W3C home > Mailing lists > Public > public-web-and-tv@w3.org > August 2011

Fwd: Re: [MEDIA_PIPELINE_TF] ISSUE-37: ViewPort-Support

From: Kazuyuki Ashimura <ashimura@w3.org>
Date: Sat, 13 Aug 2011 06:23:45 +0900
Message-ID: <4E4599E1.1070601@w3.org>
To: TV and WEB <public-web-and-tv@w3.org>
forwarding to archive with proper ISSUE ID (ISSUE-37)

-------- Original Message --------
Subject: Re: [MEDIA_PIPELINE_TF] ISSUE-34: ViewPort-Support
Resent-Date: Thu, 11 Aug 2011 21:32:00 +0000
Resent-From: public-web-and-tv@w3.org
Date: Fri, 12 Aug 2011 07:31:03 +1000
From: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
To: Cyril Concolato <cyril.concolato@telecom-paristech.fr>
CC: public-web-and-tv@w3.org

On Fri, Aug 12, 2011 at 6:34 AM, Cyril Concolato
<cyril.concolato@telecom-paristech.fr> wrote:
> Le 11/08/2011 12:34, Silvia Pfeiffer a écrit :
>> On Thu, Aug 11, 2011 at 7:35 PM, Cyril Concolato
>> <cyril.concolato@telecom-paristech.fr>  wrote:
>>> Hi Sylvia,
>>>> Can you fill the TextTrack object and the cues from a SVG? As long as
>>>> you can make a mapping, it's possible. If the format doesn't fit with
>>>> the elements, then it's an orthogonal concept that won't fit the bill.
>>> Reading http://www.w3.org/TR/html5/video.html#text-track it says:
>>> "A text track consists of:"
>>> * "The kind of text track": would apply to SVG tracks
>>> * "A label": would apply to SVG tracks
>>> * "A language": would apply to SVG tracks
>>> * "A readiness state": would apply as well
>>> * "A mode": same
>>> * "A list of zero or more cues"
>>> A Cue is defined as:
>>> * "An identifier": applicable to SVG tracks
>>> * "A start time"/"An end time":
>>> As such SVG does not define frame-based content as Flash would do or
>>> other
>>> subtitling formats, but you can define frame-based content such as:
>>> http://perso.telecom-paristech.fr/~concolat/SVG/flash8.svg
>> This is one of the major requirements.
> Do you have a document describing those requirements ?

The HTML specification incorporates these requirements.

>> Trust me - SVG won't fit the
>> bill as a time-aligned data format.
> General purpose SVG no but SVG with some constraints yes. It's not the
> perfect time-aligned format but it works. I've demonstrated that it's
> possible to fragment some SVG into frames, store them in MP4, stream them
> ... [1]

Right. That's why it's not generally useful for the <track> purpose.
You could define a sub-language (like a profile) of SVG that might
fit, but then it's not SVG any more.

>> And browsers won't implement it.
> That me be true for now but you never know. They might be interested in it.
>> But you can always try a JavaScript implementation to prove me wrong.
> "implementation of what" ?

A demonstration of how SVG in <track> is useful. You can always extend
the HTML functionality through JavaScript to demonstrate such things
and make a point towards including it into HTML. That's in fact the
best approach to getting new features happening. Just as you've shown
SVG in MP4, you should demonstrate SVG in <track> if that is what you
want to achieve.

Received on Friday, 12 August 2011 21:23:20 UTC

This archive was generated by hypermail 2.4.0 : Friday, 17 January 2020 17:57:07 UTC