major rework

lib/compile_opts.sh

@@ -0,0 +1,26 @@
+#!/usr/bin/env bash
+
+# variables used externally
+# shellcheck disable=SC2034
+
+# complete clean before building
+CLEAN=true
+# enable link time optimization
+LTO=false
+# optimization level (0-3)
+OPT_LVL=0
+# static or shared build
+STATIC=true
+# CPU type (x86_v{1,2,3}...)
+CPU=native
+# architecture type
+ARCH=native
+# prefix to install, leave empty for non-system install (local)
+PREFIX=''
+# configure what ffmpeg enables
+FFMPEG_ENABLES=(
+	libopus
+	libdav1d
+	libsvtav1_psy
+	# libaom
+)