Hello all, since gstreamer 1.14, there is a way to associate in a gstreamer pipeline reference timestamps to each frame. As expressed by Sebastian (slomo), [https://marc.info/?l=gstreamer-cvs&m=149458219511878&w=2] buffer: Add GstReferenceTimestampMeta This is a meta that generically allows to attach additional reference timestamps to a buffer, that don't have to relate to the pipeline clock in any way. Examples of this could be an NTP timestamp when the media was captured, a frame counter on the capture side or the (local) UNIX timestamp when the media was captured. Examples of valid references would be "timestamp/x-drivername-stream" for timestamps that are locally generated by some driver named "drivername" when generating the stream, e.g. based on a frame counter, or "timestamp/x-ntp, host=pool.ntp.org,port=123" for timestamps based on a specific NTP server. I would expect the v4l2src plugin to add such a timestamp to each frame using information coming from the v4l2 driver, especially if the driver provides UTC or TAI timestamps generated in the kernel. How far are we from that goal ? Best regards Philippe De Muyter -- Philippe De Muyter +32 2 6101532 Macq SA rue de l'Aeronef 2 B-1140 Bruxelles
