- From: <bugzilla@jessica.w3.org>
- Date: Tue, 30 Aug 2011 01:34:55 +0000
- To: public-html-a11y@w3.org
http://www.w3.org/Bugs/Public/show_bug.cgi?id=13357 --- Comment #7 from Bob Lund <b.lund@cablelabs.com> 2011-08-30 01:34:54 UTC --- (In reply to comment #6) > 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. No, this is not the case. There are only two audio channels - main and secondary. Audio descriptions are mixed with the main dialogue by the programmer and carried in the secondary audio channel. This channel is a mix of dialogue and description. Receivers only tune one of the audio channels. There is no mixing in the receiver. > > So, I don't really follow your argument that this is a reason for introducing a > new @kind value. The current @kind does not support identification of an audio channel with dialogue and descriptions. Bob > > > 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? -- Configure bugmail: http://www.w3.org/Bugs/Public/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
Received on Tuesday, 30 August 2011 01:34:57 UTC