How to connect HDMI to stm32?

Question

Arduino

It is necessary to process the video stream, the option of connecting to stm32 via HDMI is being considered, but I can’t find similar connection schemes in order to supply video (not output, not CEC), please poke where you can read about it / on some implementation examples or just tell me how to connect HDMI to stm32 in circuitry?

Answer 1

How to connect schematically? Wired, I think.
You normally describe a task that it is necessary to receive, how to process. It seems to me that even if you start an HDMI signal in STM32 - well, you can and will be able to receive a signal with a resolution of 320 * 240, but there will not be enough resources for even the weakest processing. There is an incorrect choice of tool and/or task. Based on your question, it doesn't look like you can somehow solve all the input and processing tasks. Moreover, the Arduino tag, well, they would be embarrassed, the right word :)
Okay, I'm done spitting poison. Now to the point. It is obvious that this is only an FPGA and nothing more.
First, signal input. As you know, HDMI uses an LVDS signal, in order to get TTL levels from it, you need an LVDS receiver. Moreover, the standard is serial and high-speed, which means that you will need to somehow parallelize the processing. All this is done by special deserializer chips, the first thing that comes to mind is the TMDS341 chip. Maxima also has several such microcircuits, for example MAX9264. A rather convenient interface comes out of them: from 18 to 24 bits of color plus a few shreds (pixel shred and vertical / horizontal synchronization). This can already be directly plugged into an FPGA, but by the way, you can also find an FPGA with LVDS inputs, though it will come out more expensive in total. If you need to make HDMI again after processing, take a similar serializer chip, like the MAX9263.
Just a similar task, receiving video from HDMI and highlighting colors in it at the borders of the picture to create Ambilight: tqfp.org/Perfer/fonovaya-podsvetka-hdmi-fpga-led-c... It looks like the project is not finished yet, but I think that you can start with.
Second, processing. Honestly, I don't know what to say. If you need to somehow pick your elbows in the received video, such as compress it or recognize something there, drop it all and just take a computer with a video capture card. You can't do it all by hand.
In principle, you can search for computers-on-board like https://www.toradex.com/ru/products/colibri-arm-co...but you will need to somehow push this signal into it (it is clear that not through the GPIO, since direct access to the memory bus is required), and write a driver to handle this matter.
It seems that at exhibitions I saw a similar computer with an HDMI input, but one must understand that this is an extremely unclaimed feature, and it will be a great success to find one.
If, for example, you need to simply overlay text on the video (this is called OSD, on-screen display), then in principle everything is decided right inside the FPGA - you paint over the pixel with white color at the right time, and that's it. This is almost the only task in iron video processing, which is solved more or less simply.
You will not find ready-made schemes, the task is too specific. Engineers who have made this themselves will prefer to sell this solution than to share it.
Well, there is always an easy way to convert hdmi to a composite / component, and it is already easier to enter them into any computer or computer module.