Closed Captioning and Windows Media Files

Using MAGpie's export function, I created interview.smi, a file compatible with Microsoft's Synchronized Accessible Media Interchange format, or SAMI (all SAMI files use the .SMI extension). This file contains the caption text and synchronization information just created in MAGpie. Now I'll create a text metafile with an .ASX extension to link this file with interview.wmv, the Windows Media file containing the streaming audio and video file.

To play the video concurrently with the closed caption file, viewers will load the ASX file into Media Player. Similarly, to post your video and captions to a Web site, you would upload all three files to your site and have your Web page link to the ASX file. More on that in a moment.

Here's what the ASX file contains in our simple example.

   <ASX version="3.0">   <TITLE>Interview</TITLE>   <ENTRY>   <ABSTRACT>Discussion with Ken Santucci at NAB</ABSTRACT>   <TITLE>Interview</TITLE>   <AUTHOR>Jan Ozer</AUTHOR>   <COPYRIGHT>2004</COPYRIGHT>   <REF href="file://c:\interview.wmv?   SAMI=file://c:\interview.smi"   </ENTRY>   </ASX> 

Figure 11.12 shows Windows Media Player displaying both the video file and the closed captions. On the right is the Content screen accessed by clicking File > Properties > Content tab, where you can see the Abstract, Title, and Author information mapping over from the ASX file.

Figure 11.12. Video and captions playing in Windows Media Player.

Windows Media Player won't play captions if you've selected a "skin" rather than being configured in Full mode. To return to Full mode, click View > Full Mode. In addition, Media Player won't play captions unless you enable the program to play captions. To do this, click Play > Captions and Subtitles > Captions. If your viewers can't see your captions, chances are it's one or both of these configuration issues causing the problem.

If you post the files to a Web site, you must upload the ASX, WMV, and SMI files to your server and update the ASX file to reflect the new locations (also called paths) of the content files. For an excellent white paper on ASX files, including paths to use for the various types of servers that support ASX files, check out www.microsoft.com/netshow/howto/asx.htm. To read up on the SAMI language, check out: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnwmt/html/wmp7_sami.asp.

Finally, to learn how to embed Windows Media files directly into a Web site, see WebAIM's excellent description at www.webaim.org/techniques/captions/windows/3?templatetype=3.