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https://github.com/matthew1000/gstreamer-cheat-sheet.git
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64 lines
1.7 KiB
Python
64 lines
1.7 KiB
Python
#!/usr/bin/env python
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'''
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An example of how fading can work into a compositor (mixer).
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Similar to a Gist at https://gist.github.com/lsiden/649d8ef9e02758ffde30b2b10fbac45a
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'''
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import gi
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gi.require_version('Gst', '1.0')
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gi.require_version('GstController', '1.0')
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from gi.repository import GObject, Gst, GstController
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import os
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from time import sleep
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from threading import Thread
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def get_alpha_controller(pad):
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cs = GstController.InterpolationControlSource()
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cs.set_property('mode', GstController.InterpolationMode.LINEAR)
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cb = GstController.DirectControlBinding.new(pad, 'alpha', cs)
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pad.add_control_binding(cb)
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return cs
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Gst.init(None)
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mainloop = GObject.MainLoop()
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pipe = Gst.parse_launch("videotestsrc ! timeoverlay name=timeoverlay halignment=right font-desc=\"Sans, 50\" deltax=10 ! " "compositor name=compositor sink_1::width=100 ! "
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"autovideosink videotestsrc pattern=1 ! compositor.")
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compositor = pipe.get_by_name('compositor')
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sink1 = compositor.get_static_pad('sink_1')
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cs = get_alpha_controller(sink1)
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is_showing = True
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# cs.set(0*Gst.SECOND, 0)
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# cs.set(1*Gst.SECOND, 1)
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# cs.set(2*Gst.SECOND, 0)
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# cs.set(3*Gst.SECOND, 0)
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# cs.set(4*Gst.SECOND, 1)
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pipe.set_state(Gst.State.PLAYING)
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# Separate thread to provide user interaction:
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def separate_thread():
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global is_showing
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while True:
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input("Press enter to fade...")
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current = 0
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dest = 1
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if is_showing:
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current = 1
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dest = 0
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pos = pipe.query_position(Gst.Format.TIME).cur
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print('Moving from %d to %d' % (current, dest))
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cs.set(pos, current)
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cs.set(pos + 1*Gst.SECOND, dest)
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is_showing = not is_showing
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myThread = Thread(target=separate_thread, args=())
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myThread.start()
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mainloop.run()
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