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# vi:si:et:sw=4:sts=4:ts=4
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# Copyright (C) 2005 Fluendo S.L.
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# Originally from the Flumotion streaming server.
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# This library is free software; you can redistribute it and/or
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# modify it under the terms of the GNU Library General Public
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# License as published by the Free Software Foundation; either
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# version 2 of the License, or (at your option) any later version.
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# This library is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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# Library General Public License for more details.
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# You should have received a copy of the GNU Library General Public
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# License along with this library; if not, write to the
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# Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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# Boston, MA 02111-1307, USA.
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# Author: Zaheer Merali <zaheermerali at gmail dot com>
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# this VUMeter respects IEC standard
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# BS 6840-18:1996/IEC-268-18
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# and is inspired by JACK's meterbridge dpm_meters.c
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class FVUMeter(gtk.DrawingArea):
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__gsignals__ = { 'expose-event' : 'override',
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'size-allocate': 'override',
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'size-request': 'override',
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'realize' : 'override'
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'peak' : (gobject.TYPE_FLOAT,
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'peak volume level in dB',
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gobject.PARAM_READWRITE),
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'decay' : (gobject.TYPE_FLOAT,
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'decay volume level in dB',
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gobject.PARAM_READWRITE),
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'orange-threshold': (gobject.TYPE_FLOAT,
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'threshold for orange',
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'threshold for orange use in dB',
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gobject.PARAM_READWRITE),
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'red-threshold': (gobject.TYPE_FLOAT,
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'threshold for red use in dB',
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gobject.PARAM_READWRITE)
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orange_threshold = -10.0
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# Returns the meter deflection percentage given a db value
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def iec_scale(self, db):
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pct = (db + 70.0) * 0.25
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pct = (db + 60.0) * 0.5 + 2.5
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pct = (db + 50.0) * 0.75 + 7.5
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pct = (db + 40.0) * 1.5 + 15.0
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pct = (db + 30.0) * 2.0 + 30.0
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pct = (db + 20.0) * 2.5 + 50.0
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def do_get_property(self, property):
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if property.name == 'peak':
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return self.peaklevel
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elif property.name == 'decay':
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return self.decaylevel
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elif property.name == 'orange-threshold':
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return self.orange_threshold
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elif property.name == 'red-threshold':
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return self.red_threshold
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raise AttributeError, 'unknown property %s' % property.name
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def do_set_property(self, property, value):
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if property.name == 'peak':
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self.peaklevel = value
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elif property.name == 'decay':
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self.decaylevel = value
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elif property.name == 'orange-threshold':
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self.orange_threshold = value
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elif property.name == 'red-threshold':
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self.red_threshold = value
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raise AttributeError, 'unknown property %s' % property.name
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def do_size_request(self, requisition):
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requisition.width = 250
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requisition.height = 50
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def do_size_allocate(self, allocation):
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self.allocation = allocation
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if self.flags() & gtk.REALIZED:
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self.window.move_resize(*allocation)
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def do_realize(self):
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self.set_flags(self.flags() | gtk.REALIZED)
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self.window = gdk.Window(self.get_parent_window(),
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width=self.allocation.width,
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height=self.allocation.height,
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window_type=gdk.WINDOW_CHILD,
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wclass=gdk.INPUT_OUTPUT,
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event_mask=self.get_events() | gdk.EXPOSURE_MASK)
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colormap = gtk.gdk.colormap_get_system()
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green = colormap.alloc_color(0, 65535, 0)
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orange = colormap.alloc_color(65535, 32768, 0)
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red = colormap.alloc_color(65535, 0, 0)
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yellow = colormap.alloc_color(65535, 65535, 0)
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self.green_gc = gdk.GC(self.window, foreground=green)
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self.orange_gc = gdk.GC(self.window, foreground=orange)
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self.red_gc = gdk.GC(self.window, foreground=red)
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self.yellow_gc = gdk.GC(self.window, foreground=yellow)
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self.window.set_user_data(self)
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self.style.attach(self.window)
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self.style.set_background(self.window, gtk.STATE_NORMAL)
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def do_expose_event(self, event):
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x, y, w, h = self.allocation
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vumeter_width = w - (self.leftborder + self.rightborder)
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vumeter_height = h - (self.topborder + self.bottomborder)
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self.window.draw_rectangle(self.style.black_gc, True,
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self.leftborder, self.topborder,
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# 0 maps to width of 0, full scale maps to total width
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peaklevelpct = self.iec_scale(self.peaklevel)
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peakwidth = int(vumeter_width * (peaklevelpct / 100))
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draw_gc = self.green_gc
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if self.peaklevel >= self.orange_threshold:
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draw_gc = self.orange_gc
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if self.peaklevel >= self.red_threshold:
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draw_gc = self.red_gc
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self.window.draw_rectangle(draw_gc, True,
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self.leftborder, self.topborder,
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peakwidth, vumeter_height)
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# draw yellow decay level
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if self.decaylevel > -90.0:
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decaylevelpct = self.iec_scale(self.decaylevel)
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decaywidth = int(vumeter_width * (decaylevelpct / 100))
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# cheat the geometry by drawing 0% level at pixel 0,
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# which is same position as just above 0%
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self.window.draw_line(self.yellow_gc,
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self.leftborder + decaywidth - 1,
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self.leftborder + decaywidth - 1,
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self.topborder + vumeter_height - 1)
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for level, scale in scalers:
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# tick mark, 6 pixels high
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# we cheat again here by putting the 0 at the first pixel
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self.window.draw_line(self.style.black_gc,
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self.leftborder + int(scale * (vumeter_width - 1)),
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h - self.bottomborder,
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self.leftborder + int(scale * (vumeter_width - 1)),
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h - self.bottomborder + 5)
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layout = self.create_pango_layout(level)
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layout_width, layout_height = layout.get_pixel_size()
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self.window.draw_layout(self.style.black_gc,
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self.leftborder + int(scale * vumeter_width)
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- int(layout_width / 2),
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h - self.bottomborder + 7, layout)
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# draw the peak level to the right
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layout = self.create_pango_layout("%.2fdB" % self.peaklevel)
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layout_width, layout_height = layout.get_pixel_size()
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self.window.draw_layout(self.style.black_gc,
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self.leftborder + vumeter_width + 5,
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self.topborder + int(vumeter_height / 2 - layout_height / 2),
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gobject.type_register(FVUMeter)
added
removed
examples/fvumeter.py
