README file for Artix 7 HDMI processing
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Hi! 

This is my design for receiving HDMI input, then extracting the video data, the
Video Inforframe and audio samples, then using that to display audio db meters 
on the top corner of the screen. Currently for simplicity the output is only DVID.

Features
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Supports HDMI formats:
  -720p@50
 - 720p@60, 
 - 1080i (with a bug)
 - 1080p@50
 - 1080p@60
 and others....

Colourspaces / formats:
 - RGB 444
 - YCbCr 444
 - YCbCr 422

New feature 6-AUG-2015!
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Switch 0 will turn guidelines off and on. Will only show in 1080p 1080i and 720p resolutions.

Supported Boards
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 - Digilent Nexys Video 

Sources tested with:
 - Western Digital HD Live
 - HP Laptop

Sinks tested with:
 - Viewsonic Monitor
 - AOC Monitor
 - Vivo TV
 
Known issues:
 - Currently extracts only two channels of audio 

 - Does not adjust PLL settings for input clock, so the PLL is run slightly out
   of spec.

 - Image may re-sync after a few seconds if it receives errors.

 - The audio meters are drawn twice as tall in interlaced modes

 - A false VSYNC pulse is causing the meters to be displayed more than once when
   some content is shown. Very weird, but I want to leave this in for now so I can
   find the root cause.

 - There are timings errors, as generating 148.5MHz HDMI using the Artix-7 chip
   is actualy out of spec. Expect seven failing paths and about 20ns of negative 
   slack.

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-- The MIT License (MIT)
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-- Copyright (c) 2015 Michael Alan Field
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--
-- This design has taken many hours - with the industry metric of 30 lines
-- per day, it is equivalent to about 6 months of work. I'm more than happy
-- to share it if you can make use of it. It is released under the MIT license,
-- so you are not under any onus to say thanks, but....
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-- If you what to say thanks for this design how about trying PayPal?
--  Educational use - Enough for a beer
--  Hobbyist use    - Enough for a pizza
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--  Commercial use  - A weeks pay for an engineer (I wish!)
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