[40] [DFN[[[WebVTT]]]] は、[[動画]]や[[音声]]に対する[[字幕]]などの[[注釈]]を記述するための形式です。
[[HTML]] と共に利用するために開発されました。

* HTML からの参照

[43] [[WebVTT]] [[文書]]は、[[HTML]] [[文書]]から [CODE(HTMLe)@en[[[track]]]]
[[要素]]により参照します。

* 歴史

** WebSRT

[41] 当初は [[SRT]] に幾分の互換性のある [DFN[[[WebSRT]]]]
として開発されました。

[1] [CITE@en[HTML5 Revision Tracker]]
([TIME[2010-05-04 11:13:56 +09:00]] 版)
<http://html5.org/tools/web-apps-tracker?from=5068&to=5069>

[2] [CITE@en[HTML5 Revision Tracker]]
([TIME[2010-05-05 19:14:57 +09:00]] 版)
<http://html5.org/tools/web-apps-tracker?from=5077&to=5078>

[3] [CITE@en[HTML5 Revision Tracker]]
([TIME[2010-05-06 06:06:01 +09:00]] 版)
<http://html5.org/tools/web-apps-tracker?from=5078&to=5079>

[4] [CITE@en[HTML5 Revision Tracker]]
([TIME[2010-05-07 08:32:25 +09:00]] 版)
<http://html5.org/tools/web-apps-tracker?from=5079&to=5080>

[5] [CITE@en[HTML5 Revision Tracker]]
([TIME[2010-05-07 08:32:38 +09:00]] 版)
<http://html5.org/tools/web-apps-tracker?from=5080&to=5081>

[6] [CITE[IRC logs: freenode / #whatwg / 20100506]]
([TIME[2010-06-03 08:41:05 +09:00]] 版)
<http://krijnhoetmer.nl/irc-logs/whatwg/20100506>

[7] [CITE@en[HTML5 Revision Tracker]]
([TIME[2010-06-26 11:33:35 +09:00]] 版)
<http://html5.org/tools/web-apps-tracker?from=5110&to=5111>

[8] [CITE@en[HTML5 Revision Tracker]]
([TIME[2010-06-26 11:35:00 +09:00]] 版)
<http://html5.org/tools/web-apps-tracker?from=5111&to=5112>

[9] [CITE@en[HTML5 Revision Tracker]]
([TIME[2010-06-26 11:35:21 +09:00]] 版)
<http://html5.org/tools/web-apps-tracker?from=5112&to=5113>

[10] [CITE@en[HTML5 Revision Tracker]]
([TIME[2010-06-29 21:32:38 +09:00]] 版)
<http://html5.org/tools/web-apps-tracker?from=5113&to=5114>

[11] [CITE@en[HTML5 Revision Tracker]]
([TIME[2010-06-29 21:32:53 +09:00]] 版)
<http://html5.org/tools/web-apps-tracker?from=5114&to=5115>

[12] [CITE@en[HTML5 Revision Tracker]]
([TIME[2010-06-30 07:13:55 +09:00]] 版)
<http://html5.org/tools/web-apps-tracker?from=5118&to=5119>

[13] [CITE@en[HTML5 Revision Tracker]]
([TIME[2010-06-30 07:14:15 +09:00]] 版)
<http://html5.org/tools/web-apps-tracker?from=5119&to=5120>

[14] [CITE@en[HTML5 Revision Tracker]]
([TIME[2010-06-30 22:34:18 +09:00]] 版)
<http://html5.org/tools/web-apps-tracker?from=5121&to=5122>

[15] [CITE@en[HTML5 Revision Tracker]]
([TIME[2010-06-30 22:34:36 +09:00]] 版)
<http://html5.org/tools/web-apps-tracker?from=5122&to=5123>

[16] [CITE@en[HTML5 Revision Tracker]]
([TIME[2010-07-01 07:48:18 +09:00]] 版)
<http://html5.org/tools/web-apps-tracker?from=5124&to=5125>

[17] [CITE@en[HTML5 Revision Tracker]]
([TIME[2010-07-02 00:58:19 +09:00]] 版)
<http://html5.org/tools/web-apps-tracker?from=5125&to=5126>

[18] [CITE@en[HTML5 Revision Tracker]]
([TIME[2010-07-02 07:52:55 +09:00]] 版)
<http://html5.org/tools/web-apps-tracker?from=5126&to=5127>

[19] [CITE@en[HTML5 Revision Tracker]]
([TIME[2010-07-02 07:53:08 +09:00]] 版)
<http://html5.org/tools/web-apps-tracker?from=5127&to=5128>

[20] [CITE@en[HTML5 Revision Tracker]]
([TIME[2010-07-02 07:53:19 +09:00]] 版)
<http://html5.org/tools/web-apps-tracker?from=5128&to=5129>

[21] [CITE@en[HTML5 Revision Tracker]]
([TIME[2010-07-02 07:54:08 +09:00]] 版)
<http://html5.org/tools/web-apps-tracker?from=5129&to=5130>

[22] [CITE@en[HTML5 Revision Tracker]]
([TIME[2010-07-02 21:12:45 +09:00]] 版)
<http://html5.org/tools/web-apps-tracker?from=5130&to=5131>

[23] [CITE[IRC logs: freenode / #whatwg / 20100630]]
([TIME[2010-07-05 08:14:40 +09:00]] 版)
<http://krijnhoetmer.nl/irc-logs/whatwg/20100630#l-1518>

[24] [CITE@en[HTML5 Revision Tracker]]
([TIME[2010-07-17 01:33:27 +09:00]] 版)
<http://html5.org/tools/web-apps-tracker?from=5167&to=5168>

[25] [CITE[IRC logs: freenode / #whatwg / 20100702]]
([TIME[2010-07-18 00:28:05 +09:00]] 版)
<http://krijnhoetmer.nl/irc-logs/whatwg/20100702>

[26] [CITE[IRC logs: freenode / #whatwg / 20100705]]
([TIME[2010-07-19 12:21:38 +09:00]] 版)
<http://krijnhoetmer.nl/irc-logs/whatwg/20100705#l-88>

[27] [CITE@en-US-x-hixie[WebSRT]]
([TIME[2010-07-23 17:03:44 +09:00]] 版)
<http://www.whatwg.org/specs/web-apps/current-work/websrt.html>

[28] [CITE@en-US-x-hixie[WebSRT]]
([TIME[2010-07-23 17:03:44 +09:00]] 版)
<http://www.whatwg.org/specs/web-apps/current-work/websrt.html>

[29] [CITE['''['''whatwg''']''' Timed tracks for <video>]]
([TIME[2010-07-24 01:39:25 +09:00]] 版)
<http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org/2010-July/027278.html>

[30] [CITE@en-US[websrtjs: Summary]]
([TIME[2010-08-10 23:54:23 +09:00]] 版)
<http://hg.hoppipolla.co.uk/hgwebdir.cgi/websrtjs/>

[31] [CITE[WebSRT: 字幕 for HTML5]]
([TIME[2010-08-17 20:09:45 +09:00]] 版)
<http://people.opera.com/danield/html5/websrt/>

[32] [CITE@en[SRT research « Philip Jägenstedt]]
([TIME[2010-08-25 16:43:19 +09:00]] 版)
<http://blog.foolip.org/2010/08/20/srt-research/>

[33] [CITE[IRC logs: freenode / #whatwg / 20100825]]
( ([TIME[2010-09-04 09:44:11 +09:00]] 版))
<http://krijnhoetmer.nl/irc-logs/whatwg/20100825>

[34] [CITE@en[Web Applications 1.0 r5688 Remove some text from W3C version as requested by a11y task force.]]
( ([TIME[2010-12-01 05:51:00 +09:00]] 版))
<http://html5.org/tools/web-apps-tracker?from=5687&to=5688>

[35] [CITE@en[Web Applications 1.0 r5721        WebSRT fixes: added <track default> to make it possible to enable a text track by default; dropped <track charset>; dropped the voice identifier in favour of inline <v> annotations in WebSRT; dropped compatibility with legacy SRT; added a magic signature to WebSRT; added some forward-compatibility features to WebSRT for future expansion; simplified WebSRT timestamp syntax; added WebSRT <c.foo.bar> syntax and support for classes in WebSRT; added '&gt;' escape support; tightened up WebSRT timestamp parsing; added ::cue() which takes a selector; dropped ::cue-part; added :past/:future; added some explanatory material and fixed some typos.]]
( ([TIME[2010-12-25 15:28:00 +09:00]] 版))
<http://html5.org/tools/web-apps-tracker?from=5720&to=5721>

** WebVTT

[42] 既存の ([[Web]] 以外で使われている) [[SRT]] との互換性が十分ではないため、
[[SRT]] を名乗ることによる混乱を招かぬよう、 [[WebVTT]] に改称されました。

[36] [CITE@en[Web Applications 1.0 r5722        Rename SRT to VTT.]]
( ([TIME[2010-12-25 15:42:00 +09:00]] 版))
<http://html5.org/tools/web-apps-tracker?from=5721&to=5722>

[37] [CITE@en[Web Applications 1.0 r5723        Change 'timed track' to 'text track' since 'track' rather implies the 'timed' component already and 'text' is the important part of the concept. Also, this fits in better with the WebVTT name. WARNING: This is bound to have caused all kinds of mistakes; please file bugs for such editorial issues. Thanks.]]
( ([TIME[2010-12-25 15:56:00 +09:00]] 版))
<http://html5.org/tools/web-apps-tracker?from=5722&to=5723>

[38] [CITE[''''''[''''''whatwg'''''']'''''' Timed tracks: feedback compendium]]
( ([TIME[2011-01-05 08:42:33 +09:00]] 版))
<http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org/2010-December/029512.html>

[39] [CITE[''''''[''''''whatwg'''''']'''''' Google Feedback on the HTML5 media a11y specifications]]
( ([TIME[2011-01-15 01:22:26 +09:00]] 版))
<http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org/2011-January/029859.html>

[44] [CITE@en[Web Applications 1.0 r6168       Simplify the WebVTT file signature.]]
( ([TIME[2011-06-02 02:40:00 +09:00]] 版))
<http://html5.org/tools/web-apps-tracker?from=6167&to=6168>

[45] [CITE[IRC logs: freenode / #whatwg / 20110803]]
( ([TIME[2011-08-14 00:58:16 +09:00]] 版))
<http://krijnhoetmer.nl/irc-logs/whatwg/20110803>

[46] [CITE[''''''[''''''whatwg'''''']'''''' <track> / WebVTT issues]]
( ([TIME[2011-10-01 21:52:47 +09:00]] 版))
<http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org/2011-September/033259.html>

[47] [CITE[Live WebVTT Validator]]
( ([TIME[2011-10-23 20:19:04 +09:00]] 版))
<http://quuz.org/webvtt/>

[48] [CITE@en[Initial WebVTT contribution to the CG]]
( ([[Silvia Pfeiffer]] 著, [TIME[2011-11-18 11:51:33 +09:00]] 版))
<http://lists.w3.org/Archives/Public/public-texttracks/2011Nov/0017.html>

[49] [CITE@en[Web Applications 1.0 r6837 Prepare a WebVTT standard. Remove the WebVTT text from the HTML standard; refer to the WebVTT spec instead. Drop PeerConnection (moved to W3C WebRTC WG). Clean up some internal annotations (sorry, this affects a number of topics but is purely editorial). Fix some WebIDL issues flagged by recent updates to the WebIDL checker.Affected topics: Canvas, DOM APIs, HTML, HTML Syntax and Parsing, Microdata, Offline Web Applications, Rendering, Security, Server-Sent Events, Video Text Tracks, Video and Audio, Web Storage, Web Workers, WebSocket API]]
( ([TIME[2011-11-29 08:04:00 +09:00]] 版))
<http://html5.org/tools/web-apps-tracker?from=6836&to=6837>

[50] [CITE@en-US-x-hixie[WebVTT Standard]]
( ([TIME[2011-11-28 23:05:01 +09:00]] 版))
<http://dev.w3.org/html5/webvtt/>

[51] [CITE@en[WebVTT spec is now live (Was: FYI: Mercurial repo for our work)]]
( ([[Ian Hickson]] 著, [TIME[2011-11-29 08:11:51 +09:00]] 版))
<http://lists.w3.org/Archives/Public/public-texttracks/2011Nov/0027.html>

[52] [CITE@en[annevk / webvtt / overview — Bitbucket]]
( ([TIME[2011-12-06 23:16:49 +09:00]] 版))
<https://bitbucket.org/annevk/webvtt>