[Sound-open-firmware] Introduction and questions

[Liam Girdwood]

On Thu, 2018-09-13 at 16:09 -0700, chris hermansen wrote:
> Liam and list,
> 

+ Seppo for audio processing.

> Thanks for the kind reply, this is exciting!
> 
> On Wed, Sep 12, 2018 at 1:34 PM Liam Girdwood <liam.r.girdwood at linux.intel.com
> > wrote:
> > Hi Chris,
> > 
> > On Tue, 2018-09-11 at 14:12 -0700, chris hermansen wrote:
> > > I write a column on open source and music on https://opensource.com/
> > > Recently I was at Open Summit and learned of this project.  I subsequently
> > > contacted some folks at Intel to learn more about how this project might
> > > affect users of open source media players.  One of my contacts advised
> > > posting questions to this list.  To avoid spamming the list any more than
> > I
> > > already have, I'd like to confirm that a few such questions won't be a
> > > supreme annoyance to the list members.
> > > 
> > > Thanks in advance for any advice.
> > 
> > No annoyance will occur :) Feel free to ask. The reason I ask for the list
> > is
> > that the questions and answers will be all searchable.
> > 
> 
> Starting with a bit of background... there is a class of audio hardware and
> software user out there who uses a configuration like this:
> laptop, desktop, server appliance...
> running Linux
> with a dedicated DAC used for music playback
> connected to a high quality headphone amplifier or home stereo
> with an open source music player client/server installed that probably
> accesses ALSA directly
> with a bunch of music files, probably FLAC, maybe DSF, probably CD quality or
> higher
> time on their hands to enjoy this
> If the computer hardware itself is used for many and various things, then
> likely the above configuration will want to run most audio traffic through
> Pulse and out the built-in audio speakers / headphone, with only the high-
> quality music being sent to the dedicated DAC directly over ALSA to avoid
> software mixing, resampling etc.  However if the computer hardware is more or
> less dedicated to music enjoyment, then it seems reasonable to hope that the
> built-in audio hardware could itself be dedicated to the primary music
> reproduction role, in a high-quality, low noise, low distortion, "bit-perfect" 
> fashion.
> 

also low power and low latency.

> So, looking at the sound-open-firmware initiative:
> is this primarily oriented toward opening up the built-in audio processing
> chain? 

Yes, SOF is infrastructure that allows processing components or pipelines to be
constructed.

> or should we expect add-on ADC and DAC hardware?

No, it's intended to work with all standard DAC and ADC hardware.

> is it reasonable to expect really high-performance DAC implementations (low
> noise etc) coming out of this?

No this is a SW/FW project, but it is intended to use high quality DAC HW with
SOF.

Liam

> what kind of other applications might we expect to see?
> could we expect to see the ability to build a digital crossover with a FIR
> filter to drive high, medium and low frequency power amplifiers and speakers?
> what about other types of digital filtering to compensate for room acoustic
> issues?
> might we see some type of audio compensation to "pull the music out of the
> head" for headphone users?
> what about decoding DSF directly, not just PCM?
> will people build proprietary things on top of it (for example, could MQA use
> it to build an MQA decoder)?
> That's all I can think of right now; thanks in advance!
> -- 
> Chris Hermansen · clhermansen "at" gmail "dot" com
> 
> C'est ma façon de parler.