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/* GStreamer
* Copyright (C) <2011> Stefan Kost <ensonic@users.sf.net>
*
* gstspectrascope.c: frequency spectrum scope
*
* 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., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
/**
* SECTION:element-spectrascope
* @see_also: goom
*
* Spectrascope is a simple spectrum visualisation element. It renders the
* frequency spectrum as a series of bars.
*
* <refsect2>
* <title>Example launch line</title>
* |[
* gst-launch-1.0 audiotestsrc ! audioconvert ! spectrascope ! ximagesink
* ]|
* </refsect2>
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <stdlib.h>
#include "gstspectrascope.h"
static GstStaticPadTemplate gst_spectra_scope_src_template =
GST_STATIC_PAD_TEMPLATE ("src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
#if G_BYTE_ORDER == G_BIG_ENDIAN
GST_STATIC_CAPS (GST_VIDEO_CAPS_MAKE ("xRGB"))
#else
GST_STATIC_CAPS (GST_VIDEO_CAPS_MAKE ("BGRx"))
#endif
);
static GstStaticPadTemplate gst_spectra_scope_sink_template =
GST_STATIC_PAD_TEMPLATE ("sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("audio/x-raw, "
"format = (string) " GST_AUDIO_NE (S16) ", "
"layout = (string) interleaved, "
"rate = (int) [ 8000, 96000 ], "
"channels = (int) 2, " "channel-mask = (bitmask) 0x3")
);
GST_DEBUG_CATEGORY_STATIC (spectra_scope_debug);
#define GST_CAT_DEFAULT spectra_scope_debug
static void gst_spectra_scope_finalize (GObject * object);
static gboolean gst_spectra_scope_setup (GstAudioVisualizer * scope);
static gboolean gst_spectra_scope_render (GstAudioVisualizer * scope,
GstBuffer * audio, GstVideoFrame * video);
G_DEFINE_TYPE (GstSpectraScope, gst_spectra_scope, GST_TYPE_AUDIO_VISUALIZER);
static void
gst_spectra_scope_class_init (GstSpectraScopeClass * g_class)
{
GObjectClass *gobject_class = (GObjectClass *) g_class;
GstElementClass *element_class = (GstElementClass *) g_class;
GstAudioVisualizerClass *scope_class = (GstAudioVisualizerClass *) g_class;
gobject_class->finalize = gst_spectra_scope_finalize;
gst_element_class_set_static_metadata (element_class,
"Frequency spectrum scope", "Visualization",
"Simple frequency spectrum scope", "Stefan Kost <ensonic@users.sf.net>");
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&gst_spectra_scope_src_template));
gst_element_class_add_pad_template (element_class,
gst_static_pad_template_get (&gst_spectra_scope_sink_template));
scope_class->setup = GST_DEBUG_FUNCPTR (gst_spectra_scope_setup);
scope_class->render = GST_DEBUG_FUNCPTR (gst_spectra_scope_render);
}
static void
gst_spectra_scope_init (GstSpectraScope * scope)
{
/* do nothing */
}
static void
gst_spectra_scope_finalize (GObject * object)
{
GstSpectraScope *scope = GST_SPECTRA_SCOPE (object);
if (scope->fft_ctx) {
gst_fft_s16_free (scope->fft_ctx);
scope->fft_ctx = NULL;
}
if (scope->freq_data) {
g_free (scope->freq_data);
scope->freq_data = NULL;
}
G_OBJECT_CLASS (gst_spectra_scope_parent_class)->finalize (object);
}
static gboolean
gst_spectra_scope_setup (GstAudioVisualizer * bscope)
{
GstSpectraScope *scope = GST_SPECTRA_SCOPE (bscope);
guint num_freq = GST_VIDEO_INFO_WIDTH (&bscope->vinfo) + 1;
if (scope->fft_ctx)
gst_fft_s16_free (scope->fft_ctx);
g_free (scope->freq_data);
/* we'd need this amount of samples per render() call */
bscope->req_spf = num_freq * 2 - 2;
scope->fft_ctx = gst_fft_s16_new (bscope->req_spf, FALSE);
scope->freq_data = g_new (GstFFTS16Complex, num_freq);
return TRUE;
}
static inline void
add_pixel (guint32 * _p, guint32 _c)
{
guint8 *p = (guint8 *) _p;
guint8 *c = (guint8 *) & _c;
if (p[0] < 255 - c[0])
p[0] += c[0];
else
p[0] = 255;
if (p[1] < 255 - c[1])
p[1] += c[1];
else
p[1] = 255;
if (p[2] < 255 - c[2])
p[2] += c[2];
else
p[2] = 255;
if (p[3] < 255 - c[3])
p[3] += c[3];
else
p[3] = 255;
}
static gboolean
gst_spectra_scope_render (GstAudioVisualizer * bscope, GstBuffer * audio,
GstVideoFrame * video)
{
GstSpectraScope *scope = GST_SPECTRA_SCOPE (bscope);
gint16 *mono_adata;
GstFFTS16Complex *fdata = scope->freq_data;
guint x, y, off, l;
guint w = GST_VIDEO_INFO_WIDTH (&bscope->vinfo);
guint h = GST_VIDEO_INFO_HEIGHT (&bscope->vinfo) - 1;
gfloat fr, fi;
GstMapInfo amap;
guint32 *vdata;
gint channels;
gst_buffer_map (audio, &amap, GST_MAP_READ);
vdata = (guint32 *) GST_VIDEO_FRAME_PLANE_DATA (video, 0);
channels = GST_AUDIO_INFO_CHANNELS (&bscope->ainfo);
mono_adata = (gint16 *) g_memdup (amap.data, amap.size);
if (channels > 1) {
guint ch = channels;
guint num_samples = amap.size / (ch * sizeof (gint16));
guint i, c, v, s = 0;
/* deinterleave and mixdown adata */
for (i = 0; i < num_samples; i++) {
v = 0;
for (c = 0; c < ch; c++) {
v += mono_adata[s++];
}
mono_adata[i] = v / ch;
}
}
/* run fft */
gst_fft_s16_window (scope->fft_ctx, mono_adata, GST_FFT_WINDOW_HAMMING);
gst_fft_s16_fft (scope->fft_ctx, mono_adata, fdata);
g_free (mono_adata);
/* draw lines */
for (x = 0; x < w; x++) {
/* figure out the range so that we don't need to clip,
* or even better do a log mapping? */
fr = (gfloat) fdata[1 + x].r / 512.0;
fi = (gfloat) fdata[1 + x].i / 512.0;
y = (guint) (h * sqrt (fr * fr + fi * fi));
if (y > h)
y = h;
y = h - y;
off = (y * w) + x;
vdata[off] = 0x00FFFFFF;
for (l = y; l < h; l++) {
off += w;
add_pixel (&vdata[off], 0x007F7F7F);
}
/* ensure bottom line is full bright (especially in move-up mode) */
add_pixel (&vdata[off], 0x007F7F7F);
}
gst_buffer_unmap (audio, &amap);
return TRUE;
}
gboolean
gst_spectra_scope_plugin_init (GstPlugin * plugin)
{
GST_DEBUG_CATEGORY_INIT (spectra_scope_debug, "spectrascope", 0,
"spectrascope");
return gst_element_register (plugin, "spectrascope", GST_RANK_NONE,
GST_TYPE_SPECTRA_SCOPE);
}
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