I’m porting a camera application from JP 4.5 to JP 4.4.1 so I can deploy it to Jetson AGX devices that are already sent to users and cannot be reflashed with newer versions.
On JP4.5 I was using SoF tsc to convert frame timestamp to Monotonic Raw. However on JP 4.4.1 I have only access to captMetaData->getSensorTimestamp();
I tried using the relation: monotonic_raw = - offset_ns
However testing on a couple of devices I got time difference from 10 to over 30 seconds! Also the value change after a restart.
Some data I’ve collected:
monotonic raw when processing the frame: 3816622730240ns
sensor timestamp: 3816660659000ns
Frame timestamp (SensorTimestamp - offset-ns) = 246242ms
Time stamp when I received the frame in the code = 257008ms
Timestamp from internal clock displayed on the screen when capturing the frame = 256834ms
From these I calculate:
- there are 174ms delay from starting the camera capture, to the image arriving in the application;
- There are 10592ms (10 seconds) of mismatch between actual and calculated start of frame timestamps
I’ll be happy to try and suggestions to solve this issue. Thanks