budapi.u32中有对wav、mid等音量的控制函数。

SetVolume

Description:    baSetVolume sets the volume level of the sound card for wave files and audio CD.

Usage:    Result = baSetVolume( Device, Volume )

Arguments:    String, integer.
    Device is the device to change. Can be:

"master"    sets the master volume
    "wave"    sets the volume of wave and video files
    "cd"    sets the volume of audio CD playback
    "midi"    sets the volume of an external midi device
    "synth"    sets the volume of the internal FM synthesizer
    "master mute"    controls the master mute
    "wave mute"    controls the wave mute
    "cd mute"    controls the CD mute
    "synth mute"    controls the built-in synthesizer mute

Volume is the volume level to set. The volume level can be between 0 (silence) and 100 (maximum). For the mute devices, Volume can be either 1 for mute on, or 0 for mute off.

Returns:    Integer.
    Returns 1 if successful, else 0.

Examples:    Authorware:
    OK := baSetVolume( "cd" , 50 )