Yes you are correct about WASAPI's IAudioClient::Initialize. Jeff- just curious- when you reported the problems, how did you go about reporting them, and approximately when? -----Original Message----- From: wdmaudiodev-bounce@xxxxxxxxxxxxx [mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of Jeff Pages Sent: Thursday, July 22, 2010 7:18 PM To: wdmaudiodev@xxxxxxxxxxxxx Subject: [wdmaudiodev] Re: Capture with USBAudio under Windows 7 noisy Doesn't the IAudioClient::Initialize function in WASAPI require in shared mode that the sampling rate be the same as what the audio engine is set to, or in exclusive mode be a rate that the hardware supports, so that the Windows SRC is never invoked? In any case, WASAPI isn't supported on XP, so the applications our customers are using are unlikely to be using that API for a long time to come. What do we tell them when they start complaining about capture artefacts on Windows 7? Jeff -----Original Message----- From: wdmaudiodev-bounce@xxxxxxxxxxxxx [mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of Larry Osterman Sent: Friday, 23 July 2010 12:06 PM To: wdmaudiodev@xxxxxxxxxxxxx Subject: [wdmaudiodev] Re: Capture with USBAudio under Windows 7 noisy Sure - use WASAPI for capture - that will use the same resampler as is used for output. DSound uses the same resampler, but when capturing mono inputs, because DSound is primarily a game API, it tunes the resampler for performance, not fidelity (I don't know if there are knobs to make the DSound resampler operate at a higher fidelity). Larry -----Original Message----- From: wdmaudiodev-bounce@xxxxxxxxxxxxx [mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of Jeff Pages Sent: Thursday, July 22, 2010 6:47 PM To: wdmaudiodev@xxxxxxxxxxxxx Subject: [wdmaudiodev] Re: Capture with USBAudio under Windows 7 noisy The applications I've used include Cooledit and Adobe Audition, as well as a spectrum analyser program I wrote which used the wave API. On XP I believe capture always used the "best" converter regardless of API, and I don't see the problem on that platform (all the converter artefacts are below -96dB). Is there any way in Vista or Windows 7 to force it to use a better quality converter on capture? Jeff -----Original Message----- From: wdmaudiodev-bounce@xxxxxxxxxxxxx [mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of Larry Osterman Sent: Friday, 23 July 2010 11:29 AM To: wdmaudiodev@xxxxxxxxxxxxx Subject: [wdmaudiodev] Re: Capture with USBAudio under Windows 7 noisy What API are you using to capture? It's possible that you're using one of the lower quality resamplers in the box (for instance if you're using the wave APIs, I believe you'll use the ACM resampler which is basically the same resampler used in XP). Larry -----Original Message----- From: wdmaudiodev-bounce@xxxxxxxxxxxxx [mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of Jeff Pages Sent: Thursday, July 22, 2010 4:20 PM To: wdmaudiodev@xxxxxxxxxxxxx Subject: [wdmaudiodev] Re: Capture with USBAudio under Windows 7 noisy Tim wrote: >The purists might disagree, but it has been my experience that the >Windows sample rate converter is pretty good for most purposes. How >are you detecting the noise at 4 kHz? Are you injecting a pure signal >and doing a spectrum analysis on the result? While the render sampling rate converter in Windows 7 is very good, the capture converter is a different matter entirely. It has conversion artefacts at about -65dB on a pure tone. I first noticed this back when Vista was released and tried reporting it a couple of times but got nowhere, and the problem has persisted into Windows 7. Jeff ****************** 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/ ****************** 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/ ****************** 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/