Replace libmodplug with libopenmpt
I posted this before as note #303-6, however that bug is quite old (on top of being rejected) and I probably did not get noticed, so I am making a new report as a feature request.
Libmodplug is Audacious' library of choice for its official module playing input plugin, it enables playback of many old formats such as xm, it, mod, and others.
Unfortunately, libmodplug appears to be only sporadically maintained, the most recent commit listed on sourceforge as being 9357867, dated June 2nd, 2017, and on GitHub, af00e21, dated August 2nd, 2018. As listed on #303, it does have some playback issues with some modules, one of which I've attached to this report. Generally, it also plays modules back with a low amplitude, however that could be the result of Audacious' plugin's implementation.
In #303-2, libxmp was discussed, however the mentioned audacious plugin (#303-5) is no longer maintained, and libxmp itself appears to be sporadically maintained as well. The latest commit, 2a16cdf, is dated Oct 14th, 2018.
So, I suggest switching to libopenmpt, a cross-platform module playback library based off of OpenMPT, which is itself based off the open source release of ModPlug Tracker. It's actively maintained, (latest revision is rev 10998 dated November 25th, 2018) and should have better support for playing back modules accurately. The types of modules it supports should be equivalent or greater than libmodplug, a list of supported modules can be found on the features page. For example, libopenmpt handles the problematic module attached to this report flawlessly.
Chris Spiegel has created a working audacious plugin for this already, however his repo does not currently feature a code license. https://github.com/cspiegel/audacious-openmpt You might be able to get into a dialog with him about absorbing it into the audacious-plugins repo. His email listed in the git commit log is cspiegel at gmail.
I've used his plugin for a while and it works great in my experience, and the amplitude seems to be correct, so the modules don't sound so quiet compared to my other music files.