Re: Audio Engine Design question
Re: Audio Engine Design question
- Subject: Re: Audio Engine Design question
- From: Bill Stewart <email@hidden>
- Date: Fri, 20 Sep 2002 16:36:39 -0700
I'd like to second Richard's comments
Our intention with the HAL and driver models was to present a model that is
not arbitrarily complex, but one that can logically encapsulate (by DESIGN)
the complexities of some pieces of audio hardware, whilst still allowing a
simple presentation of simple feature sets.
I hope we've succeeded in doing this...
Bare in mind that this is new territory for many companies (both hardware
and software), so the initial pangs should NOT be used to drive design
decisions.
A question we've thrown back to driver writers is this:
How is your hardware configured?
How can your driver MOST EFFICIENTLY presents its capabilities?
Kernel resources are the most expensive resources on the OS, so having
drivers do extra work to satisfy doubtful objectives is both more work for
the driver writer and ultimately a disservice to the user.
That said:) - there are obviously areas where this ideal presents problems,
that may require short term workarounds or revisions of released products.
Hopefully these are far and away the exception to the rule, and those
compromises are made with the knowledge that the workaround IS temporary.
(end of lecture - back to your regularly scheduled programming)
Bill
on 20/9/02 6:54 AM, Richard Dobson wrote:
>
All of the below. Can all 12 channels be driven together with sample-accurate
>
timing? Cards such as the Sonorus STUDI/O support multiple alternative
>
configurations - 1 16ch devivce or 2 * 8Ch devices, or 4 * 4-ch devices, etc.
>
The ideal is for the user to be able to create one or more virtual devices
>
with
>
N channels, up to the available limit.
>
>
A 6-ch device has obvious uses for streaming 5.1 surround; a 4-ch device
>
supports LCRS surround, simple quad, and direct B-Format signals. 2nd-Order
>
B-Format requires 9 channels. It seems to me that any applications that crash
>
(!!) if presented with a 12ch device need fixing, and should not be used as
>
the
>
baseline for something as universally important as a device driver. To be
>
limited to multiple stereo devices seems to me the worst possible arrangement.
>
>
A user might well fancy, for example:
>
>
Device #1: stereo
>
Device #2: 4-ch for B-Format
>
Device #3: 6-CH for a 5.1 stream
>
>
That would use up all analogue 12 channels very tidily.
>
>
Out of interest, how many output channels does this device support?
>
>
>
Richard Dobson
>
>
>
>
Laurent Humbert wrote:
>
>
> Hello everyone,
>
>
>
> The device I'm working with has got 12 analogical line inputs (24bit) as
>
> well as a couple of S/PDIF (one coaxial, one optical).
>
>
>
> Which layout would be best:
>
>
>
> A: 1 input stream with 16 channels
>
>
>
> B: 1 input stream with 12 channels
>
> 1 input stream with 2 channels (coaxial)
>
> 1 input stream with 2 channels (optical)
>
>
>
> C: 6 input streams with 2 channels
>
> 1 input stream with 2 channels (coaxial)
>
> 1 input stream with 2 channels (optical)
>
>
>
> D: 12 input streams with 1 channel
>
> 1 input stream with 2 channels (coaxial)
>
> 1 input stream with 2 channels (optical)
>
>
>
> E: Other
>
>
>
>
>
> 1 input stream with 12 channels works fine in Ableton Live but crashes
>
> SoundStudio and Amadeus. Maybe it's safer not to have more than 2
>
> channels per streams. On the other hand, I've seen one audio driver do
>
> that....
>
>
>
> For the moment I use solution B but I am tempted to go for solution C,
>
> but what bothers me is that the Audio MIDI Setup displays information
>
> only for the first stream, so the user might think the device has got
>
> only one stereo input :-/
>
>
>
> Laurent
>
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