Blame gst-libs/gst/fft/gstfft.c

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/* GStreamer
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 * Copyright (C) <2007> Sebastian Dröge <slomo@circular-chaos.org>
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 *
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 * This library is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Library General Public
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 * License as published by the Free Software Foundation; either
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 * version 2 of the License, or (at your option) any later version.
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 *
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 * This library is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Library General Public License for more details.
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 *
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 * You should have received a copy of the GNU Library General Public
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 * License along with this library; if not, write to the
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 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
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 * Boston, MA 02110-1301, USA.
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 */
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/**
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 * SECTION:gstfft
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 * @title: GstFFT
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 * @short_description: General FFT functions and declarations
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 *
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 * This library includes general definitions and functions, useful for
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 * all typed FFT classes.
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 */
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include <glib.h>
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#include "gstfft.h"
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#include "kiss_fft_s16.h"
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/**
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 * gst_fft_next_fast_length:
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 * @n: Number for which the next fast length should be returned
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 *
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 * Returns the next number to @n that is entirely a product
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 * of 2, 3 and 5. Using this as the @len parameter for
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 * the different GstFFT types will provide the best performance.
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 *
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 * Returns: the next fast FFT length.
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 *
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 */
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gint
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gst_fft_next_fast_length (gint n)
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{
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  gint half = (n + 1) / 2;
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  /* It's the same for all data types so call the s16
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   * version */
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  /* The real FFT needs an even length so calculate that */
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  return 2 * kiss_fft_s16_next_fast_size (half);
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}