2 pixels per clock to 1 pixels per clock

[hariprasadb]

Hello,

I am using HDMI RX subsystem (on ZCU102) to receive the video and then I want to process it using custome video encoder. I see that HDMI subsystem IP gives out the data @2PPC. But, my custom logic expects it in 1 PPC (pixels per clock). I was checking out how to convert it to 1 PPC. Then I got below 2 links.

https://forums.xilinx.com/t5/Video/Pixels-per-clock/td-p/820565

https://forums.xilinx.com/t5/Video/AXI-Stream-Video-Dynamically-converting-2-PPC-to-4-PPC/td-p/915260

Both links concludes on using VDMA/frame buffer. Here, I can not use this solution since I don't want to use DDR4 bandwidth.

Can I use AXI-stream interconnect / AXI Stream datawidth converter to achieve 2 PPC to 1 PPC conversion?

With Regards,

Hariprasad Bhat

[watari · Accepted solution]

Hi @hariprasadb

Why don't you describe it by RTL ?

Here is a a sample code which described by Verilog.

Would you refer it ?

<Start sample code>

always@ (posedge clk or negedge rstn) begin
  if (!rstn) begin
    ld <= 1'b0;
  else
    ld <= ~ld;
  end
end

always@ (posedge clk) begin
  if (ld=1'b0) then
    pixel_reg <= pixel_lower;
  else begin
    pixel_reg <= pixel_upper;
  end
end

<End sample code>

Best regards,

[hariprasadb]

Hi @watari

Thank you for your valuable suggestion.

Yes, I have written custom RTL to convert 2 PPC to 1 PPC and it is working fine (Tested for Full HD 1080P @ 60Hz).

HDMI RX (2PPC) -> Custom RTL (2 PPC to 1 PPC) -> Frame buffer write (1PPC) -> Frame buffer read (2PPC) - HDMI TX (2PPC)

With Regards,

Hariprasad Bhat