Worldwide shipments of home media servers are expected to almost double this year to 6 million units, a market research firm said Wednesday.

By 2008, the number of shipments is expected to increase to 31 million, In-Stat/MDR said. Of that number, two thirds are expected to be consumer electronic-based, such as set-top boxes for televisions, with the remainder based on the PC.

Of the 6 million units expected to ship this year, 80 percent are based on consumer electronics, and the balance on the PC.

Despite concerns that the devices could lead to more piracy of copyrighted movies and music, record companies and movie studios have a remarkable opportunity to enter new markets through partnerships with manufacturers and service providers, In-Stat analyst Michael Paxton said. Examples include pay-per-view or pay-per-listen services, co-branded media-server products and the potential of more accurately tracking what consumers are listening to and watching.

"While there's a lot of concern over the threats that those products pose to record companies and movie studios, there's a lot of opportunity as well for content providers who roll out new services to open up new revenue," Paxton said.

However, the current tension that exists between hardware manufacturers and content providers is slowing the progress of both businesses.

"The PC and consumer-electronic manufacturers certainly want to move quite a bit faster in rolling out these products, but content providers are holding back because of concerns over property rights," Paxton said. "One industry wants to move fast, and the other is moving quite a bit slower."