On Wed, 2023-08-09 at 16:05 -0400, Mark Pearson wrote:
On 8/9/23 06:10, Ingalsuo, Seppo wrote:
On Tue, 2023-08-08 at 17:27 +0200, Sylvain Munaut wrote:
Hi Seppo,
<snip> > Yep, UP2, UPX, and Chromebooks in developer mode allow to run all open- > source components. We don't have in git main support for UP2, but UPX > with TGL platform is supported. SOF v2.2 works with UP2. > > We are developing also an ALSA plugin version of SOF. It will enable to > run all same algorithms in main CPU user space without restrictions.
Not meaning to hijack the thread - but it triggered my filters because of it being a Lenovo platform and then tweaked my interest (I'm the technical lead for the Lenovo Linux program)
Thanks for chiming in and great that you are subscribed!
I frequently get complaints about the audio quality on our platforms in Linux related to Windows. I am *not* an audiophile...but I know it's something that really bothers folks.
Windows has all the Dolby audio processing which Linux doesn't get (potentially we could get it one day...but as it would be closed source I don't know that I'm enthusiastic about it anyway.
The page linked to (https://thesofproject.github.io/latest/algos/eq/equalizers_tuning.html) was really interesting. It's quite a bit outside my experience - but if there's any opinion or thoughts on if Lenovo should perhaps look at doing some internal tuning for our Linux certified platforms and how easy/hard that would be I'd be interested.
The needed measurements can be done with hobby grade tools in normal work environments or with very professional calibrated equipment in anechoic chambers. Audible improvements are possible with first, but compliance to standards like telecommunications require the latter level. In this case I don't think any standards control the results. If a pre-installed operating system is shipped with some communications suite, need to check case by case if there are. But in any case, tuned is better and closer to possible requirements than non-tuned.
The basic acoustical measurement, tuning and small expert groups evaluation of tuning options is not a big task per product if the logistics with topologies those hold the tunings is solved.
My colleagues who know better the options may chime in. We may have in ALSA user space, linux kernel and firmware & topology everything needed in place but we do not have in SOF a full example to follow.
We're a small team with limited resources but....we have the platforms and I'm sure I can wrangle some budget for some test equipment and then it's just finding the time and skills needed to make it work. Is it a systematic process that can be followed or is it something where there is personal opinion/flavour that gets added and is better left alone?
Since the equalizers tuning is never perfect even in a limited frequency band there is always subjective part left for the result. Few options to flatten the response with least side effects (loss of loudness, increased distortion) can be checked and subjectively tested in small scale (expert listening, or with tools like those simulate subjective opinion) but usually the decisions are made in a small team.
Objective measurements like loudness and distortion can support the subjective decisions. If there are no standards based requirements and no need for certification the process is simple.
ITU-T standards are always a good resource for this subject of objective and subjective audio quality.
I don't know if it's realistic to have a goal of some equaliser files that people could use...maybe as a starting point? Curious to get input from folk who actually work with this stuff as to what might be a good target and doable (and if there is anything we can help with).
I've worked myself in the past with smartphones where the process with 3GPP requirements was on the heavy side. Most possible objective measurable parameters had a range to comply with. In this case I think it's good to evaluate a very light process first and see if it's feasible for "ROI".
Regardless - thanks for the conversation - it's interesting to follow along. Sylvain - hope the T14 is treating you well :)
Yep, very interesting and welcome topic, thanks for sharing it to us on this list!
Cheers, Seppo
Mark
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