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HDMI Extender Reverse Engineered | Hackaday

tagsExtender Tx Hdmi

[danman] has been trying various HDMI video streaming options,

. The "HDMI Extender" priced at $40 is actually HDMI to

Converter under the hood.

He had done work on a similar extender before, and later found out that the extender used

Sending the video, he naturally reversed the video and made a tender. But the non-standard format is troublesome. Therefore, when he was provided with a newer version of the same device and started using Wireshark to peek at the data packets, he was pleasantly surprised to find that the output was only MPEG encoded video on RTP. No need to hack.

So far, streaming video from any HDMI output over an IP network has been tricky, and [danman] has always been obsessed with running videos at a cheap price. In addition to the previous version of this extension, he also managed to download

. This will cost more, but it can also be recorded at the same time if needed.

However, none of these can solve the HDMI HDCP encryption problem. you are

For that.

(The Wireshark wizard at your place will notice that we just brushed the title image from the previous version of the project. There is no good image for this. Sorry.)

If the dwarf of hdmi hackers is listening, I would love to see someone make a four-in-one view multiplexer that requires 4 1080p hdmi inputs and a 4k hdmi output. Commercial units are about $1k+.

Such a task would require ASICs (very expensive unless manufactured in amazing mass production) or fast and bulky FPGAs with 5 HDMI ports (not sure if they even make... 2 ports less), which Won't be much cheaper...

Why do you still want to splice 4 HDMI streams together?

It's just a guess, but maybe it's the display of the surveillance camera, or maybe it's a PiP-type transaction for watching sports games. But until cheap hackable products come out, it may be easier and cheaper to use a PC with a GPU or accelerator to process video content.

It may be cheaper to adopt 4K NVR, stream with 4x 1080 h264 IP stream and output 4K HMDI.

If you don’t include HD channel units, you will spend about $300 through a distributor in China, and its design goal is to reach 247.

Prices will drop rapidly in the next 12 months.

Only when the PC is free...Once you increase the cost of the PC, you still have to pay a high budget...

This should not be difficult to do, and it is not that expensive. Use 4 ADI's HDMI receiver chips (unfortunately non-HDCP), an ADI's HDMI transmitter chip and cheap Altera Cyclone IV or CycloneV. The firmware will be very simple. I guess that some DDR will be needed as a frame buffer. Most (all?) Altera Cyclone FPGAs with transceivers (GX) onboard are not enough to pull 5 HDMIs. Overall, this is a very simple product. About a year ago, the management I worked for mentioned this exact same product, but it never succeeded.

Like what... 1 FPS.

You only need at least DDR3 bandwidth to read and write these streams to memory, which is the minimum...If you don't want to drop frames, you may need more bandwidth.

Even a 2k stream is about need to be within the 32GBps memory bandwidth to be able to read and write 4 1080p and 1 4k stream...without considering the overhead.

Now, once Altera releases an FPGA with onboard HBM/HBM2, you will have enough bandwidth.

What to do now? 1080p60 will not take up so much bandwidth, and 2k or 4k will not take up too much bandwidth. Here are some actual numbers... 1920 pixels wide * 1080 pixels high * 24 bits deep * 60 frames per second / 8 bits per byte = 373MB/s. There is also no pixel subsampling in this calculation. Multiply it by 4 (for writing 4 1080p60 streams) to get 1492MB/s, and then multiply by 2 (for reading 4 streams, because a single 4K equals 4 1080p) to get 2984MB/s. The peak transfer rate of DDR2-400 is 3200MB/s. These figures seem to be very cost-effective to me. A slightly faster DDR2 will bring more overhead. Even 8-bit 4:4:4 RAW 4k video is lower than 2GB/s. Uncompressed 2k video cannot reach 64Gb/s.

Yes, I believe there will be some confusion in my calculations at some point:/

As you seem to know something about the subject, a quick question is somewhat related: What is the division of HDMI input into four HDMI outputs (basically output top left, top right, bottom)? -From the original video feed to the four distinct screens-"Left" and "Bottom Right" "Rectangular Part".

I have no chance to play FPGA (although?), although I may have 4 of them that can extract such "rectangular parts" and output them to the screen (I did not consider the expanded content here, so each "rectangular second" The resolution is 1/4 of the original input.

->If this can be done [cheaply], it is indispensable that I cannot miss; p

I think 1 to 4 is about the same as 4 to 1. Non-fancy video scaling will also be easy. The hardest part of the whole project is designing and building the hardware. As a disposable device, I think it is not cheap. According to 4 sources, HDCP may still be an issue.

Thank you for your quick reply ;)

Current products involve the use of SD cards as storage devices, and some inexpensive "movie players​​" boxes with HDMI output.

(The video material is also completely ours:)

In addition to HDCP, any tips on ideal BOM and pricing (when purchasing a bottle price [may be [hope] more [hope? ^^]])

Another idea, although not ideal, is to provide a TV with the function of “enlarge the video source” (set one for each screen, which may only make a part of the original video source actually visible on the screen, while the whole is still Sending-Although it is not efficient at all/very hacky/not even sure, if this kind of TV can be provided, it might be a quick hack)

Therefore, the tips are not just welcome, I will dig out the necessary content and try my best to make some suggestions :)

It's hard to say how much the BOM cost... this is not something I do every day. Our prices on FPGAs are also very favorable, so for most people, any numbers I generate internally will be unrealistic.

This is the basic BOM table I tried... Altera Cyclone IV (EP4CE75), one Analog Devices ADV7612 HDMI receiver, one DDR2 (the bigger the better), four Analog Devices ADV7513 HDMI transmitters for FPGA/HDMI devices Proper power supply, EPCS (25P28) boot FPGA, EEPROM (24LC128) for setting, more EDID EEPROM, if you want to run Linux on Nios II, it may be another DDR2, Ethernet or RS232 for remote control. I may be missing something.

You definitely need a good PCB layout staff...DDR and HDMI and Ethernet require specific PCB layout requirements and length matching, proper impedance and termination, etc.

You can ping BlackMagic Design's MultiView 16 to see if it can meet your needs.

The video uses a 27MHz oscillator, and the Ethernet uses a 25MHz oscillator... forget this. All other useful clocks can be PLL locked in the FPGA through these two base frequencies.

Thanks~BOM, I'll dig that one: D

Can you elaborate on what you want to achieve? I suspect that creating a PCB may be the best solution to your problem. Unless it involves a challenge/learning process, be sure to continue :)

of course;)

Some client’s partners told me that he has a video feed (actually a video played on a cheap movie player) with 4 "views" on it, and each "view" must be split into a video Before he can use the HDMI cable (he is currently using 1 to 4 HDMI splitters to display the same content on each screen), he wants to know what is the cheapest way to achieve this

I have already thought of the idea of ​​ordering some cheap "HD movie players" from ebay: split the video beforehand, and then just copy the content to the SD card, and then be read by some movie players. The controls of each player are tied to the uC (or plug in the IR receiver signal line...).. The video we want to play is "synchronized" (if we have the same TV/SD card/movie player as "precise"​​ .. Hope?.. or at least a constant, beware when preparing video content).

Now, in addition to playing the video, I also hope that there is a setting that can act as an RPi in kiosk mode (boot via logo, then no boot log, and then a place where you can run WebGL stuff and interact with GPIO-presumably Chrome ?).. but able to send different output to 4 screens connected via HDMK

=> If it is implemented, I can execute Three.js things on 4 screens at a time, if some custom controllers are used for control, it will be even better (for my/my needs, at least ^^)

(In order to achieve the above "cheap", I thought of using 4 Pis and controlling them via serial or I2C to send commands to the server that is passed and parsed by the application/game running on each Chromium, and then update The screen to reflect the actions and things of the subscriber ;))

and so,

-One of the reasons is to challenge and learn new things (those FPGA...)

– Another reason is.. It will be neat/useful (if there are no devices with over-corrected devices that can accurately handle that thing.. Is it cheaper in some way? :/..): D

What do you think?

A simple and reliable solution sounds like a PC with 4 HDMI ports. They can be mirrored or split. Then use the software video player that extends on all four desktops. I have done this on 2 screens with no problems with a $600 computer.

Yes, it does seem to be a more powerful setting (but expensive :/);)

Video that stretches across the desktop is a simple and effective solution, and it is not difficult for me to handle multiple windows for a custom application instead of only displaying the video (..) later.

Let me see if I can find an "all-in-one" product with the necessary video card:)

Not really, the $40 android hdmi stick based on S905X will decode 4 full HD h264 streams and output 4K video effortlessly

That would require the video to be encoded first. HDMI is not compressed. It may be low-depth, or it may be sub-sampled, but still uncompressed.

High-quality, real-time (low latency), four channels of 1080p video are not necessarily cheap.

If you only have a $40 HDMI to RTP HDMI extender, you can buy...

I see what you did there. I said the quality is very good. You said you are truncating/zooming.

RTP to HDMI MultiViewer (decoding 4 RTP streams into a single 4k output) can be interesting.

Check out HDS 841SL. This is a four-screen viewer, which requires 4 1080p and output one. It can also display all four signals at the same time. Not quite 4k, but very close to what you want to do under $300. Only catch? As far as I know, there is no setting when the screen is divided equally. It may bring a good cracking effect.

Then look at these:

The extractor gear is great.

Never heard of this brand before. It seems that they have some neat equipment that can be used at work.

It looks like a lot of their stuff is SDI...too bad, it's not really consumer friendly. However, I also don't see any 4k support.

The MultiView 4 produced by Blackmagic Design can perform the functions required by the OP. It costs $500 and supports 4k, but also only has SDI input.

Yes... have seen these two. I really want to avoid converting 4 hdmi to sdi before 4k pins. SPLITMUX-4K-4RT is exactly what I need, not that Id wants to pay for $1,600. I am really surprised that the 4k screen does not have 4 1080 hdmi input and has this feature built in.

Check DELL P4317Q. At a resolution of 3840×2160, it can drive 4 independent 1920×1080 signals to the screen, but it only has 2xHDMI, 1xDP, 1xmini-DP, 1xVGA, so you must convert from HDMI or use a different type of input .

There are no 4 HDMI inputs at all, but Numato Opsis (

) Is an interesting platform that supports 2 HDMI inputs and 2 HDMI outputs. It may be feasible to modify this design to make it all as input.

I need an HDMI pass-through type device that also distributes audio to the LR RCA jack, provides VGA output and composite video to the RCA jack. (Essentially HDMI input, HDMI + VGA + CVBS + LR output). No one does this in a unit (I found out). To set up this type immediately, I had to blend various splitters and converters together. This is for mobile DJ/Karaoke consoles, so space is very precious, and multi-unit options will take up too much space.

Known as audio de-embedders, they are all over eBay and Amazon

You also need a scaler to convert digital video to analog video. And it does not apply to any source protected by HDCP, such as DVD or Bluray players.

There is a $20 HDMI splitter to fix HDCP

If you can watch it, you can convert it to analog (:

I can find any number of units to convert the HDMI signal to any single analog output (such as VGA or CVBS), but I cannot provide a unit that can output all formats at the same time, this is what I am looking for. As a mobile DJ/Karaoke host, it would be helpful to put the video signal on the wall-mounted display of the venue and my own singer's lyrics screen. It has the flexibility to output all the most common video signals (HDMI + VGA + composite), which means that I can not only display video in any specific place.

Hi Irishman, teleste has made a box that can do this. They are expensive though. We are using mcc201e, which can even be powered by an HDMI socket, but I don’t recommend this.

1728×1080 @ 30 frames/sec

What F? ! ? !! ??! ? ! Stupid Chinese! :/There is no overscan on the digital signal, why do you want to do this F? :/:/ :(

Oh, and even worse is its 1728×1090. They are tightened in both sizes. It seems that it is not cut off and scanned, but actually resized? So it's not even pixel perfect

Sometimes, the encoder requires the resolution to be a multiple of the macroblock size. For example, since 1920 and 1088 are both equally divisible by 16 (MPEG2 macroblock size), the MPEG2 encoder can input 1920×1088. *Maybe* explained 1728, not 1090. An encoder I have studied adds 8 rows of black pixels to 1088 at the bottom of the image before running the video through an FPGA-based encoding engine. .

I think the overscan is in the HDMI specification, which is attributed to the NTSC tradition in the 1930s.

It looks like the blog post about HDMI extenders has been updated. A new firmware was found, which allows more settings to be changed from the web interface. Obviously, this firmware can also output a more correct resolution of 1920×1090. If the extra pixels are just padding, there is no mention.

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