Phonon's backends to JACK.

[Colin Guthrie]

'Twas brillig, and Mark Constable at 12/06/11 14:56 did gyre and gimble:
> On 2011-06-12 11:45 AM, Colin Guthrie wrote:
>> No one would really want to run JACK on a standard consumer system, so
>> it's typically for people doing some degree of pro-audio work.
> 
> I've never appreciated this argument. In what sense is a consumer not
> in a position where they want to record or send audio to or from any of
> the many audio enabled applications available to them?
> 
> ie; smplayer -> mumble (or even skype) <-> arecord (for a podcast)

This is entirely possible in PulseAudio. Every output Sink has a monitor
Source that can be used to capture the audio playing on it. You can even
grab audio from individual applications (i.e. not fully mixed with other
sounds) easily enough. It's all possible.

> Regardless of the professionality of the situation, avoiding dropouts
> and xruns is a fundamental requirement when dealing with audio.

It depends. Avoiding dropouts (or rather continual drop outs) is very
much a desire but it's not the be all and end all. With consumer stuff,
power management is also relevant. Battery powered devices are very
common, from personal media players to tablets to laptops. Here we can
accepts a dropout now and then if the power consumption profile and
general CPU usage warrants it. That's what's very much focussed on in
PA, whereas JACK very much acknowledges that power consumption and CPU
usage is not an issue with the goal that any dropout at all is one too many.

The two goals are therefore quite different.

>> Therefore simply turning off the connection from PA to JACK it
>> becomes relatively easy to put up a brick wall between any consumer
>> apps that are running or start up and your pro-audio work.
> 
> But what if I want to record from consumer grade applications?

As stated above, you can use the monitor source for recording these
under PA.

>> Also, keep in mind that phonon is *not* a sound server. It's a
>> library. PA and JACK are the servers, so it's not cascading 3 sound
>> servers, just 2.
> 
> That's still one too many.

Why? I can see the principle of avoiding it but I don't like to dismiss
things out of hand just because of numbers. I mean, if you don't like
stacking things, you wouldn't use Phonon in the first place! :p

Col


-- 

+------------------------+
|     Colin Guthrie      |
+------------------------+
| http://colin.guthr.ie/ |
+------------------------+