gst/spectrum/gstspectrum.c

/* GStreamer
 * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
 *
 * 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 <string.h>

#include "gstspectrum.h"

/* elementfactory information */
static GstElementDetails gst_spectrum_details = {
  "Spectrum analyzer",
  "Filter/Audio/Analysis",
  "LGPL",
  "Run an FFT on the audio signal, output spectrum data",
  VERSION,
  "Erik Walthinsen <omega@cse.ogi.edu>",
  "(C) 1999",
};

/* Spectrum signals and args */
enum {
  /* FILL ME */
  LAST_SIGNAL
};

enum {
  ARG_0,
  ARG_WIDTH,
};


static void	gst_spectrum_class_init	(GstSpectrumClass *klass);
static void	gst_spectrum_init	(GstSpectrum *spectrum);

static void	gst_spectrum_set_property	(GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec);

static void	gst_spectrum_chain	(GstPad *pad, GstBuffer *buf);

#define fixed short
int gst_spectrum_fix_fft(fixed fr[], fixed fi[], int m, int inverse);
void gst_spectrum_fix_loud(fixed loud[], fixed fr[], fixed fi[], int n, int scale_shift);
void gst_spectrum_window(fixed fr[], int n);


static GstElementClass *parent_class = NULL;
/*static guint gst_spectrum_signals[LAST_SIGNAL] = { 0 }; */

GType
gst_spectrum_get_type (void)
{
  static GType spectrum_type = 0;

  if (!spectrum_type) {
    static const GTypeInfo spectrum_info = {
      sizeof(GstSpectrumClass),      NULL,
      NULL,
      (GClassInitFunc)gst_spectrum_class_init,
      NULL,
      NULL,
      sizeof(GstSpectrum),
      0,
      (GInstanceInitFunc)gst_spectrum_init,
    };
    spectrum_type = g_type_register_static(GST_TYPE_ELEMENT, "GstSpectrum", &spectrum_info, 0);
  }
  return spectrum_type;
}

static void
gst_spectrum_class_init (GstSpectrumClass *klass)
{
  GObjectClass *gobject_class;

  gobject_class = (GObjectClass*)klass;

  parent_class = g_type_class_ref(GST_TYPE_ELEMENT);

  g_object_class_install_property(G_OBJECT_CLASS(klass), ARG_WIDTH,
    g_param_spec_int("width","width","width",
                     G_MININT,G_MAXINT,0,G_PARAM_WRITABLE)); /* CHECKME */

  gobject_class->set_property = gst_spectrum_set_property;
}

static void
gst_spectrum_init (GstSpectrum *spectrum)
{
  spectrum->sinkpad = gst_pad_new("sink",GST_PAD_SINK);
  gst_element_add_pad(GST_ELEMENT(spectrum),spectrum->sinkpad);
  gst_pad_set_chain_function(spectrum->sinkpad,gst_spectrum_chain);
  spectrum->srcpad = gst_pad_new("src",GST_PAD_SRC);
  gst_element_add_pad(GST_ELEMENT(spectrum),spectrum->srcpad);

  spectrum->width = 75;
}

static void
gst_spectrum_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec)
{
  GstSpectrum *spectrum;

  /* it's not null if we got it, but it might not be ours */
  g_return_if_fail(GST_IS_SPECTRUM(object));
  spectrum = GST_SPECTRUM(object);

  switch (prop_id) {
    case ARG_WIDTH:
      spectrum->width = g_value_get_int (value);
      break;
    default:
      break;
  }
}

static void
gst_spectrum_chain (GstPad *pad, GstBuffer *buf)
{
  GstSpectrum *spectrum;
  gint spec_base, spec_len;
  gint16 *re, *im, *loud;
  gint16 *samples;
  gint step,pos,i;
  guchar *spect;
  GstBuffer *newbuf;

  g_return_if_fail(pad != NULL);
  g_return_if_fail(GST_IS_PAD(pad));
  g_return_if_fail(buf != NULL);

  spectrum = GST_SPECTRUM (GST_OBJECT_PARENT (pad));

  samples = (gint16 *)GST_BUFFER_DATA(buf);

  spec_base = 8;
  spec_len = 1024;

  im = g_malloc(spec_len * sizeof(gint16));
  g_return_if_fail(im != NULL);
  loud = g_malloc(spec_len * sizeof(gint16));
  g_return_if_fail(loud != NULL);

  memset(im,0,spec_len * sizeof(gint16));
  /*if (spectrum->meta->channels == 2) { */
    re = g_malloc(spec_len * sizeof(gint16));
    for (i=0;i<spec_len;i++)
      re[i] = (samples[(i*2)] + samples[(i*2)+1]) >> 1;
  /*} else */
  /*  re = samples; */
  gst_spectrum_window(re,spec_len);
  gst_spectrum_fix_fft(re,im,spec_base,FALSE);
  gst_spectrum_fix_loud(loud,re,im,spec_len,0);
  if (re != samples) g_free(re);
  g_free(im);
  step = spec_len / (spectrum->width*2);
  spect = (guchar *)g_malloc(spectrum->width);
  for (i=0,pos=0;i<spectrum->width;i++,pos += step) {
    if (loud[pos] > -60)
      spect[i] = (loud[pos] + 60) / 2;
    else
      spect[i] = 0;
/*    if (spect[i] > 15); */
/*      spect[i] = 15; */
  }
  g_free(loud);
  gst_buffer_unref(buf);
/*  g_free(samples); */

  newbuf = gst_buffer_new();
  g_return_if_fail(newbuf != NULL);
  GST_BUFFER_DATA(newbuf) = spect;
  GST_BUFFER_SIZE(newbuf) = spectrum->width;

  gst_pad_push(spectrum->srcpad,newbuf);
}

static gboolean
plugin_init (GModule *module, GstPlugin *plugin)
{
  GstElementFactory *factory;

  /* create an elementfactory for the spectrum element */
  factory = gst_element_factory_new ("spectrum",GST_TYPE_SPECTRUM,
                                    &gst_spectrum_details);
  g_return_val_if_fail (factory != NULL, FALSE);

  gst_plugin_add_feature (plugin, GST_PLUGIN_FEATURE (factory));

  return TRUE;
}

GstPluginDesc plugin_desc = {
  GST_VERSION_MAJOR,
  GST_VERSION_MINOR,
  "spectrum",
  plugin_init
};