Computer-Based Captioning Programs
Unlike web-based tools or services, these are software programs that you install onto your computer, either from a CD or via download. Most of these programs operate like a specialized video editor, except the output is a caption file. These programs do not change the video; they use its timing information to create the caption file.
Specific players use certain file formats – some are general standards and some may be unique to that player. When you create the captions and generate the caption file, you save the file in the format specified for your video's player. Here's a table of the common file formats:
| Acronym | Stands for | Players | Notes |
|---|---|---|---|
| TTML (Timed Text Markup Language) | Distribution Format Exchange Profile | Flash, YouTube | Also known as DFXP (“Distribution Format Exchange Profile”). An XML markup language and draft standard defined by W3C. |
| SMIL | Synchronized Multimedia Integration Language | Quicktime, RealPlayer | Also an XML markup language that is a W3C standard |
| SAMI | Synchronized Accessible Media Interchange | Windows Media Player, YouTube | Microsoft's format |
| SRT | SubRip | YouTube | A YouTube-supported and documented format |
| SUB | SubViewer | YouTube | A YouTube-supported and documented format |
Each player has different specifications for where to store the file on your website for reference. If you have a customized interface, such as for a Flash video, you may have to create your own reference point in your web program, typically in an XML file.