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The Fox Report Barry Fox’s technology column The analog loophole is now digital T he analog loophole is alive and well, and extremely useful. But it is now seldom mentioned because young executives in the music and movie industries have never heard of it and wouldn’t understand it, anyway. The few older execs who once tried, and failed, to plug the hole now understand it will always exist. All manner of clever technical tricks based on encryption are used to try to control digital copying or ‘cloning’ of words, graphics, speech, music and movies. They can at least frustrate the process. But if the material is analog – and it always has to end up that way because humans have analog senses – it is simple to copy. Yes, there are ways to watermark or fingerprint analog sound and pictures with invisible or inaudible codes, but this is used mainly to identify the source. Yes, this can be extended to copy control, but only if the copy system is hard-wired to recognise the codes and block the copy process. No-one chooses to buy hardware that is designed not to do what’s wanted. Blu-ray disc players can impose copy control, but this roadblock has been sidelined by ripping software for PCs with Blu-ray drives. The main and most frustrating copy control system in real-world use is HDCP (High-bandwidth Digital Content Protection, developed by Intel) which is part of the HDMI (High-Definition Multimedia Interface) cable system which is now universally used for digital sound and vision connection. When an HDMI cable is connected between a “source”, such as a Blu-ray player, DVD player, DVR, computer, game console or music player, and a “sink”, such as a TV set, projector or hifi system, the two ends of the HDMI chain ‘talk to each other’ in an attempt to allow listening or viewing while blocking copying. Some years ago, even some legitimate connections (for instance, between a TV tuner or game console and video projector) were frustrated because projectors did not have HDMI inputs, just analog ‘component’ video sockets. This is why Sky put high-definition component outputs on its early digital boxes. Also, gamers wanted to capture or stream their gameplay. Home moviemakers wanted to do the same with their own creations. Practical Electronics | January | 2026 Enterprising companies like Hauppauge then designed boxes that converted analog component high-definition (or composite standard-definition) video to USB digital video that could be digitally captured by a PC running free software such as OBS (for video) or Audacity (for audio). This created an analog loophole. Then, without any fanfare, conversion dongles from China slid onto internet sale sites; these little units, the size of a USB memory stick, converted HDMI to USB digitally. Most importantly, the Chinese dongles simply ignored HDCP. And they cost only around £20-30, quickly falling to the current price of around £10. Plug one end of the dongle into any HDMI output socket and the other end into a PC running OBS or Audacity (or similar video capture software) and what you get is a digital recording or stream of whatever the HDMI socket is outputting, be it gameplay, music or movie material. This isn’t even an analog loophole; it’s an easy and convenient digital loophole because there is no need for any digitalanalog-digital conversion; just an HDMI digital signal converted directly to a USB digital signal. It has always been a mystery why the HDMI licensing authorities, music and movie industries let this happen. Perhaps they thought the dongles were hard-tofind and sold only in small quantities by under-the-radar companies. Perhaps they never got their heads around the clever technical trick the Chinese were playing with these absurdly inexpensive dongles. I’ve been experimenting with HDMIto-USB dongles for years. Forget about perish-the-thought uses like copying TV recordings from a PVR; these dongles are a wonderful tool for capturing and storing old audio and video recordings such as amateur recordings and home movies. Just convert the original analog to HDMI using one of the many readily available, low-cost analog-to-digital units and then use the low-cost HDMI-to-USB dongle and a PC to capture PCM audio and high-definition video. Now, finally there is what I believe to be the first HDMI-to-USB converter dongle available from a ‘legitimate’ Western source. It’s made in China, of course – what now isn’t? – but it carries the highly respectable Sandberg name (which I have previously mentioned in connection with other electronics and IT gadgetry). Sandberg’s brief instruction guide shows how to connect the dongle to a PC or Mac running OBS (obsproject.com) or Debut (nchsoftware.com). Debut is new to me, so I can’t vouch for it with the confidence I have in OBS, after years of using OBS. Sandberg says the dongle can also be used for live-streaming with online video chat software such as Zoom or MS Teams, or uploading to YouTube, with a video camera serving as a webcam. The physical connections on the dongle are standard HDMI with USB 3.0 C and A. Input quality up to 4K 30 FPS is handled with capture output up to 1080p. The unit self-powers from the USB connection. No software drivers are needed. Rather confusingly, the dongle shows up on a PC as a “USB 3.0 audio” device. The official technical specifications from Sandberg reads: • Input video: 720p/1080p up to 60 FPS, 4K up to 30 FPS • Input maximum resolution: 4K<at>30Hz • Output maximum resolution (minimum USB 3.0): 1080p <at> 60Hz • Supports UVC standard • 24/30/36-bit deep colour • Captured video size: maximum 1080p, 60 FPS • Chipset: MS2130 Says Martin Hollerup, CEO at Sandberg A/S: “It’s a missing link. I’ve personally been on a film shoot in a forest with a laptop and thought it would have been smart if I could just use the laptop’s screen as a field monitor during the shoot. I couldn’t do that back then, but with this new adapter, it would have been super easy.” The only mention in the documentation that may raise an eyebrow with the entertainment industry is: “You can also load your favourite DVDs onto your laptop before a flight”. But as almost no-one buys DVDs any more (the charity shops are bursting with them for peanut prices), this is hardly likely to ring alarm bells in Hollywood. It’s the other unmentioned uses of all these capture dongles that would clang bells, but my bet is that only a handful of managers in Hollywood have any idea what a capture dongle is or does and how it creates a barn-door-wide loophole. The Sandberg price is a bit higher (around £30, compared to around £20 plus postage for a no-name dongle), but with the Sandberg name, you get a fivePE year warranty and support. 67