From Wikipedia

:

Slow-scan television (SSTV) is a picture transmission method, used mainly by amateur radio operators, to transmit and receive static pictures via radio in monochrome or color.

A literal term for SSTV is narrowband television. Analog broadcast television requires at least 6 MHz wide channels, because it transmits 25 or 30 picture frames per second (see ITU analog broadcast standards), but SSTV usually only takes up to a maximum of 3 kHz of bandwidth. It is a much slower method of still picture transmission, usually taking from about eight seconds to a couple of minutes, depending on the mode used, to transmit one image frame.

Since SSTV systems operate on voice frequencies, amateurs use it on shortwave (also known as HF by amateur radio operators), VHF and UHF radio.

SSTV: visuall, with extra headache!!

Although the format can transmit decent-quality color images (and encoding formats vary), it is usually a trade-off between transmission time, bandwidth, and signal integrity.

I envision this as essentially being a size-limited format (i.e. entries can only be X seconds long, or entry files can only be X megabytes large). With that limitation, the !!FUN!! is no longer just in designing the image, but making sure it's legible AND transmittable when converted to an SSTV signal!

Tools

The most comprehensive tool I've used to create SSTV broadcasts has been RX-SSTV

. There are a few others, but this one I've found to be the most useful (also, super rad 90s webpage!!). It can be used to both broadcast and decode SSTV signals, although recording to a file is not supported. A virtual audio cable routed to Audacity works just fine though! The same thing with decoding: it uses a mic input. That can either be routed from your DAW of choice, playback through line-in or an ACTUAL microphone, or as mentioned before, a virtual audio cable.

This format would be a trick to set up properly, so if it gets accepted I'm pledging to create a guide on how to create an SSTV broadcast as well as decode one!

This format would give signalist points!

Any thoughts?

Edit: whipped up a quick icon for the format. Any other designs are absolutely welcome! (link

)

how fine it works on those composite artifact colours? would be cool exploring them if possible

@nitrofurano it's a big toss-up. Encoding affects it, signal strength affects it, speed affects it. It tends to get worse as you speed up the transmission (go figure), so fast transmissions shouldnt have much detail.

much more cooler than adding Another Fakebit Tool imho

how would file submissions work, and would it be viable in an xhb scenario?

@retrokid104 good question... I'd say the signal itself is submitted (it's all in the audible range), but much like how someone can "up mp3"s, you would need to be able to upload images to display this format on the site. as far as I know there isn't a tool to convert them automatically... :/

as for xhbs, yeah it's totally doable as long as you've set it up beforehand. I woe the n00b who tries to set this up on the clock...

in xhbs, this format would require careful planning when designing your broadcast image and choosing your encoding style / bandwidth, as recording and playback of the broadcast to check its quality takes valuable time! If you use a low-quality broadcast (B&W only, low res), you may get worse votes unless you do something really cool. But if you use a higher quality broadcast (color, high res), either the broadcast might be too long or the image might become distorted with too much optimization (you can literally speed up the audio of the broadcasts by a little bit to save some time, with some impact to your image quality, and RX-SSTV should be able to pick it up and read it.)

Thinking about it some more, I think file size would be the best limitation on uploads since compressing the audio also deteriorates the signal quality, so it creates more of a challenge than just limiting the time. Plus, there's some cool visual effects you can do by degrading the transmission quality :P