MIDI(4) BSD Programmer's Manual MIDI(4)NAMEmidi - device-independent MIDI driver layer
SYNOPSIS
midi* at autri?
midi* at mpu?
midi* at opl?
midi* at pcppi?
midi* at sb?
midi* at wss?
pseudo-device sequencer [count]
#include <sys/types.h>
#include <sys/midiio.h>
DESCRIPTION
The midi driver provides support for various MIDI peripherals. It pro-
vides a uniform programming interface layer above different underlying
MIDI hardware drivers. The MIDI hardware can be of many different kinds,
e.g., an external synthesizer on a MIDI port (or a serial port), the PC
speaker, an internal FM synth, or a wavetable synth.
There are two device file types available for MIDI operation:
/dev/rmidiN, and /dev/music. The /dev/rmidiN devices provides raw access
to a MIDI device. Data written is sent to the physical device as fast as
possible and is uninterpreted. Reading from the device returns data as
soon as it becomes available. A moderate amount of buffering is available
both for reading and writing. The raw MIDI devices are mostly useful for
non realtime operations, such as downloading patches to a device, since
it is hard to get the accurate timing needed for quality music from a
user program. But the devices can act as a simple patchboard for MIDI
devices. For example, a MIDI keyboard could be connected to a synthesizer
by the command
$ cat -u /dev/rmidi1 >/dev/rmidi2
The /dev/music device is a MIDI sequencer device. Data sent to and from
this device not only contains the information sent to the MIDI device,
but also timing information. The kernel will make sure that data is sent
to the physical device at the indicated time. The sequencer device uses
the /dev/midiN devices internally and they are unavailable when used by
the sequencer.
The API for the sequencer device is binary compatible with the OSS
sequencer interface.
FILES
/dev/rmidiN
/dev/music
/dev/sequencer
SEE ALSOmidiplay(1), ioctl(2), ossaudio(3), audio(4), autri(4), mpu(4), opl(4),
pcppi(4), sb(4), wss(4), ym(4)HISTORY
The midi driver first appeared in NetBSD 1.4.
MirOS BSD #10-current August 6, 1998 1
