[wdmaudiodev] Re: sample rate control on Vista

  • From: "Dugan Porter" <duganp@xxxxxxxxxxxxxxxxxxxxx>
  • To: <wdmaudiodev@xxxxxxxxxxxxx>
  • Date: Tue, 18 Jul 2006 10:24:48 -0700

That is our intention, yes.
Dugan Porter - Game Audio Team - Microsoft 
This posting is provided "as is" with no warranties, and confers no
rights

________________________________

        From: wdmaudiodev-bounce@xxxxxxxxxxxxx
[mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of Andrew Elder
        Sent: Tuesday, July 18, 2006 5:58 AM
        To: wdmaudiodev@xxxxxxxxxxxxx
        Subject: [wdmaudiodev] Re: sample rate control on Vista
        
        

        Are the "Core Audio APIs" going to be supported in future (ie
post Vista) OSes ?
        
        - Andrew
        
        Larry Osterman wrote: 

                Core Audio APIs in Windows Vista:
http://windowssdk.msdn.microsoft.com/en-us/library/ms678710.aspx
                
                
                This posting is provided "as is" with no warranties, and
confers no rights
                
                
                -----Original Message-----
                From: wdmaudiodev-bounce@xxxxxxxxxxxxx
[mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of stephen turner
                Sent: Monday, July 17, 2006 7:09 PM
                To: wdmaudiodev@xxxxxxxxxxxxx
                Subject: [wdmaudiodev] Re: sample rate control on Vista
                
                  

                        Is this API documented anywhere yet?
                            

                
                Thanks Jeff.  This was going to be my next question.
                All I can find is:
                
        
http://blogs.msdn.com/larryosterman/archive/2005/12/07/501306.aspx
                
                -steve
                ----------------------
                Stephen Turner
                AudioScience, Inc.
                www.audioscience.com
                
                -------- Original Message --------
                  

                        From: "Jeff Pages" <jeff@xxxxxxxxxxxxxxxx>
<mailto:jeff@xxxxxxxxxxxxxxxx> 
                        Sent: Monday, July 17, 2006 6:26 PM
                        To: wdmaudiodev@xxxxxxxxxxxxx
                        Subject: [wdmaudiodev] Re: sample rate control
on Vista
                        
                        Is this API documented anywhere yet?
                        
                        Jeff
                        
                        ----- Original Message -----
                        From: "Hakon Strande"
<hakons@xxxxxxxxxxxxxxxxxxxxx> <mailto:hakons@xxxxxxxxxxxxxxxxxxxxx> 
                        To: <wdmaudiodev@xxxxxxxxxxxxx>
<mailto:wdmaudiodev@xxxxxxxxxxxxx> 
                        Sent: Tuesday, July 18, 2006 9:51 AM
                        Subject: [wdmaudiodev] Re: sample rate control
on Vista
                        
                        
                            

                                Windows Audio Session API
                                
                                The Vista low level audio APIs
                                
                                HakonS
                                
                                -----Original Message-----
                                From: wdmaudiodev-bounce@xxxxxxxxxxxxx
        
[mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of Stephen Turner
                                Sent: Monday, July 17, 2006 4:47 PM
                                To: wdmaudiodev@xxxxxxxxxxxxx
                                Subject: [wdmaudiodev] Re: sample rate
control on Vista
                                
                                      

                                3. However, if an app uses the new
WASAPI API in exclusive mode
                                          

                                What the heck is WASAPI?.
                                ------------------------
                                Stephen Turner
                                AudioScience, Inc.
                                www.audioscience.com
                                
                                ----- Original Message -----
                                From: "Dugan Porter"
<duganp@xxxxxxxxxxxxxxxxxxxxx> <mailto:duganp@xxxxxxxxxxxxxxxxxxxxx> 
                                To: <wdmaudiodev@xxxxxxxxxxxxx>
<mailto:wdmaudiodev@xxxxxxxxxxxxx> 
                                Sent: Monday, July 17, 2006 4:40 PM
                                Subject: [wdmaudiodev] Re: sample rate
control on Vista
                                
                                
                                Hi Nikolay.  Here's a multi-part answer
for you:
                                
                                1. There is no programmatic way for an
app to set the mmsys.cpl capture
                                rate, because the Vista philosophy is
that no audio app can make
                                configuration changes that affect any
other apps.  The setting in
                                mmsys.cpl
                                is only meant to be changed by the user.
                                
                                2. If an app uses the legacy APIs
(waveIn and DirectSoundCapture) to
                                capture
                                audio at a rate other than mmsys.cpl's,
the system will convert from the
                                mmsys.cpl rate to the app's requested
rate using a sample rate
                                converter.
                                
                                3. However, if an app uses the new
WASAPI API in exclusive mode (by
                                using
                                the AUDCLNT_SHAREMODE_EXCLUSIVE flag),
it can open the device in any
                                format
                                supported by the driver, and no SRC will
be used.  The downside is that
                                no
                                other app will be able capture audio.
                                
                                4. If you need to use a legacy API, you
can at least *discover* the
                                system
                                capture rate setting using the new Vista
APIs, and then capture at that
                                rate, to avoid the SRC; however this
doesn't let you *control* the rate.
                                
                                Hope that helps -
                                Dugan Porter - Game Audio Team -
Microsoft
                                This posting is provided "as is" with no
warranties, and confers no
                                rights
                                
                                
                                -----Original Message-----
                                From: wdmaudiodev-bounce@xxxxxxxxxxxxx
        
[mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of Nikolay V.
                                Pyatkov
                                Sent: Sunday, July 16, 2006 3:22 PM
                                To: wdmaudiodev@xxxxxxxxxxxxx
                                Subject: [wdmaudiodev] sample rate
control on Vista
                                
                                Hi,
                                
                                We have an input only WDM portcls audio
driver on Vista 5456. The driver
                                can
                                support 48,000 and 44,100 sample rate.
The application needs to open
                                this
                                driver at 48,000. Here is the code:
                                
                                WAVEFORMATEX wf;
                                wf.wFormatTag = WAVE_FORMAT_PCM;
                                wf.nChannels =  2;
                                wf.nSamplesPerSec = 48000;
                                wf.nAvgBytesPerSec = 192000;
                                wf.nBlockAlign = nBlockAlign;
                                wf.wBitsPerSample =
UCODEC_BIT_PER_SAMPLE_PCM;
                                wf.cbSize = 0;
                                
                                mmResult = waveInOpen(
                                &m_hWaveIn,
                                nInputDeviceId,
                                &m_WaveFormat,
                                (DWORD_PTR)m_hWaveInEvent,
                                 0,
                                CALLBACK_EVENT);
                                
                                mmResult is 0.
                                
                                But the trace in the driver shows:
                                
                                00000431 9.63108540 ValidatePcm :
                                00000432 9.63109016 ---- cbSize
= 22
                                00000433 9.63109398 ---- nChannels
= 2
                                00000434 9.63109875 ---- nSamplesPerSec
= 44100
                                00000435 9.63110352 ---- wBitsPerSample
= 16
                                
                                The Vista audio subsystem took the
parameters from "Audio
                                Devices->Recording->My
Device->Properties->Options" .If I manually
                                modify
                                value in the Options panel Vista will
use the value to open my device.
                                
                                I tried to check/uncheck "exclusive
control" box. Does not help. How do
                                I
                                get
                                control over the bit rate back to the
application?
                                
                                Thanks,
                                Nikolay
                                
                                
                                      


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