[PD] table size limit

Alexis Baskind Alexis.Baskind at ircam.fr
Tue May 30 12:47:23 CEST 2006


Hi all,

Thanks for your answers. Actually I need a phase vocoder to perform an 
extreme time compression of the recording of a music piece (22 minutes 
-> 5 seconds). I want the final sound to keep as much as possible of the 
original recording's timbral colour and dynamics evolution.  Thus I 
don't need to do it in realtime, but I wanted anyway to use pure data, 
because of the quality of Miller's implementation of the pvoc, which 
sounds amazingly better than any other I know, even without phase 
locking (I guess it's because ffts are computed on the fly, and not by 
interpolating between fixed frames).

Kyle, thanks for the infos about recompiling. Anyway I already looked in 
the sources and  among others in d_soundfile.c, but only found the 
soundfiler's default maximum size. As I mentionned the limitation is 
independent from soundfiler and seems to be inherent to table.

I think I will follow Miller's suggestion to use several successive 
tables. Of course they should overlap on at least one block, since 
(correct me if I'm wrong) it may be difficult to switch from one table 
to another at the middle of a block.

Cheers,

Alexis

 > Message: 3
 > Date: Mon, 29 May 2006 09:45:55 -0700
 > From: Miller Puckette <mpuckett at imusic1.ucsd.edu>
 > Subject: Re: [PD] table size limit
 > To: Piotr Majdak <piotr at majdak.com>
 > Cc: pd-list at iem.at
 > Message-ID: <20060529164555.GA11160 at imusic1.ucsd.edu>
 > Content-Type: text/plain; charset=us-ascii
 >
 > Hi all,
 >
 > It's probably not too hard to fix the phase vocoder to use a series of
 > short tables.  The "bang~" object resets two tabread4~ objects every
 > block, so at the same time one could hop to the next table when
 > appropriate.
 >
 > Although audacity will do this too, it's interesting to be able to scroll
 > through a long soundfile (Kontakte in 4 channels for instance) at any
 > forward or backward speed.  One can listen to a 6-channel version of the
 > entire 35-ish-minute long piece to test Stochhausen's assertion that the
 > large scale structure has the same identity as the piece does locally...
 >
 > cheers
 > Miller
 >
 > On Mon, May 29, 2006 at 11:17:12AM +0200, Piotr Majdak wrote:
 >> Hi Alexis,
 >>
 >> Alexis Baskind wrote:
 >> >I am trying to use Miller's wonderful phase-locked vocoder on a big
 >> sound
 >> >file (i.e. some 20 minutes on 2 channels). My problem is that "table",
 >> in
 >> >which the audiofile is supposed to be loaded, even including the
 >> 'maxsize'
 >> >option in soundfiler, does not seem to afford sizes bigger than some
 >> >1.700.000 elements, i.e. 24 bits I guess. Is there a means to overcome
 >> >this limit ?
 >>
 >> I don't know the answer, but I have a (maybe stupid) question:
 >> One great advantage of pd is processing audio in real-time. Why do you
 >> want
 >> to load signals into tables and perform the processing offline?
 >>
 >> br, Piotr
 >>
 >>
 >> --
 >> Piotr Majdak
 >> Institut f?r Schallforschung
 >> ?sterreichische Akademie der Wissenschaften
 >> Reichsratsstr. 17
 >> A-1010 Wien
 >> Tel.: +43-1-4277-29511
 >> Fax: +43-1-4277-9296
 >> E-Mail: piotr at majdak.com
 >> WWW: http://www.kfs.oeaw.ac.at
 >>
 >>
 >>
 >> _______________________________________________
 >> PD-list at iem.at mailing list
 >> UNSUBSCRIBE and account-management ->
 >> http://lists.puredata.info/listinfo/pd-list





More information about the Pd-list mailing list