float noise = (UnityEngine.Random.value - 0.5f) / 5f;
                float noise = 0f;
                makeOrb(maxFreq, new Vector3(10 + noise, 7, 25));
                makeOrb(maxFreq, new Vector3(-10 + noise, 7, 25));
                //makeOrb (maxFreq, new Vector3 (-15+ noise, 1, -35));
                //makeOrb (maxFreq, new Vector3 (15+ noise, 1, -35));
            }
            if (maxFreqIndex == 4)
            {
                //float noise = (UnityEngine.Random.value - 0.5f) / 5f;
                float noise = 0f;
                makeOrb(maxFreq, new Vector3(0 + noise, 10, 30));
                //makeOrb (maxFreq, new Vector3 (0+ noise, 2, -45));
            }
        }
    }
コード例 #15
0
    public void UpdatePLP(ref double[] dAudioSamples, int channelCount, int sampleRate, bool applyHannWindow = true)
    {
        if (dAudioSamples == null)
        {
            return;
        }

        if (_fftScript == null)
        {
            _fftScript   = new LomontFFT();
            _fftScript.A = 1;
            _fftScript.B = -1;
        }

        System.Array.Clear(_fftBinsRaw, 0, _fftBinsRaw.Length);
        System.Array.Clear(_fftBinsActual, 0, _fftBinsActual.Length);

        //channel bin the data
        for (int sampleIndex = 0; sampleIndex < dAudioSamples.Length; sampleIndex += channelCount)
        {
            int binIndex = sampleIndex == 0 ? 0 : sampleIndex / channelCount;
            for (int channelIndex = 0; channelIndex < channelCount; ++channelIndex)
            {
                _fftBinsRaw [binIndex] = dAudioSamples [sampleIndex + channelIndex];
            }
            _fftBinsRaw [binIndex] /= channelCount;
        }

        //apply hanning window on audio samples
        if (applyHannWindow)
        {
            Utilities.Hann(ref _fftBinsRaw);
        }

        //perform fft.
        _fftScript.RealFFT(ref _fftBinsRaw, true);

        //aggregate fft output into fftActual
        for (int i = 2; i < _fftBinsRaw.Length; i += 2)
        {
            float real = (float)_fftBinsRaw [i];
            float im   = (float)_fftBinsRaw [i + 1];
            float val  = Mathf.Sqrt(Mathf.Pow(real, 2) + Mathf.Pow(im, 2));
            if (i == 2)
            {
                _fftBinsActual [0] = val;
            }
            else
            {
                _fftBinsActual [(i / 2) - 1] = val;
            }
        }


        //left shift the spectrogram
        for (int i = 1; i < _spectrogram.Length; ++i)
        {
            LeftShiftArray <float> (ref _spectrogram [i]);

            /*for (int j = 0; j < _spectrogram [i - 1].Length; ++j) {
             *      _spectrogram [i - 1][j] = _spectrogram [i][j];
             * }*/
        }

        //apply logarithmic compression and fill in place
        float[] toFill = _spectrogram [_spectrogram.Length - 1];
        for (int i = 0; i < toFill.Length; ++i)
        {
            toFill [i] = _fftBinsActual [i];            //Mathf.Log ((float)(1+_fftBinsActual [i]));
        }


        //compute discrete derivative
        if (_frameIndex > 0)
        {
            float[] prev = _frameIndex > _spectrogram.Length - 1? _spectrogram[_spectrogram.Length - 2]:_spectrogram [_frameIndex - 1];
            float[] curr = _frameIndex > _spectrogram.Length - 1 ? _spectrogram [_spectrogram.Length - 1] : _spectrogram [_frameIndex];


            for (int i = 0; i < curr.Length; ++i)
            {
                float diff = curr[i] - prev[i];
                if (diff > 0)
                {
                    curr[i] = diff;
                }
                else
                {
                    curr[i] = 0;
                }
            }
        }


        ++_frameIndex;

        if (_frameIndex > _spectrogram.Length)
        {
            bool firstRun = _frameIndex == _spectrogram.Length + 1;
            ComputeNoveltyCurve(firstRun);
            ComputeTempogram(false, firstRun);
            UpdateBPM();
            ComputePeriodicLocalPulse(firstRun);
            //CorrelateNoveltyCurveWithSinCurve ();

            LeftShiftArray <double> (ref _noveltyCurve);
            //LeftShiftArray<double> (ref _tempogramActual);
            for (int i = 1; i < _tempogramActual.Length; ++i)
            {
                LeftShiftArray <double> (ref _tempogramActual[i]);
            }
            LeftShiftArray <double> (ref _tempo);
            LeftShiftArray <double> (ref _tempoMaxCoeff);

            LeftShiftArray <double> (ref _plpCurve);
        }
    }
コード例 #16
0
        public void FFT(bool forward)
        {
            data.CopyTo(copy, 0);

            fft.RealFFT(copy, forward);
        }