Subtitles and closed captions – which standards are supported?

How do I work with subtitles, and what do you support? Can I use SRT-subtitle files?

Streamio works with WebVTT, a W3C standard for text in HTML5, making it possible to display subtitles in Apple’s iPhone and iPad, for example. It is possible to add more than one track to provide different languages.

You can upload files in the SRT format; these will automatically be converted to WebVTT. If you have access to other formats, there are tools available that convert between different formats.

One tool that we have tried is Caption Converter, but there are others, and we do not offer any support for the usage of these tools.

“The caption format converter lets you convert from SRT (SubRip subtitle) or SBV to Flash DFXP, SMI or SAMI (Windows Media), SCC, CPT.XML (Flash Captionate XML), QT (QuickTime), STL (Spruce Subtitle File), and WebVTT (HTML5 media players).

Caption and Subtitle Formats Explained

  • CAP – This is a common subtitle/caption file format for broadcast media. Cheetah International developed it.
  • CPT.XML – XML format used for encoding captions into Flash video. It originated in the caption-embedding software Captionate.
  • DFXP – This is the most common format used for captioning Flash video. It’s a timed-text format that was developed by W3C and stands for “Distribution Format Exchange Profile.”
  • EBU.STL – This is a common subtitle/caption file format for PAL broadcast media. The European Broadcast Union developed it.
  • QT – Caption format used for QuickTime video or audio. Apple developed it.
  • RT – RealText captions for RealMedia video or audio.
  • SAMI (SMI) – Used for Windows Media video or audio. It was developed by Microsoft and stands for “Synchronized Accessible Media Interchange.”
  • SBV – This is a YouTube caption file format that stands for “SubViewer.” It’s what you get when you download captions from YouTube. It’s a text format that is very similar to SRT.
  • SCC – Popular standard used for Line 21 broadcast closed captions, web media, DVD, and subtitles for iTunes, iPods, iPads, and iPhones. It was initially developed by Sonic and stands for “Scenarist Closed Caption.”
  • SRT is the most common subtitle/caption file format, especially for YouTube or Facebook captioning. It is a text format that originated in the DVD-ripping software SubRip and stands for “SubRip Subtitle” file.
  • STL – Used for DVD Studio Pro. It was developed by Spruce Technologies and is known as “Spruce Subtitle File.”
  • WebVTT – Caption format for HTML5 media players.”