TDA2PXEVM: TDA2PXEVM ADAS 6 cameras performance

Hello Sergey,

Currently, example usecases support only upto 4 cameras. SoC can support 6 cameras but there is no SW example yet.

On TDA2P there is only 1 ISP instance which has to be timeshared between all camera processing contexts. The number of cameras is limited only by ISP frquency. At 533MHz, there is enough horsepower to process 6 cameras 2MP @30fps.

Regards,

Mayank

Hello Mayank

Thank you for the answer, it is very good that SoC ISP is able to process 6 cameras.

But we also faced the same ISS Capture restriction that was described here: e2e.ti.com/.../2593582

We have to select SYSTEM_BPP_BITS12_PACKED_MIPI for 6 cameras because as we understood pixel processing can be enabled only for four channels, and such define disables some part of pixel processing.

And because of it images from the cameras look strange, probably because they are processed improper way.

Brijes Jadav wrote in e2e.ti.com/.../3209374 that images without pixel processing look not fine. Looks like we have the same issue.

Brijesh also wrote in e2e.ti.com/.../2593582 that the issue would be resolved in a new version of SDK. It was three year ago, so maybe you have the solution now?

Hi,

CAL only has 4 pixel processing context, so RAW12 cannot be captured for more than 4 channels, in this case, can you use DPI input ports, ie VIP for capturing other 2 channels?

Regards,

Brijesh

Hello Brijesh,

Thank you for the suggestion, we will try it and will share the result with you.

Regards,

Sergey

Hello Brijesh,

As I wrote before we have started checking VIP for capturing, but haven't received any frames yet.

I tried to use https://e2e.ti.com/support/processors/f/processors-forum/932390/faq-how-to-connect-cal-to-vip-on-tda2px/3444390 as a reference, but it is more for cameras that generate YUV not RAW.

As I understand my case is very similar to https://e2e.ti.com/support/processors/f/processors-forum/868360/tda2pxevm-provide-frames-from-csi-cal-to-vip-on-the-fly
Could you confirm if it is true or not please? And if it is true, is there an implemented example for such case or I have to repeat all actions that were described in the topic?

Just to clarify our case, we need to work with 6 cameras connected via CSI-2 interface and working in RAW12, so we need to convert them to YUV420 using ISS ISP Bayer.

Regards,
Sergey

Hi Sergey,

When i meant VIP as input, i meant to use parallel input. CAL does not support more than 4 channels for RAW12 data. 

Regards,

Brijesh

Hello Brijesh,

If I understand you correctly, there is no way to perform more than 4 pixel processing lines at the same time on tda2px because of CAL restrictions.
But we just followed the picture below. It is from https://www.ti.com/lit/pdf/sprace3 I've mentioned before.

So, our case is:
    - 6 2MP x 30 FPS (1080p stream) cameras.
    - Each camera is connected via CSI-2 interface
    - Each camera generates RAW12 stream (that should be pixel processed as I understand)
    - All the streams should be converted to an YUV420 format from the RAW
    - Auto-exposure, AWB and other color-correction stuff are also necessary

How to reach this result?

Regards,

Sergey

Hi Sergey,

Well, one possible way is to capture 4 channels via pixel processing context and remaining 2 channels as it is in the memory. Then convert mipi format into linear format for the other 2 channels and then use ISP for processing all 6 channels.. 

But we don't have kernels to convert mipi format to linear, you would have to add it.

Regards,

Brijesh

Hello Brijesh.

OK, it is one way. But I'm afraid the new cores would need some horse power, and it would be nice to avoid it.

As I saw in documentation, Iss Capture uses CAL that is called CAL_B. There is also just CAL that is described in CAMSS section. As I understand, it can work in conjunction with VIP and it also has 4 pixel processors.

Is it possible to connect four cameras to CAL_B as usual and use another CAL for the rest ones?

Regards,

Sergey

Hi Sergey,

CAL B cannot be used for camera input. This is used in the ISP path.

But CALB can interestingly be used for mipi to raw conversion, although not verified. We can read in CALB read path, use pixel processing block to convert into linear format and then write back into memory using CAL write DMA.

But this is not verified/supported in the SW.

Regards,

Brijesh