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aamir_sheikh
Contributor
Contributor
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Registered: ‎11-02-2020

determining resolution of video through VDMA errors.

Hi everyone, consider the following scenario,

There is a DVP camera, generating rgb585 video. It is then connected to a axi subset converter, which is then connected to a VDMA. which has s2mm, and mm2s enabled.

now the VDMA is configured for 800x600 through software. and i get the output of camera, on an hdmi monitor, just fine.

Is it possible that the vdma might correct resolution errors in this case? i.e. the input is configured for lets say some other resolution, but it just uses tlast and tuser to align the data?

this is what i get when i read 0x43000034

mwr 0x43000034 0xFFFFFFFF
mrd 0x43000034

43000034: 00011000

I am using the vdma example provided by xilinx,

attached is block diagram, configuration settings of VDMA, and xilinx api.

I am trying to isolate an error in a different project.. and i want to make sure that the camera is initialized okay

Screenshot from 2021-06-11 17-05-00.png
Screenshot from 2021-06-11 16-54-55.png
Screenshot from 2021-06-11 17-04-54.png
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florentw
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Moderator
322 Views
Registered: ‎11-09-2015

Hi @aamir_sheikh 

I am not sure what you mean here.

So let me try to give an explanation based on what I understand from your question:

  • On the S2MM interface, the AXI VDMA will count the number of pixels transmitted per line (number of time tready and tvalid are high between 2 tlast) and the numbers of lines (number of tlast between 2 tuser). If this does not match with what you have configured, then the AXI VDMA will stop. So you need to send the correct amount for data based on what is configured
  • One the MM2S interface, the AXI VDMA does not really care about the input. It will read whatever resolution you tell it to read. You might end up with a crop of the input of with additional data (picture in picure), see Video Series 26: Examples of advanced uses of the AXI VDMA IP.

Florent
Product Application Engineer - Xilinx Technical Support EMEA
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aamir_sheikh
Contributor
Contributor
312 Views
Registered: ‎11-02-2020

ah, that answers the question.
I wasn't sure if i was configuring the camera correctly, the same configuration when i use somewhere else, in a separate project, where i use hls to read the axi stream, and then publish the raw data i get this image,...

there is some noise, and then it repeats

Screenshot from 2021-06-10 14-53-31.png
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florentw
Moderator
Moderator
163 Views
Registered: ‎11-09-2015

HI @aamir_sheikh 

There is not much I can say on this picture. If the S2MM interface of the AXI VDMA is not stopping on error then the received resolution matches the one which was configured.

Then you need to look at the value of the data to check what the camera is sending.

If this is raw data, make sure you are displaying it as RAW data and not RGB/Ycbcr.


Florent
Product Application Engineer - Xilinx Technical Support EMEA
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