examples/vumeter.py: New file, a VU meter application that reads from alsasrc.

Original commit message from CVS:
2005-07-13  Andy Wingo  <wingo@pobox.com>

* examples/vumeter.py: New file, a VU meter application that reads
from alsasrc.

* examples/fvumeter.py: New file, imported from Flumotion and
relicensed under the LGPL. Implements a simple VU meter widget.

1 files changed, 103 insertions, 0 deletions

diff --git a/examples/vumeter.py b/examples/vumeter.py
new file mode 100755
index 0000000..631f66f
--- /dev/null
+++ b/examples/vumeter.py
@@ -0,0 +1,103 @@
+#!/usr/bin/env python
+#
+# gst-python
+# Copyright (C) 2005 Andy Wingo <wingo@pobox.com>
+#
+# 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., 59 Temple Place - Suite 330,
+# Boston, MA 02111-1307, USA.
+
+
+# A test more of gst-plugins than of gst-python.
+
+
+import pygtk
+pygtk.require('2.0')
+import gtk
+import gobject
+
+import pygst
+pygst.require('0.9')
+import gst
+
+import fvumeter
+
+
+def clamp(x, min, max):
+    if x < min:
+        return min
+    elif x > max:
+        return max
+    return x
+
+
+class Window(gtk.Dialog):
+    def __init__(self):
+        gtk.Dialog.__init__(self, 'Volume Level')
+        self.prepare_ui()
+
+    def prepare_ui(self):
+        self.set_default_size(200,60)
+        self.set_title('Volume Level')
+        self.connect('delete-event', lambda *x: gtk.main_quit())
+        self.vu = fvumeter.FVUMeter()
+        self.vu.show()
+        self.vbox.pack_start(self.vu)
+
+    def error(self, message, secondary=None):
+        m = gtk.MessageDialog(self,
+                              gtk.DIALOG_MODAL | gtk.DIALOG_DESTROY_WITH_PARENT,
+                              gtk.MESSAGE_ERROR,
+                              gtk.BUTTONS_OK,
+                              message)
+        if secondary:
+            m.format_secondary_text(secondary)
+        m.run()
+                              
+    def on_message(self, bus, message):
+        t = message.type
+        if t == gst.MESSAGE_STATE_CHANGED:
+            pass
+        if (t == gst.MESSAGE_APPLICATION and
+            message.structure.get_name() == 'level'):
+            s = message.structure
+            self.vu.set_property('peak', clamp(s['peak'][0], -90.0, 0.0))
+            self.vu.set_property('decay', clamp(s['decay'][0], -90.0, 0.0))
+        else:
+            print '%s: %s:' % (message.src.get_path_string(),
+                               message.type.value_nicks[1])
+            print '    %s' % message.structure.to_string()
+        return True
+
+    def run(self):
+        try:
+            self.set_sensitive(False)
+            s = 'alsasrc ! level signal=true ! fakesink'
+            pipeline = gst.parse_launch(s)
+            self.set_sensitive(True)
+            watch_id = pipeline.get_bus().add_watch(self.on_message)
+            if pipeline.set_state(gst.STATE_PLAYING) == gst.STATE_SUCCESS:
+                gtk.Dialog.run(self)
+            else:
+                self.error('Could not set state')
+            pipeline.set_state(gst.STATE_NULL)
+            gobject.source_remove(watch_id)
+        except gobject.GError, e:
+            self.set_sensitive(True)
+            self.error('Could not create pipeline', e.__str__)
+        
+if __name__ == '__main__':
+    w = Window()
+    w.show()
+    w.run()