foo_sc68

SC68 (Atari ST / Amiga music) decoder component for foobar2000, based on the sc68 r599 SVN version (2015-09-13) -- the best version for emulation quality in testing.

Changes

1. Move configuration from right-click menu to Preferences->Playback->Decoding->SC68 and fixed the issue that the change in config can't be applied at meanwhile.

2. Added seeking function. Now you can drag the playback progress bar!

3. Added a macOS version of the foobar2000 component (Apple Silicon / arm64).

   • The Windows build links prebuilt foobar2000 SDK .lib files checked into sc68-fb2k/lib/, but no equivalent prebuilt libraries exist for mac, so sc68-fb2k-mac/Makefile compiles file68/libsc68/unice68 and the foobar2000 SDK sources directly instead (bypassing autotools the same way sc68-msvc bypasses it with a hand-written config.h).
   • Run make package in sc68-fb2k-mac/ to produce a distributable foo_sc68.fb2k-component; see that Makefile's header comment for the one prerequisite (an unpacked copy of the foobar2000 SDK next to the sc68-fb2k-mac/ folder).
   • The Preferences -> Playback -> Decoding -> SC68 page is reimplemented for mac as a native NSViewController built entirely in code (no .xib), exposing the same settings as the Windows dialog: sampling rate, default track length, aSIDifier, YM engine/filter/volume model, L/R blend, and the Amiga low-pass filter. Unlike the Windows dialog there's no separate Apply/Reset step -- each control applies immediately, matching how foobar2000's own sample component behaves on mac.

4. Fixed the "Default length (s)" setting having no effect (a pre-existing bug in libsc68, fixed on both platforms).