MPEG 4 Information

[soledade]

There is no such thing as a "real time codec." Equipment is either available for real-time encoding with a codec, or it is not. Real-time HD encoding solutions are not currently sold for WM9 and H.264. However, real time encoding solutions for WM9 are in development. For example, Harmonic and TANDBERG are both demonstrating their new real-time encoding solutions for WM9 SD, and both are developing products for WM9 HD.

See this Microsoft announcement from NAB2004.

Sure there is. MPEG 4 does not require doing discrete cosine transforms while encoding/decoding. This means I can write an MPEG 4 decoder on a very simple real time platform (like ARM) in a cell phone. Similarly an encoder is not too bad to write either (although much more complex).

No such luck for WM. The real time requirements are much much much higher. It is possible to build a real time codec but it will require an extremely powerful custom ASIC. On a P4 the WM encoder cannot output the encoded stream at the same rate that uncompressed video is fed in. This is what I mean by real time. With MPEG 4 one can easily pipe out the encoded stream as fast as the video frames are feed in on a 500 MHz powerpc.

 

[Ken F]

soledade,

You're referring to limitations with existing technology in phones. Cell phone vendors have already indicated that they expect to have mobile reception of H.264 television signals by 2006 in Japan. Silicon vendors are already at work on ICs with H.264 and WM9 decoding for handsets. In the future, handsets will do real-time encoding too for video talk.

Obviously, a P4 is not comparable to a custom ASIC in a $50,000 to $100,000 Divicom encoder. Just as PC and graphics processors become faster and more feature-rich, so too will the ASICs as they move from the current 0.15 and 0.18 processes (in existing Harmonic products) to 0.09 um and beyond.

 

[Sean Mota]

Source

VOOM designed its set-top box with the goal of using a next-generation compression technology to deliver additional programming in the limited amount of available satellite space. The company considered the MPEG-4 format but decided to use Windows Media 9 Series for SD channels later this year and for HD channels early next year. The technology will let the company double its offerings, offer better quality, and save money.

It looks like MPEG-4 is out.

 

[madpoet]

Well now... STB upgrades for everyone?

 

[Ken F]

Repost...

The technology within the VOOM box was never going to do MPEG-4 H.264 decoding anyway. An upgrade was always going to be required. The first chips for H.264 decoding began shipping in the past month or two, so it's not possible that they are in the STB now.

The existing box does have an upgrade slot, which we currently use for the OTA module. I've always thought that the plan was to replace the OTA module with a new module integrating both OTA and H.264; perhaps they will do that with WM9 instead.

Note that most upcoming decoders for WM9 will probably do H.264 as well. Thus, it's quite possible that the switch from H.264 to WM9 requires no changes to their previous upgrade plan for the STBs.

 

[madpoet]

Yeah, we're talking across 2 threads. I suppose we should let this one die and stick with the WM9 one now

 

[Sean Mota]

Ok, keep all your posting of MPEG-4/WM9 at this thread VOOM to employ WM9

This thread is closed...