Pallavi Joshi wrote: > > I have a USB audio device and I enumerate the device, get the file > name and create a handle to it using the CreateFile function. I then > use kernel streaming (from the DirectKS sample by MS) to communicate > with this USB device. I basically first instantiate a capture and a > render pin on the filter using the KsCreatePin function from > ksuser.dll. I then use DeviceIoControl function with > IOCTL_KS_READ_STREAM and IOCTL_KS_WRITE_STREAM codes to read and > write data from my USB audio device. But the audio playback I hear is > not good....in the sense its quality is not good. If I play a sine > wave it sounds broken as if parts of its data are missing. I used a > USB analyzer to see the USB frames which are being sent and received > every 1 ms. Here the input frames from the USB are good but the output > frames going to the USB have "zero packets" periodically. This might > explain why my audio quality is not good and broken. > > Can anybody tell me why is this happening? Any pointers will be of > immense help to me. How are you sending the sine wave data? How large are the buffers, how often do you send them, how are you doing the pacing? -- 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/