Re: does anyone currently fail colour contrast for text in timed media

TL; DR:

The WebVTT specification allows for both CSS styling and positioning of
Closed Captions and their bounding box, and can be manipulated by the
author (in theory - unsure of practice)

*****

Gregg wrote:

> But most captions are closed captions — which means that they are
generated by the player - outside of the control of the author  (e.g. the
presentation is a function of the user agent) - and users can choose to
have captions be large or small, with background or without.


Uhm... sorta.

One of the goals behind the creation of WebVTT (as opposed to TTML) was
that, because it was more HTML-syntax-like than TTML (which uses an
XML-based syntax), that it could be "styled" using CSS - at least that is
the intent. See: https://w3c.github.io/webvtt/#styling

(Note: while this is part of the current WebVTT spec, I am unaware of any
browser support, and more importantly, I've never seen an example of this,
although I've been keeping my eye open for one. If anyone has ever seen
this, can you ping me off-list please? Thanks)


When we worked on the MAUR (Media Accessibility User Requirements
<https://www.w3.org/TR/media-accessibility-reqs/>) we captured this under a
number of different requirements:


   - [CC-9] Permit a range of font faces and sizes.

   - [CC-10] Render a background in a range of colors, supporting a full
   range of opacity levels.

   - [CC-11] Render text in a range of colors. The user should have final
   control over rendering styles like color and fonts; e.g., through user
   preferences.


...so there **ARE** some author requirements there, although, again it is
early days and I've never seen an example of this.

Gregg also commented on the positioning of the captions bounding box (and
it concealing part of the scene) - again, we've articulated the NEED for
this to be adjustable even if we do not have current examples to illustrate
this, although, again, WebVTT allows for positioning (
https://w3c.github.io/webvtt/#regions).

   - [CC-5] Support positioning in all parts of the screen - either inside
   the media viewport but also possibly in a determined space next to the
   media viewport. This is particularly important when multiple captions are
   on screen at the same time and relate to different speakers, or when
   in-picture text is avoided.

   - *(Related)* [CC-14] Allow the use of mixed display styles— e.g.,
   mixing paint-on captions with pop-on captions— within a single caption cue
   or in the caption stream as a whole. Pop-on captions are usually one or two
   lines of captions that appear on screen and remain visible for one to
   several seconds before they disappear. Paint-on captions are individual
   characters that are "painted on" from left to right, not popped onto the
   screen all at once, and usually are verbatim. Another often-used caption
   style in live captioning is roll-up - here, cue text follows double
   chevrons ("greater than" symbols), and is used to identify different
   speakers. Each sentence "rolls up" to about three lines. The top line of
   the three disappears as a new bottom line is added, allowing the continuous
   rolling up of new lines of captions. When displaying captions using the
   paint-on style, it is important to ensure that the final words that are
   displayed are visible for enough time for them to be read.

   - *(Related)* [CC-15] Support positioning such that the edge of the
   captions is a sufficient distance from the nearest screen edge to permit
   readability (e.g., at least 1/12 of the total screen height above the
   bottom of the screen, when rendered as text in a right-to-left or
   left-to-right language).


​HTH

JF​


On Wed, Feb 8, 2017 at 12:11 PM, Gregg C Vanderheiden <greggvan@umd.edu>
wrote:

> Just some thoughts.
>
>
>    - if they are open captions — then mandating contrast mandates that
>    captions be of the kind that have a block of solid color behind the text,
>    hiding the scene - since there is no way to really control the background
>    otherwise.    This is not the preferred captioning for most people because
>    it blocks the scene.
>
>    - But most captions are closed captions — which means that they are
>    generated by the player - outside of the control of the author  (e.g. the
>    presentation is a function of the user agent) - and users can choose to
>    have captions be large or small, with background or without.
>
>    - What is not clear to me is what control the page author has of the
>    viewer that will be used.
>       - how much control does the author have over which viewer is used —
>       and the features of the viewer?
>          - types of caption features  (background/transparent, size,
>          color, position, etc)
>       - what about the content viewed on different platforms with
>       different viewers?
>       - how much can we require authors to use particular viewers with
>       particular capabilities
>
>
>
>
> Gregg C Vanderheiden
> greggvan@umd.edu
>
>
>
> On Feb 8, 2017, at 3:51 AM, Detlev Fischer <detlev.fischer@testkreis.de>
> wrote:
>
> I can't see why poor contrast of captions should not fail SC 1.4.3. Why
> just advisory? Captions are clearly a form of text, and screenshots can
> provide clear evidence of failure.
> In audits I frequently see white caption text on transparent grey
> background which means contrast is FAR below 4.5:1 whenever the video
> background happens to be bright.
> Detlev
>
> --
> Detlev Fischer
> testkreis c/o feld.wald.wiese
> Thedestr. 2, 22767 Hamburg
>
> Mobil +49 (0)157 57 57 57 45 <+49%201575%207575745>
> Fax +49 (0)40 439 10 68-5
>
> http://www.testkreis.de
> Beratung, Tests und Schulungen für barrierefreie Websites
>
> Jonathan Avila schrieb am 07.02.2017 18:14:
>
>
> David, I have not failed videos with insufficient contrast.  However, that
> situation and open captions with poor contrast are something I would point
> out as advisory or best practice.
>
>
>
> Jonathan
>
>
>
> From: David MacDonald [mailto:david100@sympatico.ca
> <david100@sympatico.ca>]
> Sent: Tuesday, February 07, 2017 6:50 AM
> To: Glenda Sims; Gregg C Vanderheiden; Jonathan Avila
> Cc: Aparna Pasi; WCAG
> Subject: Re: does anyone currently fail colour contrast for text in timed
> media
>
>
>
>
> Thanks Glenda
>
>
>
>
>
> Hey Gregg, I'll loop you in.
>
>
>
>
>
> Yes, I agree audio description (or transcript) should reflect important
> visual information including text, but I'm thinking about 1.4.3 Colour
> contrast of text in movies ... In this case it's yellow text on the
> whiteboard in an animated movie.
>
>
>
>
>
> Here's my take.
>
>
>
>
>
> 1.4.3 applies to "images of text" which have been "rendered in a non-text
> form *in order to achieve a particular effect* ..."
>
>
>
>
>
> So the glossary is assigning an intention to the creation of the text. The
> author put it in an image because she wanted it in a special font, or a
> special position in relation to a background which might have been hard to
> do with CSS etc... This is not the case for a movie. Authors rarely make
> movies with the intention of achieving a particular text effect.
>
>
>
>
>
> I haven't been watching movies looking for colour contrast failures of
> significant text. I was wondering if any others (Glenda, Jon, John, Gregg,
> etc.) would agree.
>
>
> Cheers,
> David MacDonald
>
>
>
> CanAdapt Solutions Inc.
>
> Tel:  613.235.4902 <(613)%20235-4902>
>
> LinkedIn  <http://www.linkedin.com/in/davidmacdonald100>
>
>
> twitter.com/davidmacd <http://twitter.com/davidmacd>
>
> GitHub <https://github.com/DavidMacDonald>
>
> www.Can-Adapt.com <http://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 11:50 PM, Glenda Sims <glenda.sims@deque.com <
> mailto:glenda.sims@deque.com <glenda.sims@deque.com>> > wrote:
>
>
> Hey David,
>
>
>
>
>
> Looking at the glossary term for "image of text" leads me to believe that
> I'd need to watch the video to know for sure.  If the text on the
> blackboard is significant and there is not audio reference to it....then, I
> think I would fail it under 1.2.5 Audio Description (Prerecorded)
>
>
> image of text
>
>
> text that has been rendered in a non-text form (e.g., an image) in order
> to achieve a particular visual effect
>
>
> Note: This does not include text <http://www.w3.org/TR/2008/
> REC-WCAG20-20081211/#textdef>  that is part of a picture that contains
> significant other visual content.
>
>
> Example: A person's name on a nametag in a photograph.
>
>
> Cheers,
>
>
> G
>
>
> glenda sims    |   team a11y lead   |    deque.com <http://deque.com>
>     |    512.963.3773 <(512)%20963-3773> <tel:(512)%20963-3773>
>
> web for everyone. web on everything. -  w3 goals
>
>
>
>
>
> On Mon, Feb 6, 2017 at 10:24 PM, Aparna Pasi <aparna.pasi@deque.com <
> mailto:aparna.pasi@deque.com <aparna.pasi@deque.com>> > wrote:
>
>
> Hey David,
>
>
> To be honest, I haven't failed video animation or captions as I haven't
> seen such a scenario.
>
>
> I believe we should fail them as they are conveying information however,
> success criteria doesn't include anything about timed media.
>
>
> Thanks,
>
>
> Aparna
>
>
>
>
>
> On Tue, Feb 7, 2017 at 4:30 AM, David MacDonald <david100@sympatico.ca <
> mailto:david100@sympatico.ca <david100@sympatico.ca>> > wrote:
>
>
> For instance a video an animation of someone in front of a blackboard with
> text on it.
>
>
>
>
>
> The definition appears to limit the SC to static images...
>
>
>
>
>
> Thoughts?
>
>
> Cheers,
> David MacDonald
>
>
>
> CanAdapt Solutions Inc.
>
> Tel:  613.235.4902 <(613)%20235-4902> <tel:(613)%20235-4902>
>
> LinkedIn  <http://www.linkedin.com/in/davidmacdonald100>
>
>
> twitter.com/davidmacd <http://twitter.com/davidmacd>
>
> GitHub <https://github.com/DavidMacDonald>
>
> www.Can-Adapt.com <http://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>
>
>
>
>
>
> --
>
>
> Satya Jaya Aparna Pasi
>
>
> CPACC Professional| Senior Accessibility Consultant
>
>
> Deque Software
>
>
> aparna.pasi@deque.com <mailto:aparna.pasi@deque.com
> <aparna.pasi@deque.com>>  | +91-7093400949 <+91%2070934%2000949> <
> tel:+91%2070934%2000949 <+91%2070934%2000949>>
>
>
>


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

Advancing the mission of digital accessibility and inclusion