Re: Carriage of WebVTT in MP4

Hi Cyril,

That's some nice work there! Great to hear you've found a good way to
encapsulate WebVTT into MP4. Also great to hear that you've already
got software support for this in mp4box and that it works with DASH!

BTW: I read back over
http://concolato.wp.mines-telecom.fr/2013/04/26/webvtt-in-mp4/ and the
slide deck there. I would say that you really don't have to worry
about encapsulating comments or invalid cues into MP4 tracks. The only
thing that I think you need to care about is that if you parse a
WebVTT file according to the WebVTT parsing algorithm and you parse
the re-extracted WebVTT file after its encapsulation in MP4, they
should result in the same information. Thus, I suggest there is no
need for the Additional TextBoxes that are in your slides. They
wouldn't be rendered anyway.

But that's just a suggestion. I think it all looks pretty good.

(I am not convinced by how you're rendering WebVTT in GPAC by
converting it to SVG Tiny, but that's an orthogonal issue and a
technology choice that may make sense for GPAC.)

I wonder if you'd like to write an article for
http://www.w3.org/community/texttracks/ about the specification of how
to encapsulate WebVTT in MP4 and it's implementation in MP4Box?

Cheers,
Silvia.

On Thu, Aug 1, 2013 at 4:52 PM, Cyril Concolato
<cyril.concolato@telecom-paristech.fr> wrote:
> Dear WebVTT addicts,
>
> I have written a blog post [1] describing my implementation within the GPAC
> project of the carriage and playback of WebVTT content in MP4 files. I
> thought it would be interesting to this list. Comments are welcome.
>
> [1]
> http://concolato.wp.mines-telecom.fr/2013/07/28/webvtt-mp4-files-dash-and-gpac/
>
> 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 Monday, 5 August 2013 11:46:05 UTC