
HbbTV or Teletext v3.0

Greetings to you, Habrasociety!
Having not found any articles on Habré about technology of Hybrid Broadcast Broadband TV (HbbTV), I decided to share my knowledge and write an introductory article about it.
Since there is simply no Russian-language article on HbbTV on Wikipedia (link to English: en.wikipedia.org/wiki/Hybrid_Broadcast_Broadband_TV ), I’ll talk a little about HbbTV itself. HbbTV is a television standard for transmitting information and "entertainment" through television channels and / or broadband Internet. In fact, HbbTV is an advanced version of the body of text on TVs (a la teletext v3.0), with full graphics, audio, video and is interactive (if information is transmitted via the Internet).
Currently, channels with HbbTV support are broadcast in Germany and France, other EU countries are also planning to add support soon. The standard is still very young, the first demonstrations were shown in the 2009th year, since then, active development of devices with support for HbbTV has been ongoing.
How it works
The whole standard is based on slightly modified HTML-e called CE-HTML (Consumer Electronics HTML). There is support for JavaScript (EcmaScript), CSS and DOM. An hbbTV program is essentially a CE-HTML site up to 1280x720px in size, which is called up by pressing a special button on the remote control.
An HbbTV program can be either tied to a specific TV show or channel, or launched in the background. If the program is tied to a specific TV show, then it displays certain information in addition to the TV show. When the TV show ends (or the viewer switches the channel), the HbbTV program closes.
As mentioned above, data for an HbbTV application can be transmitted both through the broadcast channel itself (digital signal) and through the Internet. HbbTV always first checks for the presence of the Internet, and only if it is absent does it check if there is HbbTV data in the digital signal. Transmission "over the cable" is used very rarely, as interactivity is lost (all users see the same thing). You can appreciate all the beauty of HbbTV only with connected broadband internet.
An HbbTV program can be opened or closed at any time. At a certain point in time, only one program can be started, i.e. There is no multitasking support and, judging by the specifications, it is not planned.
All HbbTV devices support age restriction settings for both TV shows and HbbTV applications.
Examples
Here are a few examples to better understand what it really is and why it is needed.
HbbTV programs with additional information

HbbTV-program for the Olympic Games, displaying the time of the current and next transmission of the Olympic Games, as well as 3 leading countries in the number of medals.
News Center on HbbTV

In addition to the latest news release and a text version of the news (a la google news), you can see the weather for a few days, sports news, etc. Please note that the current TV show is displayed in the lower left corner.
Media archive
German TV channels also offer the opportunity to completely legally watch all broadcast television programs over the past 7 days! Now you do not need to record a television series at a specific time or download it from the Internet. True, in Germany there is a special tax on the support and development of television and radio broadcasting, so cheese is not free.
HbbTV Ads
There are also ideas for creating HbbTV programs for advertising. For example, while displaying advertising about trips to Turkey, you can open the HbbTV application and immediately book tickets. I have not seen real examples yet, but the development has met, I think that the appearance of such programs is just around the corner.
Radio

There is also radio support in the HbbTV standard. When switching to the channel of the radio station, you can see both the name of the current song and the track list of the last 5 (or more) played songs.
Widgets
Of course, there is the possibility of creating all kinds of widgets, such as mini-programs and simple games that are not tied to TV shows. It can be programs, like Apps, or games.
Iron
In terms of devices, there are 2 options. Or buy a TV that supports HbbTV and is equipped with Ethernet or WiFi. Or buy a receiver that supports HbbTV. The control panel has 4 special buttons for managing HbbTV programs. Red, green, yellow and blue. Red is usually used to call or end programs, the rest are configured by the program itself. This is the only innovation at the iron level, everything else is software.
In the end
The HbbTV standard only provides for the use of CE-HTML technology, there is no talk of Flash or HTML5 support. HbbTV displays video and audio through special DOM objects. XMLHttpRequest support is present, so it is theoretically possible to write AJAX applications.