Streaming images using appsrc

[fgfernandez0321]

I have this example in python where I want to stream images via UDP. In this
case I'm testing using autovideosink in order to know how the images change.
Based on the documentation I need to free the buffer when it is used however
I haven't found a function on Python bindings to solve this. I tried to use
"push_buffer" function instead of signals but it is not exist at least in my
version. At this point, when the first images is shown, I can't push more
buffers because "enough-data" signal is emitted and "need-data" is not
emitted again in order to start push buffers. 

Could you please help me to clarify me? Thank you  

class SenderImages:
    def __init__(self):
        # Control if it is allowed push buffer in queue using "need-data"
and "enough-data" signals
        self.is_push_buffer_allowed = None

        self._mainloop = GObject.MainLoop()
        auto_video_sink_pipeline = "appsrc name=source ! decodebin !
imagefreeze ! autovideosink"
        self._pipeline = Gst.parse_launch(auto_video_sink_pipeline)

        # udp_sink_pipeline = "appsrc name=source ! decodebin ! imagefreeze
! udpsink host=localhost port=55100"
        # self._pipeline = Gst.parse_launch(udp_sink_pipeline)

        self._src = self._pipeline.get_by_name('source')
        self._src.connect('need-data', self.start_feed)
        self._src.connect('enough-data', self.stop_feed)
        # length is just a hint and when it is set to -1, any number of
bytes can be pushed into appsrc
        # self._src.set_property("length", -1)

    def start_feed(self, src, length):
        print('======================> need data length: %s' % length)
        self.is_push_buffer_allowed = True

    def stop_feed(self, src):
        print('======================> enough_data')
        self.is_push_buffer_allowed = False

    def play(self):
        self._pipeline.set_state(Gst.State.PLAYING)

    def stop(self):
        self._pipeline.set_state(Gst.State.NULL)

    def run(self):
        """ Run - blocking. """
        self._mainloop.run()

    def push(self):
        """ Push a buffer into the source. """
        if self.is_push_buffer_allowed:
            image_number = randint(1, 4)
            filename = 'images/%s.jpg' % image_number

            img = PILImage.open(filename, mode='r')
            img_byte_array = io.BytesIO()
            img.save(img_byte_array, format='JPEG')
            img_byte_array = img_byte_array.getvalue()

            buffer = Gst.Buffer.new_wrapped(img_byte_array)
            # Push the buffer into the appsrc
            gst_flow_return = self._src.emit('push-buffer', buffer)
            # gst_flow_return = self._src.push_buffer(buffer)
            
            # Free the buffer now that we are done with it            
            # Do something            
            # Not function found to unref buffer

            if gst_flow_return != Gst.FlowReturn.OK:
                print('We got some error, stop sending data')

        else:
            print('It is enough data for buffer....')


gst_app_src = SenderImages()
gst_app_src.play()

index = 0
while index < 1000:
    print('========================= Showing picture...')
    gst_app_src.push()

    time.sleep(1)
    index += 1



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