On Thursday I met LHTrevail, one of the speakers at Dorkbot, who had a box that turned images into sounds. It turned out to be an SSTV (slow scan TV) scanning device (they used the same technique to transmit some of the Moon landing images so I’d heard of it but that was the extent of my knowledge). You can transmit and receive images via sound directly from a speaker or carried over a radio signal.
Sonically it’s like a much prettier version of the chirps from Ye Olde Modems, you can hear some examples of what files sound like from the mp3s here: Essex Ham: SSTV The Basics Explained.
One nice thing that you can do, if you have a ham radio set up (I don’t, and this seems like a personal failing haha), is to capture via radio a sound file emitted from the International Space Station as it whizzes over – how cool is that!
I’ve now spent far too long on YouTube etc catching up with older methods of television-ing including the Nipkow 32 line spinning disc jobs (plenty of working examples and modern re-creations) and the whole John Logie Baird early TV work. The vids I’ve watched are below.
Possibly I should mention at this point that the television I watch in my flat is an old CRT (Cathode Ray Television). This isn’t because I’m keeping the old ways alive or am unusually nerdy (accidentally true on both counts) but it’s simply that it was there when I moved in, in 2005, and it works fine. It would be quite the palaver to replace it (I rent) and I’ve no real inclination to do so – the picture is good (also old TV programmes fit on it perfectly). Works fine with Freeview via a SCART lead. Anyway…
I spotted that there’s a smartphone app (search for SSTV and it’ll come up) which converts audio into picture so £2.99 later I now have it on my phone. Playing the files through my laptop speaker into my phone brought up some delightfully fuzzy images and fiddling with the Phase and Skew got the best picture available. It felt a bit like that moment in the film Contact when the team listening to a signal realise something else is being broadcast and it turns out to be a TV picture+sound. Oooooh!
(Content warning: this clip features a broadcast of the opening of the 1936 Berlin games with Hitler speaking, a flag with a swastika on it and Nazi saluting)
While playing around on the app I spotted a button that lets you transmit an image from your camera roll as sound! Very on board with that, so after a bit of testing (trying to work out where the mic is on my laptop for best recording) I am ready to share this image from a holiday I went on in 2015. It was broadcast as a “Scottie S2” format – literally no idea what that means but that’ll be something fun to find out later.
If you have an SSTV scanning device on your phone or anywhere else you might be able to pick up the image I’ve shared, a copy of what I transmitted is here.
– by the way to get the m4a file from Voice Memos on Mac so that I could upload it here I first had to drag the file onto my desktop and then drag it into the editing window of this blog post (or could have put it into a File Manager / Finder file hierarchy). I tried using the native upload function on Voice Memos but couldn’t work out what to do next so I’m glad the plan B worked. Not sure if I could airdrop it to myself on the same computer 😉
Right, I’m off to see a film with lots of sound design in it…