Media Requirements--Sec. 3.4 Production practice and resulting requirements.

Production Practice and Resulting Requirements (8 comments)
http://www.w3.org/WAI/PF/HTML/wiki/Media_Accessibility_Requirements#Produc
tion_practice_and_resulting_requirements

http://www.w3.org/2002/09/wbs/44061/20080526_media-requirements/results#xq
14

 

Requirements 

Systems supporting accessibility needs for media must: 

(PP-1) Support existing production practice for alternative content
resources, in particular allow for the association of separate alternative
content resources to media resources. 

(PP-2) Support the association of authoring and rights metadata with
alternative content resources. 

(PP-3) Support the simple replacement of alternative content resources
even after publishing.

 

Note: The majority of comments concur that this is an authoring
requirement. It is a understood that a common time-stamp format must be
declared in HTML5, so that authoring tools can conform to a required
output.

 

Re (PP-1):  "Support existing production practice for alternative content
resources" - browsers cannot support all forms of time-stamp formats out
there, just as they cannot support all forms of image formats (etc.). This
necessitates a clear and unambiguous declared format, so that existing
authoring tools can be configured to export finished files in the required
format.

 

Re (PP-2): The appropriate choice of time-stamp format should meet this
requirement

 

Re: (PP-3): this is again dependant on authoring practice - if the content
creator delivers a final media file that contains related accessibility
content inside the media wrapper (for example an MP4 file), then it will
require an appropriate 3rd part authoring tool to make changes to that
file - it cannot be demanded of the browser to do so, as it is technically
impossible to do so.

 

John Foliot / Eric Carlson