Subject: [clue] Capture Attribute Discussion: 4.6.2. Embedded Text

From: Christian Groves <[email-masked]>
Date: Thu, 13 Dec 2012 14:37:34 +1100

Hello,

The embedded text attribute is described in draft-groves-clue-capture-attr:

"4.6.2.   Embedded Text

    In accessible conferences textual information may be added to a
    capture before it is transmitted to the remote end.  In the case
    where multiple video captures are presented the remote end may
    benefit from the ability to choose a video stream containing text
    over one that does not.

    This attribute indicates that a capture provides embedded textual
    information.  For example the video capture may contain speech to
    text information composed with the video image.  This attribute is
    only applicable to video captures and presentation streams with
    visual information."

Does any one have concerns about adding this to the framework?

Regards, Christian

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From: Gunnar Hellström <[email-masked]>
Date: Thu, 13 Dec 2012 08:13:33 +0100

This looks good, I agree.

---------------------------------------

But I also strongly suggest that you define text capture as a proper 
capture in its own right.

The method to display text embedded in video is just a historic solution 
as an afterthought, both destroying part of the video image and 
sometimes making text hard to read.

There are three natural modalities in human communication  visual, 
textual and audible.

Gunnar

___________________________________________________
Gunnar Hellström
Omnitor
[email-masked]
+46708204288

On 2012-12-13 04:37, Christian Groves wrote:
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From: "DRAGE, Keith (Keith)" <[email-masked]>
Date: Thu, 13 Dec 2012 18:09:54 +0100

What are the language and alphabet restrictions that will exist here?

Keith

> -----Original Message-----
> From: [email-masked] [mailto:[email-masked]] On Behalf Of
> Gunnar Hellström
> Sent: 13 December 2012 07:14
> To: [email-masked]
> Subject: Re: [clue] Capture Attribute Discussion: 4.6.2. Embedded Text
>

---

From: Gunnar Hellström <[email-masked]>
Date: Fri, 14 Dec 2012 00:06:06 +0100

> What are the language and alphabet restrictions that will exist here?
First a structure needs to be defined. Will the embedded text attribute 
have its own laguage attribute(s)?

Or will the video capture have both the embedded text attribute and a 
number of language attributes, some valid for the video itself and some 
valid for the embedded text?

Someone told me that spoken language tags can be different from written 
language tags. I do not remember how. If that was true, then the 
value(s) should only be language tags for written languages.

There are extra language sub-tags about what script the language is 
expressed in, but I am not sure that sub-tag exists for all languages. 
So I do not think it was the script sub-tag that was intended to be used 
for indication of written language.

/Gunnar

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From: Christian Groves <[email-masked]>
Date: Fri, 14 Dec 2012 10:55:16 +1100

Hello Gunnar and Keith,

With regards to text being its own capture type I would tend to agree.

The embedded text attribute could have the form "EmbeddedText=[Language]".

In general I hadn't thought that the language attribute would be used 
with video captures in general. However if the video contained sign 
language the language attribute could be used. Embedded text could have 
its own language.

E.g. VC1 (Language=ase,EmbeddedText=en)

This would indicate that the video contains American Sign Language and 
embedded text in English.

With respect to language and scripts it appears that RFC5646 allows the 
use of language plus script sub-tag. i.e.
zh-Hans (Chinese written using the Simplified Chinese script)

It may be that we want to use this form for the EmbeddedText tag?

With respect to the subtags not being complete I think the IANA registry 
is fairly complete. 
http://www.iana.org/assignments/language-subtag-registry . If there's 
something missing then it could be added.

Regards, Christian

On 14/12/2012 10:06 AM, Gunnar Hellström wrote:
> First a structure needs to be defined. Will the embedded text 
> attribute have its own laguage attribute(s)?
>
> number of language attributes, some valid for the video itself and 
> some valid for the embedded text?
>
> Someone told me that spoken language tags can be different from 
> written language tags. I do not remember how. If that was true, then 
> the value(s) should only be language tags for written languages.
>
> So I do not think it was the script sub-tag that was intended to be 
> used for indication of written language.
>
> /Gunnar
>> Keith
>

---

From: Gunnar Hellström <[email-masked]>
Date: Fri, 14 Dec 2012 07:17:37 +0100

Conclusion 1:  Have a language tag  or a list of language tags as 
parameter on the Embedded text attribute.

The script subtag will in most cases not be needed and not be used.
RFC 5646 says:
" The script subtag SHOULD NOT be used to form language tags unless the 
script adds some distinguishing information to the tag."
So, when used here within the embedded text attribute it is already 
implied that the contents will be written, then the script subtag shall 
only be used when a script other than the dominating for the language is 
used.

Multiple languages in the embedded text attribute may be useful if the 
embedded text follows the language of the speaker, and the speakers can 
switch in the same video capture.

How do you want to code the possibility for the user to select what 
language appears as embedded text? As is commonly done on DVDs.
Maybe that is not coded as embedded text, it could be seen as a text 
capture with the receiving user selecting presentation placement in part 
of the video display.

Conclusion 2:  Text capture should be added to Clue.

Gunnar

On 2012-12-14 00:55, Christian Groves wrote:
> language the language attribute could be used. Embedded text could 
> have its own language.
>
> With respect to language and scripts it appears that RFC5646 allows 
> the use of language plus script sub-tag. i.e.
> With respect to the subtags not being complete I think the IANA 
> registry is fairly complete. 
>> expressed in, but I am not sure that sub-tag exists for all 
>> languages. So I do not think it was the script sub-tag that was 
>> intended to be used for indication of written language.
>>
>> /Gunnar
>>> Keith
>>