Introduction to Captioning for Windows Media

Article Contents

  1. Page 1: Introduction to Captioning for Windows Media
  2. Page 2: Creating a SAMI File
  3. Page 3: Adding Captions to Windows Media
  4. Page 4: Getting Windows Media Captions on the Web

Introduction

Windows Media Player adds captions using Microsoft's Synchronized Accessible Media Interchange (SAMI). SAMI, like SMIL, which is used by Quicktime and RealPlayer, is an XML-based text language. A SAMI file contains the captions and definitions for how and when the captions should display. Unlike SMIL, which points to an external captions file (.rt for RealPlayer and .mov or .txt for Quicktime), SAMI files contain the captions themselves. Windows Media Player uses an ASX (or sometimes WVX or WAX) to combine the SAMI captions with the media file. The captions can also be automatically added to a media file when they are both embedded within a web page.

Diagram showing ASX file combing media and caption files. Also shows Media file and captions being combined in a HTML page.

Note

For captions to display in the stand-alone Windows Media Player, they must usually be turned on manually. This can be done by selecting View > Captions or View > Now Playing Tools > Captions in older versions of Windows Media Player. In Windows Media Player 9 or newer, select Play > Captions and Subtitles > On if Available (or English). In Windows Media Player 10, you may have to enable Tools > Options > Security > Show local captions when present to view local caption files.

WebAIM is an initiative of:
Center for Persons with Disabilities (CPD) Utah State University