Why Silverlight Video in VC-1 versus H.264 ? What the heck is WMV HD?

By Don Burnett

A lot of people really like Silverlight for video, but a lot of people ask me the question of why Microsoft supports VC-1 in Silverlight itself? The other question people ask is whatever happened to WMV HD.. So I thought I might look at some of the reasons behind this. Now this is obviously not the complete answer (you'd have to ask Microsoft yourself) but these are some of the things that come to mind..

Why Microsoft went with VC-1 support instead of H.264 in Silverlight in the wake of other companies adoptions of H.264 (Notably: Apple, Adobe, and MainConcept now owned by DIVX)..

The answer I have heard at a presentation when this question was asked:

"VC-1 wins on performance when H.264 targets quality; VC-1 wins on quality when H.264 targets performance"

In other words (my words) for web based video when decoding video in certain situations VC-1 gives better performance when you are using a profile where quality is targeted... Giving Silverlight some sort of advantage in decoding, which becomes extremely important with web playback where bandwidth dictates everything..

A lot of folks are looking at their strategies for video again this week due to Warner Bros defecting away from HD-DVD to Blu-Ray. Remember both players support VC-1 as well.

However if you are examining that issue again, just rememberthat choosing one codec standard over another doesn't automatically improve video quality of your output. The codec maybe accounts 10% of the quality difference at most, being that it's an end-to-end equipment issue more than the CODEC itself.

Will Silverlight ever add H.264 support? Time will tell, Microsoft isn't saying anything at the moment..

The other question asked..

If you have never heard of WMV HD, it was an initiative back in the way early days of Windows XP, before the dual core CPUs hit and gave 720p and 1080p video thru WMV format. Some DVD makers included the files with their dvd releases (some of the files distributed even lacked any DRM) and some DVD players would actually play back these files on DVD, giving people high definition access very early. Though at the time HDTV's were just coming into existence and most people only had 480p dvd players so they could only play these back on their computer through windows media player. The standard also worked for the web that far back as well. So if anyone tells you web HD video is "new" from this or that vendor, tell them they need to get their facts right and look back a few years to Microsoft's original efforts which pre-date even Apple's Quicktime HD..

Minimum Requirement during the XP Era to Playback HD Video

Minimum Configuration
(to play 720p video)

Windows XP

Windows Media Player 9 Series

2.4 GHz processor or equivalent (At the time $$$$$)

384 MB of RAM

64 MB video card

1024 x 768 screen resolution

16-bit sound card

Speakers

Optimum Configuration
(to play 1080p video with 5.1 surround sound)

Windows XP

Windows Media Player 10

DirectX 9.0

3.0 GHz processor or equivalent (At the time $$$$$$$$$)

512 MB of RAM

128 MB video card

1920 x 1440 screen resolution

24-bit 96 kHz multichannel sound card

5.1 surround sound speaker system

Technorati tags: VC-1, H.264, WMV, Silverlight