How large is each input buffer? Does the behavior change if you decrease the buffer size by 20%? Mitch Rundle Microsoft Corp. -----Original Message----- From: wdmaudiodev-bounce@xxxxxxxxxxxxx [mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of Andrew Sherbrooke Sent: Wednesday, June 09, 2004 4:13 PM To: wdmaudiodev@xxxxxxxxxxxxx Subject: [wdmaudiodev] Direct KS question Hi all, I have a Direct KS user process which speaks to USBAudio.sys. It uses rings of buffers for input and output, submitting them via DeviceIoControl, using IOCTL_KS_WRITE_STREAM and IOCTL_KS_READ_STREAM. It then waits for one of the associated events to become signaled by calling WaitForMultipleObjects(). Everything works great until we set it up to use 96 kHz stereo input (we're not using output at that rate, because of bandwidth limitations, so it's just waiting on the input buffers). However the WaitForMultipleObjects() call returns immediately, causing our process to basically spin in a tight loop, never getting valid data. Occasionally it will work fine, but most of the time it behaves as described. Output at 96 kHz works. Both directions together work at 44.1 and 48. It appears that input even works alone at 88.2 (although I haven't tested this exhaustively), and again, infrequently, it works at 96 kHz. Has anyone seen anything like this? Are there known problems with USBAudio.sys at these higher rates, perhaps (Windows XP Pro, current release)? Thanks very much! Sincerely, Andrew Sherbrooke ****************** 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.de/ ****************** 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.de/