Pure Data: Another Integrated Computer Music Environment

Pure Data another integrated computer music environment Miller S Puckette Department of Music UCSD La Jolla Ca mspucsdedu c Kunitachi College of Music Reprinted from Pro ceedings Second Intercollege Computer Music Concerts Tachikawa pp May Abstract making software systems which were really usable by noncomputer scientists was addressed by the A new software system called Pure Data is in the Max program Max was an attempt to make early stages of development Its design attempts to a screenbased patching language that could imi remedy some of the deciencies of the Max program tate the mo dalities of a patchable analog synthesizer while preserving its strengths The most imp ortant Many other graphical patching languages had b een weakness of Max is the diculty of maintaining com prop osed that did not suciently address the real p ound data structures of the type that might arise time control asp ect and many other researchers had when analyzing and resynthesizing sounds or when by then prop osed much more sophisticated realtime recording and mo difying sequences of events of many control strategies without presenting a clear and fun dierent types Also it has proved hard to integrate touse graphical interface Max was in essence a com nonaudio signals video for instance and also au promise that got part way toward b oth goals dio sp ectra into Maxs rigid tilde ob ject system Finally the whole issue of maintaining two separate As so on as Philipp e Manourys Pluton was realized copies of all data structures one to edit and one to using Max thus proving Max to b e an interesting access in real time has caused much confusion and environment for realtime computer music a stream diculty Pds working prototype attempts to sim of criticisms of Max started to app ear Max wasnt plify the data structures in Max to make them more originally intended as a programming language yet readily combined into novel userdened data struc many users treated it as one As such Max had obvi tures Also the relationship b etween the graphical ous shortcomings some of which are rep orted in pro cess and the realtime one which is handled in Also the original version of Max b eing written for one way on the Macintosh and another way on the a Mac Plus computer didnt address the question of ISPW is replaced by yet a third solution computergenerated audio remaining instead in the realm of MIDI This was addressed in but only Introduction for sp ecial hardware The design of realtime computer music systems has b een a sub ject of active research since the RTSKED The question of how to use Max to amass and use program By several authors were prop os data arose in IRCAM during the design phase of the ing formal or semiformal realtime proto cols some ISPW A new software idea called Animal was pro times in the guise of complete systems for doing p osed and implemented Many ideas in Pd owe realtime computer music The question of their origin to the Animal program way to restore saved do cuments as in message passing N=32 −2 for realtime computer music control and synthesis Blackman In this example the new canvas ob ject is the window which names itself X The third command to X is to create a graph which then receives its −3 own messages b efore the rst p op message resets X to p oint to the original canvas Text can b e added either to the graph in the graphs own co ordinates −4 like N or to the canvas in centimeters like the string Blackman The data to b e graphed are from a le in this case but supp ort is also N=2048 taken −5 included for embedding the data in the Pd le 0 1 2 3 Canvasses which currently can hold only text and graph ob jects will so on supp ort the style Max b oxes and interconnections and also a framework Figure Sample Pdgenerated graph for collections which will generalize Maxs explode feature Pd will therefore incorp orate three window types of Max patch table explo de into a single new Design window type Pds rst application has b een to prepare the gures for an up coming signal pro cessing pap er by Puck Templates ette and Brown Commercially available software for graphing data proved unsuitable for this application In Pd the notion of a patch as in Max and the The same can often b e said of music software The notion of a dialog for searching for instance or for rst exercise for Pd has b een to render graphs such setting the range of a slider are unied There is as in Figure There is as yet no editor for these one exception the le selection panels will b e normal graphs The source for the one shown follows dialogs not patches If for instance we op en a Maxstyle number b ox a template window app ears N canvas noisesimbla as in Figure X font helveticamediumr Another example of a template would corresp ond X text Blackman to a p oint of the graph of Figure its two entries X graph noisesimblaplot would b e for the x and y values of the p oint In X xticks this case it would b e p ermissible to add a eld to the X xlabel template which would add the corresp onding eld to X yticks all the p oints b elonging to that template This could X ylabel either b e the p oints of one of the curves of the graph X style point all the p oints of the graph or all the p oints of several more style lines omitted graphs X text N Templates dier from the abstractions of Max X text N in that the template is not reinstantiated for each X pop invocation a single template acts as a nonmo dal di X pop alog window for all instances of the data structure it The format is very much like the Max le format controls If an anonymous data structure a oneo which features embedded descriptions of patchers As member of a heterogenous sequence in eect a Max with Max the message system is used in the same message as in a Max qlist is op ened a madetoorder tcl numbox Pd Pd−gui Max type: int Pd implementation show: text Figure top: 100 Pure Data also will get rid of one ma jor annoyance signal bottom: 0 in Max which is the necessity of sp ecifying ob jects to provide constant inputs Pd will allow tilde ob jects to query their connections if no signals are connected to a signal input but a oatingp oint outlet Figure The template for a number b ox is connected a scalarinput version of the tilde ob ject will b e called if available otherwise a signal ob ject template is created to show it will b e provided automatically To supp ort templates a new eld ob ject is in tro duced Fields dier from numbers in having eld names as in Figure Maxstyle patchable ob jects Implementation can query a template patch for the onset of a eld of a given name so patches can traverse data structures Pd is in two parts as shown in Figure The real through their templates Also any data structure Pd shown at left do es realtime computations using which could b e called a Pure Datum can b ecome a MaxFTSlike message interpreter and scheduler a Max message handled in the usual way All Pd do cuments reside in the address space of Pd The other pro cess named Pdgui talks to the com puters window system through the tk to olkit DSP This should allow p ortability to the X MS and Mac intosh window systems although the current proto MaxFTS which was the predecessor of Pd had a type runs only on SGI hardware severely limited notion of audio signals which has proven to o restrictive for working with frequency The realtimenonrealtime divide works very dif domain or nonaudio signals In Pd users may create ferently from that of MaxFTS the editor resides DSP blo cks in which sample rate and vector size in the realtime Pd layer not in Pdgui in MaxFTS vary This is done using two new tilde ob jects the four dierent editors all reside in the GUI layer clock and reclock The rst of these allows the Max This choice reects an imp ortant change that user to attach a symbolic name to a sp ecic combi has o ccurred in computer hardware in the last ten nation of sample rate and vector size This notion years multiprocessors like the X and ISPW are now replaces the switch mechanism of MaxFTS any giving way to unipro cessors at least in computer mu clock can b e turned on and o The reclock ob sic applications This year we can exp ect to see a ject simply converts a signal to any desired clo ck For unipro cessing computer announced which will equal example preparing a signal for overlap FFT analy the sixpro cessor ISPW in sp eed at less than half the sis is simply reclo cking to a clo ck with the necessary cost For the ISPW it was necessary to make the do c prop erties the overlapadd step for converting back ument the patch reside in the graphical layer b e into the time domain is accomplished by reclo cking cause otherwise there would b e six do cuments This to the usual clo ck caused nightmarish problems in keeping the two data sets Maxs and FTSs coherent In Pd we sidestep ference San Francisco Computer Music Asso this problem by putting all calculations b oth editing ciation p moves and realtime audio rendering in a single pro Anderson D and R Kuivila A Mo del gram Pd is therefore badly suited to multiprocessing of RealTime Computation for Computer Mu but more in line with current hardware developments sic Pro ceedings of the International Com than MaxFTS puter Music Conference San Francisco Com Pd should provide near patchlevel compatibility puter Music Asso ciation pp with Max from IRCAM and near source com patibility with externs Most of the dierences Boynton L et al MIDILISP A LISP will b e minor design changes argument types of li Based Music Programming Environment for the brary functions

Load more