Fast camera switching on a single CSI interface for i.MX8MP

mkeey — Sat, 24 May 2025 13:33:08 GMT

Hi everyone,

I am trying to connect two cameras of the same type to the same CSI interface using an external I2C and MIPI multiplexer. The cameras are configured to be in trigger mode and only one camera will be active at the same time.
As I have control over the trigger of the cameras, my goal is to have a constant frame rate and be able to switch between the cameras on the fly.

Please note that in the end, I want to have this setup twice in order to support four cameras in total, but only 2 running at the same time.

Similar questions to this topic have already been asked:

Thread 1 and 2 belong together and discuss a solution where imx8-media-dev and mipi-csi2-sam are modified, so that depending on the loaded kernel module, a different camera is registered as input.
If I understand this correctly, two cameras of the same type are not supported and a camera switch would be very slow, as kernel modules must be reloaded each time.

Thread 3 is an improvement to 1 and 2, but from the shared information, I'm not sure if the solution could be used to exactly time the switch between the two cameras (I don't want to switch while a frame is captured or transmitted).

Thread 4 and 5 are more related to my topic, but unfortunately, a final solution has not been found.

A quick search has shown, that the video-mux driver is probably the best fit for my needs. While it is used by i.MX6 and i.MX7 based-boards, it is currently not supported for the i.MX8 (imx8-media-dev.c expects an I2C device as input).

Before I start digging deeply into this topic, I would like to ask if there is any advice what's the best approach for my use-case is.

Best regards and thanks for your support.

Markus

Re: Fast camera switching on a single CSI interface for i.MX8MP

Bio_TICFSL — Mon, 26 May 2025 14:31:03 GMT

Hello,

From which board do you planned to do This? one need several MX8 doesn't have virtual channel to handle, if you need dual camera, maybe you can use MIPI CSI+ usb camera, we well you have to modify the DTB for this cause.

Regards

Re: Fast camera switching on a single CSI interface for i.MX8MP

mkeey — Mon, 26 May 2025 15:04:54 GMT

Hi,

We use a custom-designed board that includes an external MIPI and I2C multiplexer.
Although the i.MX8 lacks virtual channels (only i.MX8QM or i.MX8QXP support this), but we don't plan to use that feature.
For each pair of cameras, it is sufficient to only have one camera active at the same time.

Best regards

Markus

topic Fast camera switching on a single CSI interface for i.MX8MP in i.MX Processors

Fast camera switching on a single CSI interface for i.MX8MP

Re: Fast camera switching on a single CSI interface for i.MX8MP

Re: Fast camera switching on a single CSI interface for i.MX8MP