Accessibility/Caption Formats: Difference between revisions
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Many subtitle / caption formats come as just a sequence of triples: start-time, end-time, text (e.g. MicroDVD, SubRip). This is the rawest way of providing subtitles and it lacks further important information such as styling, title and language. | Many subtitle / caption formats come as just a sequence of triples: start-time, end-time, text (e.g. MicroDVD, SubRip). This is the rawest way of providing subtitles and it lacks further important information such as styling, title and language. | ||
Some are more informative, e.g. Substation Alpha, USF, and SAMI, which introduce styling, metadata, and events with dynamic effects. | Some are more informative, e.g. Substation Alpha, USF, and SAMI, which introduce styling, metadata, and events with dynamic effects. SAMI and USF are in XML, which has been rejected as too talkative a langauge for creating subtitles. | ||
TimedText has the most complex model, in particular for styling and layout. | |||
== Karaoke Formats == | == Karaoke Formats == | ||
Revision as of 04:18, 4 November 2008
From the requirements list we have a need for the following formats ("text codecs"):
- a closed caption format
- a closed subtitle format
- a textual audio description format
- potentially a karaoke format
- a metadata / semantic annotations format
- a transcript / script / lyrics format
These formats should specify:
- in format header: the type of text codec they represent
- in format header: the primary language
- in format header: default display mechanism
- in format header: open/closed by default
- in format body: temporal structure
- in format body: text & text styling
- in format body: allow outgoing hyperlinks
- in format body: allow naming of cue points / sections
Caption & Subtitle Formats
Icon for closed captions: 
Icon for subtitles (3-letter language): 
This is a (incomplete) list of existing caption and subtitle formats:
- W3C TimedText
- 3GPP Timed Text
- DVB Code-based subtitles
- DTV closed captioning
- QuickTime text tracks
- RealText markup
- MS SAMI .smi
- EBU subtitles
- DVD subtitles
- .sub MicroDVD subtitles
- .srt subrip subtitles
- SubStation Alpha .ssa, .ass
- .usf Universal Subtitle Format - mostly with Matroska
Previous comparative analysis:
- caption format comparison wikipedia
- Subtitle comparison
- Style comparison between different formats
- DOOM has examples of the different formats listed
- Timed Text analysis
Summary:
Many subtitle / caption formats come as just a sequence of triples: start-time, end-time, text (e.g. MicroDVD, SubRip). This is the rawest way of providing subtitles and it lacks further important information such as styling, title and language.
Some are more informative, e.g. Substation Alpha, USF, and SAMI, which introduce styling, metadata, and events with dynamic effects. SAMI and USF are in XML, which has been rejected as too talkative a langauge for creating subtitles.
TimedText has the most complex model, in particular for styling and layout.
Karaoke Formats
Icon for karaoke: http://www.istockphoto.com/file_closeup/object/5034281-karaoke-icon.php?id=5034281
- Kate
- Karaoke midi .KAR files
- CD+G Karaoke CD format (graphics)
- MP3+G .CDG karaoke files (ripped graphics)
Textual Audio Description Formats
Icon for audio descriptions (sound): 
Metadata / Semantic Annotations Formats
Icon for metadata / annotations: 
Transcript / Script / Lyrics Formats
Icon for transcript: 