Twonkyvision is demonstrating a small-footprint, embeddable media server running on an inexpensive NAS (network-attached storage) appliance, at IDF this week in San Francisco. MediaServer aggregates local media files, advertising and serving them to UPnP-compatible clients. The product is available for licensing to Linux device makers.

UPnP for A and V

UPnP technology has come a long way since its humble genesis in 1999 as a way for 10/100 switches to negotiate connection speeds. The UPnP Forum today comprises 760 members, and UPnP standards now exist for 13 classes of devices, including printers, cameras, scanners, wireless access points, internet gateways, media servers and renderers, lighting controls, HVAC equipment (heating and air-conditioning), quality of service, device/console security, “basic devices,” and more. UPnP aims for nothing less than seamless proximity-based networking of every computerized gadget in the home — and some that aren't computerized yet, such as garage door openers.

The UPnP A/V standard defines a standard communication mechanism based on HTTP, XML, and SOAP (simple object access protocol). The spec covers “MediaServers,” which are sources of media, and “MediaRenders,” which are consumers of media. Media renderers, such as the increasingly common media adapters (including Microsoft's Media Center Extender concept), use UPnP A/V to advertise their capabilities, and media servers respond with lists of content available in suitable formats.

According to Twonkyvision CTO Christian Gran, early media adapters were based on proprietary protocols, but current designs have “mostly all” moved toward UPnP. “We can now say that most of new media adapters are UPnP A/V compliant,” Gran said.

Twonkyvision maintains a list of UPnP-compliant clients that currently includes 13 media player devices, nine music player devices, and five software clients, along with a half-dozen “might be supported” devices. (Many, if not most of the supported clients are based on embedded Linux.) Additionally, Twonkyvision has contributed UPnP support to the MP3beamer project, which developes an open source media player with web-based and other graphical user interfaces, Gran says.

In addition to UPnP, MediaServer complies with guidelines from the Digital Living Network Alliance, Twonkyvision says.

Twonkyvision's MediaServer

Twonkyvision's MediaServer is “essentially an http server” that complies with the UPnP A/V specification, according to Gran. It does not have a user interface of its own, other than for configuration. Rather, it simply aggregates metadata about content found in a specified filesystem, advertising it via UPnP, and serving or streaming it via HTTP on request to one or many simultaneously connected UPnP-compliant clients.

Especially for music files, MediaServer can provide metadata in a rich logical structure that allows clients to quickly sort by genre, album, artist, or other criteria, Twonkyvision says.

MediaServer is available for x86 Linux, Windows XP, and Mac OS X, priced at 15 Euros (roughly $15 USD). A trial “MusicServer” version limited to music-only content and 30 minutes of operation is also available.

In addition to desktop PCs, the commercial version of MediaServer currently supports 13 NAS devices, including the Asus WL-HDD, KuroBox, Dream Multimedia DreamBox, Sony Playstation 2, and other devices that come with or can be made to run embedded Linux.

Twonkyvision's “SLUG” demo at IDF

At IDF this week in San Francisco, Twonkyvision is demonstrating MediaServer running on the Linksys NSLU2 (fondly dubbed the “SLUG” by the Linux hacker community), a simple NAS adapter for USB harddrives that was fingered to revolutionize NAS by early Tom's Hardware reviewer Jim Buzbee. Buzbee subsequently exploited a cgi vulnerability to hack the device, and soonafter, a number of alternative Linux firmware implementations cropped up, including one based on full Debian ARM-Linux. Alternative firmware images extend the NSLU2's capabilities, for example, enabling it to use drives formated with FAT and other Microsoft filesystems, in addition to Linux ext2/3.

Twonkyvision's MediaServer version for the NSLU2 is meant to run on uNSLUng, an alternative Linux firmware image based closely on the Linux binaries that come stock on the device, but with the root filesystem mounted on a USB flash disk of 256MB or larger, providing room for additional user-installed Linux software.

Twonkyvision's IDF demo showed video and photos stored on a USB harddrive attached to the NSLU2 being displayed on a TV through a D-Link DSM-320 media adapter, while music files stored on an iPod attached to the NSLU2 were played through loudspeakers via a Roku SoundBridge network music player (the SoundBridge is also available to device designers as an add-on module.)

Lightweight network music server?

Twonkyvision's MediaServer software is available for licensing to Linux device developers. It supports all the usual embedded architectures, including ARM and MIPS, and has a claimed footprint of 400KB. Its only library dependencies are Linux's TCP/IP stack and IP-threads — it will not work on single-threaded network devices, Gran says.

Twonkyvision plans to release portions of MediaServer under an open source license, in order to allow third-party developers to create plug-ins and extensions. Gran said, “We plan to open it in a few ways, and document how our APIs work, so developers can contribute music formats and playlist formats.”

Gran says Twonkyvision has already licensed MediaServer to several device vendors, including High Fidelio. Additionally, the software is bundled with media adapters from a number of companies, including ZenSonic's Z500, Gran said.

Additional details can be found on Twonkyvision's website.

 
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