1 files changed, 221 insertions, 0 deletions
diff --git a/gst/audiovisualizers/gstspectrascope.c b/gst/audiovisualizers/gstspectrascope.c
new file mode 100644
index 000000000..2335e9f6f
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+++ b/gst/audiovisualizers/gstspectrascope.c
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+/* GStreamer
+ * Copyright (C) <2011> Stefan Kost <ensonic@users.sf.net>
+ *
+ * gstspectrascope.c: frequency spectrum scope
+ *
+ * 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,
+      "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));
+}
+
+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);
+  guint num_freq = bscope->width + 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 (GstBaseScope * bscope, GstBuffer * audio,
+    GstBuffer * video)
+{
+  GstSpectraScope *scope = GST_SPECTRA_SCOPE (bscope);
+  guint32 *vdata = (guint32 *) 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 w = bscope->width;
+
+  if (bscope->channels > 1) {
+    guint ch = bscope->channels;
+    guint num_samples = GST_BUFFER_SIZE (audio) / (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 += 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[1 + x].r / 512.0;
+    fi = (gfloat) fdata[1 + x].i / 512.0;
+    y = (guint) (h * fabs (fr * fr + fi * fi));
+    if (y > h)
+      y = h;
+    y = h - y;
+    off = (y * w) + x;
+    vdata[off] = 0x00FFFFFF;
+    for (l = y + 1; l <= h; l++) {
+      off += w;
+      add_pixel (&vdata[off], 0x007F7F7F);
+    }
+  }
+  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);
+}