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Re: Require syntax for Media marker "Clip-Begin" for SMIL 2.0/3.0

From: Jack Jansen <Jack.Jansen@cwi.nl>
Date: Mon, 28 Jun 2010 11:09:39 +0200
Cc: www-smil@w3.org
Message-Id: <466EAF27-7D4E-4BC7-BEEF-36A76A21C50E@cwi.nl>
To: Datta321 <DS0036943@techmahindra.com>
Your problem is implementation, not standardisation.

The construct you use is correct according to the SMIL 3.0 spec. But: I know of no SMIL players that actually implement the 
clipBegin="marker=#foo" functionality. In addition, the SMIL spec is vague (and intentionally so) as to what the external
representation of markers is.

Ambulant has some minimal support for markers, but (a) only for markers defined in SmilText files, and (b) only for used
in event-based timing.

Adding support to Ambulant for markers in the way you sketch shouldn't be too hard: the infrastructure is all in place.
But: we (the CWI ambulant team) don't have the time for this, and no compelling use case right now that will let us
make time. But if you have the developer capabilities yourself we are (as always) more than willing to help.

On 28 jun 2010, at 10:27, Datta321 wrote:

> I am facing some problem while trying to read a "media" file with "markers"
> using Ambulant player. Please see the smil file below.
> It so happens, that the 1st .mp4 file, namely "Gorill2.mp4" plays well, in
> Ambulant player 2.0.2 using clipBegin element with absolute time. However,
> the Ambulant player complains of "Cannot parse clipBegin" and "Cannot parse
> clipEnd" when it tries to read Movie2.flv, which is a .mp4 file with cue
> points "Begin" and "End" in a separate file, namely "movie2.txt", the
> contents of which are listed below the smil file.
> The movie2.flv is created unsing Flash 8 encoder.
> Am I going wrong in somewhere ? Also, is there an alternative way of
> marking cue points to a .mp4 file, to be read from a SMIL file ? 
> <smil xmlns="http://www.w3.org/ns/SMIL" version="3.0"
> baseProfile="Language">
> <body>
>    <par>    
>      <video src="Gorill2.mp4" clipBegin="npt=4s" clipEnd="npt=8s"/>
> <!--
>   <video src="Movie2.flv" clipBegin="marker=movie2.txt#Begin"
> clipEnd="marker=movie2.txt#End"/>	    	     -->
>    </par>
> </body>
> </smil>
> ===============================================================================
> movie2.txt
> -----------
> Begin=34&End=24
> ===============================================================================
> -- 
> View this message in context: http://old.nabble.com/Require-syntax-for-Media-marker-%22Clip-Begin%22-for-SMIL-2.0-3.0-tp29008514p29008514.html
> Sent from the w3.org - www-smil mailing list archive at Nabble.com.

Jack Jansen, <Jack.Jansen@cwi.nl>, http://www.cwi.nl/~jack
If I can't dance I don't want to be part of your revolution -- Emma Goldman
Received on Monday, 28 June 2010 09:10:19 UTC

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