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
Argus::ICaptureMetadata::getSensorTimestamp

which moment does this timestamp was recorded? in camera or in jetson driver
EGLStream::IFrame::getTime

answered by Jerry below,

below capture the start-of-frame timestamp of the sensor signaling,
Argus::ICaptureMetadata::getSensorTimestamp

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

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.
thanks