--- /dev/null
+/* GStreamer
+ * Copyright (C) <2011> Stefan Kost <ensonic@users.sf.net>
+ *
+ * gstspectrascope.c: simple oscilloscope
+ *
+ * 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.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+/**
+ * SECTION:element-spectrascope
+ * @see_also: goom
+ *
+ * Wavescope is a simple audio visualisation element. It renders the waveforms
+ * like on an oscilloscope.
+ *
+ * <refsect2>
+ * <title>Example launch line</title>
+ * |[
+ * gst-launch 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,
+ GST_STATIC_CAPS (GST_VIDEO_CAPS_xRGB_HOST_ENDIAN)
+ );
+
+static GstStaticPadTemplate gst_spectra_scope_sink_template =
+GST_STATIC_PAD_TEMPLATE ("sink",
+ GST_PAD_SINK,
+ GST_PAD_ALWAYS,
+ GST_STATIC_CAPS (GST_AUDIO_INT_STANDARD_PAD_TEMPLATE_CAPS)
+ );
+
+
+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 (GstBaseScope * scope);
+static gboolean gst_spectra_scope_render (GstBaseScope * scope,
+ GstBuffer * audio, GstBuffer * video);
+
+
+GST_BOILERPLATE (GstSpectraScope, gst_spectra_scope, GstBaseScope,
+ GST_TYPE_BASE_SCOPE);
+
+static void
+gst_spectra_scope_base_init (gpointer g_class)
+{
+ GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
+
+ gst_element_class_set_details_simple (element_class, "Waveform oscilloscope",
+ "Visualization",
+ "Simple waveform oscilloscope", "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));
+}
+
+static void
+gst_spectra_scope_class_init (GstSpectraScopeClass * g_class)
+{
+ GObjectClass *gobject_class = (GObjectClass *) g_class;
+ GstBaseScopeClass *scope_class = (GstBaseScopeClass *) g_class;
+
+ gobject_class->finalize = gst_spectra_scope_finalize;
+
+ 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, GstSpectraScopeClass * g_class)
+{
+ /* 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 (parent_class)->finalize (object);
+}
+
+static gboolean
+gst_spectra_scope_setup (GstBaseScope * bscope)
+{
+ GstSpectraScope *scope = GST_SPECTRA_SCOPE (bscope);
+
+ if (scope->fft_ctx)
+ gst_fft_s16_free (scope->fft_ctx);
+ if (scope->freq_data)
+ g_free (scope->freq_data);
+ scope->fft_ctx = gst_fft_s16_new (bscope->width * 2 - 2, FALSE);
+ scope->freq_data = g_new (GstFFTS16Complex, bscope->width);
+ return TRUE;
+}
+
+static gboolean
+gst_spectra_scope_render (GstBaseScope * bscope, GstBuffer * audio,
+ GstBuffer * video)
+{
+ GstSpectraScope *scope = GST_SPECTRA_SCOPE (bscope);
+ guint8 *vdata = GST_BUFFER_DATA (video);
+ gint16 *adata = (gint16 *) GST_BUFFER_DATA (audio);
+ GstFFTS16Complex *fdata = scope->freq_data;
+ guint x, y, off;
+ guint l, h = bscope->height - 1;
+ gfloat fr, fi;
+ guint bpp = gst_video_format_get_pixel_stride (bscope->video_format, 0);
+ guint bpl = bpp * bscope->width;
+
+ if (bscope->channels > 1) {
+ gint ch = bscope->channels;
+ gint num_samples = GST_BUFFER_SIZE (audio) / (ch * sizeof (gint16));
+ gint 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 += adata[s++];
+ }
+ adata[i] = v / ch;
+ }
+ }
+
+ /* run fft */
+ gst_fft_s16_window (scope->fft_ctx, adata, GST_FFT_WINDOW_HAMMING);
+ gst_fft_s16_fft (scope->fft_ctx, adata, fdata);
+
+ /* draw lines */
+ for (x = 0; x < bscope->width; x++) {
+ /* figure out the range so that we don't need to clip,
+ * or even better do a log mapping? */
+ fr = (gfloat) fdata[x].r / 2048.0;
+ fi = (gfloat) fdata[x].i / 2048.0;
+ y = (guint) (h * fabs (fr * fr + fi * fi));
+ if (y > h)
+ y = h;
+ y = h - y;
+ off = (y * bpl) + (x * bpp);
+ vdata[off + 0] = 0xFF;
+ vdata[off + 1] = 0xFF;
+ vdata[off + 2] = 0xFF;
+ for (l = y + 1; l <= h; l++) {
+ off += bpl;
+ vdata[off + 0] = 0x7F;
+ vdata[off + 1] = 0x7F;
+ vdata[off + 2] = 0x7F;
+ }
+ }
+ 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);
+}
--- /dev/null
+/* GStreamer
+ * Copyright (C) <2011> Stefan Kost <ensonic@users.sf.net>
+ *
+ * gstspectrascope.h: simple oscilloscope
+ *
+ * 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.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+
+#ifndef __GST_SPECTRA_SCOPE_H__
+#define __GST_SPECTRA_SCOPE_H__
+
+#include "gstbasescope.h"
+#include <gst/fft/gstffts16.h>
+
+G_BEGIN_DECLS
+#define GST_TYPE_SPECTRA_SCOPE (gst_spectra_scope_get_type())
+#define GST_SPECTRA_SCOPE(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_SPECTRA_SCOPE,GstSpectraScope))
+#define GST_SPECTRA_SCOPE_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_SPECTRA_SCOPE,GstSpectraScopeClass))
+#define GST_IS_SPECTRA_SCOPE(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_SPECTRA_SCOPE))
+#define GST_IS_SPECTRA_SCOPE_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_SPECTRA_SCOPE))
+typedef struct _GstSpectraScope GstSpectraScope;
+typedef struct _GstSpectraScopeClass GstSpectraScopeClass;
+
+struct _GstSpectraScope
+{
+ GstBaseScope parent;
+
+ GstFFTS16 *fft_ctx;
+ GstFFTS16Complex *freq_data;
+};
+
+struct _GstSpectraScopeClass
+{
+ GstBaseScopeClass parent_class;
+};
+
+GType gst_spectra_scope_get_type (void);
+gboolean gst_spectra_scope_plugin_init (GstPlugin * plugin);
+
+G_END_DECLS
+#endif /* __GST_SPECTRA_SCOPE_H__ */
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