I made a filter driver and it will catch the audio data to do some audio enhancements. Some reasons I need to control audio volume especially Record-in and Line-in in Record side not in the play-out side. I figured out that I can use KSPROPERTY and KSPROPERTY_AUDIO_VOLUME_LEVEL. But this one was for the master volume. I don t know how can I get/set the Mic-In and Line-In volume level. My thinking was to parse the topology and get the node of Mic-In or Line-in. but I don t know how. How can parse the topology in a driver? How can I get the node at a driver? If you have a simple example it would be better. Thank you. ******************************* IMPORTANT MESSAGE ****************************** This transmission may contain information that is privileged, confidential and/or exempt from disclosure under applicable law. If you are not the intended recipient, you are hereby notified that any disclosure, copying, distribution, or use of the information contained herein (including any reliance thereon) is STRICTLY PROHIBITED. If you received this transmission in error, please immediately contact the sender and destroy the material in its entirety, whether in electronic or hard copy format. Thank you. ********************************************************************************