[LeoPanthera]

Broadcast television is amazing, and I'm so sad it's dying out. OK, maybe we don't need to tune in at 6 to watch the latest episode of "Friends" anymore, but for any kind of live events - news, sport, politics, having high-definition video you can pull right out of the air without having to worry about paying for data, latency, or bandwidth limitations, is amazing.

For certain applications the internet can never compete with "broadcast".

[perching_aix]

? Is over-the-air TV broadcast not encrypted and compressed to oblivion in the US? Cause it definitely is here, and you're expected to pay for a decoder card, except for a small handful of channels.

[vlovich123]

It’s not encrypted but compression and reliability of the signal is a mixed bag. It’s not encrypted because congress mandated it as a condition for privatizing the analog bandwidth (ie there’s a carve out for public digital and broadcasters have to broadcast publicly accessible signal just like they had to on analog)

[perching_aix]

Oh wow okay, definitely didn't expect this. That's quite the power move. I guess it's also why it's disappearing, at least partly.

[vlovich123]

Not really a power move but public broadcast will probably disappear at some point in a boiling the frog kind of way, but it’s definitely being starved and killed by corporate interests.

[ghostly_s]

Are OTA channels subscription based where you are (where)? Or the "decoder card" is just some middleware crap you buy once? Our OTA TV has always been ad-supported, they just moved the same channels to digital though in larger markets there are now quite a few new low-overhead licensed syndicated content options, presumably due to the cheaper cost of air slots.

[perching_aix]

It's a subscription, billed monthly, with a minimum one year contract period. To the best I can tell, the service provider is in a completely monopolistic position too (is the only digital OTA (analog has been banned, and OTA is more commonly referred to here as terrestrial) television broadcaster in the country and is privately owned), so yeah, good fun all around.

I looked into it a bit deeper inspired by this thread, and it seems to be an explicit feature of the European digital TV broadcast system standard (DVB-T) [0], commonly used not just here in Europe, but also elsewhere around the world apparently [1].

The formal name for the "decoder card" I recalled is apparently CAM [2], which communicates with the TV using the DVB-CI protocol(?) [3], and uses the form factor of the old PCMCIA cards. I also see that the algorithm used is the CSA [4], and even more curiously I see mentions of DES [5] in the article for the encryption (with further mentions that AES is a new addition to the standard that is presently underadopted).

The only vendor-specific bit to this, because there is a bit that is vendor-specific, seems to be the key exchange algorithm used, although the articles are unclear to me about this. Interesting subject for sure. Here where I live, the Conax system [6] is in use supposedly. To be clear, they're not the service provider and have nothing to do with them (to the best I can tell).

Addendum:

Apparently I misinterpreted how it works a bit. So the Conditional-Access Module is plugged into the TV, so far so good, but that on its own is not going to achieve anything. The actual unlock comes from a smart card bundled with the CAM, and you're to put that into the CAM. As you can tell, we've only ever watched the free channels :)

[0] Digital Video Broadcasting - Terrestrial, https://en.wikipedia.org/wiki/DVB-T

[1] https://en.wikipedia.org/wiki/File:Digital_terrestrial_telev...

[2] Conditional-Access Module, https://en.wikipedia.org/wiki/Conditional-access_module

[3] Digital Video Broadcasting - Common Interface, https://en.wikipedia.org/wiki/Common_Interface

[4] Common Scrambling Algorithm, https://en.wikipedia.org/wiki/Common_Scrambling_Algorithm

[5] Data Encryption Standard, https://en.wikipedia.org/wiki/Data_Encryption_Standard

[6] https://en.wikipedia.org/wiki/Conax

[LeoPanthera]

It's not encrypted, no. And the picture quality is very good. Not 4K, but good quality 720 or 1080, depending on the channel.

[gorbypark]

Most every OTA channel here in Spain (at least in Valencia) is 1080i, with a few being 720i, but there's two 4K test channels, one SDR and one HDR. Not sure of the bitrate, but the SDR one looks stunning on my TV (which "supports" HDR but looks horrible in HDR mode). They usually just play loops of B roll of various Spanish things, festivals, random clips of theatre productions and things like that. It's pretty neat!

[perching_aix]

That's pretty cool. Do you know what kind of codec and bitrate is involved / should I just do my own research?

[LeoPanthera]

H.264 video with AC3 audio.

https://en.wikipedia.org/wiki/ATSC_standards