Re: [Jack-Devel] incompatible version of ffado error message

Hi Allan

On Wed, May 02, 2012 at 08:32:45AM +1000, Allan Klinbail wrote:
> > > Oh hang on: Allan, you said "the latest jack svn version".  Did you
> > > literally use jack's subversion repository?  That is no longer carrying the
> > > latest jackd source as far as I know: if you want the latest jackd you need
> > > to get it using git.  This is described at
> > > 
> > >   http://jackaudio.org/download
> > 
> > Okay, jackd was built from the "live" ebuild in the gentoo pro-audio
> > repository, I would have to look at the ebuild for that to determine if
> > it was taking the older svn version or the git version. 
> 
> and there lies the problem ..
> 
> DESCRIPTION="Jackdmp jack implemention for multi-processor machine"
> HOMEPAGE="http://www.grame.fr/~letz/jackdmp.html"
> 
> ESVN_REPO_URI="http://subversion.jackaudio.org/jack/jack2/trunk/jackmp"
> 
> LICENSE="GPL-2"
> SLOT="0"
> KEYWORDS=""
>
> it's using SVN..

It is indeed.  Using the above URL I just checked out the code tree that
this would result in and it definitely pre-dates the latest round of work on
the JACK firewire driver (which uses libffado, in case that wasn't obvious).

In this version of jack the conditional determining libffado compatibility
is

  if (ffado_get_api_version() != FIREWIRE_REQUIRED_FFADO_API_VERSION) {
    printError("Incompatible libffado version! ...
  }

Now, what's interesting is that FIREWIRE_REQUIRED_FFADO_API_VERSION is 8
here (see the top of the linux/firewire/JackFFADODriver.cpp file).  Having
compiled libffado against the old jackd, ffado_get_api_version() should
still be returning 8, so again this shouldn't have tripped up.

Allan, if convenient, could you run scons again in the libffado directory
and post the initial lines reported prior to compilation started?  I'm
particularly interested in the "Checking for" lines, especially those
relating to jack.  Perhaps libffado was mis-detecting the version of jack on
this system.

Having written that, I've taken a closer look at the source that gentoo was
pulling.  Interestingly enough, it appears that its version is set to 1.9.9. 
If this is indeed the version reported on your system (check with 
"jackd --version") then that may explain the problem.

Jackmp 1.9.9 is, as far as I can tell, still in pre-release.  When released
it will be the first version to support the new libffado API revision (which
adds setbufsize support).  If compiled on a system whose jackmp reports a
version of 1.9.9 then libffado will enable the new API version.

On your system, it seems almost certain that jackmp will report a version
number of 1.9.9 even though this hasn't been released yet and evidently
isn't a true 1.9.9 (since it's lacking all the changes made since jack moved
to git from svn).  The libffado configuration script will enable the new API
version on this system, since it sees a jackmp version 1.9.9.

With the new API enabled, ffado_get_api_version() will return 9.  That then
completely explains why you're getting the "Incompatible libffado version"
message.

To work around the issue for now, you could recompile libffado and force the
use of the older API revision:

  scons ENABLE_SETBUFFERSIZE_API_VER=false

That should at least get you up and running again until the jackmp issue is
resolved.

> I will report this back to the gentoo pro-audio list 

That sounds like a good idea.

Regards
  jonathan

1335927103.10239_0.ltw:2, <20120502025136.GE22252 at marvin dot atrad dot com dot au>