Get current digital gain value from argus

[Hnil]

Hi,
On JP 4.5.1, how can I get the current digital gain value that argus is using? I have been looked at libargus APIs, but there is no API to readout the current digital gain value (exposure time and gain are also not available to read via argus, but can read via v4l2-ctrl).
Thank you for reading & sharing.

[JerryChang]

hello nvl1109,

may I know what’s the actual use-case?
you could enable the debug logs for checking the applied values, but this output lots of logs to the console which might effect the performance.
for example,

$ sudo su 
# pkill nvargus-daemon
# export enableCamCoreLogs=5
# nvargus-daemon

please have a terminal executed to gather the logs, then enable argus_camera to see the details.
there’re lot of logs, you may looking for convergenceStatus for the related AE info applied to the captured frame.
for example,
it’ll show the analog gain, digital gain, exposure time,…etc.

runBreakDownAlgorithm output ---: convergenceStatus: 2, framerate 30.00000, requiredCain 0.00526 totalAchievedCGains 0.00526 with AA 0.17361 {step 0, f-Number 2.40000}, ET 0.03000, AG 1.00986, ISPDG 1.00000

[Hnil]

Hi Jerry, thank you for your reply.

My use-case is to develop a service that controlling IR filter and some lens adjustment likes conversion gain based on the brightness of the image.
The need for reading current value of digital gain, analog gain, exposure time is to check if they are all in setting range or close to their boundary, then we can adjust IR/conversion gain/etc.
Reading these from log of nvargus-daemon is okay for inspecting or debugging, but not for monitoring those value all the time.
I can get exposure time and analog gain from v4l2-ctrl of video device, but it is better if they can be read directly from argus :), and digital gain isn’t available for reading from v4l2 or argus.

So, is there a way to read those value from libargus? Or at least, read current digital gain only? Thank you.

[JerryChang]

hello nvl1109,

here’s API you may refer to, Argus::ICaptureMetadata::getIspDigitalGain.
ISP digital gain keep using 1.0 normally, it only increase when the capture scene is too dark.
you may also check the available range for confirmation.
thanks

[Hnil]

Thank you Jerry. Your info is a great help.