While MPEG-4 is clearly gaining plenty of momentum as a low bit-rate streaming solution for video over the Internet, wireless devices, and set-top boxes, Microsoft isn't sharing the vision. As MPEG-4 languishes in licensing limbo and plodding product development, Microsoft has hammered away on image quality and streaming features and its latest version of Windows Media, code-named Corona, reveals plenty of sunlight streaming through the MPEG forest. Microsoft has created de facto standards before-among them Windows itself, Word, and Excel-and it's trying to do it again with Windows Media.
Even the current generation of the Windows Media video codec exceeds the image quality of the standard "simple" profile of MPEG-4, and with Corona Microsoft hopes to step ahead of all other challengers as well. The Windows Media video codec is, in fact, a direct descendent of MPEG-4, and the Windows Media framework still supports ISO MPEG-4, just as it does Indeo, Cinepak, and other compression options. The default Windows Media codec, however, has had the advantage of time, continued evolution, and a lot of smart engineers at Microsoft helping to deliver a better bang for the byte.
Yet with Corona, Microsoft is pushing more than just the limits of compression. Corona also has scaled Windows Media upward to serve all levels of media distribution, including high-definition television and movies. Microsoft positioned for Corona at the annual National Association of Broadcasters convention in April with a slew of professional partners demonstrating the breadth of possibilities to the world's video experts.
Corona will support video resolutions high enough for HD formats and multiple audio channels for 5.1 surround sound. Microsoft wants you to imagine streaming not only DVD-quality movies to a home theater system, but high-definition movies as well. Even over broadband connections, efficient compression for all that data is critical.
Microsoft is also incorporating a bursting technology that will have the effect of eliminating those annoying buffering delays, making the streaming experience much more like television. Corona will send video and audio data to a local temp file faster than real-time and play it from there rather directly from the remote streaming server. That burst of data will allow video clips to start playing more quickly, ideally immediately, and Microsoft says they won't stall even if an Internet connection falters due to congestion.
If you live in Silicon Valley, this bursting idea may sound familiar. Burst.com, formally Burstware, had billboards during the height of the dot.com days touting its "don't stream, burst" approach. There begins the irony for Microsoft, a company built on the relentless assimilation of good ideas. As good as Corona seems at present, Microsoft probably isn't doing anything that can't be done within the bigger scope of MPEG-4. And if they don't derail the MPEG-4 freight train soon, Microsoft may find itself on the other side of the tracks for a change.
MPEG-4 is inherently a big-container format with the potential to hold several layers, or objects, within a given transport stream. Simple rectangular video and audio are only the most obvious. MPEG-4's great appeal to set-top boxes makers, for example, lies in its ability to support user interactivity, scripts, and security, as well as high-quality image content. MPEG-4 has its default video compression format, but an MPEG-4 stream can contain very high-quality, even HD-resolution, MPEG-2 data.
For very low bit-rates, an MPEG-4 stream could rely on multiple video streams, allowing an encoder to compress the background separately and more aggressively than the foreground, or insert a still image as background for some number of frames to save data bits. MPEG-4 supports 2D and 3D objects mixed with the video as well. Of course, general-market encoders that can accomplish those feats will be extremely difficult to achieve, but likely not impossible given time, evolution, and smart engineers.
Smart use of bandwidth is a wonderful idea, if not critical to the success of future streaming, but Microsoft's virtual photocopy of bursting technology leaves Burst.com free to form alliances with MPEG-4 companies and thereby offer the same robustness to "standard" streaming implementations.
What Microsoft does have with Corona is the advantage of time. Today, its technology is far, far ahead of MPEG-4 on the Internet, and few MPEG-4 consumer electronic devices yet exist. Cell phone and set-top box makers may be leery of using Windows CE in their products, and broadcasters and movie studios may also prove reluctant to rely on Redmond for their infrastructure needs. But the Internet is a wide world driven by what works. Today, and with the forthcoming Corona, Microsoft can make a pretty good case that the best working player uses Windows Media and that suggestion alone can generate a lot of momentum.