[wdmaudiodev] Re: AVStream vs. Portcls
- From: "Stephan" <stephan@xxxxxxxxxx>
- To: <wdmaudiodev@xxxxxxxxxxxxx>
- Date: Fri, 14 Feb 2003 10:41:15 +0100
> We are trying to decide whether to go with AVStream or Portcls for writing
> the next version of our MIDI driver.
Do you have any information whether MIDI support is available under AVStream?
I've heard rumors it is not, but no one on
this list could confirm if this is correct or not.
> With a PortCls mini-port we can easily add multiple
> "devices"(PcRegisterSubdevice) without having to create real child
> devices(causing yet another new hardware found wizard), however that's not
> possible with the current Stream minidriver model. How does this stand with
> an AVStream mini driver?
IMHO an AVStream driver may expose multiple filters (at least audio filters).
Same should be true for MIDI filters IF
they are supported by AVStream.
> but AVStream is only available on
> XP (and Me?). What happens when a user wants to use our device with an older
> OS. Do we need to maintain separate drivers? It seems very unlikely that
> AVStream will ever be back-ported to Win2K!
AVStream is supported under XP and under DirectX <= 8, so you just have to
install DirectX 8 or higher under W2k and
AVStream will be available.
Stephan
----- Original Message -----
From: "BlazeAudio Developer" <developer@xxxxxxxxxxxxxx>
To: "WDM Audio Dev List" <wdmaudiodev@xxxxxxxxxxxxx>
Sent: Thursday, February 13, 2003 11:35 PM
Subject: [wdmaudiodev] AVStream vs. Portcls
> Hi,
>
> We are trying to decide whether to go with AVStream or Portcls for writing
> the next version of our MIDI driver.
>
> The underlying device is connected on the 1394 bus. We currently have a
> Streaming mini-driver that works well.
>
> However, there are a few things that this driver lacks, that we hope will be
> fixed by going to AVStream or a Portcls miniport. Can anybody provide
> guidance with the following issues:
>
> 1. Multi-client support - (KMixer, KSplitter equivalent for MIDI). I think
> PortCls implements multi-client support (merging and splitting MIDI data)
> currently. However, Stream.sys does not provide this support. Will the
> AVStream based mini driver have to worry about this, or does AVStream
> providemulti-client support?
>
> 2. Multiple MIDI ports - the device has 8 MIDI ports. With the current
> architecture we actually have a separate bus-driver which creates child
> devices - and each of the child devices are served by a new instance of the
> the stream minidriver. With a PortCls mini-port we can easily add multiple
> "devices"(PcRegisterSubdevice) without having to create real child
> devices(causing yet another new hardware found wizard), however that's not
> possible with the current Stream minidriver model. How does this stand with
> an AVStream mini driver?
>
> 3. Legacy OS Support - both a stream minidrivers and portcls miniports are
> supported on older WDM operating systems, but AVStream is only available on
> XP (and Me?). What happens when a user wants to use our device with an older
> OS. Do we need to maintain separate drivers? It seems very unlikely that
> AVStream will ever be back-ported to Win2K!
>
> Thanks.
> Devendra.
> ******************
>
> 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/
Other related posts:
