[Mingw-cross-env-list] Introduction and general question

[Ulrich Klauer]

Hi,
my first post here, so I guess I should introduce myself ... I'm  
mainly working on SoX, a command-line audio processing tool  
(http://sox.sourceforge.net/). It also comprises a library, libsox,  
that incidentally is already included in MXE as the sox package.

However, I found here not because of that package, but because I was  
looking for better solutions to build the executable that we provide  
for Windows users. The current process is not fully automated,  
especially not regarding external libraries, and we've had a problem  
at the latest release where two of them accidentally weren't included.

I'm experimenting with MXE, and it seems really well suited for the  
task - almost no problems to get a working build, most required  
libraries are already there, and adding the remaining ones seems  
absolutely doable (I've just added wavpack; at least twolame is  
probably going to follow). So, great work!


Now for the general question: Should MXE packages be as  
feature-complete as possible (= as prerequisites allow) or should they  
only offer a sensible subset, if there are many optional features?

Taking the sox package as an example, it currently depends on flac,  
lame, libgomp, libmad, libsndfile, vorbis, and wavpack. It could also  
make use of packages file (libmagic), libpng, libtool (libtldl), and  
opencore-amr for more optional features.

Apart from the obvious issues regarding build time etc., including  
more features can also lead to licensing restrictions. Although libsox  
is, by itself, LGPL 2.1+, linking in libmad makes it GPL 2+. Linking  
in the AMR codecs from opencore-amr makes it GPL 3+ (because the  
Apache licence is incompatible with GPL 2). This is why I'd tend to  
not include libmad, at least.

There is support in libsox for dlopen()ing optional libraries at  
runtime. This is what we do for the "official" SoX Windows binary:  
libmad, opencore-amr, and lame are left out, but if the user has a  
relevant DLL, they can use it. I could set up the MXE sox package in  
this way, too, if that is desired.

Ulrich