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[Bug 13357] Additional AudioTrack.kind categories are needed to identify tracks where audio descriptions are premixed with main dialogue.

From: <bugzilla@jessica.w3.org>
Date: Tue, 30 Aug 2011 00:41:30 +0000
To: public-html-a11y@w3.org
Message-Id: <E1QyCOQ-0002Kq-4s@jessica.w3.org>
http://www.w3.org/Bugs/Public/show_bug.cgi?id=13357

--- Comment #6 from Silvia Pfeiffer <silviapfeiffer1@gmail.com> 2011-08-30 00:41:27 UTC ---
Bob, you are referring to the "pass-through" rule and references to the use of
secondary audio programming in the FCC ruling. What this refers to is the use
of multichannel video programming distributors (MVPDs), which provide a second
and separate audio channel to the main one in which additional audio content
can be distributed. Most of the concerns raised in the FCC document are about
the current use of the secondary channel for a second language audio track and
that a requirement to provide audio descriptions would require stopping that
service which is not acceptable for a different part of the MVPDs audience. All
of the discussion in the FCC document are about MVPDs, i.e. about distributing
audio descriptions in a secondary audio track. Nowhere do I see a discussion
about a mixed audio tracks. The only mixing that happens is in the receiving
device for display purposes.

So, I don't really follow your argument that this is a reason for introducing a
new @kind value.


In contrast, the ATSC Digital Television specification indeed allows an
associated visually impaired service to the main service to be either a single
channel (which is what is typically implemented) or a complete mix of all
program elements (i.e. main and audio description). See

http://www.atsc.org/cms/standards/a_54a_with_corr_1.pdf (6.6.2.3, 6.6.4.3)
and
http://www.atsc.org/cms/index.php/standards/document-download/doc_download/13-a52b-digital-audio-compression-standard-ac-3-e-ac-3-revision-b
(p. 117, full_svc flag)
However, it seems that most implementations only do a single channel. Do you
know if there are actual implementations out there that do such a mixed
delivery? And do they actually mix the channels or do they dedicate, for
example, the center channel to audio descriptions, thus retaining the
separation?

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Received on Tuesday, 30 August 2011 00:41:33 GMT

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