ISpMMSysAudio::SetLineId (SAPI 5.4)

Speech API 5.4
Microsoft Speech API 5.4


ISpMMSysAudio::SetLineId sets the line identifier associated with the multimedia device. Mixer lines are not supported for output devices.

   UINT   uLineId


[in] Value specifying the line identifier information.

Return values

S_OKFunction completed successfully.
E_INVALIDARGThe specified uLineId is not supported on the current device.
SPERR_NOT_FOUNDThe audio device must have been created from a token.
E_NOTIMPLNot implemented for output devices.
FAILED(hr)Appropriate error message.


For more information on the uses of device lines, please see the Win32 multimedia mixer API (e.g., mixerOpen, mixerGetId, mixerGetLineInfo, etc.)

For input devices, SAPI attempts to automatically identify the microphone line on the input device. On non-English versions of Windows and on a few English systems, it may not be possible for SAPI to automatically detect the correct microphone line. In this case, no error will be detected or returned. If speech input is not correctly detected, the user must set the microphone input line directly using Control Panel-->Speech properties-->Speech Recognition tab-->Audio Settings-->Properties. It may be necessary to adjust the microphone input line used on devices with multiple microphone inputs such as the SoundBlaster Live Platinum. In these cases, the automatically chosen line may not be the input preferred by the user.