Thread Subject: Re: Three Fundamental Options for caption issue.
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From: Gregg Vanderheiden
Date: Wed, Aug 29 2007 2:35 PM
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You are right. This is ongoing in two lists.
How about the following to pull it all together. I think there are
fundamentally just 3 options.
OPTION 1: - ONE "Preferred" Caption Format per media format
1) MEDIA FORMATS that support audio must specify one PREFERRED format for
captioning. (though many caption techniques may exist)
2) CONTENT must use the PREFERRED format for captioning (though it may
provide additional redundant versions of captions in other formats as well.)
3) PLAYERS must support playing of captions that are in PREFERRED format
for any media type they play (thought they may support other caption formats
as well)
4) PLAYERS must allow captions to be turned on /off via a mechanism that
can be discovered from the player (without advanced knowledge of activation
sequence) OR the captions must always be rendered by the player. This
includes stand alone players or players embedded in content where media
controls are not usually visible.
OPTION 2: - MULTIPLE "Preferred" Caption Formats per media format
Same as option 1 except.
1) MEDIA FORMATS - could have more than one PREFERRED caption formats
2) CONTENT can choose between the PREFERRED formats and implement the one
they like.
3) PLAYERS - EVERY player has to support ALL PREFFERED formats (for the
media types they play).
4)(no change to #4)
OPTION 3: NO "Preferred" Caption Formats per media format
Same as option 1 except
1) MEDIA FORMATS - could have any number of formats. No caption format is
required or preferred.
2) CONTENT can use any format for captioning that they like.
3) PLAYERS - EVERY player has to support ALL possible formats for
captioning for their media types.
4)(no change to #4)
CONCLUSION
Option 1 is easiest for players
Option 2 is easiest and most flexible for content providers.
Option 3 does not seem practical.
Gregg
-- ------------------------------
Gregg C Vanderheiden Ph.D.
> -----Original Message-----
> From: = EMAIL ADDRESS REMOVED =
> [mailto: = EMAIL ADDRESS REMOVED = ] On Behalf Of
> Hoffman, Allen
> Sent: Wednesday, August 29, 2007 11:51 AM
> To: TEITAC Audio/Video Subcommittee
> Subject: Re: [teitac-video] FW: Revised proposal for Sec.
> 4.AdditionalProvisions for Audio-Visual Players or Displays
>
> If it helps:
>
> We have two groups talking a bit about similar topics now.
> A/V and web/software, regarding both a/v content requirements
> and a/v hardware/software user-agent requirements. We also
> have to some extent authoring tool requirements discussion
> for a/v, but in the authoring tool area this didn't come up
> really with a/v specifically in mind.
>
> So, I think we have content-format requirements that could
> include a/v requirements regarding how captions are stored,
> and could include how video-description is also stored.
>
> I think we have specific captioning content storage format
> requirements which allow for broadcast transport, e.g. 608/708.
>
> I think we have user-agent requirements that say things like,
> provide ability to turn captions on/off if not open, ditto
> for video-descriptions, and some other options. Some of this
> may be scoped by type of playback platform, e.g. a DVD player
> vs. a media-player running on a PC, vs. a media player taking
> streaming from a web page.
>
> The part that's missing in web/software is user-agent part
> and our user-agent requires might be defined in a/v and
> scoped to fit in web/software?
>
> The content storage requirements should be defined in a/v and
> then migrated to content format.
>
> The authoring tool requirements if definable should be
> defined here and inserted in authoring tool section.
>
> I hate to say it this way but in the end most of this gets
> split up here and there--but that's because a/v is so
> integrated into everything now.
>
> So, how can we facilitate this assemblage and distribution?
>
>
>
>
>
>
> Allen Hoffman -- = EMAIL ADDRESS REMOVED = ; v: 202-447-0303
>
> -----Original Message-----
> From: = EMAIL ADDRESS REMOVED =
> [mailto: = EMAIL ADDRESS REMOVED = ] On Behalf Of
> Larry Goldberg
> Sent: Wednesday, August 29, 2007 12:37 PM
> To: TEITAC AV list
> Subject: Re: [teitac-video] FW: Revised proposal for Sec. 4.
> AdditionalProvisions for Audio-Visual Players or Displays
>
> I agree that this is an authoring issue, but we do need to
> know what to author to and the capabilities of the engines
> we're authoring for.
>
> ... Larry ...
>
>
> Sean Hayes wrote:
>
> > That's partly true. The caption data needs to be stored in a master
> > format somewhere that can be converted to any and all
> play-out formats
>
> > by the copyright owner. That does not imply that it needs to be
> > converted from playback format A to playback format B by all and
> > sundry. While it is technically possible for example to go
> from 708 to
>
> > SAMI or vice-versa, it is fairly hard, likely a lossy
> conversion, and
> > an N-squared problem to accommodate all the playback formats.
> >
> > The lock in and interoperability problem today is largely
> due to the
> > various proprietary subtitling equipment being used and
> formats at the
>
> > authoring level; not with the delivery format. DFXP was
> created to try
>
> > and build a lingua-franca at the authoring level, however
> it is early
> > days for that process.
> >
> > Re-authoring for various delivery formats is the practical
> reality for
>
> > a multiplicity of reasons, codec's; aspect ratio; resolution etc.
> > Captioning should be an ingrained part of this process, just like
> > audio is. If we want to put 508 constraints out there to help the
> > state of captioning, the content format and authoring tools
> provisions
>
> > may be the place to do it. The player rules are not.
> >
> > Sean Hayes
> > Incubation Lab
> > Accessibility Business Unit
> > Microsoft
> >
> > Office: +44 118 909 5867,
> > Mobile: +44 7875 091385
> >
> >
> > -----Original Message-----
> > From: = EMAIL ADDRESS REMOVED =
> > [mailto: = EMAIL ADDRESS REMOVED = ] On Behalf Of Larry
> > Goldberg
> > Sent: 29 August 2007 14:18
> > To: TEITAC AV list
> > Subject: Re: [teitac-video] FW: Revised proposal for Sec. 4.
> > AdditionalProvisions for Audio-Visual Players or Displays
> >
> > The caption data need to be interoperable, not the playback media.
> > That is, we can readily convert 608 to 708 to SMIL to SAMI to DFXP
> > caption formats. A new format developed by HD-DVD and/or
> BluRay to be
> > functionally equivalent to 708 needs to be readily
> transferable to and
> from other accepted formats.
> > If this is not the case, then a government agency would be
> forced to
> > re-author their captions for this special new format (anticipating
> > that media will be distributed in multiple formats for training and
> > public information).
> >
> > - Larry
> >
> >
> > Sean Hayes wrote:
> >
> >> What do you mean by interoperability here? And why is this
> an issue?
> >> the world is full of non interoperable systems, Flash, HTML, Java,
> >> SMIL, blah blah blah.
> >>
> >> If an agency picked VHS then they couldn't play it back on
> computers
> >> or DVD players. If they picked Flash to publish a
> multimedia course
> >> then they couldn't use a Java player to view it.
> >>
> >> If an agency wants to do electronic distribution, they
> would need to
> >> procure a complete system. If for example the agency chose to use
> >> windows media for something, then they would need to acquire tools
> >> that can generate, caption, and stream it, and players to view it.
> >> There exists many tools for importing and exporting various media
> >> formats if that is an issue.
> >>
> >> I don't see any new problem here which isn't true of all E&IT.
> >>
> >> Sean Hayes
> >> Incubation Lab
> >> Accessibility Business Unit
> >> Microsoft
> >>
> >> Office: +44 118 909 5867,
> >> Mobile: +44 7875 091385
> >>
> >> From: = EMAIL ADDRESS REMOVED =
> >> [mailto: = EMAIL ADDRESS REMOVED = ] On Behalf Of Gregg
> >> Vanderheiden
> >> Sent: 29 August 2007 04:19
> >> To: 'TEITAC Audio/Video Subcommittee'
> >> Subject: Re: [teitac-video] FW: Revised proposal for Sec. 4.
> >> AdditionalProvisions for Audio-Visual Players or Displays
> >>
> >> Thanks
> >>
> >> Couple questions about the part where you changed it to "Uses this
> >> standard...
> >> Captions or timed text (as defined by procuring agency) or display
> >> open caption video"
> >>
> >>
> >> - How would you get interoperability if each agency picks its own
> standards?
> >> - Will purchasing agents have any idea what to specify?
> >> - And how would a mfgr know how to design products if they
> don't know
>
> >> what standard will apply until the get the P.O.?
> >>
> >> Maybe I'm missing something
> >>
> >> Thanks
> >>
> >>
> >> Gregg
> >> -- ------------------------------
> >> Gregg C Vanderheiden Ph.D.
> >>
> >>
> >>
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