gst/spectrum/: added another example

Original commit message from CVS:
* gst/spectrum/Makefile.am:
* gst/spectrum/demo-audiotest.c: (on_frequency_changed),
(spectrum_chain), (main):
* gst/spectrum/demo-osssrc.c:
added another example
* sys/v4l2/gstv4l2src.c:
fix typo

gst/spectrum/Makefile.am

@@ -9,11 +9,15 @@ libgstspectrum_la_LDFLAGS = $(GST_PLUGIN_LDFLAGS)
 noinst_HEADERS = gstspectrum.h
 
 if HAVE_GTK
-noinst_PROGRAMS = demo-osssrc
+noinst_PROGRAMS = demo-osssrc demo-audiotest
 endif
 
 demo_osssrc_SOURCES = demo-osssrc.c
 demo_osssrc_CFLAGS  = $(GST_BASE_CFLAGS) $(GST_CFLAGS) $(GTK_CFLAGS)
 demo_osssrc_LDFLAGS = $(GST_BASE_LIBS) $(GST_LIBS) $(GTK_LIBS)
 
+demo_audiotest_SOURCES = demo-audiotest.c
+demo_audiotest_CFLAGS  = $(GST_BASE_CFLAGS) $(GST_CFLAGS) $(GTK_CFLAGS)
+demo_audiotest_LDFLAGS = $(GST_BASE_LIBS) $(GST_LIBS) $(GTK_LIBS)
+
 EXTRA_DIST = README

sys/v4l2/gstv4l2src.c

@@ -37,7 +37,7 @@
  * <programlisting>
  * gst-launch v4l2src use-fixed-fps=true ! xvimagesink
  * </programlisting>
- * This exemplo should be used to capture from web-cams
+ * This exemple should be used to capture from web-cams
  * </para>
  * </refsect2>
  */

tests/examples/spectrum/demo-audiotest.c

@@ -0,0 +1,99 @@
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+#include <gst/gst.h>
+#include <gtk/gtk.h>
+
+#define SPECT_BANDS 256
+
+static GtkWidget *drawingarea = NULL;
+static gint ct = 0;
+
+static void
+on_frequency_changed (GtkRange * range, gpointer user_data)
+{
+  GstElement *machine = GST_ELEMENT (user_data);
+  gdouble value = gtk_range_get_value (range);
+
+  g_object_set (machine, "freq", value, NULL);
+}
+
+static void
+spectrum_chain (GstElement * sink, GstBuffer * buf, GstPad * pad,
+    gpointer unused)
+{
+  ct = (ct + 1) & 0x15;
+  if (!ct) {
+    gint i;
+    guchar *data = buf->data;
+    gint width = GST_BUFFER_SIZE (buf);
+    GdkRectangle rect = { 0, 0, width, 50 };
+
+    gdk_window_begin_paint_rect (drawingarea->window, &rect);
+    gdk_draw_rectangle (drawingarea->window, drawingarea->style->black_gc,
+        TRUE, 0, 0, width, 50);
+    for (i = 0; i < width; i++) {
+      gdk_draw_rectangle (drawingarea->window, drawingarea->style->white_gc,
+          TRUE, i, 64 - data[i], 1, data[i]);
+    }
+    gdk_window_end_paint (drawingarea->window);
+  }
+}
+
+int
+main (int argc, char *argv[])
+{
+  GstElement *bin;
+  GstElement *src, *spectrum, *sink;
+
+  GtkWidget *appwindow, *vbox, *widget;
+
+  gst_init (&argc, &argv);
+  gtk_init (&argc, &argv);
+
+  bin = gst_pipeline_new ("bin");
+
+  src = gst_element_factory_make ("audiotestsrc", "src");
+  g_object_set (G_OBJECT (src), "blocksize", (gulong) 1024 * 2, NULL);
+
+  spectrum = gst_element_factory_make ("spectrum", "spectrum");
+  g_object_set (G_OBJECT (spectrum), "width", SPECT_BANDS, "threshold", -80,
+      NULL);
+
+  sink = gst_element_factory_make ("fakesink", "sink");
+  g_object_set (G_OBJECT (sink), "signal-handoffs", TRUE, NULL);
+
+  g_signal_connect (sink, "handoff", G_CALLBACK (spectrum_chain), NULL);
+
+  gst_bin_add_many (GST_BIN (bin), src, spectrum, sink, NULL);
+  if (!gst_element_link_many (src, spectrum, sink, NULL)) {
+    fprintf (stderr, "cant link elements\n");
+    exit (1);
+  }
+
+  appwindow = gtk_window_new (GTK_WINDOW_TOPLEVEL);
+  vbox = gtk_vbox_new (FALSE, 6);
+
+  widget = gtk_hscale_new_with_range (50.0, 20000.0, 10);
+  gtk_scale_set_draw_value (GTK_SCALE (widget), TRUE);
+  gtk_scale_set_value_pos (GTK_SCALE (widget), GTK_POS_TOP);
+  gtk_range_set_value (GTK_RANGE (widget), 440.0);
+  g_signal_connect (G_OBJECT (widget), "value-changed",
+      G_CALLBACK (on_frequency_changed), (gpointer) src);
+  gtk_container_add (GTK_CONTAINER (vbox), widget);
+
+  drawingarea = gtk_drawing_area_new ();
+  gtk_drawing_area_size (GTK_DRAWING_AREA (drawingarea), SPECT_BANDS, 64);
+  gtk_container_add (GTK_CONTAINER (vbox), drawingarea);
+
+  gtk_container_add (GTK_CONTAINER (appwindow), vbox);
+  gtk_widget_show_all (appwindow);
+
+  gst_element_set_state (bin, GST_STATE_PLAYING);
+  gtk_main ();
+  gst_element_set_state (bin, GST_STATE_NULL);
+
+  gst_object_unref (bin);
+
+  return 0;
+}

tests/examples/spectrum/demo-osssrc.c

@@ -7,7 +7,7 @@
 #define DEFAULT_AUDIOSRC "alsasrc"
 #define SPECT_BANDS 256
 
-GtkWidget *drawingarea;
+static GtkWidget *drawingarea = NULL;
 
 static void
 spectrum_chain (GstElement * sink, GstBuffer * buf, GstPad * pad,