Checks if analog playback is in progress on a drive.
DWORD BASS_CD_Analog_IsActive(
    DWORD drive
);
| drive | The drive... 0 = the first drive. | 
| BASS_ACTIVE_STOPPED | Analog playback is not in progress, or drive is invalid. | 
| BASS_ACTIVE_PLAYING | Analog playback is in progress. |