[Jack-Devel] something else (Was: Re: Jack 1.9.7 on ARM crashes when killing a client)

On Fri, Feb 11, 2011 at 12:02 PM, Henry W. Peters <[hidden]> wrote:

> This may be superfluous to this thread... (please advise, if so)... I sent

yes, its a total thread hijack.

> I have tried to decipher this present discussion... I use Jack1. I know from
> a past experience that Jack2 requires a rebuild of programs that use Jack.

This is not true.

>  Question is; instead of trying (presently) to trouble shoot my installation
> of  Jack1/Alsa... or whatever, I might have an easier time of it in the long
> run (Jack2 is probably the need to do at some point or another): How can I
> install Jack2...  do I need to uninstall Jack1?

there's no reason to believe that jack2 or jack1 will make your life
easier. there is a very small amount of evidence at present that jack2
has slightly more trouble with some versions of ALSA (and/or FFADO)
than jack1 at this particular moment in time, which is what the thread
that you replied too was attempting to resolve.

lets go over this again:

    * jack1 and jack2 are two implementation of the same API
    * they are ABI compatible with each - that is, you can replace one
implementation with the other and (with very few or zero exceptions)
not need to rebuild or recompile anything
    * jack2 can run multiple clients on multiple CPUs *if and only if*
there is parallel data flow
    * jack2's default run mode will not cause clicks when there are
changes to the connections, for a small increase in latency
    * jack2 can be run in the same mode as jack1, where changes to the
connections may cause clicks but at no cost in latency
    * unless you really deeply understand unix-like operating systems,
you should NEVER EVER have more than one copy of JACK
        installed on your machine. If you want to install a different
implementation you should first completely remove the existing one
        OR ensure that you completely overwrite it. How easy these
tasks are depends a lot on the packaging system that your
        distribution uses (and/or whether you install from source)


> I ask this, because some of
> the discussion on this thread, seemed to indicate the possibility some
> programs are not compatible, somehow, with Jack2.

there are a couple of programs that use esoteric details (or
unspecified) parts of the JACK API and have issues with one of the
implementations. these are rare, and generally not something for users
to care about unless they are specifically bitten by this.

> I'd be more than happy if there was a link to a reference on the matter.

There is no reference because the principle is very simple and very
clear: released JACK implementations are API and ABI compatible. The
details are obviously a bit more complicated than this, but that's the
basic reference to follow.


> P.s., will Alsa, & my drivers (Echo, Mia card) need to be rebuilt?

not because of anything related to JACK.

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