Argus getFrameReadoutTime

[Mylou]

Hello,

Can you please explains the value returned by getFrameReadoutTime from libArgus ?

I have a sensor connected to the Jetson Orin.
Video acquisition is done at 30fps.

I printed the different meta data retrieved using the following functions:
std::cout << "Frame Readout " << m_iMetadata->getFrameReadoutTime() << std::endl;
std::cout << "Frame duration " << m_iMetadata->getFrameDuration() << std::endl;
std::cout << "Timestamp " << m_iMetadata->getSensorTimestamp() << std::endl;
std::cout << "SOF " << iSensorTimestampTsc->getSensorSofTimestampTsc() << std::endl;
std::cout << "EOF " << iSensorTimestampTsc->getSensorEofTimestampTsc() << std::endl;

And I get a result similar to:
Frame Readout 61704616
Frame duration 33333333
Timestamp 3158036092000
SOF 3176939776000
EOF 3176969789000

Frame Readout 61704616
Frame duration 33333333
Timestamp 3158069302000
SOF 3176973004000
EOF 3177006220000

Frame Readout 61704616
Frame duration 33333333
Timestamp 3158102550000
SOF 3177006233000
EOF 3177036246000

I can see that

• SOF - EOF is around 30ms
• Timestamp image 2 - timestamp image 1 is around 30ms

Why do I have a Frame Readout of around 60ms ?

Thanks

[ShaneCCC]

The read out time is define by “Specifies time taken to read out active region.”
It should be height*line_length/pixel_clock.
Maybe confirm the line_length in you device tree.

[Mylou]

thanks for the information,
Where is this read in the pipeline ?
is this the time to read out in CSI driver, in ISP or in application using Argus ?

[ShaneCCC]

It’s from the camera core driver.