But how does it perform? Plug the HDMI into your TV and its USB-A end into a suitable power source (my TV had one nearby).

After a few seconds, my TV displayed this splash-screen.

The QR code appears to be vestigial. It tells you the Wi-Fi details of the device, but the USB-C dongle is pre-paired. I plugged the dongle into my Linux laptop and, a few moments late:

Success! It works pretty damn well! The resolution was 1920x1080, stereo sound was clearly separated and was in sync, video quality was reasonably smooth.

There's a pass-through USB-C charging port on the side of the dongle. It will only do 40W - so you don't get ultra-fast charging, but it should be more than sufficient for your average laptop.

It claims a range of 30 metres. My house isn't that big. Once I was about 5m away, video and audio started getting stuttery. A message popped up on screen suggesting changing Wi-Fi channels. For basic presenting, it was absolutely fine while at the other side of the house.

Linux Compatibility

This worked instantly with Linux. Somewhat uninventively, it does not present as a USB-C device! You'll see nothing in lsusb - instead, it shows up as a screen:

As it is just another monitor, you can either extend your desktop to it or mirror your main screen.

Similarly, it presents as a generic audio device:

You can route stereo audio to it.

Android Compatibility

Android's DP Alt Mode support is still a bit shaky. Nevertheless, this Benfei dongle worked! The screen was auto-detected and I was able to play audio without any problems.

Screen mirroring worked - so I could view my apps on the big screen.

Note that if your screen isn't 16:9, you'll get black bars to maintain the aspect ratio. I think that's an Android limitation.

It is hard to take a photo of a TV and have it look good - but, please rest assured, the colours looked exactly as expected.

Playing video and audio worked fine.

Technical Background

The QR code it presents gives an SSID and a (base64 encoded?) password. It says it is a softap which makes me think this is ESP8266 powered. It also seems to advertise KOM.to - whose products come from EZCast.

The HDMI dongle presented both 2.4GHz and 5GHz Wi-Fi networks - both with hidden SSIDs. Given the power draw of a typical USB-A port, they weren't overly powerful, but got the job done. There's no way to update firmware on it that I can see.

Downsides

These are some minor quibbles.

The dongle only has an LED on one side. It will work either way up, but you won't see the status light if you plug it in upside down.

While video quality is excellent, it is limited to 30fps. It will take a 60fps signal, but there's only so much data you can squeeze over a wireless connection.

The USB-C dongle gets warm during use. Nothing too hot - but it was surprising to me just how quickly it heated up. There are plenty of grilles on the casing to let the heat out.

The USB-A cable is a bit less than 1 metre. That's fine if your screen has a socket - but you might need an extension if not.

None of these are show-stoppers. Just something to be aware of.

Verdict

For slideshow presentations, this is excellent. No faffing around or software to install - just proper plug and play.

For watching videos, it is good enough. Perfect for streaming your laptop or phone to a hotel TV.

The Benfei Wireless USB C to HDMI kit retails at around £56. I think that's fairly reasonable for a bit of kit like this. It comes with its own hard-shell carry-case to protect it. It is light enough to throw in your bag as a "just in case" item. If you're regularly presenting on other people's monitors, you'll know what a pain it can be to get right - this simplifies everything. USB-C means no looking for adapters on your side, and every monitor seems to come with a USB-A socket for power.

Thanks to Benfei for the review unit.

HDMI was supposed to be our saviour, but now DisplayPort threatens its dominance. What's the difference? For the average user - nothing. They both carry high-fidelity video and audio at resolutions higher than the human brain can interpret. Unless you are trying to pump 8K streams 5cm from your eyeballs at 200Hz, you're not going to notice the difference between the standards. They both do surround sound which your home cinema speakers are woefully under-specced for.

The main differences boil down to:

• DisplayPort has a spring-loaded latching mechanism which prevents cables coming loose.
• Lots of laptops and phones support DisplayPort via USB-C's DP Alt Mode.
• DisplayPort monitors can be "daisy chained" to each other.
• HDMI supports ARC (Audio Return Channel) which means your screen's sound can be sent back down the HDMI cable to an amp.
• DisplayPort uses Packetized Data Transmission which, in theory, is more efficient than HDMI.

But, in the end, it all comes down to this:

• What port your screen has.

My USB-C Docking Station has two DisplayPort outputs and a single HDMI socket. My 4K Vertical Monitor has DP, but my older monitor is stuck with HDMI. Is there anything I can do to convert the DisplayPort signal from my USB-C hub into an HDMI signal the monitor will understand?

Yes!

The good folks at Benfei have chucked me a couple of their adapters to test out. Let's put them through their paces.

Here's their 4K one:

And their 1080p one:

Rather handily, there are little instructions on the dongle to tell you which end is which.

The important thing to note is that they are both "plug and play", no drivers needed.

The main difference between the cables is that the lower-resolution one has a locking latch on the DisplayPort end.

I just couldn't get the lower-resolution one to work. My laptop saw it, it identified the monitor and its available resolutions, my sound output could be routed to it - but no video appeared. Yes, I tried rebooting and updating, and unplugging, and sacrificing a chicken - no dice.

The other one worked perfectly. Video came through crisp and clear. Instant detection. Like any modern electronics, it did get a little warm with constant use - but nothing too serious.

Bonus Flipmo Selekta!

What if you want to go the other way? Converting HDMI to DP? Let's go!

Wait? Why is there a USB plug on this thing?

The standard DisplayPort can supply 3.3V @ 0.5A. That's usually enough to power a converter chip. However HDMI can only do 5V @ 0.05A which is insufficient to power anything useful⁰.

Does it work? Yes! The USB plug is only used for power - it doesn't require any drivers or configuration. Plug it into your laptop or hub, plug the HDMI jack into your port, run a DisplayPort cable from it to your monitor. Done.

Buy

Please click the affiliate links so that I can feed my crippling technology addiction.

• DisplayPort to HDMI (HD & latching)
• DisplayPort to HDMI (4K non-latching)
• HDMI to DisplayPort adapter

And then I stumbled on the answer thanks to a random forum post.

Perform the following procedure when the unit is on.

1. While pressing DIMMER on the main unit, press AUTO/DIRECT to display the current setting on the display. While this is being displayed, while pressing DIMMER on the main unit, repeatedly press AUTO/DIRECT to switch the setting.

2. To exit the settings, release your finger. After a few seconds, the display goes out and the switching is complete.

Once the setting was changed to "Enhanced" HDR worked! But why isn't it in the manual? A bit of searching for the text finds a file called manual/sup/upd/hdmi_4k_pio.pdf .

So I assume that this is a supplement meant to update the original manual - it is mentioned as new functionality introduced after a firmware update. But why isn't it in the main manual?

If you visit the VSX-933 product page you can download the manual, but there's no mention of a supplement or an update. The original manual was released in 2018, and the supplement in 2019.

I wonder what other features this amp is hiding that Pioneer simply haven't bothered to tell anyone about?

But is it any good? No. Not really.

Hardware

It's a fairly chunky hub, with a tragically short USB cable.

The USB cable has a dongle which converts it from C to A. That's handy if you don't have enough C ports. But the cable being so short means it is sort of awkward to place. If you're on a narrow desk, the weighty adapter will just be left swinging.

On the back are four ports - two DisplayPorts and two HDMI.

But you can only use two at a time. I stuck a DP in the left and an HDMI in the right and (eventually) it worked! I was able to get 4k @ 60Hz and 1080p @ 60Hz on my screens.

It also passed through audio, although I couldn't find a way to select which monitor received the output.

There's also the requisite blue LED to let you know it is working.

Sadly, it is a bit of a faff to get set up because it is a DisplayLink adapter, rather than a USB-C hub. The manual spends 11 pages talking about driver installation!

Linux

Plugging it in to Linux shows 17e9:6000 DisplayLink USB3.0 5K Graphic Adapter - so it was detected without issue. That said, there were some warnings in dmesg:

Warning! Unlikely big volume range (=672), cval->res is probably wrong.
[7] FU [USB Audio Playback Volume] ch = 6, val = -10752/0/16

But plugging it in doesn't give you extra screens. Instead, you need to visit DisplayLink.com to download the drivers. They are only available for Ubuntu Linux. There are also drivers for Windows, ChromeOS, Mac, and Android.

Despite my best efforts, I couldn't get them to work. It looks pretty buggy. Instead, I downloaded a random GitHub repo which installed the right drivers and got it working.

Once that was done, my laptop happily detected both external screens - one HDMI, one DisplayPort. It was able to change resolution, rotation, and refresh rate using Wayland. It even worked through the USB-A socket as well as the C.

Verdict

It's hard to know who this adapter is for. On the one hand, it does its job brilliantly. It turns your USB3 / USB-C port into a dual output device for two 4k monitors. On the other hand, that's all it does.

It costs £80 - which is a large chunk of change. Especially considering you can get USB-C hubs with dual DisplayPort for literally half that price - and most of those also come with extra USB ports, Power Delivery, Ethernet, audio etc.

Installing the DisplayLink software is a pain. USB-C means that I should be able to plug in an adapter and have it just work. With this, you have to manually install drivers and reboot before it will work. Good luck getting those drivers installed on a corporate laptop!

In theory, it can go up to 5K (5120x1440) on each DisplayPort - but I don't had a screen to test it on. If you need that sort of resolution, that's the only reason I can think for buying this.

It works - but it isn't plug-and-play, the drivers are a pain, USB cable is too short, it has limited functionality, it is too bulky, and is over-priced.

The Amazon 4K Fire Stick is a pretty cool bit of kit. It's an Android device which can push 4K HDR video with surround sound to your TV. But, like any technology, it's buggy. Here's the bug report I've tried to send to Amazon and the BBC. They haven't answered - so I'm publishing it here as well.

BBC iPlayer supplies 4K video - but the app doesn't switch to 4K mode, it stays at 1080p.

Amazon debug

To turn on the Fire stick's debug mode - and get access to X-Ray - follow these instructions.

This lets you see the bandwidth being used, HDCP information, and audio/video information. Here's a 4K presentation via Amazon's own video player. In the top left is the HDMI output information and bandwidth stats. On the right is the video codec data.

iPlayer

Within iPlayer you can opt-in to the beta programme, this gives you access to 4K content. But let's take a look at the debug information. 4K video is being streamed at 25fps. But if we look in the top left corner, the app hasn't switched out of 1080p @ 60fps.

The end result is a juddering rescaled mess.

So, if you or a friend works for either Amazon or the BBC, please ask them to take a look, eh?

Here's the problem:

Why am I getting the error "This content can not be displayed because your TV does not support HDCP 2.2."?

I have four pieces of kit in the mix, all of which claim to support HDCP's Digital Restrictions Management:

• Amazon Fire TV Stick - the new 4K version
• Toshiba 49U6863 - a 4K TV
• Denon AVR-X2500H - a 4K surround sound amp
• HDMI 2.0 cable - an 18Gbps rated cable

Easy, right? No!

Here's what does work: Fire -> TV If I plug the Fire Stick directly into the TV, it works! I get 4K HDR. So I'm confident the TV does support HDCP.

Here's what does not work:

Fire -> Denon -> HDMI cable -> TV Causes the Denon to display the "your TV does not support HDCP 2.2." error message when 4K content is played.

Is it the cable?

The HDMI cable claims to support 4K video. The Denon has a built in cable tester which confirms that the cable meets the "4K (6G)" specification.

The cable is short - under 2 meters - so shouldn't run into any latency issues.

Is it the TV's config?

I don't think so. There is an HDMI Full Range settings, which I have enabled.

I've set the HDMI input to "Advanced".

The Fire seems to think the TV is compatible, and lets me switch to 4K, even when it is going through the Denon.

To be clear, Fire -> Denon -> HDMI cable -> TV (Enhanced) does not show an error on the Fire but shows an error on the Denon about HDCP..

Is it the signal pathway?

Despite Denon's marketing material claiming that every port can do 4K HDR, their support pages tell a different story!

I've tried plugging the Fire stick into the closest HDMI port - but it made no difference.

Is it the amp's settings?

There are dozens of permutations of settings, but I think I've narrowed it down to the essentials.

I've turned off all video processing and set the amp to "bypass" all video processing from the HDMI video path.

I think this is where the problem lies - the 4K Signal Format setting.

If I set it to "Standard", I can watch 4K video without HDR.

As soon as I set it to "Enhanced", the Denon shows the HDCP error.

The Denon shows the TV as accepting 4K HDR.

Can you strip the DRM?

Possibly. Devices like Dr HDMI's HD Fury claim they can fix these problems. But I'm loathe to spend another €90 to fix a problem not of my own making.

Conclusion?

I have no clue! Either the Fire or the Denon are doing the HDCP handshake incorrectly. Or, perhaps, the TV doesn't handshake when connected to an amp.

You'd think it would be simple to pass a digital signal from one device to another, via a 3rd - but the paranoia of DRM means paying customers have to put up with all manner of user-hostile limitations.

Next steps?

• Both the TV and Amp were purchased from RicherSounds - so I might give them a call to see if they've any ideas.
• Amazon support don't think it is a problem with the Fire but will pass my comments onto their engineering team.
• I've contacted Toshiba - but they outsource their manufacturing to Vestel, so who knows if I'll ever get an answer.
• Denon have promised to contact me in 48 hours.

Is it my fault for being a media snob?

Well, probably. I should spend less time watching the picture quality, and more time watching the show.

But I'm an innocent customer. I've spent good money to watch high-def media and I'm being stymied because of DRM.

I'd love there to be an open source AV amp so I could actually be in control of what I watch.

If you've got any smart ideas for how to fix this - please drop me a comment!

Update

I returned the Denon thinking it was faulty and got the Pioneer VSX-933. Sadly, it also has the same error! So, next steps are to find another 4K HDR source to see if that works, or... I dunno!

I disagree. The hardware is as poor as the software. I think this picture symbolises that problem.

N8 and HDMI lead

The N8 has an HDMI port. A mini HDMI port. The image is of a full sized HDMI plug trying to fit into the mini port. It won't fit, of course. But what you can see is that there is easily enough space for Nokia to have placed a full sized port in there.

Instead, we're left in the daft situation where N8 owners have to carry around the ridiculous adapter if they want to plug their N8 into a friend's TV. Every modern TV and STB has a full sized HDMI port - virtually none have the mini version.

Someone in Nokia has thought "We need to save space!" A fine and noble thought. But one which should have been followed with the thoughts "What are the consequences to the customer?" "Will it cost us more to ship an adapter than to use a full sized port?" "What will we do with the saved space?" "Do we even need to save space?"

When is a Unibody not a Unibody?

"Look! Look! Look! We've got a unibody! We're just as cool as the iPhone," screams Nokia.

No. No you haven't, and no you aren't.

Firstly, the plastic rubbery flaps on the N8 - three of them - are all flimsy and annoyingly easy to break. This isn't a sleek and elegant design.

Secondly, the embedded battery. Having an embedded battery is great. You save space by not needing so much chunky plastic around it, and you don't need mechanical contacts inside the phone. You can use that to make a bigger battery, or a smaller lighter phone.

Nokia hasn't done that. They've just shoved a regular battery inside their phone and then sealed it. All the disadvantages of a sealed system with exactly none of the advantages.

The Devil Is In The Detail

On paper, the hardware of the N8 beats that of the iPhone. The implementation is what lets the N8 down.

I'm grateful to the friend who came round with her N8 but without her cable adaptor. I hope my snarky laughter didn't upset you too much!