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authorJohn Glover <glover.john@gmail.com>2011-06-24 18:17:23 +0100
committerJohn Glover <glover.john@gmail.com>2011-06-24 18:17:23 +0100
commit416bd737074a287ea47106c73ea6bcfde40a75a8 (patch)
tree74562303d4f4f2f2e010f7e13cba41dc4852b50c /src/sms/tables.c
parentd26519464dcbf8c3682348167c29454961facefe (diff)
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Change to using distutils.
Currently only builds the simplsndobj module
Diffstat (limited to 'src/sms/tables.c')
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diff --git a/src/sms/tables.c b/src/sms/tables.c
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+/*
+ * 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 tables.c
+ * \brief sin and sinc tables.
+ *
+ * contains functions for creating and indexing the tables
+ */
+#include "sms.h"
+
+/*! \brief value to scale the sine-table-lookup phase */
+static sfloat fSineScale;
+/*! \brief inverse of fSineScale - turns a division into multiplication */
+static sfloat fSineIncr;
+/*! \brief value to scale the sinc-table-lookup phase */
+static sfloat fSincScale;
+/*! \brief global pointer to the sine table */
+static sfloat *sms_tab_sine;
+/*! \brief global pointer to the sinc table */
+static sfloat *sms_tab_sinc;
+
+/*! \brief prepares the sine table
+ * \param nTableSize size of table
+ * \return error code \see SMS_MALLOC in SMS_ERRORS
+ */
+int sms_prepSine(int nTableSize)
+{
+ register int i;
+ sfloat fTheta;
+
+ sms_tab_sine = (sfloat *)malloc(nTableSize * sizeof(sfloat));
+ if(sms_tab_sine == NULL)
+ {
+ sms_error("Could not allocate memory for sine table");
+ return SMS_MALLOC;
+ }
+ fSineScale = (sfloat)(TWO_PI) / (sfloat)(nTableSize - 1);
+ fSineIncr = 1.0 / fSineScale;
+ fTheta = 0.0;
+ for(i = 0; i < nTableSize; i++)
+ {
+ fTheta = fSineScale * (sfloat)i;
+ sms_tab_sine[i] = sin(fTheta);
+ }
+ return SMS_OK;
+}
+/*! \brief clear sine table */
+void sms_clearSine()
+{
+ if(sms_tab_sine)
+ free(sms_tab_sine);
+ sms_tab_sine = NULL;
+}
+
+/*! \brief table-lookup sine method
+ * \param fTheta angle in radians
+ * \return approximately sin(fTheta)
+ */
+sfloat sms_sine(sfloat fTheta)
+{
+ int i;
+ fTheta = fTheta - floor(fTheta * INV_TWO_PI) * TWO_PI;
+
+ if(fTheta < 0)
+ {
+ i = .5 - (fTheta * fSineIncr);
+ return -(sms_tab_sine[i]);
+ }
+ else
+ {
+ i = fTheta * fSineIncr + .5;
+ return sms_tab_sine[i];
+ }
+}
+
+/*! \brief Sinc method to generate the lookup table
+ */
+static sfloat Sinc(sfloat x, sfloat N)
+{
+ return sinf((N/2) * x) / sinf(x/2);
+}
+
+/*! \brief prepare the Sinc table
+ *
+ * used for the main lobe of a frequency domain
+ * BlackmanHarris92 window
+ *
+ * \param nTableSize size of table
+ * \return error code \see SMS_MALLOC in SMS_ERRORS
+ */
+int sms_prepSinc(int nTableSize)
+{
+ int i, m;
+ sfloat N = 512.0;
+ sfloat fA[4] = {.35875, .48829, .14128, .01168};
+ sfloat fMax = 0;
+ sfloat fTheta = -4.0 * TWO_PI / N;
+ sfloat fThetaIncr = (8.0 * TWO_PI / N) / (nTableSize);
+
+ sms_tab_sinc = (sfloat *)calloc(nTableSize, sizeof(sfloat));
+ if(sms_tab_sinc == NULL)
+ {
+ sms_error("Could not allocate memory for sinc table");
+ return (SMS_MALLOC);
+ }
+
+ for(i = 0; i < nTableSize; i++)
+ {
+ for (m = 0; m < 4; m++)
+ sms_tab_sinc[i] += -1 * (fA[m]/2) *
+ (Sinc (fTheta - m * TWO_PI/N, N) +
+ Sinc (fTheta + m * TWO_PI/N, N));
+ fTheta += fThetaIncr;
+ }
+
+ fMax = sms_tab_sinc[(int) nTableSize / 2];
+ for (i = 0; i < nTableSize; i++)
+ sms_tab_sinc[i] = sms_tab_sinc[i] / fMax;
+
+ fSincScale = (sfloat) nTableSize / 8.0;
+ return SMS_OK;
+}
+
+/*! \brief clear sine table */
+void sms_clearSinc()
+{
+ if(sms_tab_sinc)
+ free(sms_tab_sinc);
+ sms_tab_sinc = 0;
+}
+
+/*! \brief global sinc table-lookup method
+ *
+ * fTheta has to be from 0 to 8
+ *
+ * \param fTheta angle in radians
+ * \return approximately sinc(fTheta)
+ */
+sfloat sms_sinc(sfloat fTheta)
+{
+ int index = (int) (.5 + fSincScale * fTheta);
+ return sms_tab_sinc[index];
+}
+
+