[LAD] Do professionals use Pulse Audio? ; xfce4-mixer

[Nikita Zlobin]

In Wed, 25 Apr 2018 11:38:47 -0700 (PDT)
Len Ovens <len at ovenwerks.net> wrote:

> On Wed, 25 Apr 2018, Philip Rhoades wrote:
> 
> > I am not a professional LA user but I have regard for what serious
> > LA users have to say.  A post turned up on the Fedora XFCE list
> > about removing xfce4-mixer for F29 - I responded with:
> >
> > "Every time I upgrade I immediately UNinstall PA and use ALSA only
> > - so I still depend on xfce4-mixer . ."
> >
> > Someone replied that PA has greatly improved since the early days 
> > especially and "controlling streams separately is an added feature"
> > - but I can do that with the .asoundrc I have now - are there any
> > good reasons for me to reconsider the situation the next time I do
> > a fresh install?  (I realise I am likely to get biased comments
> > here but I am not going to post on a PA list . .).  
> 
> Having some kind of ALSA mixer is still required. Pulse controls
> levels as a mix of sound card and digital gain stage levels. You have
> no way of knowing what it is really doing. This is great for desktop
> use, absolutely useless for any kind of profesional use. Note that
> input levels are worse as pulse uses a mix of input level, input/mic
> boost (even on aux inputs) and digital gain stage.
> 
> An interesting experiment is to run alsamixer and watch the audio
> card control levels while adjusting pulse's one level control full
> range. Input levels on the internal audio card will see the input
> level go up then bounce to 0 as the boost is set up a notch then the
> level goes up again, then down plus more boost. I have found that
> each boost level has it's own unique noise that I can work around
> with alsamixer that pulse tramples all over.
> 
> Pulse offers no guaranty of any particular audio card being used for
> sync or of any source not having SRC applied.
> 
> Pulse offers no guaranty of no drop outs or stable latency.
> 
> Pulse offers no guaranty that some other application (skype is 
> particularely bad) will not change your audio card levels for you.
> 
> pulse makes a good audio front end for desktop applications so long
> as Jackd is it's _only_ output. The Pulse-jackd bridge appears to be
> set up as a client (using jack terms) rather than a device or back
> end. This means that even when another device connected to pulse is
> not being used for output, pulse continues to rely on it for sync :P
> This means that jack free wheel will not work correctly if pulse has
> a connection to any audio HW.

For complemention, PA may be configured to run with jack sink/source,
without alsa, udev, may be bluetooth - only necessary minimum. Not sure
about PA resampler... Some examples could be found around in web
(places like userquestions, stackexchange, etc).

One question from me - is this enough to fix pulse->jack sync,
including mentioned freewheel issue?

> 
> I personally use jackdbus as my audio server, started at session
> start. I use pulse as a desktop front end with the pulse-jack bridge,
> but with the udev and alsa modules removed so that jackd is it's only
> audio in/output. This means pulse does not ever control audio device
> levels, and free wheel works correctly.
> 
> Jack (or alsa direct) is the only way to do profesional audio is you
> want bit perfect throughput. Pulse offers no such thing. I agree
> pulseaudio has improved a whole lot, but it is no replacement for
> jack or alsa direct. Alsa direct is great except if you want to be
> able to mix two audio sources without stopping your proaudio
> application.
> 
> I have no comments on xfce4-mixer. I don't use it because I have an 
> ice1712 based card that has it's own much better control utility 
> (mudita24) and I find qasmixer (and it's extra tools) easier to use.
> I also still use alsamix in a terminal because it is faster to access
> in many cases :)
> 
> So I am not of the "pulse must be removed" community, but I still
> feel that pulse is a long way from usable in any kind of profesional
> audio (or even semiprofesional) environment. I would even go so far
> as to say it never will be because it's original design goal was as
> an easy to use desktop application/server. The possibility to do
> pro-audio would require starting over not patching.
> 
> 
> --
> Len Ovens
> www.ovenwerks.net
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