Re: [fluid-dev] Link error for iOS

[Pedro Lopez-Cabanillas]

On Monday 21 November 2011, MINGFEN WANG wrote:
> Hi Pedro,
> He/she must release all changes to the FluidSynth source code under the 
LGPL.
> He/she must release all other code of the application, either as source or 
as linkable object files, so that an independent user can relink the 
application with a different version of FluidSynth.
> LGPL should be a standard to judge legal or not, if people use fluid and 
contribute their modified part to the project, why they should also release 
other part code of their software as GPL?

Because this is written in the terms of the LGPL license, section 6. 

See: http://www.gnu.org/licenses/lgpl-2.1.html

6. As an exception to the Sections above, you may also combine or link a "work 
that uses the Library" with the Library to produce a work containing portions 
of the Library, and distribute that work under terms of your choice, provided 
that the terms permit modification of the work for the customer's own use and 
reverse engineering for debugging such modifications.

You must give prominent notice with each copy of the work that the Library is 
used in it and that the Library and its use are covered by this License. You 
must supply a copy of this License. If the work during execution displays 
copyright notices, you must include the copyright notice for the Library among 
them, as well as a reference directing the user to the copy of this License. 
Also, you must do one of these things:

    a) Accompany the work with the complete corresponding machine-readable 
source code for the Library including whatever changes were used in the work 
(which must be distributed under Sections 1 and 2 above); and, if the work is 
an executable linked with the Library, with the complete machine-readable 
"work that uses the Library", as object code and/or source code, so that the 
user can modify the Library and then relink to produce a modified executable 
containing the modified Library. (It is understood that the user who changes 
the contents of definitions files in the Library will not necessarily be able 
to recompile the application to use the modified definitions.)
    b) Use a suitable shared library mechanism for linking with the Library. A 
suitable mechanism is one that (1) uses at run time a copy of the library 
already present on the user's computer system, rather than copying library 
functions into the executable, and (2) will operate properly with a modified 
version of the library, if the user installs one, as long as the modified 
version is interface-compatible with the version that the work was made with.
    c) Accompany the work with a written offer, valid for at least three 
years, to give the same user the materials specified in Subsection 6a, above, 
for a charge no more than the cost of performing this distribution.
    d) If distribution of the work is made by offering access to copy from a 
designated place, offer equivalent access to copy the above specified 
materials from the same place.
    e) Verify that the user has already received a copy of these materials or 
that you have already sent this user a copy.



> This is why I hesitate to use fluid in my iOS project, other part of my 
project contains my original  real time voice recognition engine, and I have 
no plan to release its code to the public.
> 
> 在 2011-11-20，下午9:11， Pedro Lopez-Cabanillas 写道：
> 
> > On Sunday 20 November 2011, MINGFEN WANG wrote:
> >> I will consider other commercial products to avoid the risk.
> > 
> > I'm sorry to read that. The fact is that there isn't any legal 
uncertainty;  
> > you can use and run FluidSynth under iOS like any other operating system. 
The 
> > only concern was raised about distributing FluidSynth in Apple's AppStore, 
but 
> > that is another matter. You only need to respect the terms of the LGPL 
license 
> > if you want to distribute a modified version of FluidSynth or a derived 
work.
> > 
> > The guy that answered your original mail has no authority to talk in the 
name 
> > of the whole FluidSynth project, and he is not a copyright holder for 
> > FluidSynth 1.0.9; please ignore his words.
> > 
> >> The code of yesterday can really work on iOS device, I wish to contribute 
it 
> > to fluid project.
> > 
> > Thank you very much. This is exactly our expectation, and part of the LGPL 
> > requirements. The development of FluidSynth 1.0.9 is closed now, as we are 
> > currently focused in the 1.1.x development branch, but we may think about 
> > opening a branch for a future release 1.0.10 (or whatever other name) if 
there 
> > is enough interest and people involved.
> > 
> > Regarding your original question, you need to add a linker directive to 
> > include the AudioToolbox framework. This may be done with a shell 
variable, 
> > before running configure:
> > 
> > $ LDFLAGS="-Wl,-framework AudioToolbox" ./configure
> > 
> > Or more permanently, editing the file "configure.ac" (that creates the 
> > configure script after running "autogen.sh")
> > 
> > COREAUDIO_LIBS="-Wl,-framework,CoreAudio,-framework,AudioToolbox"
> > 
> > Hope this helps.
> > 
> > Regards,
> > Pedro
> 
>