PD ONLINE DOCUMENTATION CHAPTER 3: AUDIO, MIDI, and GRAPHICS

This chapter describes how to get audio and MIDI I/O working in Pd.

AUDIO

Pd's audio input and output are always configured as stereo.  The audio sample
rate is 44100 Hz. unless you ask for a different rate at startup
as in "pd -r 32000".  On SGIs, Pd checks that the system is running at the
rate you asked Pd for and warns you if not; you can then change the hardware
sample rate using teh "audio panel".  On PCs, the audio driver might or might
not do this for you automatically.

On Pcs, 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.

To test audio and MIDI, open the "START HERE" patch from the "help" menu.

MIDI

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

    startmidi -d /dev/ttyd2

to get port 2 speaking MIDI, and

    stopmidi

to stop it.  You can test whether MIDI is configured by typing,

    ps -dafe | grep midi

and looking for "startmidi" processes.

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.

The O2 apparently has RS232 ports, not RS422.  I think SGI's web site says
something about how to deal with this.

On PCs, most 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.

This file was last updated for release 0.23.


