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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<HTML>
<HEAD>
<TITLE>Pd Documentation 3</TITLE>
<meta http-equiv="Content-Type" content="text/html">
<link rel="stylesheet" type="text/css" href="pdmanual.css" media="screen">
</HEAD>
<BODY>
<H2>Pd Documentation chapter 3: Getting Pd to run</H2>
<P>
<A href="index.htm#s3"> back to table of contents </A>
<BR><BR>
</P>
<P>Pd runs under Irix, Microsoft Windows, Linux, and MacOS 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.
<P> Installation instructions are platform-specfic; the following four
sections
will describe what to do for various operating systems you might have.
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.
The rest of this section describes how to get audio and MIDI to work.
<P>
To test audio and MIDI, start Pd and select "test Audio and MIDI" from the
"Media" menu. You should see a window like this:
<CENTER><P>
<IMG src="fig11.1.png" ALT="test tone patch">
</P></CENTER>
<P> First, try to get Pd to play a sine wave over your speakers. The "TEST
TONE" control at top left turns this on and off. Normally, all the output
channels are turned on so that when you turn the tone on (to a soft -40 dB or a
louder -20 dB) you should get output on the first six of your output channels.
(If you have fewer than six output channnels open, the extra
channels aren't played; and if you have more, this particular patch won't
use them.)
<P> If there's anything wrong, the most likely outcome is that you will hear
nothing at all. This could be for any of at least three reasons: Pd might
have failed to open the audio device; the audio card's output volume might
be set to zero; or your audio system might not be set to amplify the computer
output.
<P> The number boxes labeled "AUDIO INPUT" show the levels of incoming
audio, in dB, with 100 being maximum. (Incoming signals may clip at
RMS levels below 100; for instance, a sinusoid clips at about 97 dB.)
Any DC present in the input (such as you get with cheap audio hardware)
will show up as level unless you turn on the "input hipass" toggle
at right; then the DC component is filtered out before metering.
<P> To test the quality of audio input and output, turn on "monitor"
(also at right) which causes the inputs to be played to the outputs at
unit gain. You should hear a faithful, non-distored copy of whatever is
sent through the patch.
<P> It is easy to get two copies of Pd running by accident; on most machines
only one at a time may be inputting and outputting sound. (Some copy of Pd
might have audio or MIDI devices open and prevent the copy you're trying to use
from getting access to them.) Having extra
copies of Pd around will also eat CPU cycles uselessly.
<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 may be specified in Pd's command line flags or using the
"audio settings" dialog panel.
<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> 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
audio latency in the command line or the "audio settings" dialog (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> In addition to the "test audio and MIDI" patch, the "Media" menu
contains items for controlling audio and MIDI settings. The first two
items, "Audio on" and "Audio off", open or close the audio devices and
start or stop Pd's audio computation.
<P> If there is a choice of
audio API to make, the Media menu will display them. (On Linux, they are
OSS, ALSA, and Portaudio; on Windows, you get MMIO and ASIO). More information
about the APIs appears in the sections below.
<P> Next is the "Audio settings..." menu item, which opens a dialog like this:
<CENTER><P>
<IMG src="fig11.2.png" ALT="audio settings dialog">
</P></CENTER>
The exact choices you get depend on the operating system and API. The sample
rate controls both audio output and input. The audio throughput delay is
the nominal amount of time, in milliseconds, that a sound coming into the
audio input will be delayed if it is copied through Pd straight to the
output. Naturally you would like this to be as small as possible, but,
depending on OS, API, and even the specific choice of audio hardware, there
will be a limit to how small you can make this. You can typically get
10 msec on linux (and lower still if you use special tricks), 30 msec on Mac
OSX, and 60 msec on Windows (but note that there might be ways that a
patient Windows user can reduce this).
<P> Next you get a choice of input and output device. If you want to open
more than one, hit "use multiple devices" and you'll be allowed up to 4
in and 4 out. Each audio device is 2 channels by default, but you may
specify more if your hardware supports it.
<H3> <A name=s1.1> 3.1. Installing Pd in Microsoft Windows </A> </H3>
<P> Pd is compiled under NT, but should work under any version of Windows since
95. Pd will appear as a self-extracting archive (a ".exe" file). Run this and
select a destination directory when prompted, such as "\pd" or "Program
Files\pd".
<P>
If for example you put Pd in "C:Program Files\pd", the executable program will be
"C:Program Files\pd\bin\pd". You can simply adjust your path to include
C:\pd\bin and then
invoke "pd" in a command prompt window. You can also make a shortcut to the
executable program (left-click on it and drag to the desktop, for example.)
<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" (locally) to intercommunicate.
<H4> The vanishing window </H4>
<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.
<H4> Audio in Microsoft Windows </H4>
<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. You can modify the Pd shortcut (or batch file) to
set these.
<P>
Alternatively, (and especially when just starting out) you can experiment
with different audio configurations using the "audio settings"
item in the Media menu.
<P>
You can list and
choose MIDI devices in the same way as audio; note that, by default, MIDI
input is disabled in Windows (because it's possible to hang up some MIDI
devices if Pd exits unexpectedly).
<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). The "first edition" used to crash
occasionally; this might be fixed in the "second edition".
<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.
<H4> ASIO </H4>
<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.
<H3> <A name=s1.2> 3.2. Installing Pd in Linux </A> </H3>
<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> If you're running RedHat or Mandrake you might want to use RPM to install
Pd. For other linux distributions, download the "tar.gz" version and compile
Pd.
<H4> Getting Pd as an RPM </H4>
<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.
<H4> Getting Pd as a .tar.gz </H4>
<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>
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>
tar xzf pd-linux-033.tar.gz
</PRE>
<P>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
<P>
<BR> ./configure
<BR> make depend
<BR> make
</P>
<P> You can pass flags to "configure" to customize your compilation:
<PRE>
To enable debugging (and losing code optimization) add "--enable-debug".
To use Portaudio version 19 (experimental), add "--enable-portaudio".
To put Pd in /usr/bin instead of /usr/local/bin, add "--prefix=/bin".
</PRE>
Alsa and Jack support should auto-configure, but "--enable-alsa" od
"--enable-jack" will force their inclusion.
<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.
<H4> Testing audio and MIDI. </H4>
<P>
Next try audio. We want to know whether audio output works, whether audio
input works, and whether they work simultaneously. First run "aumix" (or
any newer audio mixer app) to
check audio input and output gains and learn which input (mic; line;
etc.) is "recording".
Then test audio output by running
<PRE>
pd -noadc
</PRE>
<P>and selecting "test audio and MIDI" from the "Media" 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>
<P>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.
<H3> Audio hardware in Linux </H3>
<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> 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.
<H4> Installing and configuring FREE OSS </H4>
<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>
<P>then OSS is running, and if all you see is:
<PRE>
eepro100 3 1 (autoclean)
aic7xxx 23 2
</PRE>
<P>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>
<P>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.
<H4> ALSA (Advanced Linux Sound Architecture) </H4>
<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".
<H4> Which sound card? </H4>
<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> Word on the Pd mailing list is that the only way at present (7/04) to use
Hammerfall boards in Pd is via ALSA and jack.
<H6> MIDIMAN </H6>
<P>Midiman sells PCI devices (delta 44, 66, 1010, and 1010LT)
with between 4 and 10 channels in and out, for
which there are ALSA drivers. 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>
<P>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.
<H3> <A name="s1.3"> 3.3. Installing Pd in Macintosh OSX </A> </H3>
<P>Pd version 0.35 and up support Macintosh OSX. You need the OSX Jaguar
distribution (10.2) or later.
<P> To install Pd you can always just download
the sources and compile them yourself, or (easier)
find a MacOSX-style "package". The first package was put together by Adam
Lindsay; the most current one seems to be the one by Hans
on
<A href="http://www.pure-data.info/Members/hans/">
http://www.pure-data.info/Members/hans/</A>.
The package simply installs itself
and you needn't follow the directions below.
</P>
<H4> To install on OSX from the binary tarball: </H4>
<P> The binary tarballs on
<A HREF="http://www.crca.ucsd.edu/~msp/software.html">
http://www.crca.ucsd.edu/~msp/software.html</A>
take more steps to install but are more "official". To install them:
<P> If you haven't already, first download and install Tcl/Tk; there are pointers on
Hans's page, or try: http://tcltkaqua.sourceforge.net/
<A href="http://tcltkaqua.sourceforge.net/">
http://tcltkaqua.sourceforge.net/</A>. Double click on what you
get (a disk image opens) and then double click on the "package" icon, and the
installer should tell you how to proceed from there.
<P> Then download a tarball like pd-0.37-0.mac.tar.gz, and expand it
(I think that's done just by clicking on the thing in OSX.) You can install
it into your home directory for example. Then start a shell window and
type "~/pd/bin/pd" to it, and pd should start.
<H4> To install on OSX from source: </H4>
<P>
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 as described above.
<P> Then, just as for linux, just unload pd-whatever.tar.gz into a directory
such as ~/pd-0.36-0, 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 a line such as,
<pre>
alias pd ~/pd/bin/pd
</pre>
<P>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>
<P>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>
<P>to get MIDI working.
<H3> <A name=s1.4> 3.4. Installing Pd in IRIX (SGI machines) </A> </H3>
<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>
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:
</P>
<PRE>
alias pd ~/pd/bin/pd
</PRE>
<P>(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.
<H4> Audio and MIDI in IRIX </H4>
<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>
<P>to get port 2 speaking MIDI, and
<PRE>
stopmidi
</PRE>
<P>to stop it. You can test whether MIDI is configured by typing,
<PRE>
ps -dafe | grep midi
</PRE>
<P>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.
<H3> <A name=s3> 3.5. graphics rendering using GEM </A> </H3>
<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>.
<H3> <A name=s4> 3.6. The Pd command line </A> </H3>
<P>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>
<P>although you may have to specify a path (such as "~/pd/bin/pd" or
"C:\program files\pd\bin\pd") so your command interpreter can find
Pd. Possible options include:
<PRE>
audio configuration flags:
-r <n> -- specify sample rate
-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
-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 I/O 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
(linux specific audio:)
-frags <n> -- specify number of audio fragments (defeats audiobuf)
-fragsize <n> -- specify log of fragment size ('blocksize' is better...)
-oss -- use ALSA audio drivers
-alsa -- use ALSA audio drivers
-pa -- use portaudio (experimental version 19)
-alsadev <n> ----- obsolete: use -audiodev
-32bit ---- (probably obsolete) -- use 32 bit OSS extension
(Windows specific audio:)
-mmio -- use MMIO drivers and API
-asio -- use ASIO drivers and API
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
-helppath <path> -- add to help 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
-version -- don't run Pd; just print out which version it is
-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>
<P>Here are some details on some of the audio, MIDI, and scheduler options (but
see also the next section on file management.)
<H4> multiple devices. </H4>
<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.
<P> Audio device selection is similar, except that you can also specify
channels by device: "-audioindev 1,3 -inchannels 2,8" will try to open device 1
(2 channels) and device 3 (8 channels.)
<H4> sample rate. </H4>
<P>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.
<H4> audio buffer size, block size, and sleep grain. </H4>
<P>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> You can also specify the audio block size in sample
frames. This is 64 by default (except for MMIO for which it's 256), and may
be 64, 128, or 256.
<P> The "sleepgrain" controls how long (in milliseconds) Pd sleeps between
periods of computation. This is normally the audio buffer divided by 4, but
no less than 0.1 and no more than 5. On most OSes, ingoing and outgoing MIDI
is quantized to this value, so if you care about MIDI timing, reduce this to 1.
<H4> MIDI </H4>
<A> 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> System exclusive MIDI message inupt and output is theoretically supported
in version 0.37 but has not been tested.
<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."
<H3> <A name="s5"> 3.7. dealing with files </A> </H3>
<P>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.
<P> You can see and edit the path while Pd is running using the "path..."
item in the "File" menu. The path must be correctly set before you load
a patch or it may fail to find abstractions, etc., that are needed to
construct the patch.
<P>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> Path entries may be relative to the patch directory; for instance,
if your path has an item, "../sound", and your patch is in "my stuff/all mine",
then Pd will look in "my stuff/sound". Spaces should be OK in the path to
the patch, but not in the path entry (../sound) itself. This is useful if
you have a patch and supporting files (even a supporting snapshot of pd)
that you want to distribute or carry around together.
<P> Regardless of path, Pd should look first in the directory containing
the patch before searching down the path. (However, sometimes, for
reasons I can't explain yet, you have to put the entry "." in the
search path for this to happen, as least within linux!)
<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 specified 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.
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