RTP timestamping with rtp264depay

[Kreyer, Steve]

Hi,

Iam streaming video data via RTSP with gstreamer on a nvidia-jetson board with the following pipeline:
./test-launch -p 8554 "nvarguscamerasrc sensor-id=0 ! video/x-raw(memory:NVMM),width=1024, height=768, framerate=10/1, format=NV12 ! nvv4l2h264enc ! h264parse ! rtph264pay name=pay0 pt=96"

When I film the boards “Eigenzeit” from a UART terminal with the camera and compare this filmed time against the received RTP timestamp the received RTP timestamp is 300ms younger than the filmed “Eigenzeit”. At https://github.com/GStreamer/gst-plugins-good/tree/master/gst/rtp I read about timestamping on the sender side that this is performed using the following formular:
          RTP = ((RT - RT-base) * clock-rate / GST_SECOND) + RTP-offset
Further reading the README is mentioning this example:

Some pipelines to illustrate the process:



    gst-launch-1.0 v4l2src ! videoconvert ! avenc_h263p ! rtph263ppay ! udpsink



  v4l2src puts a GStreamer timestamp on the video frames base on the current

  running_time. The encoder encodes and passed the timestamp on. The payloader

  generates an RTP timestamp using the above formula and puts it in the RTP

  packet. It also copies the incoming GStreamer timestamp on the output RTP

  packet. udpsink synchronizes on the gstreamer timestamp before pushing out the

  packet.

So if I’m not mistaken this is the reason for the delay of 300ms (= pipeline latency) I’m experiencing. However in my use-case I need a timestamp which is not depending on the pipeline latency. I want to have a timestamp received via the network that is jitter free and independent of any running time of the pipeline. Is RTP then maybe for my use-case? Or if I can use RTP how I can get the pipeline to produce / generate a RTP timestamp  which is independent of the pipelines runtime?

Thanks in advance for any help on this issue.

Kind regards,
Steve

P.S. Iam not on the mailing list, so please don’t forget to CC: me, thanks 😊

Best regards,

Steve Kreyer
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Senior Software Development Engineer
PMC45

Vector Informatik GmbH
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steve.kreyer at vector.com<mailto:steve.kreyer at vector.com>
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