Re: Why is there no alt attribute associated with the poster attribute on a video element (or, what's the accessible name calculation on a video element

> You'll need to talk to the current editors if the HTML5 specification.

> Who is ''THE PERSON'' that we need to discuss this with? Do you have any idea?

Actually, at this point HTML is maintained and advanced by our friends at the WHATWG, who have been very receptive and responsive to making improvements to the spec's accessibility.

The place to file the issue is: https://github.com/whatwg/html/issues/new and the person to discuss this with is the editor, @Domenic Denicola<mailto:domenic@google.com>.
________________________________
From: thrishma reddy <thrishmareddy@gmail.com>
Sent: Tuesday, May 19, 2020 4:39 PM
To: John Foliot <john.foliot@deque.com>
Cc: Silvia Pfeiffer <silviapfeiffer1@gmail.com>; public-html <public-html@w3.org>
Subject: Re: Why is there no alt attribute associated with the poster attribute on a video element (or, what's the accessible name calculation on a video element

Hi Silvia,

Depreciating the @poster attribute and creating the <poster> element with alt attribute also makes sense.

Who is ''THE PERSON'' that we need to discuss this with? Do you have any idea?



On Tue, May 19, 2020 at 3:02 PM John Foliot <john.foliot@deque.com<mailto:john.foliot@deque.com>> wrote:
Hi Thrishma,

The problem is an architectural one: you cannot attach an attribute to another attribute (and @poster is just that, an attribute).

We have two visual assets: one that moves (the mp4) and one that does not (the jpg/png/"poster') - both will potentially require text alternatives.   The video itself will also require 2 types of textual alternative: likely a summarization of the video, as well as the captions which are actually the text equivalent for the *audio* track.

The solution is to recognize that the poster is another related asset associated with the movie, but not always *part* of the movie. We already do that today with caption files and audio description files, where both are called as child elements of the parent <video> element.

So, to really fix this and address the outstanding accessibility concern, the solution would be to deprecate the @poster attribute and instead create a <poster> element, which would be a different kind of child element (in the same way that <track> is today). That way, we could then do something like this:

<video>
    <track src="" kind="captions">
    <track src="" kind="descriptions"> <!-- audio descriptions -->
    <poster src="" alt="" aria-describedby=""> (and so on)
</video>

Respectfully,

JF

On Tue, May 19, 2020 at 10:32 AM thrishma reddy <thrishmareddy@gmail.com<mailto:thrishmareddy@gmail.com>> wrote:
Hey Silvia,

So to who do we ask/raise this issue for the alt attribute to be included in the <video> tag?

This issue has been open for years and I wish there is finally someone we can reach out to who would actually solve this in 2020.

Thanks,
Thrishma


On Mon, May 18, 2020 at 2:48 AM Silvia Pfeiffer <silviapfeiffer1@gmail.com<mailto:silviapfeiffer1@gmail.com>> wrote:
Hi Thrisma,

Hmm.... you're right - it only has a "title" attribute.
FWIW, I think it should have an explicit "alt" attribute.

Just my 2c worth though.

Cheers,
Silvia.


On Mon, May 18, 2020 at 8:02 AM thrishma reddy <thrishmareddy@gmail.com<mailto:thrishmareddy@gmail.com>> wrote:
Hi Silvia,

Thanks for your reply.. So when you say alt attribute for the video do you mean it looks like the below example?

Example  -

<video width="320" height="240" poster="/images/w3schools_green.jpg" controls alt="Bear catching a fish in a river">
   <source src="moviea.mp4" type="video/mp4">
   <source src="movaie.ogg" type="video/ogg">
   Your browser does not support the video tag.
</video>

There is no example of the video's alt attribute that I could find on the internet.

I agree with you that there should be only one alternative field describing the video. The poster  image is the visual summary and the alt attribute is the textual summary of the video. There is no need to have an alt attribute for the poster image as it's only purpose is to be a visual summary of the video. This is true only when there exists an alt attribute for the <video> tag as shown in the above example. Otherwise, the poster property needs to have an alt attribute.

Another question for you- When the source of an image is broken we display the alt text of the <img> tag. Does the alt property (if present) for the <video> tag do the same?

Thanks,
Thrishma

On Sun, May 17, 2020 at 4:56 PM Silvia Pfeiffer <silviapfeiffer1@gmail.com<mailto:silviapfeiffer1@gmail.com>> wrote:
Hey John,

That's all a possibility, yes.

So if your poster has different content from the video, your alt text should include the poster description, too, because it's supported by accessibility software. Introducing another attribute would require all accessibility software to be updated with two text alternatives for one element, which becomes very confusing very fast.

Hope that helps.

Best regards,
Silvia.

On Sun, May 17, 2020, 11:17 PM John Foliot <john.foliot@deque..com<mailto:john.foliot@deque.com>> wrote:
Silvia writes:

> In essence: the poster is a visual summarisation of the video.

Actually,  the poster  is  WAS ENVISIONED TO BE a visual summarisation of the video, by the former HTML5 editor, who also demonstrated on multiple occasions that he knew nothing of the accessibility space: the needs, the users, their user experience, etc. and he frequently demonstrated his lack of empathy in that regard.

The reality is that the content author can point that @poster attribute to ANY graphic image URI, including interstitials and/or 'placeholder' slides (which may or may not contain "burned in" text intended for the end-user) a reality that some engineers simply refuse to accept as a possibility.

Breaking this down:

<video src="file.mp4"   <!-- this is a visual asset that requires a text alternative, AKA an AccessibleName. Given its complexity, it also needs an AccessibleDescription -->
           poster="image.png">    <!-- this is a DIFFERENT visual asset that also potentially requires a text alternative, AKA an AccessibleName -->




> You only need one summary in text.

Respectfully, you are wrong. I do not know where or how you arrive at this assertion, but it is simply and clearly wrong:

Success Criterion 1.1.1 Non-text Content (Level A):
All non-text content that is presented to the user has a text alternative that serves the equivalent purpose... (JF: ALL, not some)

The text alternative is not a "summary", it is an alternative to the visual representation. Any time there is an image with text burned into it the textual alternative is not a summarization of that text: it must be faithfully and accurately replicated in text that can be processed by machine (i.e. a screen reader).

Evidence for all of this was also brought forward "back in the day", along with multiple impassioned and detailed explanations about this topic by daily screen reader users. Please, listen to the end users - they know better than a sighted engineer will ever understand what they need and want.

JF

On Fri, May 15, 2020 at 5:18 PM Silvia Pfeiffer <silviapfeiffer1@gmail.com<mailto:silviapfeiffer1@gmail.com>> wrote:
There were lengthy discussions about this back in the day - you should be able to Google them.

In essence: the poster is a visual summarisation of the video. The video's alt tag is a text summarisation of the video. You only need one summary in text.

Hope this helps.

Best regards,
Silvia.


On Fri, May 15, 2020, 12:59 AM thrishma reddy <thrishmareddy@gmail.com<mailto:thrishmareddy@gmail.com>> wrote:
Hello,

I was wondering if there was ever any solution to the question asked here - https://github.com/w3c/html/issues/1431<https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fw3c%2Fhtml%2Fissues%2F1431&data=02%7C01%7CTravis.Leithead%40microsoft.com%7C144ad5e579af4b12a27b08d7ff19ac06%7C72f988bf86f141af91ab2d7cd011db47%7C0%7C0%7C637258358614089740&sdata=Qqav0cXoX2opLUAmbT03OuqHMzKFhi5WXhlTSV9FF%2BU%3D&reserved=0> (Why is there no alt attribute associated with the poster attribute on a video element (or, what's the accessible name calculation on a video element)?


Thanks,
Thrishma



--
​John Foliot | Principal Accessibility Strategist | W3C AC Representative
Deque Systems - Accessibility for Good
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"I made this so long because I did not have time to make it shorter." - Pascal





--
​John Foliot | Principal Accessibility Strategist | W3C AC Representative
Deque Systems - Accessibility for Good
deque.com<https://nam06.safelinks.protection.outlook.com/?url=http%3A%2F%2Fdeque.com%2F&data=02%7C01%7CTravis.Leithead%40microsoft.com%7C144ad5e579af4b12a27b08d7ff19ac06%7C72f988bf86f141af91ab2d7cd011db47%7C0%7C0%7C637258358614099696&sdata=HOjpGbgQmAlwAA7YecQfOUvoqr%2BdKFFyP4mh3ic6n6k%3D&reserved=0>
"I made this so long because I did not have time to make it shorter." - Pascal