Who’s got the better WMP – Vista or XP?
By now, you’ve probably downloaded Beta 2 of WMP 11 on your Windows XP system. Is it better? There are quite a few blogs already debating that topic, but if you ask my opinion – it is. This is the first version of WMP that I can actually use to manage my music collection instead of relying on Windows Explorer – so in my mind, that is definitely a step forward. But usability and pretty/ugly UI are not what I want to talk about in this post, so I digress…
You also may have installed a Beta or Release Candidate (RC) of Windows Vista and tried that version of WMP. It looks and feels just like WMP11 Beta 2, but there is quite a substantial difference between them, and that is in the infrastructure it uses to playback media content. The playback infrastructure has been mostly replaced by Media Foundation, which is a new media platform technology only available in Windows Vista.
Media Foundation (MF) is the next-generation media pipeline technology that we’re betting on to replace DirectShow in the long term. Windows Vista is a much more sophisticated OS and has higher constraints on the hardware required to run it – one of the biggest new features is the Desktop Window Manager (DWM), that allows for the desktop to run in 3D. Video itself has been projected onto 3D surfaces since Windows 2000 (thanks to the Video Mixing Renderer), but in Windows Vista now it is only one 3D surface of many that has to be timed/mixed/composited all in real-time – and oh, don’t drop any frames! It’s quite a challenge, but Media Foundation offers resilience to all of the other goings-on in the system, and helps to keep audio/video flowing freely through the pipeline (much like the internet, the a/v pipeline is not a truck… it’s a series of tubes… oh wait, wrong topic J). MF can be a separate blog topic if people are interested in digging into specifics – I’d rather keep this post focused on the playback infrastructure.
If you’ve been running the Windows Vista betas, you may have hit some pain points where videos that used to play on XP now won’t play on Vista. I’ve spent the better part of this last year tracking down this sort of issue, so I know your pain. A/V playback is not an easy problem to solve when you’re building it on a house of moving parts – new graphics driver model, new desktop compositing model, new a/v pipeline, and new apps sitting on top of them all – but we’ve come a long way and it’s really taking shape. A helpful aspect of our design with the playback infrastructure that WMP uses (and MCE to some extent), is the ability to rollback to legacy playback mechanisms if there is an error trying to play certain media content. WMP (and the OCX) will rollback to DirectShow or Format SDK pipelines, so that the file will just play.
If you have feedback or questions on this post, let me know. Or let me know if there’s a specific topic you’d like me to hit!
Eric
