HDMI input for Nexys Video.

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I've finally got my HDMI input project to a point where I have something to show. This little picture makes me really happy:

Hdmi audio meters.jpg

This project does the following actions:

  • Advertise HDMI support over EDID/DCC
  • Receive the TMDS signals
  • De-serialize them into 10-bit symbols
  • Align the symbols using bitslips
  • Tune the input delays for best reception
  • Convert the TMDS symbols into data values
  • Extract CTL, Aux Data Periods (ADPs) and Video Data Periods (VDPs)
  • Extract Video Infoframes from the ADP data
  • Extract Audio Samples from the ADP data.
  • Extract Raw Pixels from the VDPs
  • Perform 422 to 444 conversion, if required by video format
  • Perform YCbCr to RGB conversion, if required by video format
  • Convert Studio Level RGB to Full Range RGB, if required by video format
  • Convert Audio smaples to a relative db level
  • Overlay Audio level meters over the video stream
  • Convert the video stream and sync signals back to TMDS symbols
  • Serialize them through a 10:1 serialisers
  • Transmit the TMDS.

I think that this is an awesome base for any video experimentation.

I've even got to the trouble of making a GitHub repo for it:


Please feel free to fork and extend.

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Is the issue with the 20ns solved now?  It is mentioned in the design sources. What I do not understand is the problem with the 148.5MHz and the spec. Why is that not possible?


Would you say it is possible to port this design to the atlys?



Edited by mwagner

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