Crowdsourcing the Development of a FPGA Based HDMI Output Analyzer

I would like thoughts and inputs from the community about a project idea I have in mind. I envisage that the design will be open source, and that the cost of the components should not exceed $300. Comments about feasibility are also welcome (since I don't have direct domain experience in FPGAs):

The purpose of this project is to build a FPGA based system to analyze the output of HDMI sources when connected to a HDMI sink. The HDMI sources are going to be non-HDCP in nature, i.e, they will not be playing back protected content. The specifications of the system are as follows:

(a) Determine the vertical and horizontal resolutions of the video stream
(b) Determine whether the video stream is progressive or interlaced
(c) Determine the refresh rate of the video stream (23.976 / 24 / 25 / 29.97 / 30 / 59.94 / 60 fps)
(d) Determine the colour space of the video (RGB 4:4:4, YCbCr 4:4:4, YCbCr 4:2:2 etc.)
(e) Determine the audio type coming over HDMI (LPCM / Dolby or its HD variants / DTS or its HD variants)
(f) Determine the number of audio channels coming over HDMI
(g) Miscellaneous items of interest such as black levels (0-255 or 16-235)

It would be nice if the design can be updated to determine any other characteristics of the AV data coming over the HDMI cable down the road.

I did some research over the weekend and found a few different development kits

"Xilinx Development Board(kit)":http://www.xilinx.com/products/devkits/AES-S6IVK-LX150T-G.htm

"Lattice Development Board(kit)":http://www.latticesemi.com/corporate/newscenter/newsletters/newsoctober2010/videodisplayinterfaces.cfm

"Altera Development Board(kit)":http://www.altera.com/products/devkits/altera/kit-siv-gx.html#contents

They are all pretty spending and much more complex than this project needs. My suggestion is to just build up a board from scratch and use it for development purposes. The hardware requirements need to be specified. Here are a few items that need addressed:

1. What FPGA manufacturer and product family do we work with. I would start with one of these options(Altera-Cyclone, Xilinx-Spartan6, or Lattice-XP2)
2. What interface would be best to communicate with the PC to transmit the information from the HDMI analysis. I am sure we will want it to be bidirectional. Maybe USB or Serial port.
3. Do we need any external memory for storage. Most of these devices have some memory that might be enough, but hard to say until you are in the details.

Any other thoughts?

Cody, Thanks for looking into this.

I agree that the Xilinx and Lattice boards are overkills for the project in question. For the Altera board, I am unable to find HDMI-In.

As you suggest, starting with a board from scratch is the best bet. We need some sort of LVDS I/O to interface with the HDMI input and send it over to the FPGA. This is where I believe some of our fellow members at EEWeb can help!

I think the USB port is the best way to interface with the PC, and there should be no need for any external memory or storage (just reading out some registers from the FPGA through the USB port should give us the interesting metrics?).

Hey Ganesh,

Can't say I know very much about HDMI but from what I've read, HDMI has DDC, TMDS, and CEC interconnects. The DDC is basically I2C, the TMDS is like the differential video/audio data, and CEC is a communication link for devices.

You mention you need some sort of LVDS I/O? I think you should be able to hook that directly to the FPGA's differential inputs. Double check the electrical characteristics against what the FPGA can actually handle but typically they have a descent range. Otherwise if you need something to convert explicitly to LVDS try the MAX9392 or DS25CP152.

The rest would really just be up to the FPGA programmer.

Hopefully this helps

Paul

Have you considered the Digilent Atlys board? It is relatively cheap and has plenty of HDMI inputs.