High FPS pi camera

[louisldthesamui]

I have a raspberry pi camera NoIR V2 and I want to grab 720p video with 120fps.

I use the same command as here :

Raspberry Pi v2 camera unexpectedly high frame rate

I am trying to get my Raspberry Pi v2 NoIR camera to run at 120fps. I was only expecting to manage this as VGA 640x480 resolution, but in fact, I can set the resolution to 1280x720 and get 120fps. (CPU utilisation is very high at 70% but such is life…) This page suggests also that at 1280x720 you should only get 90fps. How is it that I am getting 120fps? Taken from this page OpenCV GStreamer Capture really slow I was able to run this command to double check and it does seem to be about 120fp…

gst-launch-1.0 -v nvarguscamerasrc exposuretimerange="1 1" gainrange="1 1" ! 'video/x-raw(memory:NVMM), format=NV12,width=1280, height=720, framerate=120/1' ! fpsdisplaysink video-sink=fakesink text-overlay=false

but I only reach 60 fps like the latest says. Why is this ?

[Honey_Patouceul]

120 fps has been removed in recent JetPack versions (since R32.5 I think).
You can get it working by rebuilding IMX219 driver in kernel and modifying device tree.
Here are the steps for Xavier NX, you would adapt for your Nano.

However, be aware that Argus will use about 1 CPU core just for this low resolution at 120 fps.
This may be the reason why it has been removed from JetPack.

[louisldthesamui]

Thank you for you answer. I built the kernel with success but I’m not able to boot on it. After editing extlinux.conf, I don’t see any prompt at booting. Do you have any hint why ?

[Honey_Patouceul]

@louisldthesamui

After editing extlinux.conf, I don’t see any prompt at booting

You would use a serial console.

[louisldthesamui]

I see, thank you ! I didn’t have one so I just replaced the older kernel with the custom one in extlinux.conf but it’s always good to know how it works.