Loopback midi driver.
The loopback midi driver makes it possible to create special purpose virtual midi devices based on user land server processes.
MIDI loopback devices are like named pipes or pseudo terminals. They are grouped in client and server device pairs. The server side device must be open before the client side device can be opened.
The server side device is used by some special application (such as a software based MIDI synthesizer) to receice MIDI events from the applications that want to play MIDI.
Client applications such as MIDI players open the client side device when they need to play some MIDI stream (file). The client side device behaves like any "ordinary" MIDI device. However it cannot be opened when there is no program connected to the server side.
MIDI loopback devices differ from "normal" MIDI devices because an application is needed at the both ends of the loop. The loop device will return a "Connection reset by peer" error (ECONNRESET) error. Applications designed to be used as loopback based server applications can/should use this error (returned by read or write) as an end-of-stream indication.
o midiloop_instances: Specifies how many loopback client/server MIDI device pairs to be created.
Values: 1-16 Default: 1
/etc/oss4/conf/oss_midiloop.conf Device configuration file