Reviving Obsolete Set-Top Boxes

[settopboxing]

This thread is a continuation of the discussion of a project attempting to operate popular and now non-functional digital TV receivers built for use in the UK during the late 1990s and early 2000s. Previous discussion and screenshots can be found at https://tvforum.uk/mediatech/candw-ntl- ... info-45942 (archived as of 31st March 2021).

The project has experienced something of a lull, but work is expected to recommence soon, and as the forum hosting the original thread is very soon to become read-only it seemed necessary to give the project a new home before it does.

[settopboxing]

Just to give the thread a bit of substance, a sneaky teaser from some further efforts a few months ago:

[PFML84]

I was always a fan of the set top boxes that had a display on the front telling you the time and channel name. It was mainly only ever seen on analogue satellite receivers though a very small selection of digital terrestrial boxes has them at the start.

[settopboxing]

I was always a fan of the set top boxes that had a display on the front telling you the time and channel name. It was mainly only ever seen on analogue satellite receivers though a very small selection of digital terrestrial boxes has them at the start.

Yeah, it never was much of a thing when everything switched to digital, presumably because there was no need now that everything had an EPG and on-screen now/next displays. The cable boxes and the ONdigital/ITV Digital boxes do have channel number displays at least, despite them being pretty unnecessary, which does feel pleasantly retro. Also allows them, particularly the cable boxes, to show diagnostic codes too, which can come in handy. Makes the Sky Digital boxes seem a little dull in comparison, having only a few basic status LEDs for power/standby, remote control indicator, modem online, and unread messages.

[AJ]

I'm really glad you've joined here to continue sharing your journey of set top boxing! Looking forward to seeing what you're working on next!

[settopboxing]

I'm really glad you've joined here to continue sharing your journey of set top boxing! Looking forward to seeing what you're working on next!

Cheers. Hopefully I can provide something interesting!

[Mike]

Just to give the thread a bit of substance, a sneaky teaser from some further efforts a few months ago:

I remember being very excited the middle UI appearing on a Scientific Atlanta ex Telewest box, around 2007. For some reason it originally had the white on blue Telewest Broadband splash screen but that EPG, the black and yellow home screen and Telewest banners for about a day before they all updated to the then new VM branding.

Interesting in the revived version that BBC One is listed as 1, it was always 101 on the actual service.

[settopboxing]

I remember being very excited the middle UI appearing on a Scientific Atlanta ex Telewest box, around 2007. For some reason it originally had the white on blue Telewest Broadband splash screen but that EPG, the black and yellow home screen and Telewest banners for about a day before they all updated to the then new VM branding.

Interesting in the revived version that BBC One is listed as 1, it was always 101 on the actual service.

Yeah, I'm not sure what the split between bootloader/splash screen/UI is. I know I have boxes here which still have ancient old-logo Telewest bootloaders, for example, but I think they have non-Telewest UIs (Virgin, probably, I don't recall - I really must keep better records).

As for the channel numbers, it probably should be 101 for BBC One, but as my hacky transmissions aren't entirely on spec with the original transmissions there are still issues to iron out. As such, channel numbers are inaccurate (entirely configurable by me, but only if the relevant data is present for the box to read, and in the correct format), there's no EPG data either as you can see in the image. The Sky screenshot is missing its channel number entirely as I haven't quite nailed down the mechanism for defining all that stuff, so in that specific test run it's being viewed as an "Other Channels" channel rather than via the Sky EPG.

There's quite a lot of metadata that needs to be present and (quite specifically) correct in order for all of those little bits and bobs to show up correctly, which is quite the pain in the backside because any slight error can cause the whole thing to fall on its arse, anything from the channel missing trivial metadata to the boxes not even seeing a valid signal at all (especially some cable boxes, which won't boot past the splash screen without the right signal/data). That's most of what takes so long, having to analyse and try to recreate the correct data structures so that the boxes don't see invalid or incomplete data and give up trying or act weirdly.

[PFML84]

To be honest, I have no idea about the technical aspects of all this, but I enjoy reading this sort of stuff so I'll be watching this thread with interest to see how you get on and what you can achieve with this.

[settopboxing]

To be honest, I have no idea about the technical aspects of all this, but I enjoy reading this sort of stuff so I'll be watching this thread with interest to see how you get on and what you can achieve with this.

Well, without getting too far into the weeds, there's a whole bunch of blobs of data that come along with the video and audio you see on the screen, describing everything from the core layout of the network (eg: on satellite that describes the satellites, the transponders present on them, and what channels each transponder has on it) to the time and date you see on the EPG, with everything inbetween like the TV guide data, the channel numbers, etc. As the boxes are designed to expect that to be present and perfectly formatted, that's super important stuff (even if, to the end viewer, it might be trivial if it's missing/inaccurate).
That all has to correspond with each other, so it makes a coherent "database" if you like for the box to know what channels are available, where to find them when someone selects a channel, what's currently playing on them and what's upcoming (sometimes into the future by a week or two), basically every aspect of a TV provider/interface that you see when you're watching it. Channel names, channel numbers, channel categories, transmitter frequencies or satellite transponders, now/next and EPG, data describing which audio and video streams belong to which channel, firmware update streams, all that stuff.

If any of that data, particularly anything critical to the displaying of the EPG or the tuning of the channels, if any of those things disagree with each other, are somehow incorrect or don't match then the box's expectations (relatively simplistic as it is, being an embedded system that expects a precise input as it's designed to work very specifically with the network it's designed for) then there's a good chance it'll fall over. It won't be able to make sense of, and match up, the data it's seeing (or not seeing, if it's missing), and it doesn't necessarily know what to do with that, so it may just misbehave, give up, or straight up crash.

That might not have helped explain much, but in any case, I'm glad you're enjoying watching the progress, and I hope to be able to bring more soon.

[Mike]

There's quite a lot of metadata that needs to be present and (quite specifically) correct in order for all of those little bits and bobs to show up correctly, which is quite the pain in the backside because any slight error can cause the whole thing to fall on its arse, anything from the channel missing trivial metadata to the boxes not even seeing a valid signal at all (especially some cable boxes, which won't boot past the splash screen without the right signal/data). That's most of what takes so long, having to analyse and try to recreate the correct data structures so that the boxes don't see invalid or incomplete data and give up trying or act weirdly.

I have no idea how it all works or how you do it, I know it's quite technically involved and I take my hat off to you for trying. In theory could you create your own EPG data?

Would you ever consider doing a YouTube style 'this is how I do it' video or is that too much work and effort for little reward?

[PFML84]

Yes, that has explained it perfectly for me, thank you. Reading it has made me even more interested to see how you get on now!

[settopboxing]

There's quite a lot of metadata that needs to be present and (quite specifically) correct in order for all of those little bits and bobs to show up correctly, which is quite the pain in the backside because any slight error can cause the whole thing to fall on its arse, anything from the channel missing trivial metadata to the boxes not even seeing a valid signal at all (especially some cable boxes, which won't boot past the splash screen without the right signal/data). That's most of what takes so long, having to analyse and try to recreate the correct data structures so that the boxes don't see invalid or incomplete data and give up trying or act weirdly.

I have no idea how it all works or how you do it, I know it's quite technically involved and I take my hat off to you for trying. In theory could you create your own EPG data?

Would you ever consider doing a YouTube style 'this is how I do it' video or is that too much work and effort for little reward?

Creating custom EPG data is definitely possible, although it varies in difficulty depending on the service you're trying to recreate. Sky, for example, uses a very non-standard EPG mechanism with custom streams containing compressed data, so not as simple as ONdigital.

I'm not really the YouTube type tbh, but I do intend to write this stuff up so other people can have a go, but I want to get to a point where I understand it sufficiently to be able to do that and to be able to provide code/scripts to those who want to give it a try, largely because of the issues described in the previous post. Because it's so difficult to get the data stuff right and so that it doesn't have to cause others a headache, I want to be able to provide tools which can do the tricky stuff automatically (as that's clearly how the broadcasters do it so it doesn't cause peoples' receivers to get confused).

[i.h]

How do you do the actual RF stuff? I can imagine it's pretty involved to generate the DVB-S signals at 1-2GHz? Is this with a Hack RF or similar SDR device?

[settopboxing]

How do you do the actual RF stuff? I can imagine it's pretty involved to generate the DVB-S signals at 1-2GHz? Is this with a Hack RF or similar SDR device?

Yeah, HackRF, with gnuradio powering the software part. Perfectly adequate for cable and terrestrial, although satellite (or Sky, specifically) is a bit trickier since it requires more bandwidth than the HackRF can produce. That's worked around by jacking up the error correction and hoping for the best, which works surprisingly well (but not flawlessly). Would be alright if it were a generic DVB-S receiver as they tend to be more flexible, but Sky Digital boxes are designed with very few specific configurations locked in, so you have to mimic the exact parameters they chose to use.