Re: [clue] Incoming liaison statement from MPEG
Bert Greevenbosch <Bert.Greevenbosch <at> huawei.com>
2012-06-20 00:49:43 GMT
Hi all,
I have reviewed the MPEG LS (link below) and associated new MPEG document.
I noticed that the 3D frame packing related text comes from 14496-10. In 14496-10, the 3D signalling is in
the context of SEI messages. Including this text in the new MPEG document indicates MPEG has plans of
expanding its use, although the SEI messages are left out of scope and only field values and associated
descriptions are provided.
The relationship of the MPEG document with the SDP signalling draft (link below) is the high-level
definition of the frame-compatible video formats. For this reason, there is already a reference to
14496-10 in the draft. Depending on the status of the new MPEG document, that reference may need to be updated.
Best regards,
Bert
http://datatracker.ietf.org/liaison/1158/
http://datatracker.ietf.org/doc/draft-greevenbosch-mmusic-sdp-3d-format/
---
From: mmusic-bounces <at> ietf.org [mailto:mmusic-bounces <at> ietf.org] On Behalf Of Thomas Stockhammer
Sent: 02 June 2012 03:12
To: Stephan Wenger
Cc: clue <at> ietf.org; mmusic <at> ietf.org
Subject: Re: [MMUSIC] [clue] Incoming liaison statement from MPEG
Stephan, all,
a bit more background.
MPEG is NOT defining the mapping of the code points to any specific syntax, such as XML or SDP or a bitstream
format. However, it provides common code points (generally unsigned integers) and common definitions
of the code points.
One of the relevant code points for IETF SDP are the frame-compatible video formats such as SbS or TaB.
Others may relate to audio properties such as the number and configuration of audio channels.
One of the main motivations is to avoid copying such code points from one specification to the next as it
happens today for example in video coding standards.
The IETF is encouraged to support the unification of such code points and by providing input to MPEG and by
using references to the MPEG specification in IETF documents.
Thomas
On Jun 1, 2012, at 7:17 PM, Stephan Wenger wrote:
Hi Roni,
The statement was sitting in my inbox for a few days, and I have forwarded it to the secretariat for posting
only this morning. Therefore, it is not yet on the tracker, but should be on the tracker sometime soon.
Color primaries, as one example, can actually being sent in SDP today, as part of the VUI in the sequence
parameter set of H.264. And, color primaries are an interoperability point, at least for high quality
applications (such as video contribution). If your receiving box does not understand, or cannot
meaningfully process color primaries as sent, then you may get a picture but it will look odd. There is
also other stuff in the MPEG doc that is even more needed for interoperability; for example, association
of audio channels inside the codec bitstream with a speaker location.
The key point of the MPEG doc is that they are out farming generic codec things from the audio/video specs
into this MPEG-A format, and we (as we are not using MPEG-A) will probably have to find a way to either
encapsulate MPEG-A XML for cap exchange, or translate the code points to SDP-ish things.
Stephan
From: Roni Even <ron.even.tlv <at> gmail.com>
Date: Friday, 1 June, 2012 10:00
To: Stephan Wenger <stewe <at> stewe.org>, "mmusic <at> ietf.org" <mmusic <at> ietf.org>, "clue <at> ietf.org" <clue <at> ietf.org>
Subject: RE: [clue] Incoming liaison statement from MPEG
Stephan,
I did not see the liaison statement yet in MMUSIC, so I hope it will be available in time for us to review.
From the example of color primaries I am not sure why we need to have this in SDP. if this is something that is
sent as part of the payload do we need to send it also in SDP?
Roni
From: clue-bounces <at> ietf.org [mailto:clue-bounces <at> ietf.org] On Behalf Of Stephan Wenger
Sent: Friday, June 01, 2012 7:29 PM
To: mmusic <at> ietf.org; clue <at> ietf.org
Subject: [clue] Incoming liaison statement from MPEG
Hi all,
MPEG is working towards codec independent code points, and has sent to MMUSIC a liaison statement asking
for our input. Especially the audio stuff may also be relevant to CLUE, so I copy CLUE here as well. No
deadline is provided, but I note that MPEG meets two weeks before the Vancouver IETF meeting and the text
they sent us is already a CD, so our time to influence their decisions (if we choose to do so) is limited.
MPEG has observed that many code points relevant for audio and video are generic in the sense that they can be
applicable to many video or audio codecs. Recent MPEG (and joint MPEG/ITU) video coding standards have
occasionally copy-pasted whole sections of code points concerning things like color primaries. They
want to avoid this in the future. So they farm out stuff that is historically located in video/audio
codec specs, but are likely to be common between different codecs.
My hunch is that the code point in their draft standard could be translated to SDP-ish syntax. At this
point, it is XML-ish.
Stephan
_______________________________________________
mmusic mailing list
mmusic <at> ietf.org
https://www.ietf.org/mailman/listinfo/mmusic
---
Dr. Thomas Stockhammer (CEO) || stockhammer <at> nomor.de || phone +49 89 978980 02 || cell +491725702667
|| http://www.nomor-research.com
Nomor Research GmbH - Sitz der Gesellschaft: München - Registergericht: München, HRB 165856 -
Umsatzsteuer-ID: DE238047637 - Geschäftsführer: Dr. Thomas Stockhammer, Dr. Ingo Viering.
RSS Feed