Set up new PulseCasterSource object

1 files changed, 132 insertions, 0 deletions

diff --git a/pulsecaster/source.py b/pulsecaster/source.py
new file mode 100644
index 0000000..7ab62d3
--- /dev/null
+++ b/pulsecaster/source.py
@@ -0,0 +1,132 @@
+# Copyright (C) 2011 Paul W. Frields and others.
+# -*- coding: utf-8 -*-
+#
+# 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 3 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, see <http://www.gnu.org/licenses/>.
+#
+#
+# Author: Paul W. Frields <stickster@gmail.com>
+
+from config import *
+import gtk
+import pygst
+import gobject
+pygst.require('0.10')
+import gst
+from pulseaudio.PulseObj import PulseObj, PulseSourceInfo
+
+class PulseCasterSource:
+    '''A source object that provides sound data for PulseCaster'''
+    def __init__(self):
+        '''Construct the source object'''
+        # Should include a PA source, a GtkCombBox, and a GtkProgressBar
+        self.store = gtk.ListStore(gobject.TYPE_STRING,
+                                   gobject.TYPE_STRING,
+                                   gobject.TYPE_PYOBJECT)
+        self.bus = None
+        self.cbox = gtk.ComboBox(self.store)
+        self.cell = gtk.CellRendererText()
+        self.cbox.pack_start(self.cell, True)
+        self.cbox.add_attribute(self.cell, 'text', True)
+        self.cbox.connect('changed', self.set_meters)
+        self.pbar = gtk.ProgressBar()
+        self.pipeline = None
+        print 'out of __init__'
+        
+    def repopulate(self, pa, use_source=True, use_monitor=True):
+        '''Repopulate the ComboBox for this object'''
+        print 'in repopulate'
+        sources = pa.pulse_source_list()
+        self.store.clear()
+        for source in sources:
+            if source.monitor_of_sink_name == None:
+                if use_source == True:
+                    self.store.append([source.name,
+                                       source.description,
+                                       source])
+            else:
+                if use_monitor == True:
+                    self.store.append([source.name,
+                                       source.description,
+                                       source])
+        print 'out of repopulate'
+
+    def create_level_pipeline(self, *args):
+        '''Make a GStreamer pipeline that allows level checking'''
+        print 'in create_level_pipeline'
+        pl = 'pulsesrc device=%s' % (self.pulsesrc)
+        pl += '! level message=true interval=50000000 ! fakesink'
+        print pl
+        self.pipeline = gst.parse_launch(pl)
+        self.pipeline.get_bus().add_signal_watch()
+        self.conn = self.pipeline.get_bus().connect('message::element', self.update_level)
+        self.pipeline.set_state(gst.STATE_PLAYING)
+        print 'out of create_level_pipeline'
+    
+    def remove_level_pipeline(self, *args):
+        '''Tear down the GStreamer pipeline attached to this object'''
+        print 'in remove_level_pipeline'
+        self.pipeline.set_state(gst.STATE_NULL)
+        self.pipeline.get_bus().remove_signal_watch()
+        self.pipeline.get_bus().disconnect(self.conn)
+        self.conn = None
+        self.pipeline = None
+        print 'out of remove_level_pipeline'
+    
+    def set_meters(self, *args):
+        print 'in set_meters'
+        self.cbox.set_sensitive(False)
+        if self.pipeline is not None:
+            self.remove_level_pipeline()
+        active = self.cbox.get_active()
+        i = self.cbox.get_active_iter()
+        self.pulsesrc = self.cbox.get_model().get_value(i, 0)
+        self.create_level_pipeline()
+        self.cbox.set_sensitive(True)
+        print 'out of set_meters'
+        
+    def update_level(self, bus, message, *args):
+        '''Update this object's GtkProgressBar to reflect current level'''
+        print 'in update_level'
+        print message
+        if message.structure.get_name() == 'level':
+            peaks = message.structure['peak']
+            channels = len(peaks)
+            for peak in peaks:
+                v = v + peak
+            v = iec_scale(v/channels)
+            self.pbar.set_fraction(v)
+        self.main.queue_draw()
+        print 'out of update_level'
+        return True
+    
+    def iec_scale(self, db):
+        '''For a given dB value, return the iEC-268-18 standard percentage''' 
+        pct = 0.0
+        if db < -70.0:
+            pct = 0.0
+        elif db < -60.0:
+            pct = (db + 70.0) * 0.25
+        elif db < -50.0:
+            pct = (db + 60.0) * 0.5 + 2.5
+        elif db < -40.0:
+            pct = (db + 50.0) * 0.75 + 7.5
+        elif db < -30.0:
+            pct = (db + 40.0) * 1.5 + 15.0
+        elif db < -20.0:
+            pct = (db + 30.0) * 2.0 + 30.0
+        elif db < 0.0:
+            pct = (db + 20.0) * 2.5 + 50.0
+        else:
+            pct = 100.0
+        return pct