1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
|
<HTML>
<HEAD>
<TITLE>Pd Documentation 3</TITLE>
</HEAD>
<BODY bgcolor="#ffffff">
<SMALL>
<div style="width:6.5in; margin-left:.5in">
<CENTER> <B>
Pd Documentation chapter 3: Getting Pd to run
</B> </CENTER>
<BR>
<A href=index.htm#s3> back to table of contents </A>
<BR><BR>
Pd runs under Irix, Microsoft Windows, Linux, and Mac OS 10.2 (Jaguar).
How to get Pd up and running depends on your operating system,
but the overall strategy is the same.
You must first get and install it, and
then untangle whatever problems arise in handling audio and MIDI input
and output, and finally get Pd to meet its real-time obligations reliably.
In case of trouble also consult the Pd mailing list archive on
<A href="http://iem.kug.ac.at/mailinglists/pd-list/">
http://iem.kug.ac.at/mailinglists/pd-list/</A>
, which often has late-breaking news about configuration problems and solutions.
<P>
You may be interested in getting only audio output or audio input, or
you may need both to run simultaneously. By default, Pd will try to run
both, but if you don't need either input or output, you may find that Pd
runs more reliably, or at least more efficiently, with the unused direction
turned off. This is controlled by Pd's command line flags.
<P>
Depending on your application you will have a more or less stringent latency
requirement. Ideally, when any input (audio, MIDI, keyboard, network) is
available, the outputs (in particular the audio output) should react instantly.
In real life, it is necessary to buffer the audio inputs and outputs, trying
always to keep some number of milliseconds ahead of real time to prepare for the
inevitable occasions where the CPU runs off to service some different task
from Pd. How small this latency can be chosen depends on your OS and your
audio driver.
<P>
To test audio and MIDI, start Pd and select "test Audio and MIDI" from the
"help" menu.
<P> TIP: If Pd starts up but you get distortion or glitches in the audio
output, this could be either because the "audio I/O buffer" isn't big enough,
or else because the CPU load of the patch you're running is too great for the
machine you have, or else because the ADC and DAC are out of sync or even at
different sample rates. To test for the first possibility, try increasing the
"-audiobuf" parameter in the command line (but see also under your OS below.)
For the second, start up your favorite performance monitor program; and for the
third, try starting Pd up with ADCs disabled.
<P> Here are instructions for getting and installing Pd for the four
operating systems it runs on: IRIX, MS Windows, Linux, and Max OSX.
<H4> <A name=s1.1> 3.1. IRIX (SGI machines) </A> </H4>
<P> (NOTE: as of release 0.35 I haven't had an IRIX machine to compile
Pd on. Soeren Bovbjerg has kindly compiled 0.35 and 0.36 for IRIX;
you can find these at
<A href=http://www.cvmt.dk/~sb/> http://www.cvmt.dk/~sb/. </A>)
<P> Download Pd, which will be a "tar.Z" file. You can unpack this by
typing "zcat [name].tar.Z | tar xf -" to a shell. This creates a directory
named "pd".
<P>
Starting with release 0.25, Pd should come in "n32" and "o32" versions.
"o32" is the default and will run on IRIX 5.x and up. "n32" runs faster,
but only on 6.x and up. Also, "externs" have to be updated for n32. The
"pd" executable (bin/pd in the distribution) is a symbolic link to either
"pd-o32" or "pd-n32."
<P> NOTE: "externs" appear to be broken in the N32 version... I'm not sure
how long this has been true. If you want to use external objects, you have
to use the O32 version.
<P>
Please note that the path to the Pd executable program can't contain
space characters; don't put it in a directory named "Program Files"
for example.
<P>
If for example you put Pd in ~, the executable program
will be ~/pd/bin/pd. The program looks at its command line to
figure out where it is, so it's best to invoke Pd by its full pathname.
You should always invoke Pd from a Unix shell because many important
messages appear on the standard error.
<P>
The simplest way to invoke Pd is to
make an alias in your ".cshrc" file (assuming you use the "c" shell) such as:
<PRE>
alias pd ~/pd/bin/pd
</PRE>
(assuming your Pd distribution landed in ~, for example).
<P>
Pd will open the "default" audio input and output devices, without regard
for whether they are in sync or not. This will be bad if they aren't; use
the "-noadc" or "-nodac" flag to disable either the input or output. Pd is
supposed to handle up to 8 channels of audio in and/or out. (But at least
one user had to recompile Pd on his Onyx to get 8 channels working.)
<P>
As to MIDI, Pd simply attempts to open all available MIDI devices for input and
output, which is probably very bad on anything more recent than my Indy. If
any MIDI ports fail to open either for input or output, all MIDI is disabled.
<P> Pd has not been fixed to request real-time priority from Irix; it will
compete with all other processes on your machine for CPU time.
<H5> Audio and MIDI in IRIX </H5>
<P>
Pd takes command line arguments to set the number of input and output channels
and the sample rate. These don't affect the SGI's audio settings, which you
have to set separately using the "audio panel." Pd does detect the audio
sample rate if you don't specify one on the command line.
<P>
On SGI machines, you have to work to get MIDI running. Before you start Pd, verify
that least one MIDI port is configured open. Pd opens the FIRST MIDI port
that's open. You might want to get rid of the "software" MIDI port if you're
running 6.x. On Indys, the usual practice is to open serial port number 2
because some systems configure port 1 as "console" by default. You can use the
GUI if you want, or else just type
<PRE>
startmidi -d /dev/ttyd2
</PRE>
to get port 2 speaking MIDI, and
<PRE>
stopmidi
</PRE>
to stop it. You can test whether MIDI is configured by typing,
<PRE>
ps -dafe | grep midi
</PRE>
and looking for "startmidi" processes.
<P>
It's a good idea to connect your serial port to your MIDI interface before
typing the "startmidi" command, not afterward, at least in 5.x. We use the
Opcode Studio 3 interface but in principle any Mac-compatible one should work.
<P>
The O2 apparently has RS232 ports, not RS422. I think SGI's web site says
something about how to deal with this.
<H4> <A name=s1.2> 3.2. Microsoft Windows </A> </H4>
<P> Pd is compiled under NT, but shoould work under any version of Windows
since 95. Pd will appear as a "zip" file. Unzip this, creating a directory
such as \pd. (You can put it wherever you like but the path should have no
spaces in it; so "Program Files" would be a bad place.)
<P>
If for example you put Pd in C:\pd, the executable program will be
C:\pd\bin\pd. You can simply adjust your path to include C:\pd\bin and just
invoke "pd" in a command prompt window. You can also make a "command prompt"
shortcut to start Pd.
<P> Pd requires "TCP/IP networking" to be turned on. This doesn't mean you
have to be on a real network, but simply that Pd actually consists of two
programs that make a "network link" to intercommunicate.
<H5> The vanishing window </H5>
<P> Pd is a "command line" program. Most error and diagnostic
messages from Pd appear on the command prompt window Pd runs from.
<P> If you start Pd from the "run" menu or as a shortcut, and if there's
a problem with run-time flags (see the Pd command line below), Pd will
print an error and exit. You won't see this error unless you arrange for the
"command prompt" or "msdos" window to stay open after Pd exits. One way
to do this is to make a "batch" file ("run.bat", say) containing the Pd
command line.
<H5> Audio in Microsoft Windows </H5>
<P>
You can ask for a list of audio and MIDI devices by typing
"pd -listdev"; you can then specify which audio and MIDI device to use.
Type "pd -help" (or make any mistake) to get the syntax for specifying
which device to use.
<P>
Most PC sound cards seem to have MIDI built in; you don't seem to have to
do anything special to get Pd to send and receive MIDI. You can list and
choose MIDI devices in the same way as audio.
<P>
MIDI timing is very poor if you are using simultaneous audio input and output;
if you suppress either audio input or output things will improve somewhat under
NT; you can apparently get the jitter down to ~40 msec. On W95 performance is
simply terrible. W98, with either audio input or output suppressed, offers
fairly good MIDI timing (~5 msec jitter) but crashes occasionally.
<P> Some NT and W98 drivers greet you with a constant trail of "resyncing
audio" messages. Sometimes you can fix this by invoking Pd with the "-noresync"
flag.
<H5> ASIO </H5>
<P> As of version 0.35 Pd supports ASIO. Invoke Pd as "pd -asio" and, if
needed, specify "-sounddev" (etc.) flags to specify which device (see
"the Pd command line" below.) You can also specify a "-blocksize" different
from the default (256 samples) and "-audiobuf" in milliseconds. Pd will
round this down to a power of two buffers, each of "-blocksize" in sample
frames.
<P> Using an RME Hammerfall, and specifying "-audiobuf 5 -blocksize 32" I
was able to get about 7 milliseconds of throughput delay (as measured by
the latency-measurement patch in 7.stuff/tools.) As always, you can specify
"-channels" to any even number up to the maximum (32, I think) or can specify
channel count separately for input and output (-inchannels and -outchannels).
<H5> The special joys of Windows 95 </H5>
<P>
On Windows 95 you can expect a hard time. Every user who tries it seems to
encounter a new problem. The best way to run Pd is to get into the "MSDOS
Prompt" program and type \pb\bin\pd to it (or whatever the path ends up being.)
You can probably put pd's "bin" directory in your path so that you just type
"pd" to the prompt.
<P>
You don't want to run Pd from the "run" menu because if it fails to start up
the window holding the error message will disappear instantly. Ditto for
clicking on "batch files" or on the Pd executable itself.
<P>
The most common reason Pd might fail to start up in W95 is not having
"networking" turned on. Pd is actually two programs that establish an IP
interconnection. Beware that this sometimes fools Windows into calling your
ISP for no reason.
<P>
It is often necessary to specify a huge audio buffer to get steady audio
output in W95; see the command line arguments below.
<H4> <A name=s1.3> 3.3. Linux </A> </H4>
<P> What to do depends on which flavor of Linux you are running (e.g., Debian
or Red Hat). The instructions here should work for Pd 0.33 and up regardless of
your situation. (If not, you can read the Pd mailing list archives for
recent problems; if you have found a new problem you're welcome to post it
to the list.)
<P> Before you start, you might want to check that you have the resources Pd
needs. The main things you need are the C compiler, X windows (including
the X development package for Pd to link against) and TK. If you're running
Redhat or Mandrake 7.x or up, I think these are all present by default.
The RedHat X client developer "RPM" package is called XFree86-devel.
<P> You don't absolutely have to have the X server package running; you can run
Pd on the microprocessor in your refrigerator as long as it can connect to an X
server on another machine.
<P> If you're running RedHat you might want to use RPM to install Pd. For
other linux distributions, download the "tar.gz" version and compile it.
<H5> Getting Pd as an RPM </H5>
<P> Download Pd, perhaps from
<a href="http://www.crca.ucsd.edu/~msp/software.html">
http://www.crca.ucsd.edu/~msp/software.html</A> ,
to a file such as "pd-0.33-0.i386.rpm".
Open a "shell" window, cd to
the directory containing the file, and type the command,
<PRE>
rpm -i pd-0.33-0.i386.rpm
</PRE>
<P> (substituting the real file name.) Then you should be able to type "pd"
to a shell and watch the Pd main window appear.
<H5> Getting Pd as a .tar.gz </H5>
<P>
Download Pd, perhaps from
<a href="http://www.crca.ucsd.edu/~msp/software.html">
http://www.crca.ucsd.edu/~msp/software.html</A> ,
to file such as "pd-linux-033.tar.gz". Open a "shell"
window, cd to
the directory containing the file, and type the command,
<PRE>
zcat pd-linux-033.tar.gz | tar xf -
</PRE>
which creates a directory named "pd". I do this from my home directory.
Next, compile it. "CD" to pd and read the INSTALL.txt, or else just cd
to "pd/src" and type
<BR> ./configure
<BR> make depend
<BR> make
<P> You can pass flags to "configure" to customize your compilation:
<PRE>
To enable ALSA 0.9x (the latest one), add "--enable-alsa".
To enable the older ALSA 0.5x, add "--enable-old-alsa".
To enable Ritsch's RME 9652 driver, add --enable-rme".
To put Pd in /usr/bin instead of /usr/local/bin, add "--prefix=/bin".
</PRE>
<P> After "make", just type "~/pd/bin/pd" to run pd.
<P> Alternatively, as superuser, you can run "make install" after "make depend"
and then anyone on your system can just type "pd" to run it.
<H5> Testing audio and MIDI. </H5>
<P>
Next try audio. We want to know whether audio output works, whether audio
input works, and whether they work simultaneously. First run "aumix" to
see audio input and output gains and which device is "recording".
Then test audio output by running
<PRE>
pd -noadc
</PRE>
and selecting "test audio and MIDI" from the "help" menu. You should see a
patch. Turn on the test tone and listen. Do the usual where's-the-signal
business.
<P>
Then quit Pd and test audio input via
<PRE>
pd -nodac
</PRE>
Re-open the test patch and hit "meter"; look at the levels. 100 dB is a
hard clip; arrange gains so that the input signal tops out around 80 or 90,
but no higher.
<P> Now see if your audio driver can do full duplex by typing "pd" with no
flags. If you see error messages involving /dev/dsp or /dev/dsp2, you're
probably not able to run audio in and out at the same time. If on the other
hand there's no complaint, and if the audio test patch does what you want, you
might wish to experiment with the "-audiobuffer" flag to see what values of
audio latency your audio system can handle.
<H4> Audio hardware in Linux </H4>
<P>
Be forewarned: installing and testing audio and MIDI drivers in Linux can take
days or weeks. There apears to be no single place where you can get detailed
information on Linux audio.
<P>
Depending on your hardware and software, you might or might not be able to
run "full duplex," i.e., use audio input and output at the same time. For
many applications it's important to be able to do this, but if by any chance
you don't need simultaneous input and output you will have much less trouble
than if you do.
<P>
There are two widely-used driver sets, called "OSS" and "ALSA". OSS is
included in the standard Linux kernels since version 2.2. However, for some
audio cards you can find newer versions than are included in the kernel
releases. You can get ALSA from
<a href="http://www.alsa-project.org/">
http://www.alsa-project.org/</A> .
<P>
(There is also a commercial version of the OSS drivers which costs $30 (slightly
more for certain audio cards.) Hit
<a href="http://www.opensound.com/">
http://www.opensound.com/</A> .
These might be easier to use than the free OSS drivers, but I've never tried
them.)
<P> ALSA is able to emulate OSS, so that you can usually run Pd using the
default "OSS" settings even if it's actually ALSA that's running.
<H5> Installing and configuring FREE OSS </H5>
<P>
OSS is really a collection of loadable device drivers. The commands
for loading and unloading the drivers are "insmod" and "rmmod".
You can see if the audio drivers are
running using "lsmod" (as root.) If you see something like:
<PRE>
Module Pages Used by
eepro100 3 1 (autoclean)
opl3 3 0
opl3sa2 1 0
ad1848 4 [opl3sa2] 0
mpu401 5 [opl3sa2] 0
sound 15 [opl3 opl3sa2 ad1848 mpu401] 0
soundcore 1 [sound] 6
soundlow 1 [sound] 0
aic7xxx 23 2
</PRE>
then OSS is running, and if all you see is:
<PRE>
eepro100 3 1 (autoclean)
aic7xxx 23 2
</PRE>
then it isn't. You can turn OSS off by running "rmmod" repeatedly, starting
with "opl3" (or whatever) so as not to remove any module before you remove
all the modules that depend on it. In the above listing, "opl3*" is device
dependent and you might see different names.
<P>
The file, "/etc/modules.conf" apparently controls which sound drivers are
started at boot time. The sndconfig program updates this file but you can
also change things manually, for instance to switch between two different sound
cards. In Redhat 6.x and earlier, the file is named "conf.modules."
<P> Here is a modules.conf file for OSS:
<PRE>
alias eth0 e100
alias parport_lowlevel parport_pc
alias char-major-81 bttv
alias usb-controller usb-uhci
alias sound-slot-0 i810_audio
alias sound-slot-1 es1371
</PRE>
Here the two sound cards are the (motherboard resident) i810 driver and an
ensoniq es1371.
<P> In RedHat at least, the "sndconfig" program tries to automatically search
for your soundcard. Unfortunlately it only finds the "first" one which is
often not the one you want to use!
<P> Under OSS, programs can stream sound using either
"block" or "stream" mode. Stream mode is the more modern and better of the
two, but the majority of drivers, even for new sound cards, only
support "block." Pd makes "block" the default.
<H5> ALSA (Advanced Linux Sound Architecture) </H5>
<P> ALSA is newer, hence less stable and harder to use, than OSS.
Alsa comes in a "finished" version (0.5.x) and a
different, redesigned, "beta" version, 0.9. Installing ALSA can be tricky
and/or confusing.
<P> As of version 0.37 Pd works only with 0.9.x versions.
The RPM version of Pd is compiled for 0.9.x.
<P> By default, Pd uses OSS. If you are running ALSA, Pd will use ALSA's OSS
emulation. To make Pd use ALSA "natively", i.e., the way ALSA is designed
to be used, include the "-alsa" flag in the command line.
<P> In ALSA, you can specify which sound card to use using the "-alsadev"
flag. So, for instance, "-alsadev 3" means your third card, counting from
one. You can also specify it the ALSA way: "-alsadev hw:3,0".
<H5> Which sound card? </H5>
<P>
Here's a rundown on my experiences with sound cards so far. See
also the Pd mailing list archives.
<H6> RME 9652 (Hammerfall) </H6>
<P> This is the best sound card out there; it costs around $500 and has 3 ADAT
I/O ports and one SPDIF. There is a "baby hammerfall" also, which I think is
the "9632." DO NOT CONFUSE THE 9652/9632 WITH OTHER RME BOARDS WHICH MIGHT
NOT WORK WITH PD.
<P> Guenter Geiger has an OSS driver for Hammerfall for 2.4 kernels (such as
RedHat 7.1 and up). You have to download and compile it:
<A HREF=http://gige.xdv.org/pages/rme>
http://gige.xdv.org/pages/rme </A>.
<P> You must then run Pd using the "-32bit' flag, because this uses a
non-standard extension of OSS to 32 bit samples.
<P> Hammerfalls now have an ALSA driver; from what I hear
it won't work yet with Pd. I was unable to install the ALSA driver on the
two machines I tried ("no such device").
<H6> MIDIMAN </H6>
Midiman sells devices with between 4 and 12 analog channels in and out, for
which there are ALSA drivers. It seems to work fine with the old ALSA driver
(0.5). I'm running mine in Alsa 0.9 beta 10. The driver name is "ice1712".
<P> Alsa provides an "envy24control" program (in "utils". You should run
this and check that your ice1712's sync source is internal if you have no
SPDIF input, or "SPDIF" if you do. I think the default is now "internal"
but don't take it for granted...
<H6> i810/i815 </H6>
In RedHat 7.0, motherboards with native i810 audio systems don't work in
full duplex (they crash linux). Either run Pd -noadc or else (better) install
ALSA.
<H4> <A name=s1.4> 3.4. Macintosh OSX </A> </H4>
Pd version 0.35 and up support Macintosh OSX, although there are still some
problems. You can always just download
the sources and compile it yourself, or (easier)
find a MacOSX-style "package". The first package was put together by Adam
Lindsay and can be found on
<A href=http://homepage.mac.com/atl/sw>
http://homepage.mac.com/atl/sw</A>. The package simply installs itself
and you needn't follow the directions below.
<H5> To install on OSX from source: </H5>
Whether you've downloaded the source or the "package" you can
always compile Pd for yourself, whether to make your own improvements, or
possibly so that you can get the newest version before it shows up compiled for
Mac OS X.
<P> To be able to compile Pd, you must have installed Tcl/Tk
specifically in
/Applications/Wish Shell.app
and /Library/Frameworks/Tk.framework and /Library/Frameworks/Tcl.framework.
<P> First download and install TK for OSX
(http://sourceforge.net/projects/tcl/). Get a recent one compiled for
OSX, by chasing through "latest file releases", and finding a "download"
link for TCL. Then download "TclTkAqua-8.4.1-Jaguar.dmg" (the version
number may change). Click on this file and a "folder" will open. Click
on the "package" icon in that folder and an auto-installer will put Tcl/Tk
on your system.
<P> For old versions of Tcl/Tk you also had to get the "h" files from XFree86
and put them in
/usr/X11R6/include. You can download just the H files from:
<pre>
http://www.crca.ucsd.edu/~msp/x.tgz
</pre>
(the individual files seem to have adequate copyright notices so that
I can just redistribute them.) ((I hope this is no longer necessary but I
notice people keep downloading these files anyway, so I'll leave them there
a while longer until I'm sure they're not needed.))
<P> Then, just as for linux, just unload pd-whatever.tar.gz into a directory
such as ~/pd-0.35-test17 , cd to pd-0.36-0/src, type "./configure"
and "make". Then type ~/pd-0.36-0/bin/pd to a shell and enjoy!
<P> If you wish you can put the line,
<pre>
alias pd ~/pd/bin/pd
</pre>
in the file, ~/.tcshrc, so that you can later just type "pd" to a shell. (The
shell only reads the ~/.tcshrc file on startup, so this won't take effect in
any existing shells unless you specially type
<pre>
source ~/.tcshrc
</pre>
to them.)
<P> In some cases you have to explicitly give "-soundindev" and "-soundoutdev"
flags for Pd to open audio correctly; "pd -listdev" should show you the
correct device numbers.
<P> To get MIDI working, you have to do the Mac OSX magic to get a USB
MIDI interface installed. I've seen this done with Midisport devices and
I think you just download the OSX driver and follow directions.
<P> On the machine I tried, it was necessary to type,
<pre>
pd -midiindev 1 -midioutdev 2
</pre>
to get MIDI working.
<H4> <A name=s3> 3.5. graphics rendering using GEM </A> </H4>
<P>
GEM, originally by Mark Danks but now supported by Iohannes Zmoelnig, is essentially an extension of Pd that allows you to do OpenGL programming
using a suite of "GEM objects" roughly parallel to the tilde objects built
into Pd for audio. Find out more from
<a href="http://iem.kug.ac.at/~zmoelnig/index.html"> Johannes's page</a>.
<H4> <A name=s4> 3.6. The Pd command line </A> </H4>
Pd is a "command line" program. The best way to run it is from your
"terminal emulator," "shell," or "MSDOS prompt." The command line is:
<PRE>
pd [options] [patches to open]
</PRE>
although you may have to specify a path so your command interpreter can find
Pd (OS dependent.) Possible options include:
<PRE>
audio configuration flags:
-r <n> -- specify sample rate
-inchannels ... -- number of audio in channels (by device, like "2" or "16,8")
-outchannels ... -- number of audio out channels (by device)
-channels ... -- specify both input and output channels
-audiobuf <n> -- specify size of audio buffer in msec
-blocksize <n> -- specify audio I/O block size in sample frames
-sleepgrain <n> -- specify number of milliseconds to sleep when idle
-nodac -- suppress audio output
-noadc -- suppress audio input
-noaudio -- suppress audio input and output (-nosound is synonym)
-listdev -- list audio and MIDI devices
-audioindev ... -- sound in device list; e.g., "2,1" for second and first
-audiooutdev ... -- sound out device list, same as above
-audiodev ... -- specify both -audioindev and -audiooutdev together
(linux specific audio:)
-frags <n> -- specify number of audio fragments (defeats audiobuf)
-fragsize <n> -- specify log of fragment size ('blocksize' is better...)
-stream -- use stream mode audio (e.g., for es1370 audio cards)
-alsa -- use ALSA audio drivers
-alsadev <n> -- ALSA device # (counting from 1) or name: default hw:0,0
MIDI configuration flags:
-midiindev ... -- midi in device list; e.g., "1,3" for first and third
-midioutdev ... -- midi out device list, same format
-mididev ... -- specify -midioutdev and -midiindev together
-nomidiin -- suppress MIDI input
-nomidiout -- suppress MIDI output
-nomidi -- suppress MIDI input and output
general flags:
-path <path> -- add to file search path
-open <file> -- open file(s) on startup
-lib <file> -- load object library(s)
-font <n> -- specify default font size in points
-verbose -- extra printout on startup and when searching for files
-d <n> -- specify debug level
-noloadbang -- suppress all loadbangs
-nogui -- suppress starting the GUI
-guicmd "cmd..." -- substitute another GUI program (e.g., rsh)
-send "msg..." -- send a message at startup (after patches are loaded)
-rt or -realtime -- use real-time priority (needs root privilege)
-frags <n> -- specify number of audio fragments (defeats audiobuf)
-fragsize <n> -- specify log of fragment size ('blocksize' is better...)
-blocksize <n> -- specify audio I/O block size in sample frames
-stream -- use stream mode audio (e.g., for es1370 audio cards)
-alsa -- use ALSA audio drivers
-alsadev <n> -- ALSA device # (counting from 1) or name: default hw:0,0
(MS Windows specific audio:)
-resync -- resynchronize audio (default if more than 2 channels)
-noresync -- never resynchronize audio I/O (default for stereo)
-asio -- use ASIO audio driver (and not the 'MMIO' default)
MIDI configuration flags:
-midiindev ... -- midi in device list; e.g., "1,3" for first and third
-midioutdev ... -- midi out device list, same format
-nomidiin -- suppress MIDI input
-nomidiout -- suppress MIDI output
-nomidi -- suppress MIDI input and output
general flags:
-path <path> -- add to file search path
-open <file> -- open file(s) on startup
-lib <file> -- load object library(s)
-font <n> -- specify default font size in points
-verbose -- extra printout on startup and when searching for files
-d <n> -- specify debug level
-noloadbang -- suppress all loadbangs
-nogui -- suppress starting the GUI
-guicmd "cmd..." -- substitute another GUI program (e.g., rsh)
-send "msg..." -- send a message at startup (after patches are loaded)
-rt or -realtime -- use real-time priority (needs root privilege)
</PRE>
Here are some details on some of the audio and MIDI options (but see also the
next section on file management.)
<H5> sample rate </H5>
The sample rate controls Pd's logical sample rate which need not be that of
the audio input and output devices. If Pd's sample rate is wrong, time will
flow at the wrong rate and synthetic sounds will be transposed. If the output
and input devices are running at different rates, Pd will constantly drop frames
to re-sync them, which will sound bad. You can disable input or output if this
is a problem.
<H5> audio buffer size </H5>
You can specify an audio buffer size in milliseconds, typically between 10 and
300, depending on how responsive your OS and drivers are. If this is set too
low there will be audio I/O errors ("data late"). The higher the value is,
on the other hand, the more throughput delay you will hear from the audio
and/or control inputs (MIDI, GUI) and the audio coming out.
<P> In Linux and Windows, you can also specify the audio block size in sample
frames (but in Windows, this is only effective when using ASIO).
<H5> MIDI devices </H5>
<P> You can specify multiple MIDI input and output devices. For example,
"pd -midiindev 3 -midioutdev 4,2" asks for the third MIDI input device and the
fourth and second MIDI output device. The "channel message" midi objects in Pd
such as notein or pgmout will take channels 1-16 to mean the first open MIDI
port, 17-32 the second one, and so on. The midiin, sysexin, midiout objects
give you a separate inlet to specify which of the open MIDI port numbers
you want.
<P> In Linux, if you
ask for "pd -midioutdev 1" for instance, you get /dev/midi0 or /dev/midi00
(or even /dev/midi). "-midioutdev 45" would be /dev/midi44. In NT, device
number 0 is the "MIDI mapper", which is the default MIDI device you selected
from the control panel; counting from one, the device numbers are card
numbers as listed by "pd -listdev."
<H4> <A name=s5> 3.7. dealing with files </A> </H4>
Pd has a search path feature; you specify the path on the command line
using the "-path" option. Paths may contain any number of files. If you
specify several files in a single "-path" option they're separated by colons
in unix or semicolons in NT. When Pd searches for an abstraction or an
"extern" it uses the path to try to find the necessary file. The "read"
messages to qlists and arrays (aka tables) work the same way. NO SPACES MAY
APPEAR ANYWHERE IN THE SEARCH PATH, e.g., "c:\my nonsense\goobers" won't
work.
<P> Filenames in Pd are always separated by (unix-style) forward slashes, even
if you're on Windows (which uses backslashes). This is so that patches can be
ported more easily between operating systems. On the other hand, if you
specify a filename on the command line (as in "pd -path c:\pdlib") the file
separator should agree with the operating system. <BR>
<P> If a filename in a patch has any "/" characters in it, the "path" is not
used; thus, "../sounds/sample1.wav" causes Pd only to look relative to the
directory containing the patch. (You may also invoke externs that way.)
<P> As of version 0.35, there may be spaces in the path to Pd itself; also,
the "openpanel" and "savepanel" objects can handle spaces. But still not
the search path.
</BODY>
</HTML>
|
