Image caption More sociable: but the BBC says it will not be building its own social network

The BBC iPlayer has launched a trial service inviting users to share favourite programmes via social networks such as Facebook and Twitter.

People can now choose to log-on to the revamped video player, allowing them to personalise the service and see recommendations based on prior viewing.

It will also aggregate content from other broadcasters including Channel 4.

Users will also soon be able to chat using Microsoft's Messenger service while watching live TV streams.

"We spent more time designing [the new interface] than building it," said the BBC's Anthony Rose, chief technology officer for Project Canvas, a new online broadcast initiative currently under development.

"It's a complete social ecosystem."

Mr Rose also addressed complaints about dips in the streaming quality sometimes experienced by viewers.

A new "adaptive bit-rate system" will continually adjust video to changes in individual broadband connections, he said.

This means that the quality should adapt more quickly when the connection is slower and improve as it gets faster.

Slow start

The new personalisation features relies on a log-in using the same credentials people already use around the BBC website, including commenting on blog posts, added Mr Rose.

This log-in can be linked with Twitter and Facebook so that friends on those networks can see what they are watching or listening to.

Later in the year the BBC iPlayer will begin to take data feeds from other catch-up services including 4OD, Demand Five, ITV Player and SeeSaw as well as Welsh broadcasters S4C and Clic. However, it will not feature content from the Sky Player, as the broadcaster had not responded to an invitation to take part.

The feature means that if a person searches the service for a non-BBC programme they will be directed to the site where it appears, unless it is only available on Sky.

The trial launch marks its third regeneration since the BBC iPlayer service first launched in December 2007.

"It was unproven content - I used to come in to look at the stats and do a high five when we hit 20 downloads," recalled Erik Huggers, director of Future, Media and Technology at the BBC.

The service is now available on 25 devices but the majority of users still access it via a computer.

In April this year 88 million page requests came from computers, 20m via Virgin Media, 6m from mobiles, 5m from PlayStation 3 consoles and 4m from the Nintendo Wii channel.