W3C home > Mailing lists > Public > public-html@w3.org > March 2010

Re: [Bug 5758] insufficient accessibility fallback for <audio> or <video>

From: Simon Pieters <simonp@opera.com>
Date: Mon, 15 Mar 2010 13:46:47 +0100
To: public-html@w3.org, "Joe D Williams" <joedwil@earthlink.net>
Message-ID: <op.u9l0f9qfidj3kv@zcorpandell.linkoping.osa>
On Mon, 15 Mar 2010 13:37:19 +0100, Joe D Williams <joedwil@earthlink.net>  
wrote:

> Joe >> This follows the model set by <object> and could result in use of  
> the following construction:
>
> .<video autoplay controls>
>  <source src="tgif.vid">
>  <source src="lgif.zvid">
>   <p><a href="tgif.vid">Download the video file.from this
> link.</a></p>
> </video>
>
>>> In this example if the UA recognizes <video ...> but does not  
>>> recognize  vid content then the the potential fallback video content  
>>> .zvid will be  tried. If still no go, then the html "fallback" content  
>>> enclosed in <p>  element would be shown according to the <video>, <p>,  
>>> and <<a> styles.
>
> Simon > No, it wouldn't.
>
> OK, I must be really off in my thinking of how it could work. SInce I  
> haven't found an example in the spec that is giving me understanding (or  
> changing my preconceptions), please tell me if the above is even a  
> legitimate contruction, and how you are expecting <video> to work.


> Now, again for this case where the <video> is recognized but none of the  
> <source> resources work:
>
>>> In this example if the UA recognizes <video ...> but does not  
>>> recognize .vid content then the the potential fallback video content  
>>> .zvid will be tried. If still no go, then the html "fallback" content
> enclosed in <p> element would be shown according to the <video>, <p>,  
> and <a> styles.
>
> Please tell me what actually should happen in the case where none of the  
> listed <videdo> resources are playable.

A blank video box would be rendered. If you later insert a <source>  
element with script, the browser will try to play that one as well.


> The following description of the example did not get a comment so I am  
> supposing that thie following is a reasonable description of what should  
> happen if <video> is not recognized by the (legacy) UA at all. :
>
>>> In this example if the UA did not recognize the <video> element then  
>>> the html "fallback" content enclosed in <p> and <a> element would be  
>>> shown. This operation is more than just a specification for <video>,  
>>> <audio>, or <object> but just intrinsically how the web UA should  
>>> work: Skip elements that are not in the vocabulary. So, here, an old  
>>> UA would just naturally skip <video ... >, <source ... >, and <source  
>>> ... > and end up showing the html link according to the <p> and <a>  
>>> style, although the UA will probalbly also apply CSS specified for  
>>> <video>..
>
> This seemed reasonable to me for this example because I suppose in this  
> case the UA follows the same sort of rules as <object>.

Yes, if <video> is not supported then the contents are rendered.

-- 
Simon Pieters
Opera Software
Received on Monday, 15 March 2010 12:47:26 UTC

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