ONE OF the toughest issues facing the computing and electronics worlds is TV's transition to a new way of getting programmes into homes, but a lot of companies are still fumbling for a solution.

This isn't the transition from analogue to digital, but the switch from cable, satellite, fibre and over-the-air transmissions to also tuning to shows over the web. It faces much bigger problems.

The web abounds with sources of video: iTunes Store purchases and rentals, Amazon's video-on-demand service, network websites, third-party TV portals such as Hulu, YouTube and so on. Depending on your tastes, these options could almost let you drop cable or satellite service entirely.

But the only way to bring all this content to your TV is to plug a laptop or desktop into your TV.

Manufacturers have been trying to build simpler, cheaper solutions to this problem, but the evidence at the Macworld and Consumer Electronics Shows earlier this month suggests that TV's web transition remains years from completion.

At Macworld, Apple failed to announce an update to its Apple TV box, a small box that hooks up to a TV and plays music, photos and videos from nearby computers and from some online sources.

This device works great for iTunes and YouTube video, but not any other site (although crafty users can install hacks, such as CES exhibitor Boxee's software, to add access to extra sites). Now we'll have to wait longer yet to see whether Apple TV can deliver on its promise.

At CES, many high definition TVs and Blu-ray players came with their own web video access. For example, LG, Samsung, Sony and Vizio plan to ship sets with Yahoo software to play video from a handful of big-name sites (developers at other sites can write their own "TV widgets" to make them viewable on these TVs).

Panasonic, meanwhile, is including its own software in its TVs and Blu-ray players to connect to a different set of video sources.

Note the phrase "different set": Unlike a web browser, these internet-connected TVs can't play video from any old site, even though most sites use the same Adobe Flash software to present clips online.

While it is understandable that manufacturers don't want to build in a fully-fledged web browser, it raises the question as to whether users will resent having web video spoon-fed to them in such limited portions?

The problems of TV's web transition, however, go beyond manufacturers not bookmarking the right web video sites in devices like Apple TV or those Yahoo-enabled sets.

Almost all web video downloads and many streaming-video services employ "digital rights management" (DRM) software to stop viewers from making unauthorised use of these films and TV programmes - at the cost of greater complexity and reduced compatibility. Movie studios have kept demanding this so-called DRM even as record labels have consigned it to oblivion.

At Macworld, Apple announced that its iTunes Store - the largest music outlet in the United States and the biggest digital music retailer worldwide - would join the ranks of such competitors as Amazon's MP3 store to sell only DRM-free music by the end of March.

Purchased movie downloads, by contrast, continue to come locked up in various types of DRM that limit their utility. (On rentals, DRM can serve a legitimate role in enforcing expiration dates - but many online rentals come as streaming video that never constitute a single, easily copied file.)

So the best web-connected TV still cannot play a movie "protected" by DRM that it cannot unlock.-