path: root/voctocore/experiments/sync-videomix.py

#!/usr/bin/python3
import gi, time
import socket

# import GStreamer and GTK-Helper classes
gi.require_version('Gst', '1.0')
from gi.repository import GLib, Gst, GObject

# init GObject before importing local classes
GObject.threads_init()
Gst.init(None)

class Example:
    def __init__(self):
        self.mainloop = GObject.MainLoop()

        pipeline = """
            videotestsrc pattern=red !
            {caps} !
            videoscale !
            capsfilter name=caps0 !
            identity sync=true signal-handoffs=false !
            mix.

            videotestsrc pattern=green !
            {caps} !
            videoscale !
            capsfilter name=caps1 !
            identity sync=true signal-handoffs=false !
            mix.

            videomixer name=mix !
            {caps} !
            identity name=sig !
            videoconvert !
            pngenc !
            multifilesink location=frame%04d.png
        """.format(
            caps='video/x-raw,width=800,height=450,format=I420,framerate=25/1'
        )

        self.pipeline = Gst.parse_launch(pipeline)
        sig = self.pipeline.get_by_name('sig')
        sig.connect('handoff', self.handoff)

        self.pad0 = self.pipeline.get_by_name('mix').get_static_pad('sink_0')
        self.pad1 = self.pipeline.get_by_name('mix').get_static_pad('sink_1')

        self.caps0 = self.pipeline.get_by_name('caps0')
        self.caps1 = self.pipeline.get_by_name('caps1')

        self.state = False

    def handoff(self, object, buffer):

        if self.state:
            padA = self.pad0
            padB = self.pad1
            capsA = self.caps0
            capsB = self.caps1
        else:
            padA = self.pad1
            padB = self.pad0
            capsA = self.caps1
            capsB = self.caps0

        padA.set_property('xpos', 10)
        padA.set_property('ypos', 10)
        padA.set_property('alpha', 1.0)
        padA.set_property('zorder', 1)
        capsA.set_property('caps', Gst.Caps.from_string('video/x-raw,width=400,height=225'))

        padB.set_property('xpos', 390)
        padB.set_property('ypos', 215)
        padB.set_property('alpha', 1.0)
        padB.set_property('zorder', 2)
        capsB.set_property('caps', Gst.Caps.from_string('video/x-raw,width=400,height=225'))

        self.state = not self.state

    def run(self):
        self.pipeline.set_state(Gst.State.PLAYING)
        self.mainloop.run()

    def kill(self):
        self.pipeline.set_state(Gst.State.NULL)
        self.mainloop.quit()

example = Example()
example.run()