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Community & Business Groups

Audio Description Community Group

Mission: To create an open standard file format to support audio description all the way from scripting to mixing. Scope: To agree requirements and propose a workable open standard file format for audio description, probably a profile of TTML2, with the intention of moving to the Rec track within a Working Group. Deliverables:
  • Requirements document
  • Draft specification document
  • Explainer


Group's public email, repo and wiki activity over time

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DAPT First Public Working Draft published today

W3C Blog post:

Latest published version of DAPT on /TR:

Plus, you may find it helpful to have a reminder of the requirements document:

This specification is now suitable for “wide review” so do take a look and feed back any issues or questions, or indeed answers – there are some open issues labelled as “question” embedded in the document.

Audio Description work moved to DAPT

Our previous work on “ADPT” has now been absorbed into a new Recommendation Track specification called DAPT, being worked on by the Timed Text Working Group (TTWG). The latest Editor’s Draft is at and the TTWG recently approved its publication as a First Public Working Draft. When the URL for that is available I’ll post it, but TTWG has also agreed to a working mode where any changes made to the Editor’s Draft will be published as a new Working Draft, at least until the specification moves to Candidate Recommendation, so the two should stay closely in synchronisation.

DAPT stands for “Dubbing and Audio description Profiles of TTML2” and incorporates most of what was in ADPT before. The Requirements part was published as a separate document at and, observing that there is a large overlap between the requirements for creating audio description scripts and dubbing scripts, it seemed to make sense to combine them into a single specification. Having worked on it as Editor for a while now, alongside my co-Editor, Cyril Concolato of Netflix, I think it still does!

Next steps

During the Working Draft stage, we can make substantive changes in response to wide review feedback, which can come from anyone, especially you! This stage also provides a patent exclusion opportunity, in case anyone has IPR in this specification that they want to flag.

Our goal in producing this specification is to make it easier for everyone to write, exchange, archive and play back visual media either dubbed or described. That’s across the whole chain including scripting, recording and mixing.

So please think about whether the specification meets your needs, and if it does not, let us know. That can be by email or even better, by raising an issue on the GitHub repository. The ways to provide feedback are listed in the “More details about this document” section right at the top of the document.

After that…

After the Working Draft stage the next step is Candidate Recommendation, in which we will invite people to implement the specification and let us know. We will be producing a test suite against which we can verify that those implementations meet the specification, and logging implementations so that we can demonstrate that we have reached the bar to move to a W3C Recommendation.

Who is supporting this?

The Editors work for BBC and Netflix, and we have been talking with many others in the industry too. Nobody has yet told me they think this is a bad idea! If you would like to participate and support this, or even if you can see the benefit of the work but can’t commit a lot of time right now, why not tell the group?

What are the big questions now?

There are several issues marked as “question” open at the moment, covering aspects such as referenced and embedded audio, audio encodings, and what extended support for SSML might be useful.

One of the questions that I have is how much support might be needed to support the editing process. Creating a script can take a while: do people need to be able to add markup showing the work in progress, or what they need to come back to? Does that markup need to be standardised?

Another is if we need to define different classes of implementation for support of audio features and support of the script (text) transcription, translation and adaptation. Does it make sense to introduce a stronger distinction between audio description features and dubbing features, or do some people want to use the audio recording and mixing capabilities that we need for audio description within their dubbing workflows?

I really want to take part!

Great, if you can, please join the newly chartered Timed Text Working Group, but if not, your contributions are still welcome. I’m happy to talk this through as Chair of TTWG and of this Community Group – you can email me to start a conversation in private, or email this community group, or reply to this post to do so more publicly.

Press clipping: [Broadcast] “Where is TV audio description heading in 2019?”

On 31 January 2019, Claudia Cahalane, blogs editor and accessibility advocate of AbilityNet, wrote in Broadcast, in article “Where is TV audio description heading in 2019?”:

[…]It seems that on top of tech and financial challenges around growing AD across more platforms and services, broadcasters are grappling with how to create appealing, fitting and engaging AD scripts that slot between dialogue and sound within programmes.

We heard that the formation of the W3C (World Wide Web Consortium) Community Group on audio description last year is looking to address this. The group aims to release an open standard file format for AD by the end of this year, according to Nigel Megitt, executive product manager at the BBC and chair of the W3C group.

The impetus, he said, is that “Audio description is fantastic, but all the tools you use to make it are proprietary – there’s no way to exchange information about the production of audio description.”

Having some ‘standard tooling’ to do this would make it cheaper and easier for more people to create AD, Meggitt told delegates at the Google-sponsored event.[…]

Face to face meeting at TPAC2018

Our first face to face meeting is planned for W3C’s TPAC in Lyon.

The schedule shows this meeting will be held on Thursday 25th October 10:30-12:30 in Saint Clair 3B, Level 2 – Saint Clair. I hope you can make it. Some people have registered already and some people have asked to observe as well.

We should have a draft agenda for the meeting.

Suggestions for topics are welcome of course. Here is a starter:

  • Requirements for Audio Description: have we got them right?
  • Progress in TTML2: what features are available for use?
  • Run-through of proposed outline specification (no actual document exists yet!)
  • Implementation progress: demonstration of BBC prototype “adhere”
  • Next steps: making a specification for a profile of TTML2; roles, tools, timelines etc.

W3C won’t provide a conference phone but I’m hoping to arrange for a dial-up to be available – please let me know if you’d like to use one.

Call for Participation in Audio Description Community Group

The Audio Description Community Group has been launched:

Mission: To create an open standard file format to support audio description all the way from scripting to mixing.

Scope: To agree requirements and propose a workable open standard file format for audio description, probably a profile of TTML2, with the intention of moving to the Rec track within a Working Group.


  • Requirements document
  • Draft specification document
  • Explainer

In order to join the group, you will need a W3C account. Please note, however, that W3C Membership is not required to join a Community Group.

This is a community initiative. This group was originally proposed on 2018-04-05 by Nigel Megitt. The following people supported its creation: Nigel Megitt, Mike Dolan, Chris O'Brien, Gradimir Kragić, Gandharv Bhagat, Gian Wild, Marisa DeMeglio, Sally Cain, John Paton, John Birch, Matthew Paradis, Owen Edwards, Jonathan Penny. W3C’s hosting of this group does not imply endorsement of the activities.

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