It contains defines that should be available from scummsys.h.
Also, it contains defines to support ancient and
now unsupported versions of MSVC (2013 and earlier)
No need to explicitly set it to 1.0. (There may have been in an
earlier version, to avoid any possible rounding error. But if so,
that reason is long gone.)
The high-resolution videos play back at much lower volume than the
original ones. This adds hard-coded values for how much to amplify
each cutscene. It's all done by ear, and it does introduce some
clipping, but I think it should be acceptable.
Of course, it could also be a problem with the audio decoder, so
this may be the wrong approach entirely.
