Changing Internal MIDI Synthesizer Volume
Windows provides the following functions to retrieve and set the volume level
of internal MIDI synthesizer devices:
||Retrieves the volume level of the specified internal MIDI synthesizer device.
||Sets the volume level of the specified internal MIDI synthesizer device.
Not all MIDI output devices support volume changes. Some devices can support
individual volume changes on both the left and right channels. For information
on how to determine if a particular device supports volume changes, see Querying MIDI Output Devices
Unless your application is designed to be a master volume-control application
(provides the user with volume control for all audio devices in a system), you
should open an audio device before changing its volume. You should also check
the volume level before changing it and restore the volume level to its previous
level as soon as possible.
Volume is specified as a doubleword value. The upper 16 bits specify the
relative volume of the right channel, and the lower 16 bits specify the relative
volume of the left channel.
For devices that do not support individual volume changes on both the left and
right channels, the lower 16 bits specify the volume level and the upper 16
bits are ignored. Values for the volume level range from 0x0 (silence) to 0xFFFF
(maximum volume) and are interpreted logarithmically. The perceived volume
increase is the same when increasing the volume level from 0x5000 to 0x6000 as it
is from 0x4000 to 0x5000.
- Software for developers
Software for Android Developers
- More information resources
Unix Manual Pages