Re: Captioning verbiage for the Text Spacing Understanding doc

Looks good to me.

JF

On Fri, Jan 5, 2018 at 12:26 PM, Laura Carlson <laura.lee.carlson@gmail.com>
wrote:

> Hi John,
>
> Added the captioning verbiage per your info. I tweaked it a bit
> (adding a list) to simply and promote scanability.
>
> If you see anything that should be changed please let me know:
> https://rawgit.com/w3c/wcag21/text-spacing/understanding/21/
> text-spacing.html
>
> Thanks again. Much appreciated.
>
> Kindest Regards,
> Laura
>
> On 1/4/18, Laura Carlson <laura.lee.carlson@gmail.com> wrote:
> > Hi John,
> >
> > Thank you very much for the detailed explanation and excellent text for
> > the  understanding document. I'll incorporate it soon as I get a chance.
> >
> > Kindest Regards,
> > Laura
> >
> > On Jan 4, 2018 10:58 AM, "John Foliot" <john.foliot@deque.com> wrote:
> >
> >> Hi Laura,
> >>
> >> I had to go back and figure out what this was about, but after reading
> >> [2]
> >> http://rawgit.com/w3c/wcag21/master/understanding/21/text-spacing.html,
> >> it comes back to me now. Note that my concern/issue is similar to
> >> @steverep's issue (canvas = images of text).
> >>
> >> At issue is that not all captions are provided as stand-alone text
> files,
> >> and as such, not all captions will have the technical ability to be
> >> 'reformatted' because they are, for all intents and purposes, "images of
> >> text" burned into the "moving pictures" video file (in a similar way
> that
> >> text may be part of a JPEG or PNG file).
> >>
> >> In effect, there are multiple ways of providing captions. The most
> common
> >> are:
> >>
> >>    1. The caption file is and remains a stand-alone text file (using a
> >>    timed-text markup language, either TTML or WebVTT), and the caption
> >> file is
> >>    supplied via the @track element, like this:
> >>          <video poster="myvideo.png" controls>
> >>              <source src="myvideo.mp4" srclang="en" type="video/mp4">
> >>              <track src="myvideo_en.vtt" kind="captions" srclang="en"
> >>    label="English">
> >>          </video>
> >>    (This is often referred to as out-of-band captions)
> >>
> >>    2. The caption file (again, similar to above, a time-stamped text
> >>    file) is "bundled" inside of the video wrapper (i.e. .mp4 or .mkv) -
> >> these
> >>    are file formats that are wrappers or containers that traditionally
> >> include
> >>    the H.264 encoded video stream, the AAC encoded audio stream, and the
> >>    wrapper formats can also include other associated data files such as
> >> the
> >>    WebVTT file. Here, the user-agent "looks inside" the video wrapper
> for
> >> text
> >>    files that correspond to caption files, and when present exposes them
> >> to
> >>    the end user. See https://www.w3.org/TR/2011/WD-html5-20110113/video
> .
> >>    html#sourcing-in-band-text-tracks
> >>
> >> <https://www.w3.org/TR/2011/WD-html5-20110113/video.html#
> sourcing-in-band-text-tracks>
> >>    for more specifics, but the key thing to remember is that the
> captions
> >> are
> >>    still being supplied via a seperate time-stamped text file, it's just
> >> that
> >>    the delivery method (in-band) is different: the caption file is
> >> 'embedded'
> >>    into the video wrapper, and not referenced via the stand-along @track
> >>    attrribute.
> >>
> >>    3. A third method of providing captions is done at the
> post-production
> >>    level, where text is 'burned' directly into the moving image files.
> >> While
> >>    less common today than in the past, for certain languages and under
> >> certain
> >>    conditions this remains a valid and viable option (as it meets the
> >>    functional need of providing captions). These types of captions are
> >> also
> >>    traditionally known as "Open Captions" as they are present and
> >>    persistent to all users, and cannot be disabled or hidden, as the
> text
> >>    rendered on screen is actually part of each individual frame of the
> >> video
> >>    asset itself.
> >>
> >> It is this third condition that, due to technical limitations, needs to
> >> be
> >> exempted from the SC - there is no way for the end user to manipulate
> the
> >> on-screen 'text', because it isn't text, it's a special type of image.
> >> The
> >> core difference is that there is no "text file" being used to provide
> the
> >> captions, so there is nothing that can be further modified by the
> >> user-agent(s).
> >> (The following video may help better explain the production process:
> >> https://www.youtube.com/watch?v=WzADacd7NMo)
> >>
> >> To wrap things up, perhaps the following may meet your need?
> >>
> >> Examples of text that are typically not affected by style properties
> >> <https://www.w3.org/TR/WCAG21/#dfn-style-properties> are images of text
> >> <http://rawgit.com/w3c/wcag21/master/guidelines/index.html#
> dfn-images-of-text>
> >> and
> >> video captions embedded directly into the video frames, and not provided
> >> as an associated caption file, which are not expected to adapt.
> >>
> >> ​HTH.
> >>
> >> JF​
> >>
> >>
> >>
> >>
> >>
> >>
> >> On Thu, Jan 4, 2018 at 6:32 AM, Laura Carlson
> >> <laura.lee.carlson@gmail.com
> >> > wrote:
> >>
> >>> Hi John,
> >>>
> >>> At the November 13, 2017 AGWG teleconference, you mentioned that the
> >>> Text
> >>> Spacing Understanding doc should have verbiage to explain what types of
> >>> captions are not expected to adapt to the SC's metrics [1].
> >>>
> >>> I put a place holder in the document [2] so it wouldn't fall through
> the
> >>> cracks. Would it be possible for you please suggest appropriate
> verbiage
> >>> to
> >>> use?
> >>>
> >>> We are very fortunate that you have deep expertise in captioning. Thank
> >>> you very much for your consideration.
> >>>
> >>> Kindest Regards,
> >>>
> >>> Laura
> >>>
> >>> [1] http://rawgit.com/w3c/wcag21/master/guidelines/index.htm
> >>> l#text-spacing
> >>> [2] http://rawgit.com/w3c/wcag21/master/understanding/21/tex
> >>> t-spacing.html
> >>>
> >>
> >>
> >>
> >> --
> >> John Foliot
> >> Principal Accessibility Strategist
> >> Deque Systems Inc.
> >> john.foliot@deque.com
> >>
> >> Advancing the mission of digital accessibility and inclusion
> >>
> >
>
>
> --
> Laura L. Carlson
>



-- 
John Foliot
Principal Accessibility Strategist
Deque Systems Inc.
john.foliot@deque.com

Advancing the mission of digital accessibility and inclusion