/* GStreamer FFTW-based signal-to-spectrum converter
* Copyright (C) 2006 Joseph Rabinoff <bobqwatson@yahoo.com>
*/
/***************************************************************************
* *
* 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. *
* *
***************************************************************************/
/**
* SECTION:element-fftwspectrum
*
* <refsect2>
* <title>Example launch line</title>
* <para>
* <programlisting>
* gst-launch audiotestsrc ! audioconvert ! fftwspectrum ! fftwunspectrum ! audioconvert ! alsasink
* </programlisting>
* </para>
* </refsect2>
*/
/* This is a simple plugin to take an audio signal and return its
* Fourier transform, using fftw3. It takes a specified number N of
* samples and returns the first N/2+1 (complex) Fourier transform
* values (the other half of the values being the complex conjugates
* of the first). The modulus of these values correspond to the
* strength of the signal in their various bands, and the phase gives
* information about the phase of the signal. The step by which the
* transform increments is also variable, so it can return redundant
* data (to reduce artifacts when converting back into a signal).
*/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <gst/gst.h>
#include <fftw3.h>
#include <string.h>
#include <math.h>
#include "gstfftwspectrum.h"
#include "spectrum.h"
GST_DEBUG_CATEGORY (gst_fftwspectrum_debug);
#define GST_CAT_DEFAULT gst_fftwspectrum_debug
/* Filter signals and args */
enum
{
/* FILL ME */
LAST_SIGNAL
};
/* The size and step arguments are actually only default values
* used to fixate the size and step properties of the source cap.
*/
enum
{
ARG_0,
ARG_DEF_SIZE,
ARG_DEF_STEP,
ARG_HIQUALITY
};
#define DEF_SIZE_DEFAULT 1024
#define DEF_STEP_DEFAULT 512
#define HIQUALITY_DEFAULT TRUE
static GstStaticPadTemplate sink_factory
= GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS
( SPECTRUM_SIGNAL_CAPS )
);
/* See spectrum.h for a definition of the frequency caps */
static GstStaticPadTemplate src_factory
= GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS
( SPECTRUM_FREQ_CAPS )
);
GST_BOILERPLATE (GstFFTWSpectrum, gst_fftwspectrum, GstElement,
GST_TYPE_ELEMENT);
static void gst_fftwspectrum_set_property (GObject *object, guint prop_id,
const GValue *value, GParamSpec *pspec);
static void gst_fftwspectrum_get_property (GObject *object, guint prop_id,
GValue *value, GParamSpec *pspec);
static gboolean gst_fftwspectrum_set_sink_caps (GstPad *pad, GstCaps *caps);
static gboolean gst_fftwspectrum_set_src_caps (GstPad *pad, GstCaps *caps);
static void gst_fftwspectrum_fixatecaps (GstPad *pad, GstCaps *caps);
static GstCaps *gst_fftwspectrum_getcaps (GstPad *pad);
static GstFlowReturn gst_fftwspectrum_chain (GstPad *pad, GstBuffer *buf);
static GstStateChangeReturn gst_fftwspectrum_change_state (GstElement *element,
GstStateChange transition);
#define OUTPUT_SIZE(conv) (((conv)->size/2+1)*sizeof(fftw_complex))
/***************************************************************/
/* GObject boilerplate stuff */
/***************************************************************/
static void
gst_fftwspectrum_base_init (gpointer gclass)
{
static GstElementDetails element_details =
{
"FFTW-based Fourier transform",
"Filter/Converter/Spectrum",
"Convert a raw audio stream into a frequency spectrum",
"Joe Rabinoff <bobqwatson@yahoo.com>"
};
GstElementClass *element_class = GST_ELEMENT_CLASS (gclass);
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&src_factory));
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&sink_factory));
gst_element_class_set_details (element_class, &element_details);
}
/* initialize the plugin's class */
static void
gst_fftwspectrum_class_init (GstFFTWSpectrumClass * klass)
{
GObjectClass *gobject_class;
GstElementClass *gstelement_class;
gobject_class = (GObjectClass *) klass;
gstelement_class = (GstElementClass *) klass;
gobject_class->set_property = gst_fftwspectrum_set_property;
gobject_class->get_property = gst_fftwspectrum_get_property;
g_object_class_install_property (gobject_class, ARG_DEF_SIZE,
g_param_spec_int ("def-size", "Default Size",
"Apply a Fourier transform to this many samples at a time (default value)",
1, G_MAXINT32, DEF_SIZE_DEFAULT, G_PARAM_READWRITE));
g_object_class_install_property (gobject_class, ARG_DEF_STEP,
g_param_spec_int ("def-step", "Default Step",
"Advance the stream this many samples each time (default value)",
1, G_MAXINT32, DEF_STEP_DEFAULT, G_PARAM_READWRITE));
g_object_class_install_property (gobject_class, ARG_HIQUALITY,
g_param_spec_boolean ("hiquality", "High Quality",
"Use a more time-consuming, higher quality algorithm chooser",
HIQUALITY_DEFAULT, G_PARAM_READWRITE));
gstelement_class->change_state
= GST_DEBUG_FUNCPTR (gst_fftwspectrum_change_state);
}
/* initialize the new element
* instantiate pads and add them to element
* set functions
* initialize structure
*/
static void
gst_fftwspectrum_init (GstFFTWSpectrum * conv,
GstFFTWSpectrumClass * gclass)
{
GstElementClass *klass = GST_ELEMENT_GET_CLASS (conv);
conv->sinkpad =
gst_pad_new_from_template
(gst_element_class_get_pad_template (klass, "sink"), "sink");
gst_pad_set_setcaps_function (conv->sinkpad,
GST_DEBUG_FUNCPTR (gst_fftwspectrum_set_sink_caps));
gst_pad_set_getcaps_function (conv->sinkpad,
GST_DEBUG_FUNCPTR (gst_fftwspectrum_getcaps));
gst_pad_set_chain_function (conv->sinkpad,
GST_DEBUG_FUNCPTR (gst_fftwspectrum_chain));
conv->srcpad =
gst_pad_new_from_template
(gst_element_class_get_pad_template (klass, "src"), "src");
gst_pad_set_setcaps_function (conv->srcpad,
GST_DEBUG_FUNCPTR (gst_fftwspectrum_set_src_caps));
gst_pad_set_getcaps_function (conv->srcpad,
GST_DEBUG_FUNCPTR (gst_fftwspectrum_getcaps));
gst_pad_set_fixatecaps_function (conv->srcpad,
GST_DEBUG_FUNCPTR (gst_fftwspectrum_fixatecaps));
gst_element_add_pad (GST_ELEMENT (conv), conv->sinkpad);
gst_element_add_pad (GST_ELEMENT (conv), conv->srcpad);
/* These are set once the (source) capabilities are determined */
conv->rate = 0;
conv->size = 0;
conv->step = 0;
/* These are set when we change to READY */
conv->fftw_in = NULL;
conv->fftw_out = NULL;
conv->fftw_plan = NULL;
/* These are set when we start receiving data */
conv->samples = NULL;
conv->numsamples = 0;
conv->timestamp = 0;
conv->offset = 0;
/* Properties */
conv->def_size = DEF_SIZE_DEFAULT;
conv->def_step = DEF_STEP_DEFAULT;
conv->hi_q = HIQUALITY_DEFAULT;
}
static void
gst_fftwspectrum_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstFFTWSpectrum *conv = GST_FFTWSPECTRUM (object);
switch (prop_id)
{
case ARG_DEF_SIZE:
conv->def_size = g_value_get_int (value);
break;
case ARG_DEF_STEP:
conv->def_step = g_value_get_int (value);
break;
case ARG_HIQUALITY:
conv->hi_q = g_value_get_boolean (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_fftwspectrum_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
GstFFTWSpectrum *conv = GST_FFTWSPECTRUM (object);
switch (prop_id)
{
case ARG_DEF_SIZE:
g_value_set_int (value, conv->def_size);
break;
case ARG_DEF_STEP:
g_value_set_int (value, conv->def_step);
break;
case ARG_HIQUALITY:
g_value_set_boolean (value, conv->hi_q);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
/* Allocate and deallocate fftw state data */
static void
free_fftw_data (GstFFTWSpectrum *conv)
{
if(conv->fftw_plan != NULL)
fftw_destroy_plan (conv->fftw_plan);
if(conv->fftw_in != NULL)
fftw_free (conv->fftw_in);
if(conv->fftw_out != NULL)
fftw_free (conv->fftw_out);
conv->fftw_in = NULL;
conv->fftw_out = NULL;
conv->fftw_plan = NULL;
}
static void
alloc_fftw_data (GstFFTWSpectrum *conv)
{
free_fftw_data (conv);
GST_DEBUG ("Allocating data for size = %d and step = %d",
conv->size, conv->step);
conv->fftw_in = (double *) fftw_malloc (sizeof(double) * conv->size);
conv->fftw_out = (double *) fftw_malloc (OUTPUT_SIZE (conv));
/* We use the simplest real-to-complex algorithm, which takes n real
* inputs and returns floor(n/2) + 1 complex outputs (the other n/2
* outputs are the hermetian conjugates). This should be optimal for
* implementing filters.
*/
static GStaticMutex mutex = G_STATIC_MUTEX_INIT;
g_static_mutex_lock(&mutex);
conv->fftw_plan
= fftw_plan_dft_r2c_1d(conv->size, conv->fftw_in,
(fftw_complex *) conv->fftw_out,
conv->hi_q ? FFTW_MEASURE : FFTW_ESTIMATE);
g_static_mutex_unlock(&mutex);
}
/***************************************************************/
/* Capabilities negotiation */
/***************************************************************/
/* The input and output capabilities are only related by the "rate"
* parameter, which is propagated so that an audio signal can be
* reconstructed eventually. This module does no rate conversion.
*
* The way I understand it, there are two times when caps negotiation
* takes place: (1) when a sink pad receives either its first buffer,
* or a buffer with a new caps type, and (2) when a source pad request
* a buffer from something downstream, and the returned allocated
* buffer has different caps from the ones already negotiated. In the
* first case, _set_sink_caps is called, and in the second, _set_src_caps
* is called.
* When (1) occurs, we remember the rate (the only variable parameter
* in the source) and set the source caps. Then _set_src_caps is called.
* In _set_src_caps, we check that the rate hasn't changed, and figure out
* or remember appropriate size and step attributes. If _set_src_caps is
* called from _set_sink_caps, this completes our setting up our internal
* configuration; if it is called from (2), we reconfigure just the source
* part of the internal configuration.
*/
static gboolean
gst_fftwspectrum_set_sink_caps (GstPad * pad, GstCaps * caps)
{
GstFFTWSpectrum *conv;
GstCaps *srccaps, *newsrccaps;
GstStructure *newstruct;
gint rate;
gboolean res;
conv = GST_FFTWSPECTRUM (gst_pad_get_parent (pad));
srccaps = gst_pad_get_allowed_caps (conv->srcpad);
newsrccaps = gst_caps_copy_nth (srccaps, 0);
gst_caps_unref (srccaps);
newstruct = gst_caps_get_structure (caps, 0);
if (!gst_structure_get_int (newstruct, "rate", &rate))
{
gst_caps_unref (newsrccaps);
gst_object_unref (conv);
return FALSE;
}
/* Fixate the source caps with the given rate */
gst_caps_set_simple (newsrccaps, "rate", G_TYPE_INT, rate, NULL);
gst_pad_fixate_caps (conv->srcpad, newsrccaps);
conv->rate = rate;
res = gst_pad_set_caps (conv->srcpad, newsrccaps);
if (!res)
conv->rate = 0;
gst_caps_unref (newsrccaps);
gst_object_unref (conv);
return res;
}
static gboolean
gst_fftwspectrum_set_src_caps (GstPad * pad, GstCaps * caps)
{
GstFFTWSpectrum *conv;
gboolean res = FALSE;
GstStructure *newstruct;
gint rate;
conv = GST_FFTWSPECTRUM (gst_pad_get_parent (pad));
newstruct = gst_caps_get_structure (caps, 0);
if (!gst_structure_get_int (newstruct, "rate", &rate))
goto out;
/* Assume caps negotiation has already taken place */
if (rate == conv->rate)
{
gint size, step;
if (!gst_structure_get_int (newstruct, "size", &size))
goto out;
if (!gst_structure_get_int (newstruct, "step", &step))
goto out;
if (conv->size != size || conv->step != step)
{
conv->size = size;
conv->step = step;
/* Re-allocate the fftw data */
if (GST_STATE (GST_ELEMENT (conv)) >= GST_STATE_READY)
alloc_fftw_data (conv);
}
res = TRUE;
}
out:
gst_object_unref (conv);
return res;
}
/* The only thing that can constrain the caps is the rate. */
static GstCaps *
gst_fftwspectrum_getcaps (GstPad *pad)
{
GstFFTWSpectrum *conv;
GstCaps *tmplcaps;
conv = GST_FFTWSPECTRUM (gst_pad_get_parent (pad));
tmplcaps = gst_caps_copy (gst_pad_get_pad_template_caps (pad));
if(conv->rate != 0)
{
/* Assumes the template caps are simple */
gst_caps_set_simple (tmplcaps, "rate", G_TYPE_INT, conv->rate, NULL);
}
gst_object_unref (conv);
return tmplcaps;
}
/* This is called when the source pad needs to choose its capabilities
* when it has a choice and nobody's forcing its hand. In this case
* we take our hint from the def_size and def_step properties.
*/
static void
gst_fftwspectrum_fixatecaps (GstPad *pad, GstCaps *caps)
{
GstFFTWSpectrum *conv;
GstStructure *s;
const GValue *val;
conv = GST_FFTWSPECTRUM (gst_pad_get_parent (pad));
s = gst_caps_get_structure (caps, 0);
val = gst_structure_get_value (s, "size");
if (val == NULL)
gst_caps_set_simple (caps, "size", G_TYPE_INT, conv->def_size, NULL);
else if (G_VALUE_TYPE (val) == GST_TYPE_INT_RANGE)
{
gint sizemin, sizemax;
sizemin = gst_value_get_int_range_min (val);
sizemax = gst_value_get_int_range_max (val);
gst_caps_set_simple (caps, "size", G_TYPE_INT,
CLAMP (conv->def_size, sizemin, sizemax), NULL);
}
/* else it should be already fixed */
val = gst_structure_get_value (s, "step");
if (val == NULL)
gst_caps_set_simple (caps, "step", G_TYPE_INT, conv->def_step, NULL);
else if (G_VALUE_TYPE (val) == GST_TYPE_INT_RANGE)
{
gint stepmin, stepmax;
stepmin = gst_value_get_int_range_min (val);
stepmax = gst_value_get_int_range_max (val);
gst_caps_set_simple (caps, "step", G_TYPE_INT,
CLAMP (conv->def_step, stepmin, stepmax), NULL);
}
/* else it should be already fixed */
/* Assume rate is already fixed (if not it'll be fixed by default) */
gst_object_unref (conv);
}
/***************************************************************/
/* Actual conversion */
/***************************************************************/
static GstStateChangeReturn
gst_fftwspectrum_change_state (GstElement * element,
GstStateChange transition)
{
GstFFTWSpectrum *conv = GST_FFTWSPECTRUM (element);
GstStateChangeReturn res;
switch (transition)
{
case GST_STATE_CHANGE_NULL_TO_READY:
alloc_fftw_data (conv);
break;
case GST_STATE_CHANGE_READY_TO_PAUSED:
conv->samples = (gdouble *) g_malloc (sizeof(gdouble));
conv->numsamples = 0;
conv->timestamp = 0;
conv->offset = 0;
break;
case GST_STATE_CHANGE_PAUSED_TO_PLAYING:
break;
default:
break;
}
res = parent_class->change_state (element, transition);
switch (transition)
{
case GST_STATE_CHANGE_PLAYING_TO_PAUSED:
break;
case GST_STATE_CHANGE_PAUSED_TO_READY:
g_free(conv->samples);
conv->samples = NULL;
conv->numsamples = 0;
conv->timestamp = 0;
conv->offset = 0;
break;
case GST_STATE_CHANGE_READY_TO_NULL:
free_fftw_data (conv);
break;
default:
break;
}
return res;
}
/* Adds the samples contained in buf to the end of conv->samples,
* updating conv->numsamples.
*/
static void
push_samples (GstFFTWSpectrum *conv, GstBuffer *buf)
{
gint newsamples = GST_BUFFER_SIZE (buf) / sizeof (gdouble);
gint oldsamples = conv->numsamples;
conv->numsamples += newsamples;
conv->samples = g_realloc (conv->samples, conv->numsamples * sizeof (gdouble));
memcpy (&conv->samples[oldsamples], GST_BUFFER_DATA (buf),
newsamples * sizeof (gdouble));
/* GST_LOG ("Added %d samples", newsamples); */
}
/* This basically does the opposite of push_samples, but takes samples
* off the front.
*/
static void
shift_samples (GstFFTWSpectrum *conv, gint toshift)
{
gdouble *oldsamples = conv->samples;
conv->numsamples -= toshift;
conv->samples = g_malloc (MAX (conv->numsamples, 1) * sizeof (double));
memcpy (conv->samples, &oldsamples[toshift],
conv->numsamples * sizeof (gdouble));
g_free (oldsamples);
/* Fix the timestamp and offset */
conv->timestamp
+= gst_util_uint64_scale_int (GST_SECOND, toshift, conv->rate);
conv->offset += toshift;
/* GST_LOG ("Disposed of %d samples (time: %" GST_TIME_FORMAT " offset: %llu)",
toshift, GST_TIME_ARGS(conv->timestamp), conv->offset); */
}
/* This function queues samples until there are at least
* max (conv->size, conv->step) samples to process. We
* then process samples in chunks of conv->size and increment
* by conv->step.
*/
static GstFlowReturn
gst_fftwspectrum_chain (GstPad * pad, GstBuffer * buf)
{
GstFFTWSpectrum *conv;
GstBuffer *outbuf;
GstFlowReturn res = GST_FLOW_OK;
conv = GST_FFTWSPECTRUM (gst_pad_get_parent (pad));
push_samples (conv, buf);
gst_buffer_unref (buf);
while (conv->numsamples >= MAX (conv->size, conv->step))
{
res = gst_pad_alloc_buffer_and_set_caps
(conv->srcpad, conv->offset, OUTPUT_SIZE (conv),
GST_PAD_CAPS(conv->srcpad), &outbuf);
if (res != GST_FLOW_OK)
break;
GST_BUFFER_SIZE (outbuf) = OUTPUT_SIZE (conv);
GST_BUFFER_OFFSET (outbuf) = conv->offset;
GST_BUFFER_OFFSET_END (outbuf) = conv->offset + conv->step;
GST_BUFFER_TIMESTAMP (outbuf) = conv->timestamp;
GST_BUFFER_DURATION (outbuf)
= gst_util_uint64_scale_int (GST_SECOND, conv->step, conv->rate);
/* Do the Fourier transform */
memcpy (conv->fftw_in, conv->samples, conv->size * sizeof (double));
fftw_execute (conv->fftw_plan);
{ /* Normalize */
gint i;
gfloat root = sqrtf (conv->size);
for (i = 0; i < 2*(conv->size/2+1); ++i)
conv->fftw_out[i] /= root;
}
memcpy (GST_BUFFER_DATA (outbuf), conv->fftw_out, OUTPUT_SIZE (conv));
res = gst_pad_push (conv->srcpad, outbuf);
shift_samples (conv, conv->step);
if (res != GST_FLOW_OK)
break;
}
gst_object_unref (conv);
return res;
}