2 # vi:si:et:sw=4:sts=4:ts=4
5 # Copyright (C) 2005 Fluendo S.L.
6 # Originally from the Flumotion streaming server.
8 # This library is free software; you can redistribute it and/or
9 # modify it under the terms of the GNU Library General Public
10 # License as published by the Free Software Foundation; either
11 # version 2 of the License, or (at your option) any later version.
13 # This library is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 # Library General Public License for more details.
18 # You should have received a copy of the GNU Library General Public
19 # License along with this library; if not, write to the
20 # Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
21 # Boston, MA 02110-1301, USA.
23 # Author: Zaheer Merali <zaheermerali at gmail dot com>
30 # this VUMeter respects IEC standard
31 # BS 6840-18:1996/IEC-268-18
32 # and is inspired by JACK's meterbridge dpm_meters.c
34 class FVUMeter(gtk.DrawingArea):
35 __gsignals__ = { 'expose-event' : 'override',
36 'size-allocate': 'override',
37 'size-request': 'override',
38 'realize' : 'override'
41 'peak' : (gobject.TYPE_FLOAT,
43 'peak volume level in dB',
47 gobject.PARAM_READWRITE),
48 'decay' : (gobject.TYPE_FLOAT,
50 'decay volume level in dB',
54 gobject.PARAM_READWRITE),
55 'orange-threshold': (gobject.TYPE_FLOAT,
56 'threshold for orange',
57 'threshold for orange use in dB',
61 gobject.PARAM_READWRITE),
62 'red-threshold': (gobject.TYPE_FLOAT,
64 'threshold for red use in dB',
68 gobject.PARAM_READWRITE)
79 orange_threshold = -10.0
85 # Returns the meter deflection percentage given a db value
86 def iec_scale(self, db):
92 pct = (db + 70.0) * 0.25
94 pct = (db + 60.0) * 0.5 + 2.5
96 pct = (db + 50.0) * 0.75 + 7.5
98 pct = (db + 40.0) * 1.5 + 15.0
100 pct = (db + 30.0) * 2.0 + 30.0
102 pct = (db + 20.0) * 2.5 + 50.0
108 def do_get_property(self, property):
109 if property.name == 'peak':
110 return self.peaklevel
111 elif property.name == 'decay':
112 return self.decaylevel
113 elif property.name == 'orange-threshold':
114 return self.orange_threshold
115 elif property.name == 'red-threshold':
116 return self.red_threshold
118 raise AttributeError, 'unknown property %s' % property.name
120 def do_set_property(self, property, value):
121 if property.name == 'peak':
122 self.peaklevel = value
123 elif property.name == 'decay':
124 self.decaylevel = value
125 elif property.name == 'orange-threshold':
126 self.orange_threshold = value
127 elif property.name == 'red-threshold':
128 self.red_threshold = value
130 raise AttributeError, 'unknown property %s' % property.name
134 def do_size_request(self, requisition):
135 requisition.width = 250
136 requisition.height = 50
138 def do_size_allocate(self, allocation):
139 self.allocation = allocation
140 if self.flags() & gtk.REALIZED:
141 self.window.move_resize(*allocation)
143 def do_realize(self):
144 self.set_flags(self.flags() | gtk.REALIZED)
146 self.window = gdk.Window(self.get_parent_window(),
147 width=self.allocation.width,
148 height=self.allocation.height,
149 window_type=gdk.WINDOW_CHILD,
150 wclass=gdk.INPUT_OUTPUT,
151 event_mask=self.get_events() | gdk.EXPOSURE_MASK)
153 colormap = gtk.gdk.colormap_get_system()
154 green = colormap.alloc_color(0, 65535, 0)
155 orange = colormap.alloc_color(65535, 32768, 0)
156 red = colormap.alloc_color(65535, 0, 0)
157 yellow = colormap.alloc_color(65535, 65535, 0)
158 self.green_gc = gdk.GC(self.window, foreground=green)
159 self.orange_gc = gdk.GC(self.window, foreground=orange)
160 self.red_gc = gdk.GC(self.window, foreground=red)
161 self.yellow_gc = gdk.GC(self.window, foreground=yellow)
163 self.window.set_user_data(self)
164 self.style.attach(self.window)
165 self.style.set_background(self.window, gtk.STATE_NORMAL)
167 def do_expose_event(self, event):
170 x, y, w, h = self.allocation
171 vumeter_width = w - (self.leftborder + self.rightborder)
172 vumeter_height = h - (self.topborder + self.bottomborder)
173 self.window.draw_rectangle(self.style.black_gc, True,
174 self.leftborder, self.topborder,
178 # 0 maps to width of 0, full scale maps to total width
179 peaklevelpct = self.iec_scale(self.peaklevel)
180 peakwidth = int(vumeter_width * (peaklevelpct / 100))
181 draw_gc = self.green_gc
182 if self.peaklevel >= self.orange_threshold:
183 draw_gc = self.orange_gc
184 if self.peaklevel >= self.red_threshold:
185 draw_gc = self.red_gc
187 self.window.draw_rectangle(draw_gc, True,
188 self.leftborder, self.topborder,
189 peakwidth, vumeter_height)
191 # draw yellow decay level
192 if self.decaylevel > -90.0:
193 decaylevelpct = self.iec_scale(self.decaylevel)
194 decaywidth = int(vumeter_width * (decaylevelpct / 100))
195 # cheat the geometry by drawing 0% level at pixel 0,
196 # which is same position as just above 0%
199 self.window.draw_line(self.yellow_gc,
200 self.leftborder + decaywidth - 1,
202 self.leftborder + decaywidth - 1,
203 self.topborder + vumeter_height - 1)
215 for level, scale in scalers:
216 # tick mark, 6 pixels high
217 # we cheat again here by putting the 0 at the first pixel
218 self.window.draw_line(self.style.black_gc,
219 self.leftborder + int(scale * (vumeter_width - 1)),
220 h - self.bottomborder,
221 self.leftborder + int(scale * (vumeter_width - 1)),
222 h - self.bottomborder + 5)
224 layout = self.create_pango_layout(level)
225 layout_width, layout_height = layout.get_pixel_size()
226 self.window.draw_layout(self.style.black_gc,
227 self.leftborder + int(scale * vumeter_width)
228 - int(layout_width / 2),
229 h - self.bottomborder + 7, layout)
231 # draw the peak level to the right
232 layout = self.create_pango_layout("%.2fdB" % self.peaklevel)
233 layout_width, layout_height = layout.get_pixel_size()
234 self.window.draw_layout(self.style.black_gc,
235 self.leftborder + vumeter_width + 5,
236 self.topborder + int(vumeter_height / 2 - layout_height / 2),
239 gobject.type_register(FVUMeter)