Overview: Subtitle storage and delivery

Subtitle storage and delivery connect a timed representation to the player through files, container tracks or stream signaling.

A subtitle's format and its location answer different questions. The same kind of text may be stored separately, embedded in a container or delivered through a streaming arrangement. This area follows that path and the extraction or conversion operations used when a different representation is needed.

• Subtitle transports
  Subtitle transport determines where subtitle data travels and how its identification, timing and resources reach the renderer.

• Subtitle locations
  Subtitle locations describe whether timed content is carried separately, within a media container or in-band with another stream.

• Subtitle support in media containers
  Container subtitle support requires a defined codec mapping and preserved timing/configuration, while player support determines whether that representation can be presented.

• Streaming subtitle transports
  Streaming subtitle transports relate timed text to segmented HLS or MPEG-DASH presentations.

• Extraction and conversion
  Subtitle extraction, conversion and OCR perform different changes to the location or representation of timed content.