gstreamer/gst-libs/gst/fft/gstfftf32.c
Sebastian Dröge 9022ca9d1b Add libgstfft, a FFT library based on Kiss FFT which is
Original commit message from CVS:
Reviewed by:  Stefan Kost  <ensonic@users.sf.net>
* configure.ac:
* gst-libs/gst/Makefile.am:
* gst-libs/gst/fft/Makefile.am:
* gst-libs/gst/fft/_kiss_fft_guts_f32.h:
* gst-libs/gst/fft/_kiss_fft_guts_f64.h:
* gst-libs/gst/fft/_kiss_fft_guts_s16.h:
* gst-libs/gst/fft/_kiss_fft_guts_s32.h:
* gst-libs/gst/fft/gstfft.c: (gst_fft_next_fast_length):
* gst-libs/gst/fft/gstfft.h:
* gst-libs/gst/fft/gstfftf32.c: (gst_fft_f32_new),
(gst_fft_f32_fft), (gst_fft_f32_inverse_fft), (gst_fft_f32_free),
(gst_fft_f32_window), (gst_fft_f32_magnitude), (gst_fft_f32_phase):
* gst-libs/gst/fft/gstfftf32.h:
* gst-libs/gst/fft/gstfftf64.c: (gst_fft_f64_new),
(gst_fft_f64_fft), (gst_fft_f64_inverse_fft), (gst_fft_f64_free),
(gst_fft_f64_window), (gst_fft_f64_magnitude), (gst_fft_f64_phase):
* gst-libs/gst/fft/gstfftf64.h:
* gst-libs/gst/fft/gstffts16.c: (gst_fft_s16_new),
(gst_fft_s16_fft), (gst_fft_s16_inverse_fft), (gst_fft_s16_free),
(gst_fft_s16_window), (gst_fft_s16_magnitude), (gst_fft_s16_phase):
* gst-libs/gst/fft/gstffts16.h:
* gst-libs/gst/fft/gstffts32.c: (gst_fft_s32_new),
(gst_fft_s32_fft), (gst_fft_s32_inverse_fft), (gst_fft_s32_free),
(gst_fft_s32_window), (gst_fft_s32_magnitude), (gst_fft_s32_phase):
* gst-libs/gst/fft/gstffts32.h:
* gst-libs/gst/fft/kiss_fft_f32.c: (kf_bfly2), (kf_bfly4),
(kf_bfly3), (kf_bfly5), (kf_bfly_generic), (kf_work), (kf_factor),
(kiss_fft_f32_alloc), (kiss_fft_f32_stride), (kiss_fft_f32),
(kiss_fft_f32_cleanup), (kiss_fft_f32_next_fast_size):
* gst-libs/gst/fft/kiss_fft_f32.h:
* gst-libs/gst/fft/kiss_fft_f64.c: (kf_bfly2), (kf_bfly4),
(kf_bfly3), (kf_bfly5), (kf_bfly_generic), (kf_work), (kf_factor),
(kiss_fft_f64_alloc), (kiss_fft_f64_stride), (kiss_fft_f64),
(kiss_fft_f64_cleanup), (kiss_fft_f64_next_fast_size):
* gst-libs/gst/fft/kiss_fft_f64.h:
* gst-libs/gst/fft/kiss_fft_s16.c: (kf_bfly2), (kf_bfly4),
(kf_bfly3), (kf_bfly5), (kf_bfly_generic), (kf_work), (kf_factor),
(kiss_fft_s16_alloc), (kiss_fft_s16_stride), (kiss_fft_s16),
(kiss_fft_s16_cleanup), (kiss_fft_s16_next_fast_size):
* gst-libs/gst/fft/kiss_fft_s16.h:
* gst-libs/gst/fft/kiss_fft_s32.c: (kf_bfly2), (kf_bfly4),
(kf_bfly3), (kf_bfly5), (kf_bfly_generic), (kf_work), (kf_factor),
(kiss_fft_s32_alloc), (kiss_fft_s32_stride), (kiss_fft_s32),
(kiss_fft_s32_cleanup), (kiss_fft_s32_next_fast_size):
* gst-libs/gst/fft/kiss_fft_s32.h:
* gst-libs/gst/fft/kiss_fftr_f32.c: (kiss_fftr_f32_alloc),
(kiss_fftr_f32), (kiss_fftri_f32):
* gst-libs/gst/fft/kiss_fftr_f32.h:
* gst-libs/gst/fft/kiss_fftr_f64.c: (kiss_fftr_f64_alloc),
(kiss_fftr_f64), (kiss_fftri_f64):
* gst-libs/gst/fft/kiss_fftr_f64.h:
* gst-libs/gst/fft/kiss_fftr_s16.c: (kiss_fftr_s16_alloc),
(kiss_fftr_s16), (kiss_fftri_s16):
* gst-libs/gst/fft/kiss_fftr_s16.h:
* gst-libs/gst/fft/kiss_fftr_s32.c: (kiss_fftr_s32_alloc),
(kiss_fftr_s32), (kiss_fftri_s32):
* gst-libs/gst/fft/kiss_fftr_s32.h:
* gst-libs/gst/fft/kiss_version:
* pkgconfig/gstreamer-plugins-base-uninstalled.pc.in:
* pkgconfig/gstreamer-plugins-base.pc.in:
Add libgstfft, a FFT library based on Kiss FFT which is
BSD licensed. Supported sample formats are int16, int32,
float and double. For those formats a real FFT and IFFT
can be done, different windowing functions can be applied
and functions for extracting the magnitude and phase exist.
Fixes .
* docs/libs/Makefile.am:
* docs/libs/gst-plugins-base-libs-docs.sgml:
* docs/libs/gst-plugins-base-libs-sections.txt:
Integrate libgstfft into the docs.
* tests/check/Makefile.am:
* tests/check/libs/fft.c: (GST_START_TEST), (fft_suite), (main):
Add unit tests for libgstfft, currently only testing the FFT.
Unit tests for IFFT will follow soon.
2007-09-06 07:00:36 +00:00

270 lines
7.8 KiB
C

/* GStreamer
* Copyright (C) <2007> Sebastian Dröge <slomo@circular-chaos.org>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include <glib.h>
#include <math.h>
#include "kiss_fftr_f32.h"
#include "gstfft.h"
#include "gstfftf32.h"
/**
* SECTION:gstfftf32
* @short_description: FFT functions for 32 bit float samples
*
* #GstFFTF32 provides a FFT implementation and related functions for
* 32 bit float samples. To use this call gst_fft_f32_new() for
* allocating a #GstFFTF32 instance with the appropiate parameters and
* then call gst_fft_f32_fft() or gst_fft_f32_inverse_fft() to perform the
* FFT or inverse FFT on a buffer of samples.
*
* After use free the #GstFFTF32 instance with gst_fft_f32_free().
*
* For the best performance use gst_fft_next_fast_length() to get a
* number that is entirely a product of 2, 3 and 5 and use this as the
* @len parameter for gst_fft_f32_new().
*
* The @len parameter specifies the number of samples in the time domain that
* will be processed or generated. The number of samples in the frequency domain
* is @len/2 + 1. To get n samples in the frequency domain use 2*n - 2 as @len.
*
* Before performing the FFT on time domain data it usually makes sense
* to apply a window function to it. For this gst_fft_f32_window() can comfortably
* be used.
*
* For calculating the magnitude or phase of frequency data the functions
* gst_fft_f32_magnitude() and gst_fft_f32_phase() exist, if you want to calculate
* the magnitude yourself note that the magnitude of the frequency data is
* a value between 0 and 1 and is to be scaled by the length of the FFT.
*
*/
/**
* gst_fft_f32_new:
* @len: Length of the FFT in the time domain
* @inverse: %TRUE if the #GstFFTF32 instance should be used for the inverse FFT
*
* This returns a new #GstFFTF32 instance with the given parameters. It makes
* sense to keep one instance for several calls for speed reasons.
*
* @len must be even and to get the best performance a product of
* 2, 3 and 5. To get the next number with this characteristics use
* gst_fft_next_fast_length().
*
* Returns: a new #GstFFTF32 instance.
*/
GstFFTF32 *
gst_fft_f32_new (gint len, gboolean inverse)
{
GstFFTF32 *self;
g_return_val_if_fail (len > 0, NULL);
g_return_val_if_fail (len % 2 == 0, NULL);
self = g_new (GstFFTF32, 1);
self->cfg = kiss_fftr_f32_alloc (len, (inverse) ? 1 : 0, NULL, NULL);
g_assert (self->cfg);
self->inverse = inverse;
self->len = len;
return self;
}
/**
* gst_fft_f32_fft:
* @self: #GstFFTF32 instance for this call
* @timedata: Buffer of the samples in the time domain
* @freqdata: Target buffer for the samples in the frequency domain
*
* This performs the FFT on @timedata and puts the result in @freqdata.
*
* @timedata must have as many samples as specified with the @len parameter while
* allocating the #GstFFTF32 instance with gst_fft_f32_new().
*
* @freqdata must be large enough to hold @len/2 + 1 #GstFFTF32Complex frequency
* domain samples.
*
*/
void
gst_fft_f32_fft (GstFFTF32 * self, const gfloat * timedata,
GstFFTF32Complex * freqdata)
{
g_return_if_fail (self);
g_return_if_fail (!self->inverse);
g_return_if_fail (timedata);
g_return_if_fail (freqdata);
kiss_fftr_f32 (self->cfg, timedata, (kiss_fft_f32_cpx *) freqdata);
}
/**
* gst_fft_f32_inverse_fft:
* @self: #GstFFTF32 instance for this call
* @freqdata: Buffer of the samples in the frequency domain
* @timedata: Target buffer for the samples in the time domain
*
* This performs the inverse FFT on @freqdata and puts the result in @timedata.
*
* @freqdata must have @len/2 + 1 samples, where @len is the parameter specified
* while allocating the #GstFFTF32 instance with gst_fft_f32_new().
*
* @timedata must be large enough to hold @len time domain samples.
*
*/
void
gst_fft_f32_inverse_fft (GstFFTF32 * self, const GstFFTF32Complex * freqdata,
gfloat * timedata)
{
g_return_if_fail (self);
g_return_if_fail (self->inverse);
g_return_if_fail (timedata);
g_return_if_fail (freqdata);
kiss_fftri_f32 (self->cfg, (kiss_fft_f32_cpx *) freqdata, timedata);
}
/**
* gst_fft_f32_free:
* @self: #GstFFTF32 instance for this call
*
* This frees the memory allocated for @self.
*
*/
void
gst_fft_f32_free (GstFFTF32 * self)
{
kiss_fftr_f32_free (self->cfg);
g_free (self);
}
/**
* gst_fft_f32_window:
* @self: #GstFFTF32 instance for this call
* @timedata: Time domain samples
* @window: Window function to apply
*
* This calls the window function @window on the @timedata sample buffer.
*
*/
void
gst_fft_f32_window (GstFFTF32 * self, gfloat * timedata, GstFFTWindow window)
{
gint i, len;
g_return_if_fail (self);
g_return_if_fail (timedata);
len = self->len;
switch (window) {
case GST_FFT_WINDOW_RECTANGULAR:
/* do nothing */
break;
case GST_FFT_WINDOW_HAMMING:
for (i = 0; i < len; i++)
timedata[i] *= (0.53836 - 0.46164 * cos (2.0 * M_PI * i / len));
break;
case GST_FFT_WINDOW_HANN:
for (i = 0; i < len; i++)
timedata[i] *= (0.5 - 0.5 * cos (2.0 * M_PI * i / len));
break;
case GST_FFT_WINDOW_BARTLETT:
for (i = 0; i < len; i++)
timedata[i] *= (1.0 - fabs ((2.0 * i - len) / len));
break;
case GST_FFT_WINDOW_BLACKMAN:
for (i = 0; i < len; i++)
timedata[i] *= (0.42 - 0.5 * cos ((2.0 * i) / len) +
0.08 * cos ((4.0 * i) / len));
break;
default:
g_assert_not_reached ();
break;
}
}
/**
* gst_fft_f32_magnitude:
* @self: #GstFFTF32 instance for this call
* @freqdata: Frequency domain samples
* @magnitude: Target buffer for the magnitude
* @decibel: %TRUE if the magnitude should be in decibel, %FALSE if it should be an amplitude
*
* This calculates the magnitude of @freqdata in @magnitude. Depending on the value
* of @decibel the magnitude can be calculated in decibel or as amplitude between 0.0
* and 1.0.
*
* @magnitude must be large enough to hold @len/2 + 1 values.
*
*/
void
gst_fft_f32_magnitude (GstFFTF32 * self, GstFFTF32Complex * freqdata,
gdouble * magnitude, gboolean decibel)
{
gint i, len, nfft;
gdouble val;
g_return_if_fail (self);
g_return_if_fail (freqdata);
g_return_if_fail (magnitude);
len = self->len / 2 + 1;
nfft = self->len;
for (i = 0; i < len; i++) {
val = (gdouble) freqdata[i].r * (gdouble) freqdata[i].r
+ (gdouble) freqdata[i].i * (gdouble) freqdata[i].i;
val = sqrt (val) / nfft;
if (decibel)
val = 20.0 * log10 (val);
magnitude[i] = val;
}
}
/**
* gst_fft_f32_phase:
* @self: #GstFFTF32 instance for this call
* @freqdata: Frequency domain samples
* @phase: Target buffer for the phase
*
* This calculates the phases of @freqdata in @phase. The returned
* phases will be values between -pi and pi.
*
* @phase must be large enough to hold @len/2 + 1 values.
*
*/
void
gst_fft_f32_phase (GstFFTF32 * self, GstFFTF32Complex * freqdata,
gdouble * phase)
{
gint i, len;
g_return_if_fail (self);
g_return_if_fail (freqdata);
g_return_if_fail (phase);
len = self->len / 2 + 1;
for (i = 0; i < len; i++)
phase[i] = atan2 (freqdata[i].i, freqdata[i].r);
}