imx8m plus isp maximum resolution

[malik_cisse]

Hi,

I managed to make the Imx8m plus hardware ISP work with our custom sensor using 3840x2160 pixel resolution.

When going to maximum 12.3MP resolution of our sensor (4056x3040) the ISP hangs with no miningfull feedback as if the ISP would not support that resolution.

Digging into the source code in vvcam/v4l2/video/video.h, I found VIDEO_FRAME_MAX_WIDTH is correctly set to 4056 and VIDEO_FRAME_MAX_HEIGHT is also correctly set to 3040. I did check the rest of the vvcam code and did not find other references to the resolution one can set. 

Is the ISP imited to 4K (3840x2160 pixel)?

If no, how can I activate my 12.3MP resolution?

Thank you,

[malik_cisse]

Hi,
Did anyone manage to make the ISP work with  4056x3040 resolution or higher? 

Maximum implemented video resolution in ISP is 3840x2160.

My sensor (Imx477) currently delivers 4056x3040 but ISP internally downscales this to 4K. So far I searched for hard coded limitations in the isp-imx with no success.

The support in this thread didn't help unfortunatelly.

Please help

[malik_cisse]

Hi Igor,
Thank you for the feedback.
I have seen those specifications also however this is not what is implemented in the code.
Example:
-The doc says: maximum resolution up to 12MP (4096x3072)
-Source code in vvcam/v4l2/video/video.h:
#define VIDEO_FRAME_MAX_WIDTH  4056
#define VIDEO_FRAME_MAX_HEIGHT 3040

To make it worse, my tests so far demonstrate that resolutions above  (3840x2160 pixel) will not work.
Best regards,

Malik

[malik_cisse]

After checking again It turns out the resolution is indeed clipped in the vvcam driver:

-Source code in vvcam/v4l2/video/video.h:
#define VIDEO_FRAME_MAX_WIDTH  3840
#define VIDEO_FRAME_MAX_HEIGHT 2160

This is in contradiction to the ISP spect that says 4056x3040 is supported.

[igorpadykov]

this is resolution for daA3840 basler camera.

https://www.nxp.com/design/development-boards/i-mx-evaluation-and-development-boards/4k-dart-bcon-fo...

 

Best regards
igor

[malik_cisse]

Hi Igor,
This is just the specification of Baslers 8MP sensor that ships with their ISP implementation.

As you said earlier in this thread, in "i.MX 8M Plus Applications Processor Reference Manual"

max. resolution is described in sect.13.1.2 Display Interface:

when one ISP is used, it supports:
• maximum resolution up to 12MP (4096x3072)

From that iyt should be possible to configure the ISP for 12MP. 

[igorpadykov]

right, ISP max. resolution is described in sect.13.1.2 Display Interface

>This is just the specification of Baslers 8MP sensor that ships with their ISP implementation.

right, in driver code max. resolution of custom sensor is used (not ISP max. resolution)
-Source code in vvcam/v4l2/video/video.h:
#define VIDEO_FRAME_MAX_WIDTH 3840
#define VIDEO_FRAME_MAX_HEIGHT 2160

Best regards
igor

[igorpadykov]

Hi Malik

max. resolution is described in sect.13.1.2 Display Interface

i.MX 8M Plus Applications Processor Reference Manual

When one ISP is used, it supports:
• maximum resolution up to 12MP (4096x3072)
• maximum average pixel rate (averaged over blanking time) up to
300Mpixel/s at nominal voltage and 375Mpixel/s at overdrive voltage
• maximum pixel clock (considering blanking time) up to 400MHz at nominal
voltage and 500 MHz at overdrive voltage
• When two ISPs are used simultaneously, each supports:
• maximum resolution up to 1080p (1936x1188)

maximum average pixel rate (averaged over blanking time) up to
187.5Mpixel/s at nominal and overdrive voltage
• maximum pixel clock (considering blanking time) up to 266MHz at nominal
and overdrive voltage

Best regards
igor