Misformatted translatable strings
In several places in vorbis-tools code, macros are inserted inside translatable strings. An example from ogginfo2.c:
warn(_("WARNING: granulepos in stream %d decreases from %" I64FORMAT " to %" I64FORMAT "\n"), ...
Unfortunately, gettext doesn't support macro substitution, and the po file will only contain the first part of the string, hence the final string will never be translated at runtime.
To workaround this problem, you should first create numbers in variables, somehting like this:
g_from = sprintf("%" I64FORMAT, inf->lastgranulepos);
g_to = sprintf("%" I64FORMAT, gp);
warn(_("WARNING: granulepos in stream %d decreases from %s to %s\n"), stream->num, g_from, g_to)