Hi Lokesh: Does your KSPROPERTY_RTAUDIO_BUFFER_WITH_NOTIFICATION call return successful? What codec and driver are you running? Not all the HD Audio drivers are supporting KSPROPERTY_RTAUDIO_BUFFER_WITH_NOTIFICATION yet. Do might want to check to see if the driver you are using supports it. Thanks Cheng-mean From: wdmaudiodev-bounce@xxxxxxxxxxxxx [mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of Lokesh Patakolusu Sent: Monday, April 06, 2009 4:06 PM To: wdmaudiodev@xxxxxxxxxxxxx Subject: [wdmaudiodev] Problem using KSPROPERTY_RTAUDIO_BUFFER_WITH_NOTIFICATION. Dear All, I am trying to get the property KSPROPERTY_RTAUDIO_BUFFER_WITH_NOTIFICATION but the KSRTAUDIO_BUFFER had the buffer size as 0.I am not sure why the driver is faling to allocate cyclic buffer.I tried with the two sizes : 1024 and 2048.But still it returned 0 bytes.Anybody experimented it before. Initially when i tried with KSPROPERTY_RTAUDIO_BUFFER by giving 2048 bytes,it allocated 4096 byes sucessfuly.When i switched to KSPROPERTY_RTAUDIO_BUFFER_WITH_NOTIFICATION it returned 0 bytes. If anybody have any idea pls let me know. Thanks Lokesh