[Clam-devel] clam and max

[Xavier Amatriain]

Hi Greg, and thanks for taking some time to try this out and for
your valuable feedback. Some clarifications below...

Greg Kellum wrote:
> This is
> part of what makes Max fast. Max was for instance one of the first
> applications that were able to do a real time FFT on a desktop. (That
> was over ten years ago...)
>   
First let me be clear: allocating during sound processing is a
bad practice. As a matter of fact in our first designs of CLAM this
was avoided at all costs. However soon we decided to favor
flexibility over efficiency. Besides, I have been profiling CLAM
long enough on several OS to know that allocations are not a
performance bottleneck in CLAM (except in very few cases where
that was solved). Things like trigonometric functions or bound
checking during loops, for instance, are much worse problems
in that sense.

As a matter of fact with my little experience in Max I can assure you
that you can do very inefficient things in Max, just like you can
do very efficient ones in CLAM ;-)

Also, saying that this is why Max was one of the first software to
run FFTs on a desktop is a bit of an overstatement. As far as I
know Miller Puckette did not implement an optimized version of
the FFT computation such as FFTW. These implementations are
the reason why 10 years ago people were able to do FFTs on a
desktop, not the fact that copies were avoided.

> Due to this constraint, I knew that it wouldn't be possible to run
> CLAM networks in Max. The networks are allocating new memory every
> time something is passed from one CLAM object to another over a
> network connection. 
Again a network does not strive for efficiency but rather for
flexibility. Inplace processing is possible in CLAM but not using
Networks. So, yes, in a Network a Processing Object copies its
output onto the channel. Although this does not necessarily imply
an allocation (I think that in the Audio case it doesn't) it might
imply so when dealing with complex structures (those that Max
would not allow to pass anyway, right?).
> and Max was crashing
> in the middle of a call to an object's copy constructor where it was
> calling new.
>   
I also wonder like David, how can that happen. Any idea if Pd also
implements this restriction and how it does it?

Cheers,

Xavier