Dear mihaela@xxxxxxxxx, Please note that I am out of the office but will endeavour to return your email upon my return. Best regards, franco@xxxxxxxxxxx -----8<--------- Hello I want to write a driver filter capable of trapping any kind of sound input signal (from webcam microphone, from Line input or Microphone input of a sound card) and capable of applying effect on the sound like Pitch, and any other sound effects. My problem is that I need this driver to be used on XP and Vista. For USB Audio, the solution, I think, is to write a lower filter driver that could intercept the streaming and applies the effects. This solution can be used for both systems: XP and Vista. For USB Audio on XP, I saw that can be used GFX Filters as an alternatively solution. But for sound card there is any solution? What is your opinion? I looked a lot for any documentation but found none about this part. For Vista, I saw that the solution recommended is sAPOs, but for it there are some samples on DDK and 2 docs on Microsoft site and that it is all, no more details. Thanks Mihaela ****************** WDMAUDIODEV addresses: Post message: mailto:wdmaudiodev@xxxxxxxxxxxxx Subscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=subscribe Unsubscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=unsubscribe Moderator: mailto:wdmaudiodev-moderators@xxxxxxxxxxxxx URL to WDMAUDIODEV page: http://www.wdmaudiodev.com/ ****************** WDMAUDIODEV addresses: Post message: mailto:wdmaudiodev@xxxxxxxxxxxxx Subscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=subscribe Unsubscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=unsubscribe Moderator: mailto:wdmaudiodev-moderators@xxxxxxxxxxxxx URL to WDMAUDIODEV page: http://www.wdmaudiodev.com/