表达自己的思想

Microsoft Silverlight is like the proverbial elephant; your impression depends upon w在这里 you touch it. 在本文中, I’ll touch it at the Expression Encoder, which is the encoding component of Expression Studio. 具体地说, this article describes how to produce a Silverlight-compatible "media experience" with Expression Encoder, then upload it to the Silverlight Streaming Server, a streaming service offered by Microsoft, 还有你自己的网站. 在本文中 I will focus on on-demand encoding, not live video encoding.

From my perspective, Silverlight poses two main questions. The first question is whether to adopt Silverlight as a design and development architecture, 特别是在Flash上, 我不会去那的. The other question has a very easy answer: If you’re already producing Windows Media files, should you switch to Silverlight?

T在这里 are some absolute bars to Silverlight. It currently doesn’t perform multicasting as robustly as Windows Media, it doesn’t offer server-side playlists or multiple bitrate files, and it doesn’t support the Windows Media 9 screen capture codec. 除了, Silverlight uses the same audio and video codecs as the current Windows Media Encoder, so you shouldn’t expect any increase in audio/visual quality.

那么，为什么要用Silverlight呢? For casual Windows Media producers, Silverlight lets you easily create a custom player for your video that integrates more neatly into your webpages. It also allows Macintosh viewers to play Windows Media video files more easily, and this should soon extend to Linux.

Even if you don’t make the switch to Silverlight, t在这里 are several valid reasons for Windows Media producers to consider Expression Encoder. 例如, Expression Encoder can import QuickTime files, which is great if you’re producing in Compressor, 后的效果, 或Mac上的Premiere Pro. The Expression Encoder can batch encode multiple files, and it is compatible with compression acceleration co-processors from Tarari.

我们会看到, the A/B comparison tool for assessing compressed quality is very robust, and the Expression Encoder has deinterlacing that actually works. 整体, it’s a lot more straightforward than the Windows Media Encoder, which is dowdy and has a frustratingly roundabout workflow.

But as we mentioned, the Expression Encoder does not produce multiple bitrate files. 更令人惊讶的是, it doesn’t support the advanced encoding options made available in the Windows Media Format SDK 11. 确定, the Expression Encoder supports command line encoding that implements those options, and it will respond to registry key changes invoked via the WMV9 PowerToy discussed 在这里. 然而, given that this is the first major encoding tool release after the SDK 11 release, I would have expected Microsoft to drink its own Kool-Aid and support the advanced parameters directly.

你需要什么
这里我回顾一下1.0.2905 version of the Expression Encoder. Note that Microsoft still had previous beta versions and updates to those betas on its website when I wrote this article (though, 据报道,, 他们很快就被搬走了。, so it’s easy to download and even update the wrong application (not that I did, 当然). You don’t want the Expression Media Encoder; the name has been shortened to Expression Encoder. You’ll know you have the wrong product if your interlaced source video doesn’t get deinterlaced during encoding.

If you’d like to customize your player templates, 你需要Expression Blend 2, not the version of Expression Blend that ships with the initial version of Expression Studio, making it easy to start using the wrong application (not that I did, 当然). You’ll know you have the wrong version if you get an error message when attempting to import the project file produced by Expression Encoder.

来查看生成的文件, you’ll need the Silverlight plug-in, which worked well for me on both Mac (Safari and Firefox) and Windows. Your browser should tell you that you need the plug-in. 大概是1.Windows是8MB，但实际上是4mb.6MB for the Mac because that contains both PowerPC and Intel players.

With all of this as background, let’s dive in.