Sirius taps WM9 for satellite video -

Sirius taps WM9 for satellite video


LAS VEGAS — In an attempt to get ahead of its satellite radio rival, Sirius Satellite Radio demonstrated a video service it is developing for 2006 at the Consumer Electronics Show here and disclosed it has chosen the Windows Media 9 codec to deliver it.

Sirius aims to deliver cartoons, music videos and other short videos starting in 2006, generally aimed at children watching backseat flat-screen monitors in the family car.

A team of engineers from Sirius descended on the National Association of Broadcasters and IBC (Amsterdam) shows last year to investigate which codec to use for the service. It evaluated MPEG-2, MPEG-4, MPEG-4 Part 10 (also known as Advanced Video Coding or AVC) and Windows Media 9 (WM9) among other options.

The team conducted various technical tests of signal-to-noise rations and error rates as well as side-by-side viewing tests by “golden eye” specialists. It determined AVC and WM9 were the best candidates, and that the two were very similar in most tests.

“In a lot of shows you couldn't tell the difference,” said David Birks, director of receiver platform development at Sirius (Lawrenceville, N.J.). “Basically the AVC picture was sharper, but had more motion artifacts than WM9 which had a smoother picture during motion scenes,” he added.

The group observed that WM9 is getting more market traction among encoders in the US while AVC is further ahead in encoder penetration in Europe. It also noted that WM9 is generally more stable, having been in the market longer than AVC.

“AVC is still in development at many companies, and there are five or six vendor versions of AVC that operate differently,” Birks added.

Sirius will use an off-the-shelf DSP to implement its video receiver. It must also find a way to eke out more transponder space on its satellite which is currently filled with audio programming.

Sirius currently uses the PAC audio codec. It hired the PAC design team from Lucent Technologies which is constantly refining the codec to gain room for additional audio channels on its transponder.

It's not likely Sirius would ever become a challenger to DirecTV or Echostar in full fledged broadcast TV. That's because the radio provider uses redundant network architecture to ensure cars can receive its radio signal. That architecture is not cost effective for delivering full broadcast mobile video, Birks said.

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