Enhancements to Windows Media Encoder 9 Series

The encoder has evolved significantly over the past several years and now includes a rich set of features that gives you more control and flexibility at unmatched levels of audio and video quality.

Device Control

It’s now possible to control the functions of your device—play, pause, stop, fast-forward, rewind, and eject—directly from the encoder. Device control is available for digital video cameras that are connected to an IEEE 1394 digital video port and videotape recorders (VTR) that are connected through a COM port and support the Sony RS422 protocol. You can also set up edit decision lists (EDLs) to specify the discrete segments of your content that you want to encode. Once the EDL is in place, encoding can proceed with minimal intervention on your part.

Multichannel Audio Sourcing

The encoder now enables you to encode multichannel audio for surround sound playback in six (5.1 audio) or eight (7.1 audio) channels. The format is specifically designed for CD, DVD, high-definition television (HDTV), and digital cinema audio programs.

Live DRM

You can control the use of your encoded content by protecting it with digital rights management (DRM) technology during the encoding process. You can use DRM either when encoding to a file or when broadcasting the stream. While content is being encoded it is encrypted with a key. A license is then required in order for users to play the content. This license contains the key to unlock the content and the rights that govern its use. For example, the license determines the number of times a user can play the content or when the playback period expires.

Push Distribution

From the encoder, initiate a connection with a remote Windows Media server to stream content. This is useful if the encoder is behind a firewall or if you, as the encoder user, want to control the stream.

Multiple Destinations

Optimize content for streaming or download-and-play scenarios. Or extend your reach to portable devices, set-top boxes, or physical format delivery (such as CDs or DVDs). In addition, support for interlaced content enables you to get better playback on televisions by preserving the odd and even fields of an interlaced frame. Nonsquare pixel support preserves the true resolution of DV and MPEG-2 content without distortion.

Improved MBR Streaming

Create the right file for any audience with MBR audio, multiple language support, and scalable video resolution that enables a different frame size for every bit rate in the MBR stream.

Scalable Video Resolution

When streaming over the Internet, content providers never know what connection speeds their audience will be using. And the possible range can be anywhere from 56 Kbps to 10 Mbps. While you can encode content at different rates and then provide links that allow users to choose the connection that fits them best, many users won’t know their connection speed. Asking them to choose could result in a poor user experience. Moreover, connection speeds are dynamic and subject to change as a result of network congestion and many other factors.

To ensure an optimal user experience, the encoder, in conjunction with Windows Media Services, enables you to stream MBR content that is encoded at different bit rates and resolutions. This means you can encode one stream containing multiple rates that are optimized for each connection speed. The following table lists the common resolutions and bit rates for dial-up, DSL, and broadband users.

Resolution	Bit rate	Target audience
176 x 144	29 Kbps	Dial-up users
320 x 240	100 Kbps	DSL users
640 x 480	500 Kbps	Corporate LAN and cable modem users

Throughout the broadcast, the server can dynamically measure throughput to a given player to ensure that the best possible stream is delivered to each user, as shown in figure 2.5. The process of selecting the appropriate stream is handled by the server and the Player and is invisible to the user.

Figure 2.5: Content encoded at different resolutions and delivered as an MBR stream.

Multiple Languages

Use the encoder to encode audio in different languages, and then use Windows Media Stream Editor, a utility installed with the encoder, to combine the languages into one Windows Media file. Users can choose the language they want to listen to during playback. When combining audio streams, make sure the bit rates, codecs, encoding mode, and audio format are the same for all streams.

Helpful Utilities

Installed with the encoder are several additional utilities that allow you to trim portions of your encoded video, or add scripts, markers, and attributes (Windows Media File Editor); create and edit encoding profiles (Windows Media Profile Editor); split streams into separate files or combine streams from multiple source files (Windows Media Stream Editor); or perform encoding tasks from the command line (Windows Media Encoding Script). With the exception of Windows Media Encoding Script, each of these utilities is launched from the Start menu. Windows Media Encoding Script is launched from the command line by navigating to the directory where the Encoding Script is located, and typing “cscript.exe wmcmd.vbs” followed by the appropriate encoding command.