Timestamped video frames in OpenCV video stream

Please only bid if you are an expert in Gstreamer, OpenCV, Python The problem: A Raspberry Pi with camera streams video over the network to multiple (five) clients (also raspberry Pi) running python/opencv clients. The clients buffer the stream and a user watches the video in slow motion as part of a sport judging process. It is very important that the stream quality is perfect so I use raspberry pi H264 direct from rpicamsrc with RTSP. I do not need the videos to play in a synchronized way BUT It must be possible to synchronize frames back to the original video. So if the original video stream is frames 0-10000 it must be possible for each client to know what frame they are looking at - regardless of when they opened the stream. (It is very easy to get a local timestamp from the opening of the stream but not to get a 'universal' timestamp) example: Client one starts the stream immediately Client two starts the stream a few seconds later. At any time if both clients look for frame x or timestamp [login to view URL] they should find the same frame. The RTSP server is currently running with gst-launch-1.0 "(rpicamsrc bitrate=2000000 awb-mode=auto preview=false vflip=false ! video/x-h264, width=1024, height=768, framerate=30/1 ! h264parse ! rtph264pay name=pay0 pt=96 )" The client uses [login to view URL]() I am willing to change the streaming process once the stream quality is perfect and I can run the client in Python with access to the frames in a buffer. The best solution is to access an original timestamp in the stream on each client. I believe this is possible by modifying FFMPEG and OpenCV sources [login to view URL] but I am not confident to do this Another solution would be to insert a timestamp overlay on the frames and to use OCR on the client to identify the timestamp I am open to any good solution.