1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
|
# Simple-effect.py
#!/usr/bin/env python
"""Extends basic demo with a gnl composition"""
from demo import Demo, DemoException
import gtk
import gst
import sys
import os
def create_decodebin():
try:
return gst.element_factory_make("decodebin2")
except:
return gst.element_factory_make("decodebin")
class SimpleEffectDemo(Demo):
__name__ = "Basic GStreamer Effect Demo"
__usage__ = '''python %s file
display file with a color_balance effect''' % sys.argv[0]
__def_win_size__ = (320, 500)
# <excerpt 1>
def magic(self, pipeline, sink, args):
def onPad(obj, pad, target):
sinkpad = target.get_compatible_pad(pad, pad.get_caps())
pad.link(sinkpad)
return True
assert os.path.exists(sys.argv[1])
# create the following pipeline
# filesrc location = sys.argv[1] ! decodebin ! videobalance ! ...
src = gst.element_factory_make("filesrc")
src.set_property("location", sys.argv[1])
decode = create_decodebin()
self.balance = gst.element_factory_make("videobalance")
pipeline.add(src, decode, self.balance)
src.link(decode)
decode.connect("pad-added", onPad, self.balance)
self.balance.link(sink)
return
# </excerpt>
# <excerpt 2>
# overriding from parent
def customWidgets(self):
"""Create a control for each property in the videobalance
widget"""
# to be called a property value needs to change
def onValueChanged(widget, prop):
# set the corresponding property of the videobalance element
self.balance.set_property(prop, widget.get_value())
# videobalance has several properties, with the following range
# and defaults
properties = [("contrast", 0, 2, 1),
("brightness", -1, 1, 0),
("hue", -1, 1, 0),
("saturation", 0, 2, 1)]
# create a place to hold our controls
controls = gtk.VBox()
labels = gtk.VBox()
# for every property, create a control and set its attributes
for prop, lower, upper, default in properties:
widget = gtk.HScale(); label = gtk.Label(prop)
# set appropriate attributes
widget.set_update_policy(gtk.UPDATE_CONTINUOUS)
widget.set_value(default)
widget.set_draw_value(True)
widget.set_range(lower, upper)
# connect to our signal handler, specifying the property
# to adjust
widget.connect("value-changed", onValueChanged, prop)
# pack widget into box
controls.pack_start(widget, True, True)
labels.pack_start(label, True, False)
layout = gtk.HBox()
layout.pack_start(labels, False, False)
layout.pack_end(controls, True, True)
return layout
# </excerpt>
if __name__ == '__main__':
SimpleEffectDemo().run()
|
