Function 25 - set SBPro volume.
Parameters:
- eax = 25 - function number
- ebx = what to set:
- 1 - set common volume
- 2 - set CD-audio volume
- cl = volume level: high 4 bits for the left column,
low 4 bits for the right one
Returned value:
- eax = 0 - success
- eax = 1 - SB base is not defined
- eax = 2 - incorrect subfunction
Remarks: