TimedText/EffortsAndSpecifications
Efforts (Including Implementations) and Specifications, Guides, and other Documentation
WebVTT-based efforts and specifications
- Specification (http://dev.w3.org/html5/webvtt/), Latest published version; https://www.w3.org/TR/webvtt1/
- Documentation
- VTT Authoring, was on WebPlatform Docs (http://docs.webplatform.org/wiki/concepts/VTT_Captioning) and now on the Wiki
- Getting Started With the Track Element (http://www.html5rocks.com/en/tutorials/track/basics/)
- Introduction to WebVTT and <track> (http://dev.opera.com/articles/view/an-introduction-to-webvtt-and-track/)
- WebVTT and captioning on the web (http://www.accessiq.org/news/features/2013/03/webvtt-and-captioning-on-the-web)
- WebVTT in WebM (http://wiki.webmproject.org/webm-metadata/temporal-metadata/webvtt-in-webm)
- WebVTT and TTML in MP4 (ISO/IEC 14496-30). The reference software for MP4 may be requested from the MP4 Registration Authority.
- 608/708 mapping (https://dvcs.w3.org/hg/text-tracks/raw-file/669f6b95a488/608toVTT/608toVTT.html)
- WebVTT in Apple’s HTTP Live Streaming (http://tools.ietf.org/html/draft-pantos-http-live-streaming-11)
- Implementations
- Other pointers include CanIUse, Wikipedia, and the JWPlayer pages.
- IE 10: http://ie.microsoft.com/testdrive/Graphics/VideoCaptions/Default.html
- Chrome: http://www.iandevlin.com/blog/2012/06/html5/google-chrome-supports-webvtt-subtitles
- Opera: my.opera.com/desktopteam/blog/2012/08/03/summer-core-update
- Firefox: making progress https://bugzilla.mozilla.org/show_bug.cgi?id=629350
- Safari
- Other implementations include:
- Kaltura
- BabelSubs
- LeanBack Player
- GPAC media engine
- Video.js
- JWplayer
- Brightcove
- Wowza
- Zencoder
- MediaElement.js
- Able Player
- YendifPlayer
- There is support outside the browser in Apple HTTP Live Streaming (HLS).
- There is more reporting on implementation on the Community Group pages, and on WebPlatform Docs.
- Caption authoring software/services that support WebVTT
- MediaCore
- 3plymedia
- CPC
- Telestream
- MS CaptionMaker
- CaptionGenerator
- CaptionsMaker (for YouTube videos)
- JavaScript polyfills for backwards compatibility (http://www.w3.org/community/texttracks/2012/08/23/webvtt-support-in-browsers/)
- Validator (http://quuz.org/webvtt/)
- Parser/validator from Anne, for which Silvia added region support.
- Test cases (https://github.com/w3c/web-platform-tests/tree/master/webvtt and results at https://wpt.fyi/webvtt)
TTML-based efforts and specifications
Specification
- TTML1 (http://www.w3.org/TR/ttml1/)
- IMSC 1 (https://www.w3.org/TR/ttml-imsc1/)
- IMSC 1.0.1 (https://www.w3.org/TR/ttml-imsc1.0.1/)
Documentation
- Presentation on EBU-TT-D and IMSC 1 from IBC 2015 (https://tech.ebu.ch/files/live/sites/tech/files/shared/events/IBC2015/EBU-TT-D_and_IMSC.pdf)
- BBC Subtitle Guidelines describing BBC UK editorial guidelines and how they can be achieved in TTML (https://www.bbc.co.uk/accessibility/forproducts/guides/subtitles)
- Mapping TTML style attributes to CSS (CSS Requirements wiki)
Profiles and flavours
- TTML Profiles for Internet Media Subtitles and Captions 1.0.1 (IMSC1) is intended to bring together popular profiles of TTML1, including:
- TTML Profiles for Internet Media Subtitles and Captions 1.1 extends IMSC 1, adding support for HDR, improved metadata, and more global script layout requirements such as ruby and text emphasis.
- TTML Profiles for Internet Media Subtitles and Captions 1.2 extends IMSC 1.1, adding support for external font resources.
- Dubbing and Audio Description Profile of TTML2 (DAPT) is a profile of TTML2 to support the authoring, exchange, recording and playback of dubbing and audio description
- DAPT Requirements defines the requirements that the DAPT specification needs to meet
- SMPTE ST 2052-1 aka SMPTE-TT (https://www.smpte.org/sites/default/files/st2052-1-2010.pdf)
- developed by SMPTE (http://smpte.org)
- worldwide text- and image-based captions
- mapping from CEA 608 to SMPTE-TT (https://www.smpte.org/sites/default/files/rp2052-10-2012.pdf)
- mapping from CEA 708 to SMPTE-TT (upcoming)
- CFF-TT (latest published version at ttp://www.uvcentral.com/sites/default/files/files/PublicSpecs/CFFMediaFormat-2_2.pdf)
- based on SMPTE TT (ST 2052-1)
- developed by DECE (http://uvvu.com)
- worldwide text- and image-based captions and subtitles
- TTML Simple Delivery Profile for US Captions (http://www.w3.org/TR/ttml10-sdp-us/)
- developed by the W3C TTML WG
- intended to be a subset of CFF-TT
- EBU-TT (http://tech.ebu.ch/ebu-tt)
- EBU-TT Part 1 Tech 3350 (https://tech.ebu.ch/publications/tech3350)
- EBU-TT-D Tech 3380 (https://tech.ebu.ch/publications/tech3380)
- EBU-TT Part 3 Tech 3370 (https://tech.ebu.ch/publications/tech3370)
- CEA (http://www.ce.org/)
- Closed Captioning in IP-delivered Video Programming (http://www.ce.org/Standards/Standard-Listings/R4-3-Television-Data-Systems-Subcommittee/CEA-TR-3.aspx
- YouView (https://industry.youview.com/resources/YouView_Core_Technical_Specification_1.0.pdf#page=118)
Wrappers and packaging mechanisms
- Timed Text in MPEG 4 (http://mpeg.chiariglione.org/standards/mpeg-4/timed-text-and-other-visual-overlays-iso-base-media-file-format)
- TTML and WebVTT in MP4 (ISO/IEC 14496-30, to be published)
- EBU-TT-D Carriage in ISO BMFF Tech 3381 (https://tech.ebu.ch/publications/tech3381)
Implementations
- ttconv - Library for converting between subtitle and caption formats. Supports WebVTT, SRT, TTML, EBU STL, CEA 608... (https://github.com/sandflow/ttconv)
- imscHRM - implementation of the IMSC Hypothetical Render Model (HRM) to constraint IMSC document complexity (https://github.com/sandflow/imscHRM)
- imscJS - IMSC1 polyfill for HTML5 + JS (https://github.com/sandflow/imscJS)
- Samsung SUHD JS 9 Series Prototype TV supporting EBU-TT-D for live and on demand HbbTV2.0 DASH streaming services.
- dash.js (https://github.com/Dash-Industry-Forum/dash.js/wiki)
- BBC gstreamer plugin (https://github.com/bbc/gst-ttml-subtitles)
- TTML validator on line (http://www.skynav.com:8080/ttv/verify). Source available at https://github.com/skynav/ttt/. Sample web app at https://imscv.sandflow.com/.
- EBU-TT Live Interoperability Toolkit (http://ebu.github.io/ebu-tt-live-toolkit/)
- Adhere - BBC implementation of client-side audio description mixing in the browser, using an open source BBC library adhere-lib (https://bbc.github.io/Adhere/)
See the IMSC1 Implementation Page for IMSC1-specific implementation information.
Originally copied from Timed Text Efforts, and further modified