Open Sound System
OSS 4.x User's Guide

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oss_midimix - Driver for controlling OSS mixer devices using MIDI messages

The MIDI mixer device can be used by MIDI sequencer programs to control OSS mixer devices (volumes) in real time. A list of mixer devices available in the system can be found using the ossinfo program with the -x option.

INTRODUCTION

This driver uses MIDI channel numbers to select the mixer device. The first MIDI channel (#0) connects to the first mixer device in the system and so on. When any of the mixer controls (such as volume sliders) change their value the MIDI mixer device delivers a control change message to the application listening it. An application (such as a MIDI sequencer program) can record these mixer changes during recording and play them back during playback. In this way it's possible to repeat mixer changes with precise timing during playback.

OPTIONS

None

KNOWN PROBLEMS

MIDI support is not included in OSS v4.0. It will be re-introduced in some future version of OSS.
The way how MIDI channel numbers are mapped to the mixer device numbers is system dependednt and may change depending on the order of devices are loaded in the system. The same is true with the MIDI controller numbers. For this reason recorded mixer changes may become obsolete if new devices are installed in the system or if the mixer layout changes in future OSS versions.
For the time being the MIDI controller numbers are mapped directly to the mixer control numbers. This means that only the first 128 controls in large mixers can be supported. This may change in future OSS versions.

FILES