[ardour-dev] monitoring & punch-in

Fons Adriaensen fons.adriaensen at skynet.be
Sun Oct 17 16:00:41 PDT 2004

On Sun, Oct 17, 2004 at 05:22:11PM -0400, Paul Davis wrote:

> do you have auto-input enabled? if its enabled, then what you want to
> happen should happen.

Yes, that works, thanks !

Meanwhile I've stumbled on the next problem.

I have a number of 4-channel tracks, and just want to mix them to
a four channel bus and output or record the result.
Now these are Ambisonics B-format recordings, and with the exception
of the first channel (which is just a mono signal) these signals have
no meaning at all as loudspeaker feeds - they are decoded externally
to whatever speaker layout is available. So there should be no
panning or any other operation performed on them, just mixing by
channel, with exactly the same gain for all four channels.

I've tried to understand the 2d panner, but failed so far :-(.
All I want to do is to set it in such a way that is does nothing
at all (an option to remove it would be welcome). So far that
seems to be impossible. For example, I get no output at all on
the fourth channel (I assume this is related to the panning, as
there _is_ a signal in the tracks). 

This has set me thinking about what would be required for
full scale ambisonics mixing in Ardour. An number of special
mixing strips, all with 4-ch B-format output, would be needed
(maybe all of this can be done using plugins, but even then
it would handy to have the basic controls in the strip):

1. B-format input: in it simplest form, this would have no
  special controls at all, but a  number of operations may
  be done on such a signal: all 3D rotations and the 'dominance'
  transformation. Having horizontal rotation on the strip
  would be nice, the rest could be done by plugins.

2. Mono input: 3D panning, consisting in its simplest form
  of a full 360 degrees azimuth control and an elevation
  control. At least azimuth should be on the strip.

3. Stereo input: twice the mono controls, but better setups
  that require this to be a single strip are preferred.

Auxiliary sends should be either B-format (for reverb) or for
montoring etc. use the first channel only. 

The signal processing required is simple enough for all these,
it is just the type of controls that is different. Conventional
LR panpots are quite useless for Ambisonics.

One other thing I noted during my experiments: using the 
'manual setup' option in the new track/bus dialog makes
Ardour quit without saying goodbye.




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