[wdmaudiodev] Re: External clock synchronization and sample rate issue
- From: Hakon Strande <hakons@xxxxxxxxxxxxxxxxxxxxx>
- To: Markus Bollinger <bollinger@xxxxxxxxxxxx>, <wdmaudiodev@xxxxxxxxxxxxx>
- Date: Wed, 14 Mar 2007 14:47:42 -0700
The bug "Need a way for a device to advertise realtime format caps changes" is
currently not a Windows OS Bug since the feature is part of the ongoing feature
planning/prioritization process for the next version of Windows and given the
ability for 3rd parties to work around this in the driver:
"Custom audio driver implements a different PnP device interface for each of
the possible formats."
This means it is currently not slated for QFE or SP1 release. If you feel
strongly this is unacceptable (and I think many of you will) please consider
going through Microsoft premier product support channels to file a QFE request
against Vista for this issue. We need officially documented demand to justify
working on this sooner than what is now planned.
Sincerely,
Hakon Strande | Windows Sound Team PM | (p) 425.705.0637
-----Original Message-----
From: Markus Bollinger [mailto:bollinger@xxxxxxxxxxxx]
Sent: Tuesday, March 13, 2007 2:59 AM
To: wdmaudiodev@xxxxxxxxxxxxx; Hakon Strande
Subject: Re: [wdmaudiodev] Re: External clock synchronization and sample rate
issue
Hello Hakon,
are there any news about this subject ?
-Markus.
Hakon Strande a écrit :
> We have certainly taken note of this. I can't promise that we will remedy
> this any time soon though but we will include this issue in our planning
> going forward.
>
> Sincerely,
>
> Hakon Strande
> PM Integrated, Internal, External, and Wireless Audio Devices
> MediaTech/DMD/Windows Client/Microsoft
>
> -----Original Message-----
> From: wdmaudiodev-bounce@xxxxxxxxxxxxx
> [mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of Markus Bollinger
> Sent: Thursday, January 11, 2007 1:57 AM
> To: wdmaudiodev@xxxxxxxxxxxxx
> Subject: [wdmaudiodev] Re: External clock synchronization and sample rate
> issue
>
> Stephan Kappertz a écrit :
>
>> I'm sorry but don't we agree that this is an ugly workaround? Is there
>> any chance for a better implementation of external sample rate control
>> from the Microsoft side? Please!
>>
>> I would suggest that the audio subsystem should call the intersection
>> handler if opening the driver fails at the preselected sample rate. If
>> the driver suggests a different sample rate, this should be used as
>> new default rate.
>>
>
> Hello Stephan!
> I agree with your idea;
> There are surely more than we two who would appreciate if such an
> implementation could be done by Microsoft!
>
>
>
>> - Stephan
>>
>> Jeff Pages wrote:
>>
>>> I've found under Vista stopping and starting drivers is quite fast -
>>> we have a FM radio capture card that creates 24 capture devices, and
>>> I can stop and start that in just a second or two on Vista whereas on
>>> XP you just about die of old age waiting for it!
>>>
>>> ----- Original Message ----- From: "Matt Gonzalez" <matt@xxxxxxxxxxxxx>
>>> To: <wdmaudiodev@xxxxxxxxxxxxx>
>>> Sent: Thursday, January 11, 2007 1:29 PM
>>> Subject: [wdmaudiodev] Re: External clock synchronization and sample
>>> rate issue
>>>
>>>
>>>
>>>> OK, so you don't allow the sample rate to be set by Windows. That
>>>> would certainly work.
>>>>
>>>> My descriptors are all built dynamically, so I wouldn't need
>>>> different subdevices for the different rates.
>>>>
>>>> I don't like stopping and restarting the driver 'cos it takes so
>>>> long to restart when you have a lot of audio devices. I guess if
>>>> that's what you have to do, then that's what you have to do.
>>>>
>>>> Matt
>>>>
>>>> Jeff Pages wrote:
>>>>
>>>>> Matt,
>>>>>
>>>>> My card sounds very similar with multiple inputs and outputs driven
>>>>> by a common clock. I use a property page accessible from Device
>>>>> Manager to set the card clock, storing the clock value under the
>>>>> device's hardware registry key and setting the
>>>>> DI_FLAGSEX_PROPCHANGE_PENDING flag on exit which forces the driver
>>>>> to be stopped and restarted.
>>>>>
>>>>> The driver, on starting, reads the clock setting from the registry
>>>>> and activates the appropriate set of wave subdevices for that
>>>>> sampling rate.
>>>>>
>>>>> Jeff
>>>>>
>>>>> ----- Original Message ----- From: "Matt Gonzalez"
>>>>> <matt@xxxxxxxxxxxxx>
>>>>> To: <wdmaudiodev@xxxxxxxxxxxxx>
>>>>> Sent: Thursday, January 11, 2007 12:00 PM
>>>>> Subject: [wdmaudiodev] Re: External clock synchronization and
>>>>> sample rate issue
>>>>>
>>>>>
>>>>>
>>>>>> OK, that makes sense. So you know when you create the subdevice
>>>>>> that you are only supporting one sample rate.
>>>>>>
>>>>>> The problem I have is somewhat different - my driver creates
>>>>>> multiple subdevices for each pair of inputs and outputs on the
>>>>>> card. All the subdevices share a common , internally generated
>>>>>> hardware clock, so you would want to specify the same preferred
>>>>>> format for all the inputs and outputs.
>>>>>> Obviously, having to go through the control panel and setting the
>>>>>> preferred format for each audio device is not desirable.
>>>>>> It seems like in that case, you'd want to allow the full range of
>>>>>> sample rates to be available. But then - if you change one
>>>>>> device, is there some way to propagate the change to all the
>>>>>> others? The discussion so far suggests that there is no way to
>>>>>> do this automatically.
>>>>>>
>>>>>> I'm thinking here of something along the lines of the IPortEvents
>>>>>> interface, but I'm just spitballing.
>>>>>>
>>>>>> Matt
>>>>>>
>>>>>>
>>>>>> Jeff Pages wrote:
>>>>>>
>>>>>>> No, I don't call IoSetDeviceInterfaceState anywhere - presumably
>>>>>>> the port class takes care of enabling device interfaces when the
>>>>>>> subdevice is registered. Only one wave subdevice is ever created
>>>>>>> at a time, it's just that it might have different parameters
>>>>>>> (specifically supported sampling rate) depending on what the
>>>>>>> hardware clock is when the subdevice is created. I think a
>>>>>>> different subdevice name is needed for each option because Vista
>>>>>>> stores the audio engine rate in the registry for each one.
>>>>>>>
>>>>>>> Jeff
>>>>>>>
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