Migrate all libs (remove fdk-aac due to license issue and wavpack as no longer supported)

build/libvpx.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+
+set -euo pipefail
+
+CONF_FLAGS=(
+  --prefix=$INSTALL_DIR                              # install library in a build directory for FFmpeg to include
+  --target=generic-gnu                               # target with miminal features
+  --disable-install-bins                             # not to install bins
+  --disable-examples                                 # not to build examples
+  --disable-tools                                    # not to build tools
+  --disable-docs                                     # not to build docs
+  --disable-unit-tests                               # not to do unit tests
+  --disable-dependency-tracking                      # speed up one-time build
+  --extra-cflags="$CFLAGS"                           # flags to use pthread and code optimization
+  --extra-cxxflags="$CXXFLAGS"                       # flags to use pthread and code optimization
+  ${FFMPEG_ST:+ --disable-multithread}
+)
+
+emconfigure ./configure "${CONF_FLAGS[@]}"
+emmake make install -j
+# Fix ffmpeg configure error: "libvpx enabled but no supported decoders found"
+emranlib $INSTALL_DIR/lib/libvpx.a