- From: David MacDonald <david100@sympatico.ca>
- Date: Wed, 31 May 2017 13:48:38 -0400
- To: John Foliot <john@foliot.ca>
- Cc: "Michael A. Peters" <mpeters@domblogger.net>, w3c WAI List <w3c-wai-ig@w3.org>
- Message-ID: <CAAdDpDa6JGn4o1MGnFLXE1yBZbjcTeWvF3bf4yA3a133Y2eZ0Q@mail.gmail.com>
> audio/video - alt is captioned and described video — or a SCRIPT containing all dialog and sounds and all important visual information (best for deaf blind) Just for clarity, the OR in the above statement applies to the described video OR a what Gregg refers to as a SCRIPT. The captions are always required regardless of the presence of a script. The term we used in WCAG is "An alternative for time-based media" https://www.w3.org/TR/WCAG20/#alt-time-based-mediadef I kind of wish we used SCRIPT... shorter to refer to. Cheers, David MacDonald *Can**Adapt* *Solutions Inc.* Tel: 613.235.4902 LinkedIn <http://www.linkedin.com/in/davidmacdonald100> twitter.com/davidmacd GitHub <https://github.com/DavidMacDonald> www.Can-Adapt.com <http://www.can-adapt.com/> * Adapting the web to all users* * Including those with disabilities* If you are not the intended recipient, please review our privacy policy <http://www.davidmacd.com/disclaimer.html> On Mon, Feb 6, 2017 at 12:45 PM, John Foliot <john@foliot.ca> wrote: > Michael A. Peters wrote: > > > > For html5 video it might be good to have examples for adding subtitles to > > the video itself rather than just as html5 track element because videos > are > > often saved for stand-alone play. > > > > I beliebe WebVTT subtitles can be added to mkv containers (and hence > > WebM) directly with mkvmerge, I'm not sure what has to be done to get > > WebVTT into MP4 containers, it may need to be converted to another > format. > > Hi Michael, > > Both MKV and MP4 file formats are "wrapper" formats that contain the > encoded > media (i.e. H.264 video, or AAC audio as 2 examples), and so yes, WebVTT > files > can be included in the MP4 wrapper as well. Post-production video tools > usually will allow the inclusion of other content types as part of the > export > work-flow (for example Adobe Premier Pro). Caption, sub-title, and similar > support files inside of those wrapper formats are usually referred to as > "in-band", while files referenced via the track element (child element of > Video) are referred to as "out-of-band". > > In addition to the "saving for off-line use" use-case, in-band support > materials are also pretty much the only way of ensuring that they are > delivered over lesser bandwidth conditions (i.e. Edge or 3G for mobile), > or to > many lower-power handhelds which lack the computing power to manage > multiple > discrete downloads and syncing on the client. > > JF > > > >
Received on Wednesday, 31 May 2017 17:49:13 UTC