Re: [Slim] Moving forward on draft-ietf-slim-negotiating-human-language

[Bernard Aboba <[e-mail]>]

Can we include text from Brian's suggestion? For example:

"If a sign language is signaled in a video stream, it is interpreted as an
indication that sign language will appear in the video.  A sign language
can be identified by the existence in the IANA registry of language subtags
according to BCP 47 [RFC5646] of the language subtag with the Type field
"extlang" combined with the Prefix field value "sgn".  A spoken/written
language tag can be identified by not having any such "sgn" prefix. This
document does not define any other use for language tags in video media
(such as how to indicate a desire for visible captions).

This document does not define the use of sign language tags in text or
audio media.  If a spoken/written language tag is included in text media,
it indicates a desire for written language. If a spoken/written language
tag is included in audio media, it is interpreted as an indication that
spoken language is desired.  Using the "lip sync" grouping mechanism
defined in [RFC5888], it is possible to indicate the desire to synchronize
audio and video so as to support lip reading.

Use of language tags may appear in other media, such as "message" and
"application".  Such use may be supported by further work or application
specific agreement."



On Mon, Nov 20, 2017 at 1:14 PM, Gunnar Hellström <
[e-mail]> wrote:

> A new proposal for new text taking in latest discussion of Bernard, Paul
> and Brian:
>
> -----Old text----
>
> 5.4 Undefined Combinations
>
>    The behavior when specifying a non-signed language tag for a video
>    media stream, or a signed language tag for an audio or text media
>    stream, is not defined in this document.
>
>    The problem of knowing which language tags are signed and which are
>    not is out of scope of this document.
>
> -----New text------------
> 5.4 Media, Language and Modality indications
>
> The combination of Language tags and other information in the media
> descriptions shall be composed so that the intended modality can be
> concluded by the negotiating parties. The following combinations of
> language tags and media provide obvious information about the modality:
> sign language tags in video media indicate signed modality, language tags
> in audio media indicate spoken modality and language tags in text media
> indicate written modality. The examples in this specification are all from
> this set of three obvious language/media/modality combinations.
>
> A sign language can be identified by the existence in the IANA registry of
> language subtags according to BCP 47 [RFC5646] of the language subtag with
> the Type field "extlang" combined with the Prefix field value "sgn".
> A specific spoken or written language can be identified by not having any
> such "sgn" Prefix.
>
> Use of language may appear in other media, such as "message" and
> "application". Video media may be used for other modalities than signed,
> e.g. a view of a speaker or text captions. Such use may be supported by
> further work or application specific agreements for evaluation of the
> intended modality.
>
> ---------------------------End of new text---------------------------------------
>
>
>
> Den 2017-11-20 kl. 21:44, skrev Gunnar Hellström:
>
> Den 2017-11-20 kl. 19:41, skrev Bernard Aboba:
>
> Gunnar said:
>
> "5.4 Media, Language and Modality indications
>
> The combination of Language tags and other information in the media
> descriptions should be composed so that the intended modality can be
> concluded by the negotiating parties. "
>
> [BA] Is the "should" intended to be normative?
>
> <GH>You are right that SHOULD should be avoided and it would be better to
> say MUST if we can. But I can imagine limited area applications having
> application agreements e.g. saying that a non-signed language tag in video
> media means a view of a talking person.   The negotiating applications know
> about this agreement so they can make the conclusion. So, if such
> situations can be included in how the parties make their conclusions, we
> can change to MUST.
>
>
> The following combinations of language tags and media provide obvious
> information about the modality: sign language tags in video media indicate
> signed modality... A sign language can be identified by the existence in
> the IANA registry of language subtags according to BCP 47 [RFC5646] of the
> language subtag with the Type field "extlang" combined with the Prefix
> field value "sgn".  A specific spoken or written language can be
> identified by not having any such "sgn" Prefix.
>
> Use of language may appear in other media, such as "message" and
> "application". Video media may be used for other modalities than signed.
> Such use may be supported by further work or application specific
> agreements or indications for evaluation of the intended modality. "
>
> [BA] Assume we can confirm the mechanism for distinguishing
> signed/non-signed languages, this part seems relatively solid.
>
> spoken language tags for audio media indicate spoken modality and written
> language tags for text media indicate written modality. The examples in
> this specification are all from this set of three obvious
> language/media/modality combinations.
>
> [BA]  This is where the ground gets less solid - we don't really have a
> general mechanism for distinguishing spoken and written modality among
> non-signed languages. Perhaps we should just say "language tags in audio
> media indicate spoken modality and language tags in text media indicate
> written modality".
>
> Yes, right, that is better wording.
>
> Gunnar
>
>
>
>
>
>
> On Mon, Nov 20, 2017 at 9:25 AM, Gunnar Hellström <
> [e-mail]> wrote:
>
>> It is not the signed languages that are causing the problem. It is the
>> spoken and written, when used in other media than the obvious audio and
>> text media.
>>
>> And we should specify what is obvious and well defined and not, so here
>> is a new shorter proposal for section 5.4.
>>
>> -----Old text----
>>
>> 5.4 Undefined Combinations
>>
>>    The behavior when specifying a non-signed language tag for a video
>>    media stream, or a signed language tag for an audio or text media
>>    stream, is not defined in this document.
>>
>>    The problem of knowing which language tags are signed and which are
>>    not is out of scope of this document.
>>
>> -----New text------------
>> 5.4 Media, Language and Modality indications
>>
>> The combination of Language tags and other information in the media
>> descriptions should be composed so that the intended modality can be
>> concluded by the negotiating parties. The following combinations of
>> language tags and media provide obvious information about the modality:
>> sign language tags in video media indicate signed modality, spoken language
>> tags for audio media indicate spoken modality and written language tags for
>> text media indicate written modality. The examples in this specification
>> are all from this set of three obvious language/media/modality combinations.
>>
>> A sign language can be identified by the existence in the IANA registry
>> of language subtags according to BCP 47 [RFC5646] of the language subtag
>> with the Type field "extlang" combined with the Prefix field value "sgn".
>> A specific spoken or written language can be identified by not having any
>> such "sgn" Prefix.
>>
>> Use of language may appear in other media, such as "message" and
>> "application". Video media may be used for other modalities than signed.
>> Such use may be supported by further work or application specific
>> agreements or indications for evaluation of the intended modality.
>>
>> -------------------------------------------------------------------End
>> of new text---------------------------------------
>>
>> Den 2017-11-20 kl. 15:55, skrev Randall Gellens:
>>
>> At 7:47 PM -0800 11/19/17, Bernard Aboba wrote:
>>
>>  "So let's delete Section 5.4 and be done with it.  Neither of the
>> statements is necessary."
>>
>>  [BA]  I agree that Section 5.4 does not add much value as it stands.
>>
>>  "Non-signed" is not used outside of Section 5.4, so there would not
>> appear to be a need to define it if Section 5.4 were to be deleted.
>>
>>  However, the term "signed" is used in 7 other places in the document
>> other than in Section 5.4.
>>
>>
>> But none of those instances are normative.
>>
>>  So we may need to find a reference to define that term.
>>
>>
>> Because the uses of the term are descriptive and mostly background, I do
>> not think we need to add a definition or even a reference to a definition
>> of the term.
>>
>> --Randall
>>
>>
>>  If Gunnar's suggested definition can be confirmed,  this might be as
>> simple as adding a reference to the IANA language tag repository.
>>
>>  On Sun, Nov 19, 2017 at 3:52 PM, Randall Gellens <
>> <mailto:[e-mail]> <[e-mail]>
>> [e-mail]> wrote:
>>
>>  My view of issue #43 remains that we do not need to specify a mechanism
>> for determining which tags are signed.  In the email discussion of the past
>> month or so, I fear we are drifting into adding complexity rather than
>> removing it.  I think the way forward is to keep this document as simple as
>> possible.  As Bernard notes in his email of 10/23, there is no benefit in
>> this case of explicitly saying that certain things are not defined.  Since
>> the document does not define them, they are undefined in the document.
>>
>>  At 6:51 PM -0700 10/23/17, Bernard Aboba wrote:
>>
>>   In other words,it is not clear to me how Section 5.4's discussion of
>> scope improves or clarifies the situation in any way - and there is some
>> possibility that it could cause problems.
>>
>>
>>
>>  I believe comment #43 should be closed as no longer applicable, since
>> the text against which it was generated has been deleted. (I've said this
>> before, and I believe it remains the case.)
>>
>>  The comment from which #43 derives was made against a version of the
>> document that had text explicitly discussing signed versus unsigned tags.
>> That text was subsequently deleted.
>>
>>  Here is the comment from which #43 derived:
>>
>>      5.2.  New 'humintlang-send' and 'humintlang-recv' attributes
>>
>>      Note that while signed language tags are used with a video stream
>>   to
>>      indicate sign language, a spoken language tag for a video stream
>>   in
>>      parallel with an audio stream with the same spoken language tag
>>      indicates a request for a supplemental video stream to see the
>>      speaker.
>>
>>   And there's a similar paragraph in 5.4:
>>
>>      A spoken language tag for a video stream in conjunction with an
>>
>>   audio
>>
>>      stream with the same language might indicate a request for
>>      supplemental video to see the speaker.
>>
>>
>>   I think this mechanism needs to be described more exactly, and in
>>   particular, it should not depend on the UA understanding which
>>   language tags are spoken language tags.  It seems to me that a
>>   workable rule is that there is an audio stream and a video stream and
>>   they specify exactly the same language tag in their respective
>>   humintlang attributes.  In that case, it is a request for a spoken
>>   language with simultaneous video of the speaker, and those requests
>>   should be considered satisfied only if both streams can be
>>   established.
>>
>>
>>  The offending text that was in 5.2 and 5.4 was deleted.
>>
>>  The only remaining text that even mentions the issue is Section 5.4:
>>
>>     The behavior when specifying a non-signed language tag for a video
>>     media stream, or a signed language tag for an audio or text media
>>     stream, is not defined in this document.
>>
>>     The problem of knowing which language tags are signed and which are
>>     not is out of scope of this document.
>>
>>  So, let's delete Section 5.4 and be done with it.  Neither of the
>> statements is necessary.
>>
>>  --
>>  Randall Gellens
>>  Opinions are personal;    facts are suspect;    I speak for myself only
>>  -------------- Randomly selected tag: ---------------
>>  Make it right before you make it faster.
>>
>>
>>
>>
>> --
>> -----------------------------------------
>> Gunnar Hellström
>> [e-mail]
>> [phone]
>>
>>
>
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> Gunnar Hellström
> [e-mail]
> [phone]
>
>
>
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>
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