I am trying to get basic metadata of captured frame. I am using raspberry v2 NOIR camera (IMX219) through gstreamer-1.0 with nvarguscamerasrc and opencv videocapture object.
I want the exposure time, ISO, digital/analog gain, exposure compensation, white balance, etc.
I tried using the opencv videocapture properties, but it gave a not supported error.
What is the syntax to read these values in gstreamer pipeline?
I don’t think nvarguscamerasrc can do it. You may need to implement argus APP for it.
Below are the argus API for referecing.
https://docs.nvidia.com/jetson/l4t-multimedia/group__LibargusAPI.html
I’ll give it a try and let you know if I am able to use it.
Although, the gst-inspect of nvarguscamerasrc specifies that these properties are readable and writable, that is why I want to try and figure it out
You can check the nvgstcapture-1.0 for read/write them.
Also you can download the source code for reference.
Can you send me one example command where the exposure time is read? I am not clear on the syntax and I can’t find the examples online.
You can just run the nvgstcapture-1.0 --help for more information.
And the source code can download from below link.
https://developer.nvidia.com/embedded/L4T/r32_Release_v5.0/sources/T210/public_sources.tbz2
I have already tried out nvgstcapture-1.0
In the help, setting properties syntax is explained, getting properties syntax is not:
" --exposuretimerange Property to adjust exposure time range in nanoseconds e.g., --exposuretimerange=“34000 358733000” "
If I try without giving an empty range " ", nothing happens and if I don’t give the double quotes, it results in an error. Same with nvarguscamerasrc
nvgstcapture-1.0 -A --image-res=2 --mode=1 --cap-dev-node=0 --capture-auto=1 --exposuretimerange
Encoder null, cannot set bitrate!
Encoder Profile = High
** (nvgstcapture-1.0:29784): ERROR **: 19:22:59.054: main:4537 option parsing failed: Missing argument for --exposuretimerange
Trace/breakpoint trap (core dumped)
If I remove the --exposuretimerange or add --exposuretimerange=“min max”, this code perfectly works. captures an image with an automatic name generated. I tried understanding if the name means anything (eg: nvcamtest_29683_s00_00000.jpg). Seems like it is some kind of timestamp since it is always increasing.
I’ll go through the source code that you shared for better understanding.
I have one more issue. I followed the instructions on the git Readme.md for the argus_camera but I am facing an error:
fatal error: Argus/Argus.h: No such file or directory
What library should I install?
After launch the nvgstcapture-1.0 you should be able set the gain/exposure… from below instruction.
Set Gain Range:
gr:<val><space><val> e.g., gr:1 16
Get Gain Range:
ggr
Set Exposure Time Range:
etr:<val><space><val> e.g., etr:34000 35000
Get Exposure Time Range:
getr
Set ISP Digital Gain Range:
dgr:<val><space><val> e.g., dgr:2 152
Get ISP Digital Gain Range:
gdgr
etr:35000 35500
Setting Exposure Time Range = 35000 35500
GST_ARGUS: NvArgusCameraSrc: Setting Exposure Time Range : 35000 35500
getr
Exposure Time Range = 35000 35500
@ShaneCCC This seems to be giving back the exposure time range right?
Not the exposure time at which image was captured… which would be a single value. I misunderstood when I read the properties are readable. I’ll continue to work on getting the libargus API up
You can set the min and max as same value to limit the exposure in a point like etr:34000 34000
then the exposure will be set as 34000
Hi Shane,
My problem statement is a bit different. I am trying to read the value set by auto exposure (not manual). I am using this value for my algorithm and also to add to exif when saving it
Sorry to tell current didn’t have API to get the exposure.
Even using argus_camera?
For argus you can get it by this API