Multi camera setup - Framerate lower than expected (ISP cap reached?)

Hello everyone,

we are trying to run a five camera setup on the Jetson Xavier.

The specs are as follows:
3x ~11.8 MP
2x 8 MP
45fps

As we preferably want to use the ISP of the Xavier, we tested the setup with the nvarguscamerasrc.
The results showed an average framerate of less than 45 fps. It was moving around 32 fps.
We verified, that if we use a pipeline with v4l2-ctl, we can achieve the desired framerate for all cameras. In single operational mode as well as all cameras in parallel.

For all tests we were using the MAXN nvpmodel and activated jetson_clocks. We also boosted the clk values for vi, isp and nvcsi to the value in max_rate, as some answers in other posts proposed.

Our conclusion was, that the ISP cannot handle such a high throughput. Our research yielded contradictory results, as some sources claimed a throughput of 1.5GPix/s, whereas some official NVIDIA presentations claimed 2.4 GPix/s.
Can someone confirm one of those values, or is the real number not officially known?

Maybe the problem is also elsewhere, but this was our initial guess. So any hints are welcome.

Best regards and thanks for any help,
Markus

Need to confirm what’s the ISP pipeline can support for the multiple cameras.

Hello, mrorelmy

Looks like only can guarantee for 6@30fps

https://docs.nvidia.com/jetson/l4t/index.html#page/Tegra%20Linux%20Driver%20Package%20Development%20Guide%2Fsoftware_features_jetson_xavier.html%23wwpID0ESHA

Hello ShaneCCC,

thank you for your quick reply.

It’s very unfortunate to hear, that we won’t be able to operate with our desired configuration.

A more precise communication of the ISP’s capabilities would’ve been helpful, as we relied on a value that could only be found in a presentation at the GTC2018 (https://on-demand.gputechconf.com/gtc-cn/2018/pdf/CH8601.pdf, page 11, right side). Probably not so smart, fair enough.
I checked, and the TX2 module datasheet features a precise value for the ISP of 1.4GPix/s. Maybe you could add the concise value to your future Xavier datasheets.

We’ll try to reduce the resolution as much as we can or bypass the ISP completely, which definitely would not be an ideal solution.

But again, thanks for the help. I will mark the post as resolved, but I am still open for any hints.

Have a nice weekend
Markus