Re: Embedding the track kind in WebVTT files

i am all for this, thanks cyril.

on a related note, it would be helpful if the HLS manifest enabled
differentiation by kind (subtitles vs captions). current pantos spec only
has a TYPE value of "SUBTITLES".







On 9/12/13 5:30 AM, "Cyril Concolato"
<cyril.concolato@telecom-paristech.fr> wrote:

>Hi all,
>
>WebVTT files are/will be used in environments where there might not be
>an HTML page pointing to it. Some examples are:
>- WebVTT content embedded and multiplexed with video and audio in an MP4
>file
>- Plain text WebVTT files referenced by an adaptive streaming manifest
>(DASH MPD, HLS playlist, ...)
>
>All embedding environments typically enable marking a track with a
>language (e.g. an audio track) but not all can carry the kind types
>(subtitles, captions, metadata). In order to avoid losing that
>information in those environments, I think the WebVTT file should
>declare its kind. Also, when producing WebVTT files, it should be
>possible to indicate the language, kind or even label in the file
>itself, to avoid mistakes.
>
>I would like to propose to define standard WebVTT metadata headers, as
>follows:
>- WebVTT metadata header name: kind
>- WebVTT metadata header value: as defined by kind attribute of the
>track element in the HTML 5 specification
>
>- WebVTT metadata header name: language
>- WebVTT metadata header value: as defined by srclang attribute of the
>track element in the HTML 5 specification
>
>- WebVTT metadata header name: label
>- WebVTT metadata header value: as defined by label attribute of the
>track element in the HTML 5 specification
>
>Note that some people are already using non standard name/values for
>that (e.g. 
>http://wiki.webmproject.org/webm-metadata/temporal-metadata/webvtt-metadat
>a)
>
>Of course, this introduce redundancy when the embedding environment also
>sets those attributes and might be problematic if the values differ.
>Resolving conflicts should be specified by the embedding environment. In
>HTML, the information in the HTML page should probably have precedence,
>to be able to use a caption track as metadata, if the HTML author wants
>to.
>
>Comments ?
>
>Regards,
>Cyril
>
>-- 
>Cyril Concolato
>Maître de Conférences/Associate Professor
>Groupe Multimedia/Multimedia Group
>Telecom ParisTech
>46 rue Barrault
>75 013 Paris, France
>http://concolato.wp.mines-telecom.fr/
>
>

Received on Thursday, 12 September 2013 13:14:02 UTC