SDL-mixer and SDL-sound: Problem with mp3 support

[Manuel A. Fernandez Montecelo]

2013/5/15 Vincent Prat <vinceprat at free.fr>:
> Hello
>
> As you suggested, I have reported the bug [1].

Thanks.

Adding mailing list thread to bug report:
http://lists.alioth.debian.org/pipermail/pkg-sdl-maintainers/2013-May/001650.html


> What seems odd to me is the fact that everything worked fine with the
> previous stable version of the package (with the same mp3 files).

I don't really know what's happening, just suggestions below.

Were you using the same Debian architecture in the past, or did you
switch from i386->amd64 between working and failing?

And by the way, did you also try other format types (ogg, flac, wav)
and observe any anomaly?

We didn't change the upstream version (there has been none in years),
and despite the packaging changes, we have not changed the build
dependencies (AFAICT).

The major things that changed between releases are the hardened build
options, and the changes in the toolchains (compiler, libraries like
libc [1], etc).

At least in some cases, and according to the build logs, the library
(including mpglib part) is somewhat sloppy when it comes to handling
types correctly.  For example treats equal char* and uint8_t*, signed
and unsigned, in a few places.  Maybe the new build-hardening options,
compiler or library changes are now exposing bugs due to these
underlying problems.

  mpglib.c:164:21: warning: pointer targets in passing argument 2 of
'decodeMP3' differ in signedness [-Wpointer-sign]
  mpglib/mpglib_sdlsound.h:53:5: note: expected 'char *' but argument
is of type 'Uint8 *'


Cheers.

[1] "Legit" changes to underlying libraries can change make programs
fail: http://lwn.net/Articles/414467/

--
Manuel A. Fernandez Montecelo <manuel.montezelo at gmail.com>