W3C home > Mailing lists > Public > www-smil@w3.org > October to December 2000

Re: 3GPP-T-WG3 codecs

From: Philipp Hoschka <ph@w3.org>
Date: Tue, 12 Dec 2000 13:35:03 -0500
Message-ID: <3A366FD7.A77D051A@w3.org>
To: Glenn Parsons <gparsons@nortelnetworks.com>
CC: thierry michel <tmichel@w3.org>, www-smil <www-smil@w3.org>, discuss <discuss@apps.ietf.org>, vpim <vpim@lists.neystadt.org>
Glenn,

see
http://www.w3.org/AudioVideo/#SMIL

Note that audio/basic, while ok for interoperability, is certainly
not the most frequently used audio codec in the SMIL area - but
this was the best we felt we could do in the interop area, for
the reasons already stated.

-Philipp

Glenn Parsons a écrit :
> 
> Forgive my ignorance, but could you give us an example of a SMIL player?
> 
> On 12/12/00 5:54 am, "Philipp Hoschka" <hoschka@yahoo.com> wrote:
> 
> > The rationale for picking audio/basic was that it
> > is widely supported in SMIL players today, and doesn't
> > require paying a license fee.
> >
> > If you know of another license-free, widely
> > supported audio format with better
> > characteristics than audio/basic, that may be
> > interesting.
> >
> > --- thierry michel <tmichel@w3.org> wrote:
> >> RE: 3GPP-T-WG3 codecs
> >>   ----- Original Message -----
> >>   From: Glenn Parsons
> >>   To: discuss@apps.ietf.org ; www-smil@w3.org ;
> >> 'Philipp Hoschka'
> >>   Cc: 'IETF VPIM List'
> >>   Sent: Monday, December 11, 2000 8:28 PM
> >>   Subject: [Moderator Action] RE: 3GPP-T-WG3 codecs
> >>
> >>
> >>
> >>
> >>   Philipp, I'd be interested in the rational that
> >> made you pick audio/basic
> >>
> >>     FWIW, there is a set of "recommended" codecs in
> >> the SMIL 2.0
> >>     draft of W3C, and I'm happy to explain why we
> >> chose those, if
> >>     needed:
> >>
> >>
> >>
> > http://www.w3.org/TR/2000/WD-smil20-20000921/smil20-profile.html#BaselineForma
> > tsNS
> >>
> >>
> >>> Widely Supported MIME Types
> >>>
> >>>    This section is informative.
> >>>
> >>>    The members of the W3C SYMM Working Group
> >> believe that the following
> >>>    MIME types will be widely supported by SMIL
> >> players:
> >>>      * audio/basic [592][MIME-2]
> >>>      * image/png ([593][PNG-MIME],
> >> [594][PNG-REC])
> >>>      * image/jpeg ([595][MIME-2], [596][JFIF])
> >>
> >>>    Implementers of SMIL players should thus
> >> strive to provide support for
> >>>    each of these types. Note, however, that
> >> this section is
> >>>    non-normative, and that support for these
> >> MIME types is not a
> >>>    precondition for conformance to this
> >> specification.
> >>>
> >>>    Authors are encouraged to encode media
> >> objects using one of the widely
> >>>    supported MIME types whenever possible.
> >> This will ensure that their
> >>>    SMIL documents can be played back by a wide
> >> range of SMIL players.
> >>>
> >>>    If authors use a MIME type that is not in
> >> the list of widely supported
> >>>    types, they should provide an alternative
> >> version encoded using a
> >>>    baseline format. This can be achieved by
> >> using a switch element as
> >>>    shown in the following example:
> >>> <switch>
> >>>   <audio src="non-baseline-format-object" />
> >>>   <audio src="baseline-format-object" />
> >>> </switch>
> >>>
> >>>    In this example, a player that supports the
> >> non-baseline format will
> >>>    play the first audio media object, and a
> >> player that does not support
> >>>    the non-baseline format will play the
> >> second media object.
> >>
> >>     In general, I'm a bit confused about the request
> >> - why would the
> >>     IETF have to comment on the minimal set of
> >> codecs in a format
> >>     defined by another organisation ? This would
> >> make sense if the
> >>     goal is to define a minimal set of codecs that
> >> need to be supported
> >>     by MIME mail readers, but otherwise, I don't see
> >> the point - am
> >>     I missing something ?
> >>
> >>   I don't think the IETF _has_ to comment, we've
> >> just been asked..
> >>
> >>   This is more about the codecs available on various
> >> devices.  Few if any mail clients have audio codecs
> >> included.
> >>
> >>   Cheers,
> >>   Glenn.
> >>
> >>
> >
> >
> > __________________________________________________
> > Do You Yahoo!?
> > Yahoo! Shopping - Thousands of Stores. Millions of Products.
> > http://shopping.yahoo.com/
> >
Received on Tuesday, 12 December 2000 13:39:43 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 20:34:23 UTC