DirectShow Extensions (Windows Embedded CE 6.0)

  • Article

1/5/2010

Windows Embedded CE :includes the following features that help in the creation of networked media devices.

  • Fast Start.
  • HTTP 1.1 Streaming Support for non-Windows Media media.

Fast Start

The sample application for the user interface (UI) of the networked media device takes advantage of new features that are in Windows CE 5.0 that reduce initial startup latency when you play streaming content. One of these new features is Fast Start.

Fast Start reduces the amount of initial startup time that is necessary when you play streaming content. During the buffering phase of playback, the server will stream content to the client as fast as the network link will allow, instead of streaming at the bit rate of the content. This means that the buffering phase can be much shorter depending on buffering settings, link bandwidth, and content bit rate.

For more information about Fast Start, see this Microsoft Web site.

HTTP 1.1 Streaming Support

HTTP streaming support has been extended to support non-Advanced Streaming Format (ASF) formats such as Audio Video Interleaved (AVI) and MPEG. HTTP 1.1 Streaming Support is now provided by a new DirectShow filter called the generic streamer filter. This filter does not replace the older DirectShow Filter that is used to stream Windows Media-encoded content. For more information about the generic streamer filter, see Generic Streamer Filter.

Before the development of this filter, non-ASF files were downloaded locally to the device and played from the cache. Doing this caused two significant problems:

  1. A non-ASF media file that was larger than available storage could not be played on the device.
  2. The user could not locate a specific section in the file.

The generic streamer filter solves these problems by behaving in the following ways:

  • It connects to any HTTP server that is compliant with the World Wide Web Consortium (W3C) specification for HTTP.
  • When connecting to a server that supports the HTTP 1.0 protocol, the client will be able to play a file from beginning to end.
  • When connecting to a server that supports the HTTP 1.1 protocol, the client will be able to play a file starting at any section, pause and resume playback, locate any section in the file, and reconnect to the server from the current section in the file if the server connection is lost.

The generic steamer filter provides support for the following customer scenarios:

  • If the user opens an HTTP stream by using Windows Media Connect, the stream will play on the device.
  • If the user opens an HTTP stream on the Internet, the stream will play on the device.
  • If the user pauses, and then resumes, playback of the file on the device, playback will continue at the point where it was paused.
  • If the user locates a random section of the file on the device, playback will continue from that section of the file.
  • If the connection with the server is lost due to a timeout or a bad network connection, the device will re-buffer and restart the playback of the file from the current section.

Note

This will only take place if the network is restored within 15 seconds. Otherwise, playback will stop and will not restart.

See Also

Concepts

Windows Media DRM for Network Devices

Other Resources

Networked Media Device Architecture