DetectNt4SoundDevices
EnumerateNt4ServiceSoundDevices
MMRESULT EnumerateNt4ServiceSoundDevices	(	IN LPWSTR	ServiceName,
		IN MMDEVICE_TYPE	DeviceType,
		IN SOUND_DEVICE_DETECTED_PROC	SoundDeviceDetectedProc
	)
Definition at line 23 of file detect.c.
Referenced by DriverProc().
{
    HKEY Key;
    DWORD KeyIndex = 0;

    VALIDATE_MMSYS_PARAMETER( ServiceName );

    /* Device type zero means "all" */
    VALIDATE_MMSYS_PARAMETER( IsValidSoundDeviceType(DeviceType) ||
                              DeviceType == 0 );

    while ( OpenSoundDeviceRegKey(ServiceName, KeyIndex, &Key) == MMSYSERR_NOERROR )
    {
        HKEY DevicesKey;
        DWORD ValueType = REG_NONE, ValueIndex = 0;
        DWORD MaxNameLength = 0, ValueNameLength = 0;
        PWSTR DevicePath = NULL, ValueName = NULL;
        DWORD ValueDataLength = sizeof(DWORD);
        DWORD ValueData;

        if ( RegOpenKeyEx(Key,
                          REG_DEVICES_KEY_NAME_U,
                          0,
                          KEY_READ,
                          &DevicesKey) == ERROR_SUCCESS )
        {
            /* Find out how much memory is needed for the key name */
            if ( RegQueryInfoKey(DevicesKey,
                                 NULL, NULL, NULL, NULL, NULL, NULL, NULL,
                                 &MaxNameLength,
                                 NULL, NULL, NULL) != ERROR_SUCCESS )
            {
                SND_ERR(L"Failed to query registry key information\n");
                RegCloseKey(DevicesKey);
                RegCloseKey(Key);

                return MMSYSERR_ERROR;
            }

            DevicePath = AllocateWideString(MaxNameLength +
                                            strlen("\\\\.\\"));

            /* Check that the memory allocation was successful */
            if ( ! DevicePath )
            {
                /* There's no point in going further */
                RegCloseKey(DevicesKey);
                RegCloseKey(Key);

                return MMSYSERR_NOMEM;
            }

            /* Insert the device path prefix */
            wsprintf(DevicePath, L"\\\\.\\");

            /* The offset of the string following this prefix */
            ValueName = DevicePath + strlen("\\\\.\\");

            /* Copy this so that it may be overwritten - include NULL */
            ValueNameLength = MaxNameLength + sizeof(WCHAR);

            SND_TRACE(L"Interested in devices beginning with %wS\n", DevicePath);

            while ( RegEnumValue(DevicesKey,
                                 ValueIndex,
                                 ValueName,
                                 &ValueNameLength,
                                 NULL,
                                 &ValueType,
                                 (LPBYTE) &ValueData,
                                 &ValueDataLength) == ERROR_SUCCESS )
            {
                /* Device types are stored as DWORDs */
                if ( ( ValueType == REG_DWORD ) &&
                     ( ValueDataLength == sizeof(DWORD) ) )
                {
                    if ( ( DeviceType == 0 ) ||
                         ( DeviceType == ValueData ) )
                    {
                        SND_TRACE(L"Found device: %wS\n", DevicePath);
                        SoundDeviceDetectedProc(ValueData, DevicePath);
                    }
                }

                /* Reset variables for the next iteration */
                ValueNameLength = MaxNameLength + sizeof(WCHAR);
                ZeroMemory(ValueName, (MaxNameLength+1)*sizeof(WCHAR));
                /*ZeroWideString(ValueName);*/
                ValueDataLength = sizeof(DWORD);
                ValueData = 0;
                ValueType = REG_NONE;

                ++ ValueIndex;
            }

            FreeMemory(DevicePath);

            RegCloseKey(DevicesKey);
        }
        else
        {
            SND_WARN(L"Unable to open the Devices key!\n");
        }

        ++ KeyIndex;

        RegCloseKey(Key);
    }

    return MMSYSERR_NOERROR;
}
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