Re: [Jack-Devel] Automagically connecting audio HW

On 12/15/2013 03:44 PM, Paul Davis wrote:
> On Sun, Dec 15, 2013 at 4:52 AM, Adrian Knoth <[hidden]>wrote:
> 
>> On 12/15/13 05:44, Paul Vint wrote:
>>
>>  Quick question: Has anyone ever done anything to enable new devices to
>>> JACK? (ie: plugging guitar amp via USB, USB headset, recording
>>> devices, etc)

yes.

>>> I can (and have) done UDEV rules and have them spawn things - thought it
>>> might be neato to have something listen for JACKable devices and add
>>> them to the circuit.
>>>
>>
>> For a start, have a look at <http://gareus.org/blog/jack2dbus>
>>
> 
> (not a comment on robin's work, which is about *switching* between devices)

Well, yes and no. Switching happens by stopping and starting [jackd
backends]. If jackdus is not running it can be launched when a device is
connected.

The three big issues are: port-connections, backend settings and clock
source (which devices becomes the main one).

In any professional or semi-pro environment you don't just want to add
some soundcard with some settings. Particularly if the soundcard has
more than 2 channels ("oops, just blasted the monitor speakers").
Furthermore different devices require different latency -I/-O settings,
amongst other things. -- I use a collection of dbus rules, a common
script for hierarchy and connections, plus per-device hook-scripts.
Things can quickly become complex fairly quickly.

> I guess everyone is giving up on one of the key ideas of digital audio: the
> use of single sample clock. Now its "oh, the software can do high quality
> resampling anyway, so just plugin anything in use it".
> 
> Times change, I guess. Or do they?

The Maths does not change nor does it when applied to analog electronics.

Education of listener's ears changes as does the quality of 'prosumer'
soundcards.

Most modern systems have plenty of resources to provide sufficient
high-quality resampling to those ears in realtime. Besides, the quality
bottle-neck in many cases will be the crappy soundcard, not the digital
resampling algorithm.

2c,
robin

1387214021.17420_0.ltw:2, <52AF34B9.7020307 at gareus dot org>