W3C home > Mailing lists > Public > w3c-wai-ua@w3.org > April to June 1999

Re: sect 5.2 review

From: Madeleine Rothberg <Madeleine_Rothberg@wgbh.org>
Date: 15 Apr 1999 14:36:33 -0400
Message-ID: <n1287934980.10383@wgbh.org>
To: "w3c-wai-ua" <w3c-wai-ua@w3.org>
Cc: "Geoff Freed" <Geoff_Freed@wgbh.org>
        Reply to:   RE>>sect 5.2 review

Some comments on the revised section 5.2 from me and Geoff. 
Comments follow relevant snippets from Harvey's response and
are marked MR:


>5.2.6 [Priority 1]
>If a technology allows for more than one caption track (e.g., text,
>alternative language (subtitle), etc.), allow the user to choose from among

HB: Choose one among, or mix from more than one? In that mixing case, 
hard to avoid sound classes.

MR: These are text tracks, so there shouldn't be any sound issues. 
We suggest that allowing choice of one track be priority 1 and that allowing
more than one track be priority 3, since it has educational uses but
isn't vital to access.

>5.2.7 [Priority 1]
>If a technology allows for more than one audio track (alternative language
>or overdub) for video, allow the user to choose from among tracks.
HB: ... choose one among tracks.

MR: Suggest changing the parenthesis to "(i.e. alternative languages 
created as overdubs)". Rationale: Geoff tells me this was the intent when
he worked on this checkpoint. Overdub is the term in current use in the
SMIL spec, so we want to use it. But we need to clarify that the goal of
this checkpoint is to support alternative languages as distinct from audio
description (separate checkpoint) or other kinds of audio that are less
crucial to access needs (i.e. director's comments) and whose choice is
covered by the checkpoints requiring that all controls be accessible.
Note to the editors: you may want to edit or choose priority to match other 
references to internationalization as an aspect of accessibility in the

>Checkpoints for video:
>5.2.9 [Priority 1]
>Allow the user to specify that audio descriptions for video be rendered at
>the same time as the video.
><note>separated the captions, see 5.2.5</note>

HB: does the audio description get synchronized frame-by-frame?

MR: Currently we have two ideas of how to implement description in digital
One is to create a single long description track that has silence between
the description phrases. It is timed to start at the first description
time (or the beginning of the clip) and it runs all the way through.

The other is to create a series of shorter audio clips, for each description,
and time each one to start at the correct timecode, which is essentially the
same as a frame. Does this answer your question?

>5.2.9a [Priority 1]
>If a technology allows for more than one audio description track for video,
>allow the user to choose from among tracks.</new>
><note>mirroring caption checkpoints</note>

HB: Choose [one or more] among ...

MR: "Choose one among" should work. I don't think users will need to listen
to more than one description track at once.

><new>5.2.x [Priority 2]
>Allow the user to specify that sign language video track (if available) be
>rendered at the same time as the video. </new>
><note>this was not specified before. it is possible with in the SMIL spec to
>provide this capability</note>
HB: Would a user ever want both the sign-language and another track?

MR: I concur with Jim's previous answer. Yes, you might want the sign
language at the same time as a variety of other tracks, including
program audio, program video, and captions.

-end of comments-
Received on Thursday, 15 April 1999 14:35:21 UTC

This archive was generated by hypermail 2.4.0 : Friday, 17 January 2020 20:38:21 UTC