scopes: add a simple fft based scope

Add a 2nd demo scope that uses a fft.

https://bugzilla.gnome.org/show_bug.cgi?id=651536

gst/scopes/Makefile.am

@@ -2,17 +2,20 @@ plugin_LTLIBRARIES = libgstscopes.la
 
 libgstscopes_la_SOURCES = \
     gstbasescope.c plugin.c \
+    gstspectrascope.c gstspectrascope.h \
     gstwavescope.c gstwavescope.h
 
 libgstscopes_la_CFLAGS = $(GST_PLUGINS_BAD_CFLAGS)\
 	$(GST_PLUGINS_BASE_CFLAGS) $(GST_BASE_CFLAGS) $(GST_CFLAGS)
 libgstscopes_la_LIBADD = \
 	$(GST_PLUGINS_BASE_LIBS) -lgstaudio-$(GST_MAJORMINOR) \
-	-lgstvideo-$(GST_MAJORMINOR) $(GST_BASE_LIBS) $(GST_LIBS)
+	-lgstvideo-$(GST_MAJORMINOR) -lgstfft-$(GST_MAJORMINOR) \
+	$(GST_BASE_LIBS) $(GST_LIBS)
 libgstscopes_la_LDFLAGS = $(GST_PLUGIN_LDFLAGS)
 libgstscopes_la_LIBTOOLFLAGS = --tag=disable-static
 
-noinst_HEADERS = gstbasescope.h gstwavescope.h
+noinst_HEADERS = gstbasescope.h \
+	gstspectrascope.h gstwavescope.h
 
 Android.mk: Makefile.am $(BUILT_SOURCES)
 	androgenizer \

gst/scopes/gstspectrascope.c

@@ -0,0 +1,198 @@
+/* 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);
+}

gst/scopes/gstspectrascope.h

@@ -0,0 +1,54 @@
+/* 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__ */

gst/scopes/plugin.c

@@ -22,12 +22,19 @@
 #include "config.h"
 #endif
 #include <gst/gst.h>
+
+#include "gstspectrascope.h"
+#include "gstsynaescope.h"
 #include "gstwavescope.h"
 
 static gboolean
 plugin_init (GstPlugin * plugin)
 {
-  return gst_wave_scope_plugin_init (plugin);
+  gboolean res = TRUE;
+
+  res &= gst_spectra_scope_plugin_init (plugin);
+  res &= gst_wave_scope_plugin_init (plugin);
+  return res;
 }
 
 GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,