Dave Malham wrote:
Hi Stefan,
I doubt if B+ would meet the currently perceived needs of cinema
surround mixers/producers since it does not have the ability to go
"discrete". B++ might be enough - that's first order + 5.1 (I just
made that up :-)).
:-)
I also fear(ed) that 5.1 + FOA ("B++") won't make it... 8-)
A better option would be at least third order,
preferably fifth - to get the most bang for buck - but to fit in the
22.2 channels that seem to be coming over the horizon fast, maybe
fourth would work better in terms of channel count.
Ok. But you don't have to "fit" into any channel count! We are just
talking about several (few) new file formats?!
Auro-3D is 11.1, so you have another format. (You have to decode
Ambisonics anyway, and also any object-based approach.)
I don't, personally, think that first order is a good choice for
cinema for anything other than home use. It certainly can be pressed
into use for large areas (been there, done that, got not just the T
shirt but the entire wardrobe) but it would really struggle in
anything other than the smaller art cinemas.
This was my question, so this one is < maybe > answered.
However, I believe it is helpful to start with the most basic approach,
and you/we will see < why > you would need a higher order approach.
The MPEG won't look into these issues, all the standardization process
is very much fast-track. (Necessary discussions have to happen
somewhere, so... ;-) )
The biggest limitation to
the whole thing is the availability of higher order microphones,
though Eigenmikes are becoming more widely available and one can hope
that Peter Craven's new ideas
(http://www.findaphd.com/search/ProjectDetails.aspx?PJID=40193) pan
out and give us at least a good second order microphone. However, if
you are constructing the soundscapes entirely from scratch, such
considerations do not really matter - in fact, to that end, improving
the use of spot microphones to generate convincing, realistic higher
order recordings is probably at least as important.
They will mix cinema sound from track, don't worry too much about
Eigenmikes...
On audio objects and where they should be mixed in, I have some
sympathy with your point that they should only be used in the studio
but in purely practical terms (and, again, only really for non-home
use) they can be very useful at the decoding stage where you are
dealing with very irregular arrays, so don't rule them out.
But this was/is the other issued which needed (needs...) some serious
discussion.
Thanks for the feedback,
Stefan
On 20 January 2013 04:11, Stefan Schreiber <st...@mail.telepac.pt> wrote:
Reading back, and evaluating...
http://steinhardt.nyu.edu/scmsAdmin/uploads/005/384/Miles_Fulwider_Thesis.pdf
I believe B+ "classic" could serve as a convincing "1st" proposal for a
sound-field based 3D cinema audio system. (And therefore, as a general
surround format).
The very obvious changes "could"/would be:
- You have at least 3 front channels behind the screen (up to 5 in Dolby
Atmos), not 2
- Which Ambisonics order would you need for cinema use? Might even 1st order
suffice (provided there is a "direct"/precise front)
- LFE channel(s) should (probably) be treated in a simple
channel-loudspeaker "configuration", such as the front channels. (You also
could code an "LFE soundfield", B format style. Or you don't code LFE at all
- but we are talking about cinema use, in which case LFE seems to matter.)
- If using a sound field approach, you would not want to mix soundfields
this with audio objects at rendering time. (Rather, use audio objects in the
studio. Mixing stage, not decoding stage...)
- The "object audio" proposals are all driven by the need to cope for many
different loudspeaker layouts. This issue is no problem for
Ambisonics/soundfields...
(Could say much more about this point, but it is too late, and why should
I... :-) )
Best,
Stefan Schreiber
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