• Hardware Platform (Jetson / GPU) - dGPU • DeepStream Version - 6.2 • JetPack Version (valid for Jetson only) • TensorRT Version - 126.96.36.199 • NVIDIA GPU Driver Version (valid for GPU only) - 530.xx. • Issue Type( questions, new requirements, bugs) - question
Hi Team, I just have a question. If I have two separate instances of the same deepstream application reading from the same rtsp source, can the frames in both the apps be matched based on the ntp timestamps? i.e. do they have the exact same ntp timestamps in frame_meta->ntp_timestamp? I know how to configure ntp timestamp in deepstream following this.
However the ntp timestamps of the corresponding frames I receive in two different apps pointing to the same rtsp source are not exactly same, they differ in millisec. Is it the expected behavior?
Is it not possible to associate frames from the same rtsp source in two diff. apps based on ntp timestamp?
I also see this warning in the application.
Warning: gst-library-error-quark: Either host or Source 0 seems to be out of NTP sync SYS TIME = 2023-05-24T12:53:43.035Z CALCULATED NTP TIME = 2023-05-24T18:23:43.419Z (5): gstnvstreammux_ntp.cpp(108): check_if_sys_rtcp_time_is_ntp_sync (): /GstPipeline:pipeline0/GstNvStreamMux:Stream-muxer
Can you please let me know what this function check_if_sys_rtcp_time_is_ntp_sync ()does. I think this function is able to identify that the clock is not synchronized. Can you please share how this is checked?
When you use DeepStream app as the RTSP client to receive the stream, the device you run the DeepStream app in will be treated as a network node. So the system time is the node time. We will compare it with the NTP timestamp from the RTCP SR (which is the time generated by the device who sends the RTSP stream), if the gap is larger than 10 seconds, the warning will be printed out.