Dear colleagues...
I take the opportunity to inform you about recent work at the MPEG,
presenting updates and (by documents backed) official information.
1.
http://www.itu.int/net/pressoffice/press_releases/2013/01.aspx#.UQVoNVK-Zkj
ITU-T’s Study Group 16
<http://www.itu.int/en/ITU-T/studygroups/2013-2016/16/Pages/default.aspx>
has agreed first-stage approval (consent) of the much-anticipated
standard known formally as Recommendation ITU-T H.265 or ISO/IEC
23008-2. It is the product of collaboration between the ITU Video
Coding Experts Group (VCEG) and the ISO/IEC Moving Picture Experts
Group (MPEG).
ITU-T H.265 / ISO/IEC 23008-2 HEVC will provide a flexible, reliable
and robust solution, future-proofed to support the next decade of
video. The new standard is designed to take account of advancing
screen resolutions and is expected to be phased in as high-end
products and services outgrow the limits of current network and
display technology.
Companies including ATEME, Broadcom, Cyberlink, Ericsson, Fraunhofer
HHI, Mitsubishi and NHK have already showcased implementations of
HEVC. The new standard includes a ‘Main’ profile that supports 8-bit
4:2:0 video, a ‘Main 10’ profile with 10-bit support, and a ‘Main
Still Picture’ profile for still image coding that employs the same
coding tools as a video ‘intra’ picture.
The ITU/ISO/IEC Joint Collaborative Team on Video Coding (JCT-VC)
(formerly JVT) will continue work on a range of extensions to HEVC
2. Obviously, the future standard for 3D audio belongs to the same
standard (or standard family) ISO/IEC 23008. The audio "part" is ISO/IEC
23008-3, better known as MPEG-H part 3.
3. Here a "global" update on MPEG standard, presented by Leonardo
Chiariglione himself. (Paper date: 26th June 2012)
http://www.ieee-bmsb2012.org/images/program/BMSB2012_Keynote_2_MPEG_standards_supporting_the_evolution_of_broadcast_media_Leonardo.pdf
Updates:
- p. 10 presents the intended timeline for the standardization process,
including 3D audio.
New: We might have a bit more time than I have thought, which is good
news. "CD" stands for committee draft. I guess they will start on the
first working draft in Vienna, summer 2013. (I have posted the schedule
of next MPEG meetings, within this thread.)
- p. 34ff: "No systems and video without audio"...
- p. 35-37: 3D audio requirements
Judge yourself if Ambisonics would fit to fulfill this requirement list.
(A clear yes "here", if I have anyting to say about...)
- p. 38 "Envisioned architecture"
Ambisonics is actually included, as "audio scene" input into the first
encoder.
BUT: This is still a very crude scheme, not anything eleaborated.
- The two "encoder" stages need some explication, or elaboration. I
could imagine what they mean, more or less. However, as an acitectural
diagram this is either a bit confused, or maybe "heavily underspecified".
- Indeed, the 500 bit/s for 3D audio seems to be a bit bit-starved, what
Mr. Chiariglione actually seems to admit himself. (p. 42)
Parametric compression might achieve this rate, but how to reconcile
this with the requirement list? ("quality of decoded sound
perceptionally transparent"; note also that we are talking about UHD
television and cinema audio, in this case, do it well?)
- The "64 kbit/s" stream to mobile phones/devices seems to be completely
outfashioned, in a time of readiy available UMTS, HSPA , LTE etc.)
Stay at 128kbit/s or 256kbit/s, as anybody else in this industry?
(Please don't be worse than any YouTube stream, ok? Just speaking for
the new generation, which righteously expects some minimum quality over
their handy earbuds...)
Nobody will listen to 3D audio on GSM phones, pretty safe bet.
"Smart phone TV" will be more like "video transmitted via Internet",
"classical broadcast TV" probably included but hardly the main thing...
- p.39: "Immersive and enveloping audio expeience"
"Immersive" should mean "high quality", not "cheating" in a race for the
lowest possible bitrate.
-Home theater: p. 41ff
The presented .AMB based proposal, 3rd horiz. /2nd vertical order (as
option including 3 or 5 separate front speakers) seems to be
sufficiently strong to be decoded to this "typical" but "high end"
loudspeaker configuration.
Would also need significantly less transmission rate than 22.2, which
seems to be a factor here. (Maybe they will take 1,5 MBit/s as upper
rate limit, have a look at p. 42)
- p. 46: "Flexible rendering"
I leave the rest to your own interpretation, and good judgement. I hope
there will be a little bit more support coming from this list, which is
heavily involved into Ambisonics reasearch and practical implementation.
And I fully believe that sursound is a very competent list/place...
Best regards,
Stefan Schreiber
P.S.: Further updates on the Shanghai and Genève meetings heavily
needed, IMO.
Mr. Pallone et al., the CfP is issued by now, and it is time to present
"something". Anyway, I have signed up to the Mpeg list, but couldn't see
their CfP yet.
(I hope I don't have to hack into their server, which might lead to
arrest warrants and a further life spent in prison. I really can't
afford to do THIS... :-D )
P.S. 2: (preemptive legal declaration... ;-) )
If anyone hacked into the MPEG server to steal a document which (in
theory) should be publicly available, it wasn't me!!!!!!!!! I have a
child, life...
(I am aware that I would not be jailed for stealing a publicly available
document, just for the taken measures to get into possession of it. To
have done this for the sake of science and "better 3D audio" would be a
lame duck excuse if convicted, ok...
BUT: YOU have to prove that I did it, and I didn't. :-) )
Stefan Schreiber wrote:
Dear colleagues...
I would like to remember everybody interested or already being
involved that ITU/MPEG plan to define and issue some 3D audio standard
(better: 3D audio standard framework) during this year. The 3D audio
codec is meant to be part of the (wider) MPEG-H standard.
This all makes a lot of sense, 'cos ;-) there is already some
competition around:
1. Hamasaki 22.2, well known as (audio) part of former UHDTV (Super
Hi-vision) proposals.
2. http://www.auro-3d.com/system/listening-formats
(Note:
a)
The Auro-3D® Engine comprises:
Auro Codec: The revolutionary codec that delivers native, discrete
Auro-3D® content.
Auro-Matic: The groundbreaking up-mixing algorithm that converts
legacy content into the Auro- 3D® format.
Auro-3D® Headphone: Like other audio configurations, similar results
can be achieved with headphones that use binaural technology.
b)
Film, Broadcast, Gaming, Mobile, Automotive and Multimedia industries
are all searching for a next generation sound format. With 3D
Stereoscopic imagery becoming commonplace, the time is right for an
audio experience that matches this increased level of fidelity. Sound
in 3D is clearly the next step.
3. http://www.dolby.com/us/en/consumer/technology/movie/dolby-atmos.html
(IMHO, Dolby won't participate in the MPEG standardization process.
And even if, Dolby Atmos seems to be finished.)
The current situation at MPEG:
http://www.itu.int/en/ITU-T/studygroups/com16/video/Pages/jctvc.aspx
Next meetings:
* Geneva, Switzerland, October 2013 (tentative)
* Vienna, Austria, 27 July - 2 August 2013 (tentative)
* Incheon, Korea, 20-26 April 2013 (tentative)
* Geneva, Switzerland, 14-23 January 2013 (tentative)
During the next conference (January, Genève), the important HEVC codec
should be technically finished. (Status: FDIS, for "Final Draft
International Standard")
There will also be issued a final call for an 3D audio codec:
At the 102nd MPEG meeting MPEG has issued a Draft Call for Proposals
(CfP) on 3D Audio Coding.
(This was the last meeting, Shanghai, October 2012)
MPEG-H 3D Audio is envisaged to provide a highly immersive audio
experience to accompany the highly immersive experience provided by
MPEG-H HEVC. Such an immersive listening experience will be realized
by the rendering of a realistic and compelling 3D audio scene either
by using a large number of loudspeakers, such as for 22.2 channel
audio programs, or by using headphones supporting binauralization.
Key issues to be addressed are a compact and bit-efficient
representation of multi-channel audio programs and the ability to
flexibly render an audio program to an arbitrary number of
loudspeakers with arbitrary configurations. 3D Audio support via
headphones is also a key capability in order to deliver an immersive
experience for users of mobile devices.
A final CfP will be issued at the 103rd meeting in January 2012,
(they mean January 2013, of course...)
with selection of technology from amongst the responses received at
the 105th meeting in July 2013. This technology will form the basis
for MPEG-H 3D Audio, the Audio part (Part 3) of the MPEG-H (ISO/IEC
23008) suite of technologies.
Taken together, the final deadline for any proposal seems to be around
April 2013. (Incheon, Korea meeting, April 2013)
If some Ambisonics based audio-codec is proposed (it has been done,
but as an official proposal??), I would like to add some observations.
Cinema audio and UHD TV (and this is where the push comes from) iclude
some "discrete" elements, and anybody has to be aware of this.
Firstly, there are one or two (Hamasaki 22.2) separate LFE channels.
(LFE channels make sense for movies and in the cinema, even if some
people always will dispute this...we are not talking about most music
you will listen to at home, but about cinema sound with special effects.)
Secondly, a lot of sound is tied to the screen. The narrow-spaced
front speakers might represent a problem for Ambisonics, at least for
low-order Ambisonics. (Dolby Atmos defines actually up to 5 "screen"
loudspeakers, this means three or five. Note that the front C channel
is often used as voice/conversation channel.)
A possible solution would be to offer some kind of B"+" option, the
"plus" part being the front and LFE channels. 2D/3D surround for all
the "resting" sound field would be offered via the B format (order?)
sound field, or HOA sound field. (To mix such a hybrid sound format is
rather trivial, I would say. Just leave out the front and the LFE
parts in the surround/3D field... )
So maybe define some "purist" solution (say B format 3rd order, or
horizontal 4th order mixed with vertical 1st/2nd order, or whatever),
and also some "B+" option. (The original B+ proposal was FOA + 2
stereo channels. Note that a direct consequence of the "hybrid"
Ambisonics option would be that a 2nd or 3rd order soundfield should
be enough for the representation of the surround and height channels.
In fact, you can decode to 5.1, 7.1 Hamasaki 22.2, Auro-3D and Dolby
Atmos surround layouts. The B format "resolution" should be more than
enough for any of these layouts - maybe even at 2nd order, certainly
at 3rd. The narrow-spaced front wouldn't be any problem, by
definition. LFE channels are discrete in any case, as stated before.)
I would't be afraid to offer some hybrid option, anyway. (Dolby Atmos
defines up to 64 channels, and also audio objects for different
loudspeaker layouts. Therefore, Dolby Atmos is itself a hybrid system
- based on discrete channels and audio objects.)
I just wanted to give a small hint ;-) how anybody might set up a
valid proposal. The B+ could and < should > be included as an option.
The basic idea behind for this is that cinema audio has some specific
properties, which have to be covered by any system. (The < front > is
extremely important, because voice and many sounds are tied to events
on the screen; LFE channels are discreet; the C channel is mostly used
in a discreet way, being used as the voice channel.)
Note also that the clock is already ticking, and I absolutely mean
this. The MPEG can chose from some valid proposals, (Hamasaki) 22.2
and Auro-3D among these.
Ambisonics is defining a 3D audio field since the 70s, so it would
seem logic to include Ambisonics into any 3D audio standard. There are
also some clear advantages, which are getting more and more important.
(Different cinemas won't offer anywhere the same loudspeaker layouts,
pretty safe bet)
Because the MPEG will basically chose from existing proposals,
somebody has to define some valid Ambisonics based proposal.
I am apologizing to the already involved experts to have written on a
pretty basic or say introductory level. But nobody has done this here
before, and I think not everybody is sufficiently informed about these
issues - maybe even some very competent people.
However/but:
The next two or three MPEG conferences are not just like the next
spacial audio or Linux audio conference ;-) , we are talking (also)
about the probable next real-world standard for 3D audio. After MPEG-H
3rd part (audio) and Dolby Atmos exist, every future endeavour would
face some (extremely difficult) uphill battle.
If Ambisonics is not included for reasons of laziness, infighting
tribes or whatever else, I would say: Game over for Ambisonics in the
real-world.... (I don't mean this in a rude way. The thing is just
that the MPEG won't wait for even the most beautiful HOA standard
which will be represented in the year 2015 or 2020...)
The advantages of Ambisonics are clear: It is by definition a 3D audio
theory/codec, and you can decode to different loudpeaker layouts and
headphones. (This is of course very basic, but you have to tell this
to people if presenting a proposal.)
Best regards,
Stefan Schreiber Lisbon
P.S.: I personally would/will work with any 3D audio standard. Because
MPEG-H 3rd part (audio) will be a selection of several
codecs/approaches, Ambisonics should be included. If so, I would
define two options: some "purist" approach, but also some "B+"
approach, which maybe fits more to cinema-audio in the real world.
Now Thomas Chen (still lurking on this list?) would probably agree,
because the original (6-channel) B+ proposal if from him.
Unfortunately he works at Dolby... :-X
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