W3C home > Mailing lists > Public > ietf-discuss@w3.org > April 2001

Re: MP4 Player Available for Download

From: Rob Lanphier <robla@real.com>
Date: Sun, 1 Apr 2001 22:06:18 -0700 (PDT)
To: Eliot Lear <lear@ofcourseimright.com>
cc: <discuss@apps.ietf.org>
Message-ID: <Pine.LNX.4.33.0104012058420.7193-100000@mmmm.robla.org>
On Sun, 1 Apr 2001, Eliot Lear wrote:
> I am not a multimedia expert, so please forgive what will sound like
> naive questions.  Clearly Real and Microsoft have failed to adopt enough
> common standards, since consumers have to install two players so that
> they can be assured that they can play any content.

No, you're right, there's been a breakdown here.  There's not much to
interoperate with in Microsoft's player.  I believe we support all of the
standards that they do, but that's not saying much.  We both support
playing MP3 over HTTP, I think (I know RealPlayer does).

Microsoft continues to push the MMS (Microsoft Media Server) protocol,
which is their proprietary alternative to RTSP.  We support both RTSP/RTP
(completely standard) and RTSP/RDT (our standard/proprietary hybrid).

> Can you point me at the standards organization that advanced SMIL?

The W3C:  http://www.w3.org/AudioVideo

> I'm
> familiar with H.*, G.*,  and PNG, as well as the IETF standards and the
> MPEG standards.  My understanding is that this is largely the crux of the
> problem.  If both Real and Microsoft grock the interchange formats of the
> audio and video, the thing that separates you guys is layout.

But that's the problem:  there's no standard interchange format, other
than MPEG-4, which has the problems we've been bickering about.

A very long time ago (early 1998), there were a couple of drafts submitted
to the IETF on this:

Advanced Streaming Format (Microsoft):
http://www.alternic.org/drafts/drafts-f-g/draft-fleischman-asf-01.html

RealMedia File Format (RealNetworks):
http://www.alternic.org/drafts/drafts-h-i/draft-heftagaub-rmff-00.html

...but there was never really a lot of followup on either draft.  I know
that we would have gladly participated in a working group had one been
formed around the subject at the time, but we never pushed the issue, and
I assume Microsoft nor anyone else did either.  Perhaps it's time to
revive the issue.

> And if layout is the problem, perhaps some of the people in W3C could
> comment on what standards are applicable.

As I mentioned, we've worked with the W3C for a very long time on SMIL,
and support SMIL 1.0 in our player, which is a W3C Recommendation.
Microsoft continues to support a couple of different specifications,
neither of which are the SMIL Language:

1.  Windows Media player supports a proprietary format known as ASX.  This
is a very limited format somewhere in between a simple playlist like M3U
and SMIL.  It's an XML-ish markup language that doesn't really conform to
XML.

2.  Internet Explorer supports "HTML+Time", which has morphed into
"XHTML+SMIL" in the W3C.  IE's implementation is not really geared toward
A/V layout so much as the types of animations you see in Powerpoint
presentations.  Some of the more advanced demos are a little more like
Flash, but I haven't really seen any tools with the sophistication of
Macromedia Flash that work with it (and the W3C's SVG looks like a much
more promising application for standards-based Flash-like applications).
Furthermore, the specification is a work in progress and not implemented
in any playback engine that I'm aware of other than IE.

Hope this helps.

Rob
Received on Monday, 2 April 2001 01:09:01 UTC

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