Active-TV for PC - Widescreen Demo
By definition, PC-web content can be accessed and navigated through using a keyboard and mouse; TV-web content can be navigated using just a TV infra-red remote. A TV-webpage cannot be displayed in a Windows XP browser as the former is formatted for a Media Center Edition (MCE) PC or active-TV technology-enabled PC. For demonstration purposes, we have removed the extra components so as to make the TV-web channel compatible with the Windows XP or Vista-based browser normally used to display PC-web pages. Follow this Internet Explorer link to see the example TV layout.

The example TV image, linked above, is widescreen and requires a widescreen monitor to be fully viewed. See the section Installing channel.zip files for the quick steps required for TV-web channel installation.

A ‘channel’ page like this can be viewed on any active-TV technology-enabled TV or Set-Top Box (STB), such as the recently upgraded D-Link DSM-520.
The demo-link is for those taking a quick look at an example layout before trying it on a TV; it is also for software engineers who may wish to modifying the example or better understand how it all works.

Some other functions have also been disabled to make it possible to view the TV-web page on a PC using a common browser such as Firefox or IE. Under normal operation, the video ‘window’ is highlighted and the ‘enter’ button is pressed on the TV remote to cause the video to go ‘full-screen’.

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Inside a TV chip
To understand the TV-web drawing limitations, we have to take a quick look inside a TV SOC chip (TV System-on-a-chip). There are two ways they can present video and graphic images on the TV screen: One is via the built-in video decode engine; the other is via a small, built-in 2D/3D graphics engine. Traditionally, a TV chip receives a digital broadcast stream and sends the video stream to the decode engine for TV display. Information regarding TV schedules, or Electronic Program Guide (EPG) data, is sent to the graphics engine for rendering into a TV image. TV chips have a means of combining the video and graphics images into a single TV-ready output. With the introduction of TV chips that support networking, video and graphics information can be sent to the TV via the home network, as well as by traditional broadcast reception.

Normally, Web applications run in the PC’s browser and the image is sent to the PC’s graphics engine for rendering and ultimately display on the PC monitor. With TV-web ecosystem support, the TV-web applications still run on the PC browser, but the image instead is sent over the network for display by the TV SOC graphics engine.

This approach supports the option of combining video streams (decoded by the video engine) with TV-web images rendered by the graphics engine to create overlay TV web. This is particularly useful when supporting new forms of TV advertising. In anticipation of its popularity, this approach is under evaluation by several active-TV technology developers. It is important to understand that a TV which does not support overlay TV-web cannot display graphics images over the video image. Most current active-TV technology-enabled TVs do not support overlay TV-web. For this reason the example TV-web channel does not draw any graphics images over the video image. In contrast, PC-web sites do not have to deal with this limitation.

The video image decode by the SOC’s video decoder is displayed in an area known as the “viewport”. The viewport for the example above has been turned off. To enable the video to be displayed above, a window containing a Flash video player should replace the missing viewport. This is not a big task, but the work has not yet been completed as its only priority is in support of this PC demonstration. This explains why there is no video displayed. If you want to see video play-back working on your PC, install the TV emulation software from the blog site described above.