Subject: MAX Digest - 28 Dec 1999 to 29 Dec 1999 (#1999-372)
Date: Thu, 30 Dec 1999 00:00:00 -0500
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There are 5 messages totalling 144 lines in this issue.

Topics of the day:

  1. groove~ looping behavior
  2. integers/floats/accuracies
  3. Emagic Audiowerk8
  4. Manuals
  5. question about LCD object

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Date:Tue, 28 Dec 1999 11:45:11 -0800
From:David Zicarelli <zicarell@CYCLING74.COM>
Subject: groove~ looping behavior

The 0 loop maximum input to groove~ doesn't work very well right
now. It appears that:

- by default, this value is 0, and groove~ will loop over the
length of its associated buffer~

- if you change the buffer~ size, the loop doesn't get recalculated

- if you set the loop maximum to 0, the loop now goes from 0 to 0,
i.e., not much happens. The only way to get back to looping over
the entire buffer~ is to use info~ to get the buffer size and
stuff that into the groove~

I propose to change this so that a maximum loop point of 0 always
goes to the end of the buffer~, whatever its size, and the loop point
is updated automatically whenever the buffer~ size changes.
Objections?

David Z.

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Date:Tue, 28 Dec 1999 15:22:46 -0800
From:Matt Wright <matt@CNMAT.CNMAT.BERKELEY.EDU>
Subject: Re: integers/floats/accuracies

Lawrence Ball is only slightly mistaken:
> If I'm not mistaken, Sound Manager and many sound cards will convert all
> that fine tuned accuracy into a bare lattice of 16-bit sound. Which I wonder
> is what exactly?
>
> Does this mean that the DAC voltages available are stepped in 32767 (or -8)
> intervals either side of a centre? Or is there some more complex mapping.
> Does the 32bit float get converted simply into the nearest 1/32767th ? Plus
> or minus - depending on the value? Do DACs deal in integer values these
> days?

I read somewhere that someone had built a floating point D/A converter, but
all of the commonly available audio hardware uses integers.

As we all know, MSP uses the range -1 to 1 for floating point signal values.

In MSP, it's the job of the audiodriver to convert floating point samples into


ints. Different audio I/O has different numbers of bits (16, 24, etc.), so
the audiodriver has to get this right too.

In the 16 bit case, the range -1.0 to 1.0 gets mapped to the range -32767 to
32767. This is a floating point multiply by 32767, followed by a cast to
short integer.

Note that this does not include any clipping! This table shows why just a
slight overflow produces such a, shall we say, "spectrally rich" result:

floatCorresponding 16-bit int

0.9932439
1.0032767
1.01-32442
1.02-32114

As far as I know all audio D/A converters have an analog lowpass filter after
the actual D/A part, which bascially smooths out what would otherwise be the
jagged edges of a step function of each discrete sample value. So while the
DAC voltages are indeed stepped in 32767 intervals (or more, if your converter
is more than 16 bit) either side of a centre, you'll never see these steps
from looking at the signal that comes out of your D/A converter.

> Any precision values of knowledge will be very gratefully calibrated,

My precision value on this knowledge is 0.8

-Matt

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Date:Tue, 28 Dec 1999 13:19:50 +0100
From:Aron Lagerberg <aronl@HEM.PASSAGEN.SE>
Subject: Emagic Audiowerk8

How do I get MSP to work with Audiowerk8...
I've got the preliminary ASIO drivers and I've placed them
in the MAX folder but nothing happends. Just using Sound Manager...

what to do...?

please...?
/Aron

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Date:Wed, 29 Dec 1999 14:35:53 +0100
From:Bertram Dunskus <bertram@IPF.DE>
Subject: Manuals

Hello,

a few questions about manuals:

1) Is there a way to get the Max manual in PDF form? I am travelling a lot
with my equipment, and I hate carrying the Max 3.0 and 3.5 update manuals
around with me.

2) The SDK manual and template project files seem quite outdated. I could
not even read the CW template into my version of the IDE, because it was so
old. Can we hope for anything newer soon?

Otherwise I amvery happy with the system. The performance of Max/MSP on my
G3 upgraded Umax S900 with a Motu 2408 is impressive!

Bertram


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Date:Wed, 29 Dec 1999 15:11:40 -0500
From:Alejandro Cremaschi <cremasch@OAK.CATS.OHIOU.EDU>
Subject: question about LCD object

Hello. I've been using LCD object recently. I noticed that whenever I drag
another window on top of the one containing LCD, or when I resize the
window with LCD, all the drawingsin the LCD object get erased. I need to
redraw everything every time I drag something on top of it. Is there any
way to avoid this, and to keep all the drawings "alive" even if the
windows goes temporarily to the back?


Thanks. Happy 2000.
Alejandro

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End of MAX Digest - 28 Dec 1999 to 29 Dec 1999 (#1999-372)
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