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# -*- Mode: Python -*-
# vi:si:et:sw=4:sts=4:ts=4
# gst-python
# Copyright (C) 2005 Fluendo S.L.
# Originally from the Flumotion streaming server.
#
# 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.
#
# Author: Zaheer Merali <zaheermerali at gmail dot com>
import gtk
from gtk import gdk
import gobject
# this VUMeter respects IEC standard
# BS 6840-18:1996/IEC-268-18
# and is inspired by JACK's meterbridge dpm_meters.c
class FVUMeter(gtk.DrawingArea):
__gsignals__ = { 'expose-event' : 'override',
'size-allocate': 'override',
'size-request': 'override',
'realize' : 'override'
}
__gproperties__ = {
'peak' : (gobject.TYPE_FLOAT,
'peak volume level',
'peak volume level in dB',
-90.0,
0,
-90.0,
gobject.PARAM_READWRITE),
'decay' : (gobject.TYPE_FLOAT,
'decay volume level',
'decay volume level in dB',
-90.0,
0,
-90.0,
gobject.PARAM_READWRITE),
'orange-threshold': (gobject.TYPE_FLOAT,
'threshold for orange',
'threshold for orange use in dB',
-90.0,
0,
-10.0,
gobject.PARAM_READWRITE),
'red-threshold': (gobject.TYPE_FLOAT,
'threshold for red',
'threshold for red use in dB',
-90.0,
0,
-1.0,
gobject.PARAM_READWRITE)
}
green_gc = None
orange_gc = None
red_gc = None
yellow_gc = None
topborder = 7
peaklevel = -90.0
decaylevel = -90.0
orange_threshold = -10.0
red_threshold = -1.0
bottomborder = 25
leftborder = 15
rightborder = 65
# Returns the meter deflection percentage given a db value
def iec_scale(self, db):
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
def do_get_property(self, property):
if property.name == 'peak':
return self.peaklevel
elif property.name == 'decay':
return self.decaylevel
elif property.name == 'orange-threshold':
return self.orange_threshold
elif property.name == 'red-threshold':
return self.red_threshold
else:
raise AttributeError, 'unknown property %s' % property.name
def do_set_property(self, property, value):
if property.name == 'peak':
self.peaklevel = value
elif property.name == 'decay':
self.decaylevel = value
elif property.name == 'orange-threshold':
self.orange_threshold = value
elif property.name == 'red-threshold':
self.red_threshold = value
else:
raise AttributeError, 'unknown property %s' % property.name
self.queue_draw()
def do_size_request(self, requisition):
requisition.width = 250
requisition.height = 50
def do_size_allocate(self, allocation):
self.allocation = allocation
if self.flags() & gtk.REALIZED:
self.window.move_resize(*allocation)
def do_realize(self):
self.set_flags(self.flags() | gtk.REALIZED)
self.window = gdk.Window(self.get_parent_window(),
width=self.allocation.width,
height=self.allocation.height,
window_type=gdk.WINDOW_CHILD,
wclass=gdk.INPUT_OUTPUT,
event_mask=self.get_events() | gdk.EXPOSURE_MASK)
colormap = gtk.gdk.colormap_get_system()
green = colormap.alloc_color(0, 65535, 0)
orange = colormap.alloc_color(65535, 32768, 0)
red = colormap.alloc_color(65535, 0, 0)
yellow = colormap.alloc_color(65535, 65535, 0)
self.green_gc = gdk.GC(self.window, foreground=green)
self.orange_gc = gdk.GC(self.window, foreground=orange)
self.red_gc = gdk.GC(self.window, foreground=red)
self.yellow_gc = gdk.GC(self.window, foreground=yellow)
self.window.set_user_data(self)
self.style.attach(self.window)
self.style.set_background(self.window, gtk.STATE_NORMAL)
def do_expose_event(self, event):
self.chain(event)
x, y, w, h = self.allocation
vumeter_width = w - (self.leftborder + self.rightborder)
vumeter_height = h - (self.topborder + self.bottomborder)
self.window.draw_rectangle(self.style.black_gc, True,
self.leftborder, self.topborder,
vumeter_width,
vumeter_height)
# draw peak level
# 0 maps to width of 0, full scale maps to total width
peaklevelpct = self.iec_scale(self.peaklevel)
peakwidth = int(vumeter_width * (peaklevelpct / 100))
draw_gc = self.green_gc
if self.peaklevel >= self.orange_threshold:
draw_gc = self.orange_gc
if self.peaklevel >= self.red_threshold:
draw_gc = self.red_gc
if peakwidth > 0:
self.window.draw_rectangle(draw_gc, True,
self.leftborder, self.topborder,
peakwidth, vumeter_height)
# draw yellow decay level
if self.decaylevel > -90.0:
decaylevelpct = self.iec_scale(self.decaylevel)
decaywidth = int(vumeter_width * (decaylevelpct / 100))
# cheat the geometry by drawing 0% level at pixel 0,
# which is same position as just above 0%
if decaywidth == 0:
decaywidth = 1
self.window.draw_line(self.yellow_gc,
self.leftborder + decaywidth - 1,
self.topborder,
self.leftborder + decaywidth - 1,
self.topborder + vumeter_height - 1)
# draw tick marks
scalers = [
('-90', 0.0),
('-40', 0.15),
('-30', 0.30),
('-20', 0.50),
('-10', 0.75),
( '-5', 0.875),
( '0', 1.0),
]
for level, scale in scalers:
# tick mark, 6 pixels high
# we cheat again here by putting the 0 at the first pixel
self.window.draw_line(self.style.black_gc,
self.leftborder + int(scale * (vumeter_width - 1)),
h - self.bottomborder,
self.leftborder + int(scale * (vumeter_width - 1)),
h - self.bottomborder + 5)
# tick label
layout = self.create_pango_layout(level)
layout_width, layout_height = layout.get_pixel_size()
self.window.draw_layout(self.style.black_gc,
self.leftborder + int(scale * vumeter_width)
- int(layout_width / 2),
h - self.bottomborder + 7, layout)
# draw the peak level to the right
layout = self.create_pango_layout("%.2fdB" % self.peaklevel)
layout_width, layout_height = layout.get_pixel_size()
self.window.draw_layout(self.style.black_gc,
self.leftborder + vumeter_width + 5,
self.topborder + int(vumeter_height / 2 - layout_height / 2),
layout)
gobject.type_register(FVUMeter)
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