Write opencv frames into gstreamer rtsp server pipeline

WisdomPill anas.el.amraoui at live.com
Mon Nov 20 16:13:29 UTC 2017

I'm trying to put opencv images into a gstreamer rtsp server in python.
I have some issue writing in the mediafactory, I'm new to gst-rtsp-server
ancd there's little documentation so I don't know exactly if I'm using the
right approach. I'm using a thread to start the MainLoop and I'm using the
main thread to create a buffer to push in the appsrc element of the
mediafactory pipeline. Am I using the right approach to obtain my objective?
Can anyone help me? My code is below:

    from threading import Thread
    from time import clock
    import cv2
    import gi
    gi.require_version('Gst', '1.0')
    gi.require_version('GstRtspServer', '1.0')
    from gi.repository import Gst, GstRtspServer, GObject
    class SensorFactory(GstRtspServer.RTSPMediaFactory):
        def __init__(self, **properties):
            super(SensorFactory, self).__init__(**properties)
            self.launch_string = 'appsrc !
video/x-raw,width=320,height=240,framerate=30/1 ' \
                                 '! videoconvert ! x264enc
speed-preset=ultrafast tune=zerolatency ' \
                                 '! rtph264pay config-interval=1 name=pay0
            self.pipeline = Gst.parse_launch(self.launch_string)
            self.appsrc = self.pipeline.get_child_by_index(4)
        def do_create_element(self, url):
            return self.pipeline
    class GstServer(GstRtspServer.RTSPServer):
        def __init__(self, **properties):
            super(GstServer, self).__init__(**properties)
            self.factory = SensorFactory()
            self.get_mount_points().add_factory("/test", self.factory)
    server = GstServer()
    loop = GObject.MainLoop()
    th = Thread(target=loop.run)
    print('Thread started')
    cap = cv2.VideoCapture(0)
    frame_number = 0
    fps = 30
    duration = 1 / fps
    timestamp = clock()
    while cap.isOpened():
        ret, frame = cap.read()
        if ret:
            print('Writing buffer')
            data = frame.tostring()
            buf = Gst.Buffer.new_allocate(None, len(data), None)
            buf.fill(0, data)
            buf.duration = fps
            timestamp = clock() - timestamp
            buf.pts = buf.dts = int(timestamp)
            buf.offset = frame_number
            frame_number += 1
            retval = server.factory.appsrc.emit('push-buffer', buf)
            if cv2.waitKey(1) & 0xFF == ord('q'):

By the way I tried to copy the buffer creation from opencv source code but
I'm not sure I correctly trandlated the c++ code in python.

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