Best Practices for Windows Media Encoding
Encoder Complexity
Encoder complexity controls how hard the encoder works to encode the video. There are six levels in the v11 codecs with about an eight-fold difference in encoding speed from slowest to fastest, and about a 20% improvement in compression efficiency from fastest to best (which actually isn't the slowest). Different tools present the option in different ways. In Windows Media Encoder, it is set in Tools > Options > Performance.For optimal quality, the second-to-slowest mode (listed as "4" or "80" in some tools, and second last to the left in WME) is almost always the best choice. The slowest mode is a lot slower and very rarely produces any measurable improvement in quality.
Intelligent Streaming
Intelligent Streaming is Microsoft's name for our multiple bit rate (MBR) encoding system. The idea behind MBR is to provide content in multiple bit rates in a single file in order to provide scalability in streaming. Then the player and Windows Media Services (WMS) cooperate to determine the highest data rate version of the video and audio that will fit within the available bandwidth.
Intelligent Streaming is only available when doing real-time streaming from WMS with Windows 2003 Server. Files that won't be coming off WMS should not be encoded with Intelligent Streaming, since it'll just make the files larger, but won't provide any added functionality. Also, not all clients support Intelligent Streaming. It works best when targeting WMP 9 or higher running on Windows.
Tuning for the Target Player
Windows Media Player 11
Windows Media Player 11 is the newest version of WMP. It's available as a free download for Windows XP and built into Windows Vista. With WMP, you can safely use both WMV 9 Advanced profile and WMA 10 Pro's LBR modes.
Windows Media Players 9 and 10
WMP 9 is a good baseline target for mass-market WMV delivery today. WMP 9 is preinstalled with the widely deployed Windows XP Service Pack 2, and it is available via Windows update all the way back to Windows 98. WMP 9 established much of the modern infrastructure for Windows Media, and it's functionally equivalent to WMP 11 for almost all web video. It can safely use WMV 9 and all the WMA 9 audio codecs. WMP 10 was a fine release, but was focused more on performance and media management, and didn't add much functionality specific to web video.
Windows Media Players 6, 7, and XP
Older versions of WMP can use WMV 9 and WMA 9 using codec updates (either automatically downloaded, or via an enterprise deployment). However, none of the pre-WMP 9 versions support the full Intelligent Streaming model implemented in the current version of WMS, and hence can only switch between video tracks of the same frame size, and not at all between audio tracks. WMP 6.4 (the last version for Windows NT 4.0) also isn't reliable with VBR-encoded content.
Flip4Mac
Telestream's Flip4Mac is Microsoft's current recommended solution for Windows Media playback on the Mac.
Flip4Mac handles WMV 9 and WMA 9 and WMA 9 Pro very well, but doesn't currently support WMV 9 Advanced Profile or the other audio codecs. Telestream also offers professional versions of Flip4Mac that support importing WMV into Mac tools like Final Cut Pro and After Effects, and exporting to WMV in QuickTime Pro as well.
WMP 9.1 for Mac
While development has ended on it, WMP 9.1 for Mac is still available. While Flip4Mac provides higher performance and Intel compatibility, WMP 9.1 for Mac supports DRM and some web page embedding options that Flip4Mac does not currently support, although Telestream is working on improving embedding for future versions.
Windows Mobile
Windows Mobile has included Windows Media Player for a number of generations, and any device with Windows Mobile 2003 or later (including 5.0 and the just-released 6.0), has a very capable player, supporting WMV 9, WMA 9, Pro, and Voice.Kinoma Player
Kinoma has recently introduced a new version of the Kinoma Player for PalmOS with support for Windows Media playback. Note that it currently supports only the WMV 9 and WMA 9 codecs, without support for the WMA 9 Voice codec sometimes used for low-bit rate applications.
VLC
The open-source VLC player is adding WMV support to their forthcoming 0.8.6 release. While this product is not supported by Microsoft, it may become a useful solution for WMV playback on other platforms.
WPF/E (Codename)
The Windows Presentation Foundation/Everywhere is Microsoft's codename for a forthcoming rich media browser plug-in. It will support WMV 9 and WMA 9 on Mac and Windows, and within Internet Explorer, Firefox, and Safari. It's currently available as a Community Technology Preview. Downloads and lots of other information are available here.
Advanced Registry Key SettingsThere are a variety of new advanced registry key settings supported in the v11 WMV 9 and WMV 9 AP codecs that can be used to dramatically fine-tune video quality. These were covered in detail in this article. There is also a new PowerToy to edit and share those settings, available here.