I am feeding the data using DeviceIoControl with IOCTL_KS_WRITE_STREAM as the control code. The render pin is created using the KsCreatePin function from ksuser.dll. The buffer size is 512 and it is a 2 channel, 16 bit PCM audio data. The sampling rate is 44.1 KHz. Its exactly the same way as it is done inside the DirectKS sample code. I do not know what you mean by two things: "timing" and "mismatch in data performance"? Thanks for your help. I really appreciate it. Regards, Pallavi On Tue, Jun 23, 2009 at 3:34 PM, Tim Roberts <timr@xxxxxxxxx> wrote: > Pallavi Joshi wrote: > > > > I am using Microsoft's kernel sreaming sample code (DirectKS). I > > create a render as well as capture pin in my code. This works fine > > with my laptop's built in audio card. But when I use the same code > > with a USB audio card, the output audio is scratchy. Its like the > > audio quality is not good. You can still hear the song being played > > but it won't be clear....it is scratchy. > > Assuming you don't have a mismatch in the data performance, this kind of > thing often means that the rendering device is starving. How are you > feeding the data? How much data, how large are the buffers, how are you > doing the timing? > > -- > Tim Roberts, timr@xxxxxxxxx > Providenza & Boekelheide, Inc. > > ****************** > > 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/ > > -- Pallavi Joshi (480)-280-2017