Re: Audio Engine Design question
Re: Audio Engine Design question
- Subject: Re: Audio Engine Design question
- From: Matt Gonzalez <email@hidden>
- Date: Fri, 20 Sep 2002 16:54:11 -0700
- Organization: Echo Digital Audio Corp.
That all makes sense.
Our stuff is firmware based; it's relatively straightforward to change the firmware to
handle whatever interleaving scheme is optimal. That being the case, what is the most
optimal? Or is there a single, optimal solution?
The comments below (Richard's, not Bill's) seem to suggest that it should be
user-configurable - that I should present some kind of GUI in our console app that lets
the user pick which one they want. Is this the case?
Matt
Bill Stewart wrote:
>
I'd like to second Richard's comments
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>
Our intention with the HAL and driver models was to present a model that is
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not arbitrarily complex, but one that can logically encapsulate (by DESIGN)
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the complexities of some pieces of audio hardware, whilst still allowing a
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simple presentation of simple feature sets.
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>
I hope we've succeeded in doing this...
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>
Bare in mind that this is new territory for many companies (both hardware
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and software), so the initial pangs should NOT be used to drive design
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decisions.
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>
A question we've thrown back to driver writers is this:
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How is your hardware configured?
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How can your driver MOST EFFICIENTLY presents its capabilities?
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>
Kernel resources are the most expensive resources on the OS, so having
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drivers do extra work to satisfy doubtful objectives is both more work for
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the driver writer and ultimately a disservice to the user.
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>
That said:) - there are obviously areas where this ideal presents problems,
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that may require short term workarounds or revisions of released products.
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Hopefully these are far and away the exception to the rule, and those
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compromises are made with the knowledge that the workaround IS temporary.
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>
(end of lecture - back to your regularly scheduled programming)
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>
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
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> timing? Cards such as the Sonorus STUDI/O support multiple alternative
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> configurations - 1 16ch devivce or 2 * 8Ch devices, or 4 * 4-ch devices, etc.
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> The ideal is for the user to be able to create one or more virtual devices
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> with
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> N channels, up to the available limit.
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>
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> A 6-ch device has obvious uses for streaming 5.1 surround; a 4-ch device
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> supports LCRS surround, simple quad, and direct B-Format signals. 2nd-Order
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> B-Format requires 9 channels. It seems to me that any applications that crash
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> (!!) if presented with a 12ch device need fixing, and should not be used as
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> the
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> baseline for something as universally important as a device driver. To be
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> limited to multiple stereo devices seems to me the worst possible arrangement.
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>
>
> A user might well fancy, for example:
>
>
>
> Device #1: stereo
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> Device #2: 4-ch for B-Format
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> 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?
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>
>
>
>
> Richard Dobson
>
>
>
>
>
>
>
> Laurent Humbert wrote:
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>
>
>> Hello everyone,
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>>
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>> The device I'm working with has got 12 analogical line inputs (24bit) as
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>> well as a couple of S/PDIF (one coaxial, one optical).
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>>
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>> Which layout would be best:
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>>
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>> A: 1 input stream with 16 channels
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>>
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>> B: 1 input stream with 12 channels
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>> 1 input stream with 2 channels (coaxial)
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>> 1 input stream with 2 channels (optical)
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>>
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>> C: 6 input streams with 2 channels
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>> 1 input stream with 2 channels (coaxial)
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>> 1 input stream with 2 channels (optical)
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>>
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>> D: 12 input streams with 1 channel
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>> 1 input stream with 2 channels (coaxial)
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>> 1 input stream with 2 channels (optical)
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>>
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>> E: Other
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>>
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>>
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>> 1 input stream with 12 channels works fine in Ableton Live but crashes
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>> SoundStudio and Amadeus. Maybe it's safer not to have more than 2
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>> channels per streams. On the other hand, I've seen one audio driver do
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>> that....
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>>
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>> For the moment I use solution B but I am tempted to go for solution C,
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>> but what bothers me is that the Audio MIDI Setup displays information
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>> only for the first stream, so the user might think the device has got
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>> only one stereo input :-/
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>>
>
>> Laurent
>
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>
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>
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>
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