Time stamp

i was told to start a new thread. so here it is.

orignal question.

which moment does this timestamp was recorded? in camera or in jetson driver

which moment does this timestamp was recorded? in camera or in jetson driver

answered by Jerry below,

below capture the start-of-frame timestamp of the sensor signaling,

while EGL stream capture the timestamp when it rendering the frame to display. it’s close to end-of-frame of the sensor signaling,

i attached both time stamp log, the value log by metadata looks unrealistic and questionable to me.
please advise. if the start-of-frame time is the same, why end-of-frame has much different value. and
also the image displayed has time lagged of 30ms as well. i am pointing both camera to a stop watch.

Log by Argus::ICaptureMetadata::getSensorTimestamp

L.Sensor Timestamp: 728056522558000, LUX: 9.325268, R.Sensor Timestamp: 728056522558000, LUX: 9.325268
L.Sensor Timestamp: 728056822565000, LUX: 9.325268, R.Sensor Timestamp: 728056822565000, LUX: 9.325268
L.Sensor Timestamp: 728056855890000, LUX: 9.325268, R.Sensor Timestamp: 728056855890000, LUX: 9.325268
L.Sensor Timestamp: 728056889219000, LUX: 9.325268, R.Sensor Timestamp: 728056889219000, LUX: 9.325268
Log by EGLStream::IFrame::getTime

Acquired Frame, L: 1, time 729041838303, R: 1, time 729041839635
Acquired Frame, L: 2, time 729041872631, R: 2, time 729041873374
Acquired Frame, L: 3, time 729041905072, R: 3, time 729041905625
Acquired Frame, L: 4, time 729041938511, R: 4, time 729041939728

hello j2innet,

getSensorTimestamp() fetch the timestamps from sensor hardware, i.e. hardware sync-points of CSI frame-start.
however, EGL stream capture that timestamp by system time.

as Topic 78821 discussed, there’s gap between system time and TSC HW timestamp.
please expect next public release, (i.e. JetPack-4.5 / l4t-r32.5) will using new interfaces to expose hardware timestamps into camera software stack.