Difference between revisions of "Captions"

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* Captions Habit Bleeds From Mobile Video Into TV, Laptops: https://www.mediapost.com/publications/article/364745/captions-habit-bleeds-from-mobile-video-into-tv-l.html
 
* Captions Habit Bleeds From Mobile Video Into TV, Laptops: https://www.mediapost.com/publications/article/364745/captions-habit-bleeds-from-mobile-video-into-tv-l.html
 
* Windows 11 Is Getting "Live Captions" for All Audio Content: https://www.howtogeek.com/786919/windows-11-is-getting-live-captions-for-all-audio-content/
 
* Windows 11 Is Getting "Live Captions" for All Audio Content: https://www.howtogeek.com/786919/windows-11-is-getting-live-captions-for-all-audio-content/
 +
* Why captions are suddenly everywhere and how they got there: https://apnews.com/article/technology-health-95d57b9ad5d17246d50d84c84c3127d5
  
  

Latest revision as of 08:28, 3 August 2022

Closed Captions (CC) logo

Closed Captions (commonly abbreviated CC or just referred to as Captions for short) are visual, textual cues for the hearing impaired, or sometimes also used to supplement fuzzy/vague, visually unclear or non-standard spoken slang language. The text is usually timed to the speech, conversation, display of text on the screen, musical performance, or, other audio track.

Captions are often confused with "Subtitles" which are actually used to transcribe one language into another, rather than to share the exact words being spoken, sung, showed on-screen, etc. However, because of their similarities, the same technologies and formats are sometimes used for each. The current recommendation from W3C is to use WebVTT (or for legacy device/client support SRT) for Subtitles and TimedText's latest version (replacement for earlier TTML versions and original DFXP) for Captions. If your content is web content only, it is technically possible to use WebVTT for both, as this would avoid the need to implement a separate feature or add one of the many existing software extensions for TTML, as WebVTT is more broadly supported natively by HTML5-compliant browsers. However, TTML and variations represent the formats most widely used in Television, Theatre, Electronics and similar consumer industries. [1]


Specifications

Several formal and/or informal formats & specifications exist for Closed Captioning and are listed below. [2]

SRT

The SubRip Text format (commonly abbreviated "SRT", file-extension ".srt") is preferably used only for Subtitles, but in the early "wild west" days of online video and streaming, it was also fairly frequently used as a basic stand-in data format for "Closed Captions" due to a lack of proper specifications. Then DXFP came along and replaced it as the de facto standard, which of course eventually became the TimedText specification widely used for online multimedia streaming today. SRT is still widely used for Subtitles though.

Example:

1
00:02:17,440 --> 00:02:20,375
Senator, we're making
our final approach into Coruscant.
2
00:02:20,476 --> 00:02:22,501
Very good, Lieutenant.

This format evolved out of necessity thanks to the OSS community, not really overseen by any particular standards or accreditation body.

W3C

DFXP

Distribution Format Exchange Profile (DFXP), an adopted standard which was combined with Timed-Text to create a final standard TTML for Closed Captioning on the World Wide Web.

Example:

 <body region="subtitleArea">
  <div>
    <p xml:id="subtitle1" begin="0.76s" end="3.45s">
      It seems a paradox, does it not,
    </p>
    <p xml:id="subtitle2" begin="5.0s" end="10.0s">
      that the image formed on<br/>
      the Retina should be inverted?
    </p>
    <p xml:id="subtitle3" begin="10.0s" end="16.0s" style="s2">
      It is puzzling, why is it<br/>
      we do not see things upside-down?
    </p>
    <p xml:id="subtitle4" begin="17.2s" end="23.0s">
      You have never heard the Theory,<br/>
      then, that the Brain also is inverted?
    </p>
    <p xml:id="subtitle5" begin="23.0s" end="27.0s" style="s2">
      No indeed! What a beautiful fact!
    </p>
    <p xml:id="subtitle6a" begin="28.0s" end="34.6s" style="s2Left">
      But how is it proved?
    </p>
    <p xml:id="subtitle6b" begin="28.0s" end="34.6s" style="s1Right">
      Thus: what we call
    </p>
    <p xml:id="subtitle7" begin="34.6s" end="45.0s" style="s1Right">
      the vertex of the Brain<br/>
      is really its base
    </p>
    <p xml:id="subtitle8" begin="45.0s" end="52.0s" style="s1Right">
      and what we call its base<br/>
      is really its vertex,
    </p>
    <p xml:id="subtitle9a" begin="53.5s" end="58.7s">
      it is simply a question of nomenclature.
    </p>
    <p xml:id="subtitle9b" begin="53.5s" end="58.7s" style="s2">
      How truly delightful!
    </p>
  </div>    
 </body>
TTML

Timed-Text Markup Language (TTML) is the original de facto standard for queuing and synchronously displaying a piece of multimedia's accompanying text on a timeline.

Example:

 <tt xmlns="http://www.w3.org/2006/10/ttaf1">
  <body>
    <div xml:id="captions">
      <p begin="00:08" end="00:10">- Nothing is going on.</p>
      <p begin="00:10" end="00:12.5">You liar!</p>
      <p begin="00:13" end="00:15">Are you?</p>
      <p begin="00:17" end="00:20">Violet, please!<br/>- I am not your babe!</p>
      <p begin="00:24" end="00:29">You stupid cow,<br/>look what you gone and done now, ay.</p>
      <p begin="00:34" end="00:36">Vi, please.<br/>- Leave me alone!</p>
      <p begin="00:36" end="00:38.5">- We need to talk.<br/>- Jason, are you deaf?!</p>
      <p begin="00:41" end="00:43">What's going on?</p>
      <p begin="00:43" end="00:45">Get out there and try to salvage this!</p>
    </div>
  </body>
 </tt>

[3]

SMPTE-TT

[4]

WebVTT

The main use of Web Video Text Tracks (WebVTT) format is for marking up external text track resources in connection with the HTML5 <track> element. WebVTT files provide captions or subtitles for video content, and also text video descriptions as specified in Media Accessibility User Requirements (MAUR)[5], chapters for content navigation, and more generally any form of metadata that is time-aligned with audio or video content.

Example:

 
WEBVTT
Region: id=fred width=40% lines=3 regionanchor=0%,100% viewportanchor=10%,90% scroll=up
Region: id=bill width=40% lines=3 regionanchor=100%,100% viewportanchor=90%,90% scroll=up

00:00:00.000 --> 00:00:20.000 region:fred align:left
<v Fred>Hi, my name is Fred

00:00:02.500 --> 00:00:22.500 region:bill align:right
<v Bill>Hi, I'm Bill

00:00:05.000 --> 00:00:25.000 region:fred align:left
<v Fred>Would you like to get a coffee?

00:00:07.500 --> 00:00:27.500 region:bill align:right
<v Bill>Sure! I've only had one today.

00:00:10.000 --> 00:00:30.000 region:fred align:left
<v Fred>This is my fourth!

00:00:12.500 --> 00:00:32.500 region:fred align:left
<v Fred>OK, let's go.

The above example shows two regions containing rollup captions for two different speakers. Fred's cues scroll up in a region in the left half of the video, Bill's cues scroll up in a region on the right half of the video. Fred's first cue disappears at 12.5sec even though it is defined until 20sec because its region is limited to 3 lines and at 12.5sec a fourth cue appears.

[6]



Discussion



EXAMPLES


Tools

[8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18]


Resources


Tutorials


External Links


References

  1. wikipedia:Closed_Captioning
  2. Closed Caption Formats – Understand the Differences: https://www.capitalcaptions.com/subtitles-and-captioning/closed-caption-formats-understand-the-differences/
  3. wikipedia: Timed Text Markup Language
  4. SMPTE-TT: What Is It, and How Does It Work?: https://vitac.com/smpte-tt-what-is-it-and-how-does-it-work/
  5. Media Accessibility User Requirements (MAUR) - specification: http://www.w3.org/TR/media-accessibility-reqs/
  6. Web Video Text Tracks (WebVTT) format -- <track> embedded ClosedCaption and/or Subtitle file: https://developer.mozilla.org/en-US/docs/Web/HTML/Element/track
  7. wikipedia: SubRip
  8. Edit the transcript for your video in Microsoft Stream: https://docs.microsoft.com/en-us/stream/portal-edit-transcripts
  9. Change closed caption settings: https://support.microsoft.com/en-us/windows/change-closed-caption-settings-135c465b-8cfd-3bac-9baf-4af74bc0069a
  10. Add subtitles or captions to your Microsoft Stream video: https://docs.microsoft.com/en-us/stream/portal-add-subtitles-captions
  11. Generate automatic captions and a transcript for your Microsoft Stream videos: https://docs.microsoft.com/en-us/stream/portal-autogenerate-captions
  12. Find a spoken word or phrase in Microsoft Stream videos: https://docs.microsoft.com/en-us/stream/portal-use-deep-search
  13. Adding Closed Captions to Microsoft Stream Videos (via CaptionSync tool): https://support.automaticsync.com/hc/en-us/articles/115005422806-Adding-Closed-Captions-to-Microsoft-Stream-Videos
  14. How to Add Closed Captions to MS Stream Videos (via "3-play media" tool): https://www.3playmedia.com/learn/how-to-guides/how-to-add-captions-subtitles-in-ms-stream/
  15. Microsoft Stream – An Easy Way to Make Accurate Video Captions: https://blogs.perficient.com/2017/07/03/microsoft-stream-easy-way-to-make-accurate-video-captions/
  16. Microsoft Community support -- Updated help article - Turning on Autogenerate a caption file and exporting from Microsoft Stream – HLS Show Me How: https://techcommunity.microsoft.com/t5/healthcare-and-life-sciences/updated-turning-on-autogenerate-a-caption-file-and-exporting/ba-p/1434202
  17. Problems with Autogenerating Captions: https://techcommunity.microsoft.com/t5/microsoft-stream-forum/problems-with-autogenerating-captions/m-p/328815
  18. Closed Caption is gone after i download the video: https://techcommunity.microsoft.com/t5/microsoft-stream-forum/closed-caption-is-gone-after-i-download-the-video/m-p/1400224
  19. The History of Closed Captioning: https://closedcapserv.com/blog/the-history-of-closed-captioning/
  20. Time Magazine - Closed Captioning history: https://time.com/5797491/closed-captioning-captions-history/
  21. How Deaf Advocates Won the Battle for Closed Captioning: https://time.com/5797491/closed-captioning-captions-history/

See Also

Subtitles | Video | Audio | Text | A11Y | STT