import gi
gi.require_version('Gst', '1.0')
from gi.repository import Gst, GLib

class GstRelay:
    def __init__(self):
        Gst.init(None)
        self.pipeline1 = Gst.parse_launch(
            "videotestsrc pattern=ball is-live=true ! video/x-raw,format=RGB,width=1280,height=720,framerate=240/1 ! videoconvert ! appsink name=sink"
        )
        self.appsink = self.pipeline1.get_by_name("sink")
        self.appsink.set_property("emit-signals", True)
        self.appsink.connect("new-sample", self.on_new_sample)
        self.pipeline2 = Gst.parse_launch(
            "appsrc name=src ! videoconvert ! autovideosink"
        )
        self.appsrc = self.pipeline2.get_by_name("src")
        self.appsrc.set_property("caps", Gst.Caps.from_string("video/x-raw,format=RGB,width=1280,height=720"))

    def on_new_sample(self, sink):
        """Callback when new frame arrives at appsink (Pipeline 1)."""
        sample = sink.emit("pull-sample")
        if not sample:
            return Gst.FlowReturn.ERROR
        buffer = sample.get_buffer()
        self.appsrc.emit("push-buffer", buffer)
        return Gst.FlowReturn.OK

    def start(self):
        """Start both pipelines."""
        self.pipeline1.set_state(Gst.State.PLAYING)
        self.pipeline2.set_state(Gst.State.PLAYING)

    def stop(self):
        """Stop both pipelines."""
        self.pipeline1.set_state(Gst.State.NULL)
        self.pipeline2.set_state(Gst.State.NULL)

def main():
    gst_relay = GstRelay()
    gst_relay.start()
    loop = GLib.MainLoop()
    try:
        loop.run()
    except KeyboardInterrupt:
        print("Stopping pipelines...")
        gst_relay.stop()

if __name__ == "__main__":
    main()