Change to using distutils.

Currently only builds the simplsndobj module

1 files changed, 280 insertions, 0 deletions

diff --git a/src/sms/windows.c b/src/sms/windows.c
new file mode 100644
index 0000000..46ca5be
--- /dev/null
+++ b/src/sms/windows.c
@@ -0,0 +1,280 @@
+/* 
+ * Copyright (c) 2008 MUSIC TECHNOLOGY GROUP (MTG)
+ *                    UNIVERSITAT POMPEU FABRA 
+ * 
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of 
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ * 
+ */
+
+/*! \file windows.c
+ * \brief functions for creating various windows
+ * 
+ * Use sms_getWindow() for selecting which window will be made
+ */
+#include "sms.h"
+
+/* \brief scale a window by its integral (numeric quadrature)
+ *
+ * In order to get a normalized magnitude spectrum (ex. Fourier analysis
+ * of a sinusoid with linear magnitude 1 gives one peak of magnitude 1 in
+ * the frequency domain), the spectrum windowing function should be 
+ * normalized by its area under the curve.  
+ *
+ * \param sizeWindow the size of the window
+ * \param pWindow pointer to an array that will hold the window
+ */
+void sms_scaleWindow(int sizeWindow, sfloat *pWindow)
+{
+    int i;
+    sfloat fSum = 0;
+    sfloat fScale;
+
+    for(i = 0; i < sizeWindow; i++) 
+        fSum += pWindow[i];
+
+    fScale =  2. / fSum;
+
+    for(i = 0; i < sizeWindow; i++)
+        pWindow[i] *= fScale;
+}
+
+/*! \brief window to be used in the IFFT synthesis
+ * 
+ * contains both an inverse Blackman-Harris and triangular window.
+ *
+ * \todo read X. Rodet, Ph. Depalle, "Spectral Envelopes and Inverse FFT
+ * Synthesis." Proc. 93rd AES Convention, October 1992
+ * \param sizeWindow the size of the window
+ * \param pFWindow pointer to an array that will hold the window
+ */
+void IFFTwindow(int sizeWindow, sfloat *pFWindow)
+{
+    int i;
+    sfloat a0 = .35875, a1 = .48829, a2 = .14128, a3 = .01168;
+    double fConst = TWO_PI / sizeWindow, fIncr = 2.0 /sizeWindow, fVal = 0;
+
+    /* compute inverse of Blackman-Harris 92dB window */
+    for(i = 0; i < sizeWindow; i++) 
+    {
+        pFWindow[i] = 1 / (a0 - a1 * cos(fConst * i) +
+                      a2 * cos(fConst * 2 * i) - a3 * cos(fConst * 3 * i));
+    }
+
+    /* scale function by a triangular */
+    for(i = 0; i < sizeWindow / 2; i++)
+    {
+        pFWindow[i] = fVal * pFWindow[i]  / 2.787457;
+        fVal += fIncr;
+    }
+    for(i = sizeWindow / 2; i < sizeWindow; i++)
+    {
+        pFWindow[i] = fVal * pFWindow[i]  / 2.787457;
+        fVal -= fIncr;
+    }
+}
+
+/*! \brief BlackmanHarris window with 62dB rolloff
+ * 
+ * \todo where did these come from?
+ * \param sizeWindow the size of the window
+ * \param pFWindow pointer to an array that will hold the window
+ */
+void BlackmanHarris62(int sizeWindow, sfloat *pFWindow)
+{
+    int i;
+    double fSum = 0;
+    /* for 3 term -62.05 */
+    sfloat a0 = .44959, a1 = .49364, a2 = .05677; 
+    double fConst = TWO_PI / sizeWindow;
+
+    /* compute window */
+    for(i = 0; i < sizeWindow; i++) 
+    {
+        fSum += pFWindow[i] = a0 - a1 * cos(fConst * i) +
+                a2 * cos(fConst * 2 * i);
+    }
+}
+
+/*! \brief BlackmanHarris window with 70dB rolloff
+ * 
+ * \param sizeWindow the size of the window
+ * \param pFWindow pointer to an array that will hold the window
+ */
+void BlackmanHarris70(int sizeWindow, sfloat *pFWindow)
+{
+    int i;
+    double fSum = 0;
+    /* for 3 term -70.83 */
+    sfloat a0 = .42323, a1 = .49755, a2 = .07922;
+    double fConst = TWO_PI / sizeWindow;
+
+    /* compute window */
+    for(i = 0; i < sizeWindow; i++) 
+    {
+        fSum += pFWindow[i] = a0 - a1 * cos(fConst * i) +
+                a2 * cos(fConst * 2 * i);
+    }
+}
+
+/*! \brief BlackmanHarris window with 74dB rolloff
+ * 
+ * \param sizeWindow the size of the window
+ * \param pFWindow pointer to an array that will hold the window
+ */
+void BlackmanHarris74(int sizeWindow, sfloat *pFWindow)
+{
+    int i;
+    double fSum = 0;
+    /* for -74dB  from the Nuttall paper */
+    sfloat a0 = .40217, a1 = .49703, a2 = .09892, a3 = .00188;
+    double fConst = TWO_PI / sizeWindow;
+
+    /* compute window */
+    for(i = 0; i < sizeWindow; i++) 
+    {
+        fSum += pFWindow[i] = a0 - a1 * cos(fConst * i) +
+                a2 * cos(fConst * 2 * i) + a3 * cos(fConst * 3 * i);
+    }
+}
+
+/*! \brief BlackmanHarris window with 92dB rolloff
+ * 
+ * \param sizeWindow the size of the window
+ * \param pFWindow pointer to an array that will hold the window
+ */
+void BlackmanHarris92(int sizeWindow, sfloat *pFWindow)
+{
+    int i;
+    double fSum = 0;
+    /* for -92dB */
+    sfloat a0 = .35875, a1 = .48829, a2 = .14128, a3 = .01168;
+    double fConst = TWO_PI / sizeWindow;
+
+    /* compute window */
+    for(i = 0; i < sizeWindow; i++) 
+    {
+        fSum += pFWindow[i] = a0 - a1 * cos(fConst * i) +
+                a2 * cos(fConst * 2 * i) + a3 * cos(fConst * 3 * i);
+    }
+}
+
+/*! \brief default BlackmanHarris window (70dB rolloff)
+ * 
+ * \param sizeWindow the size of the window
+ * \param pFWindow pointer to an array that will hold the window
+ */
+void BlackmanHarris(int sizeWindow, sfloat *pFWindow)
+{
+    BlackmanHarris70(sizeWindow, pFWindow);
+}
+
+/*! \brief Hamming window
+ *
+ * \param sizeWindow window size
+ * \param pWindow    window array
+ */
+void Hamming(int sizeWindow, sfloat *pWindow)
+{
+    int i;
+    sfloat fSum = 0;
+
+    for(i = 0; i < sizeWindow; i++) 
+    {
+        fSum += pWindow[i] = 0.53836 - 0.46164*cos(TWO_PI*i/(sizeWindow-1));
+    }
+}
+
+/*! \brief Hanning window
+ *
+ * \param sizeWindow window size
+ * \param pWindow    window array
+ */
+void Hanning(int sizeWindow, sfloat *pWindow)
+{
+    int i;
+    for(i = 0; i < sizeWindow; i++) 
+        pWindow[i] = (sin(PI*i/(sizeWindow-1)))*(sin(PI*i/(sizeWindow-1)));
+}
+
+/*! \brief main function for getting various windows
+ *
+ * \todo note on window scales
+ * 
+ * \see SMS_WINDOWS for the different window types available
+ * \param sizeWindow  window size
+ * \param pFWindow    window array
+ * \param iWindowType the desired window type defined by #SMS_WINDOWS 
+ */
+void sms_getWindow(int sizeWindow, sfloat *pFWindow, int iWindowType)
+{
+    switch(iWindowType)
+    {
+        case SMS_WIN_BH_62: 
+            BlackmanHarris62(sizeWindow, pFWindow);
+            break;
+        case SMS_WIN_BH_70: 
+            BlackmanHarris70(sizeWindow, pFWindow);            
+            break;
+        case SMS_WIN_BH_74: 
+            BlackmanHarris74(sizeWindow, pFWindow);
+            break;
+        case SMS_WIN_BH_92: 
+            BlackmanHarris92(sizeWindow, pFWindow);
+            break;
+        case SMS_WIN_HAMMING: 
+            Hamming(sizeWindow, pFWindow);
+            break;
+        case SMS_WIN_HANNING: 
+            Hanning(sizeWindow, pFWindow);
+            break;
+        case SMS_WIN_IFFT: 
+            IFFTwindow(sizeWindow, pFWindow);
+            break;
+        default:
+            BlackmanHarris(sizeWindow, pFWindow);
+    }
+}
+
+/*! \brief apply a window and center around sample 0
+ *
+ * function to center a waveform around sample 0, also known
+ * as 'zero-phase windowing'.  Half the samples are at the beginning,
+ * half at the end, with the remaining samples  (sizeFft-sizeWindow) 
+ * in the middle (zero-padding for an interpolated spectrum).
+ *
+ * \todo do I need to garuntee that sizeWindow is odd-lengthed?
+ *
+ * \param sizeWindow size of waveform/waveform
+ * \param pWaveform  pointer to  waveform
+ * \param pWindow    pointer to window
+ * \param sizeFft    size of FFT
+ * \param pFftBuffer pointer to FFT buffer
+ */
+void sms_windowCentered(int sizeWindow, sfloat *pWaveform, sfloat *pWindow, 
+                        int sizeFft, sfloat *pFftBuffer)
+{
+    int iMiddleWindow = (sizeWindow+1) >> 1; 
+    int iOffset = sizeFft - (iMiddleWindow - 1);
+    int i;
+
+    for(i=0; i<iMiddleWindow-1; i++)
+        pFftBuffer[iOffset + i] =  pWindow[i] * pWaveform[i];
+
+    iOffset = iMiddleWindow - 1;
+
+    for(i=0; i<iMiddleWindow; i++)
+        pFftBuffer[i] = pWindow[iOffset + i] * pWaveform[iOffset + i];
+}