<div dir="auto">I just follow the code in the article.</div><div dir="auto">Anyway it turns out the server did not send and rtcp message, I wireshark the communication between client and server.</div><div dir="auto">So the code works. </div><div dir="auto">Thanks😁</div><div> <div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Tue, 23 May 2023 at 6:26 PM, Mathieu Duponchelle <<a href="mailto:mathieu@centricular.com">mathieu@centricular.com</a>> wrote: </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Why are you requesting the pad in the first place? On Sun, 2023-05-21 at 15:27 +0800, Max Weng via gstreamer-devel wrote: > Hi, > > I am currently exploring the possibilities of using GStreamer for > a project, a territory that is relatively new to me. I am convinced, > however, that GStreamer is an ideal fit for my objectives. > > The task at hand is to extract server timestamps from RTCP packets. > For this, I referred to the article, Absolute Timestamp of Arbitrary > Frame in RTSP Stream with GStreamer > > I have been running into some difficulties during the > implementation phase. > > I am experiencing an inconsistent triggering of the "on-receiving- > rtcp" event. It appears to get activated only sporadically, > approximately once in every 20 attempts. This inconsistency makes it > challenging for me to proceed effectively with the project. > > In addition, an error message always presents itself: "Element > manager already has a pad named recv_rtcp_sink_0, the behaviour of > gst_element_get_request_pad() for existing pads is undefined!". This > error is making the situation even more complex to understand and > resolve. > > I would truly appreciate it if you could provide some insights or > suggestions regarding these issues. I am eager to understand what > might be causing these problems, and how best to address them. > > here is my code test_gstreamer.py: > > import datetime > import pickle > from multiprocessing.connection import Connection > import threading > > from time import sleep > import gi > from log import setup_custom_logger > > gi.require_version("Gst", "1.0") > gi.require_version("GstRtp", "1.0") > gi.require_version("GstVideo", "1.0") > > from gi.repository import GLib, GObject, Gst, GstRtp, GstVideo # > noqa:F401,E402 > > logger = setup_custom_logger(__name__) > > GObject.threads_init() > Gst.init() > > url = 'rtsp://localhost:8554/mystream' > pipeline = '' > > > def fly(): > main_loop = GLib.MainLoop() > main_loop_thread = threading.Thread(target=main_loop.run) > main_loop_thread.start() > command = f"rtspsrc name=rtspsrc location={url} protocols=tcp > latency=10 max-rtcp-rtp-time-diff=10 ! errorignore ! rtph265depay > name=depay ! appsink name=sink" > pipeline = Gst.parse_launch(command) > bus = pipeline.get_bus() > bus.add_signal_watch() > bus.connect("message", on_message) > bus.enable_sync_message_emission() > > rtspsrc = pipeline.get_by_name("rtspsrc") > rtspsrc.connect("new-manager", on_new_manager) > depay = pipeline.get_by_name("depay") > sinkpad = depay.get_static_pad("sink") > probeID = sinkpad.add_probe( > Gst.PadProbeType.BUFFER, calculate_timestamp) > > pipeline.set_state(Gst.State.PLAYING) > > try: > while True: > sleep(0.1) > except KeyboardInterrupt: > pass > > pipeline.set_state(Gst.State.NULL) > main_loop.quit() > main_loop_thread.join() > > > def calculate_timestamp(pad, info): > return Gst.PadProbeReturn.OK > > > def on_new_manager(rtspsrc, manager): > <a href="http://logger.info" rel="noreferrer" target="_blank">logger.info</a>(f"on_new_manager") > sinkpad = manager.get_request_pad("recv_rtcp_sink_0") > session = manager.emit("get-internal-session", 0) > session.connect("on-receiving-rtcp", on_receive_rtcp) > > > def on_receive_rtcp(session, buffer: Gst.Buffer): > <a href="http://logger.info" rel="noreferrer" target="_blank">logger.info</a>("on_receive_rtcp") > <a href="http://logger.info" rel="noreferrer" target="_blank">logger.info</a>(buffer) > rtcp_buffer = GstRtp.RTCPBuffer() > res = GstRtp.RTCPBuffer.map(buffer, Gst.MapFlags.READ, rtcp_buffer) > rtcp_packet = GstRtp.RTCPPacket() > rtcp_buffer.get_first_packet(rtcp_packet) > > while True: > if rtcp_packet.get_type() == <a href="http://GstRtp.RTCPType.SR" rel="noreferrer" target="_blank">GstRtp.RTCPType.SR</a>: > <a href="http://logger.info" rel="noreferrer" target="_blank">logger.info</a>(rtcp_packet) > si = rtcp_packet.sr_get_sender_info() > ntp_time = si[1] > rtp_time = si[2] > <a href="http://logger.info" rel="noreferrer" target="_blank">logger.info</a>("ntp_time: %d, rtp_time: %d", ntp_time, rtp_time) > if rtcp_packet.move_to_next() == False: > break > > > def on_message(bus: Gst.Bus, message: Gst.Message): > mtype = message.type > # TODO handle message > > > if __name__ == "__main__": > fly() > > > here is how I run a local RSTP server: > $ docker run --rm -it --network=host aler9/rtsp-simple-server > $ while true; do gst-launch-1.0 rtspclientsink name=s > location=rtsp://localhost:8554/mystream > filesrc location=//path/to/video.mp4 > ! qtdemux name=d d.video_0 ! queue ! s.sink_0 d.audio_0 ! queue ! > s.sink_1 ; done > > here is the output from my code, no "on-receiving-rtcp" triggered: > $ python test_gstreamer.py > test_gstreamer.py:19: PyGIDeprecationWarning: Since version 3.11, > calling threads_init is no longer needed. See: > <a href="https://wiki.gnome.org/PyGObject/Threading" rel="noreferrer" target="_blank">https://wiki.gnome.org/PyGObject/Threading</a> > GObject.threads_init() > 2023-05-21 15:05:06,467 - __main__ - INFO - on_new_manager > > (python:96503): GStreamer-CRITICAL **: 15:05:06.469: Element manager > already has a pad named recv_rtcp_sink_0, the behaviour of > gst_element_get_request_pad() for existing pads is undefined! > > here is output with "on-receiving-rtcp" triggered: > $ python test_gstreamer.py > test_gstreamer.py:19: PyGIDeprecationWarning: Since version 3.11, > calling threads_init is no longer needed. See: > <a href="https://wiki.gnome.org/PyGObject/Threading" rel="noreferrer" target="_blank">https://wiki.gnome.org/PyGObject/Threading</a> > GObject.threads_init() > 2023-05-21 15:05:10,382 - __main__ - INFO - on_new_manager > > (python:96548): GStreamer-CRITICAL **: 15:05:10.384: Element manager > already has a pad named recv_rtcp_sink_0, the behaviour of > gst_element_get_request_pad() for existing pads is undefined! > 2023-05-21 15:05:11,730 - __main__ - INFO - on_receive_rtcp > 2023-05-21 15:05:11,730 - __main__ - INFO - <Gst.Buffer object at > 0x7fbf3a6918e0 (GstBuffer at 0x166cc60)> > 2023-05-21 15:05:11,732 - __main__ - INFO - <GstRtp.RTCPPacket object > at 0x7fbf39c49860 (void at 0x7fbf2c08b390)> > 2023-05-21 15:05:11,732 - __main__ - INFO - ntp_time: > 16723062952823484284, rtp_time: 4125066893 > </blockquote></div></div>