iMX8M: virtual channel support in CSI-2?

[ensc]

Hello,

iMX8M reference manual says in 13.6.1.1 that the MIPI-CSI2 controller supports virtual channels?  How can I configure them?  E.g.:

- how can I filter out data of virtual channel 2?

- is it possible to implement HDR with iMX8M?  Lines are interleaved in difference virtual channels; how can they be recombined?

[igorpadykov]

Hi Enrico

for i.MX8M mipi virtual channel is not supported in hardware, so the driver will not automatically

split the video from each virtual channel. The software can just receive the combined stream

into memory, then it needs split it if needed.

Best regards
igor
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[weichushun]

Hi igor

The software can just receive the combined stream into memory, then it needs split it if needed.

---》are you sure that software can split the combined stream into 4 channels?  I am going to connect 8 cameras through the two MIPI CSI2

this is important， but I can not verify it in advance, thank you!

[avismn]

Hi Igor,

In case we are going to use two virtual channel. does the driver transfers all the data (VC0 + VC1) or does it ignore VC1 to VC3 ? 

Thanks,

Avi

[igorpadykov]

Hi Avi

driver receives all data, from all channels.

Best regards
igor

[florian_hierl]

Hi Igor,

is there already a software solution for separating the virtual channels in IMX8 ?

Has anyone tried this already ?

KR,

Florian

[jude_federspiel]

Hello Igor, your answer confirms what I've been reading. I want to input two cameras @720p/monochrome/30fps on two separate virtual channels into IMX8MMini, then encode H.264 on both separately. I gather from your post that I'll need to write code to manage the two virtual channels and the memory. Is there a simple way to estimate the processor loading for the memory management and encoding?

If you haven't sniffed it out, I'm an amateur. Mostly trying to evaluate a concept at this point.

Thanks in advance,

Jude