Prerequisite

You need Go environment to get blueprint build system.

export GOROOT=/your/goroot/path # My GOROOT is /usr/local/Cellar/go/1.15/libexec
export GOPATH=/your/go/path     # My GOPATH is $HOME/dev/gopath

make sure your $GOPATH/bin is in $PATH

export PATH="$GOPATH/bin:$PATH"

go get -u github.com/google/blueprint/...

check if you have bpfmt

$ bpfmt
one of -d, -l, -o, or -w is required
usage: bpfmt [flags] [path ...]
  -d	display diffs instead of rewriting files
  -l	list files whose formatting differs from bpfmt's
  -o	write result to stdout
  -s	sort arrays
  -w	write result to (source) file

For macOS, you need some GNU-version command line tools

brew install findutils # xargs
brew install gnu-sed   # sed

and then make sure GNU-version command line tools are having high priority than macOS-version

export PATH="/usr/local/opt/findutils/libexec/gnubin:$PATH"
export PATH="/usr/local/opt/gnu-sed/libexec/gnubin:$PATH"

Build instructions

upgrade libvpx's version

./update_libvpx.sh [tag/branch]

Generate files of config

./generate_config.sh

Generate files of build

./libvpx/configure --target=arm64-android-gcc --enable-external-build

valid target

arm64-android-gcc      
armv7-android-gcc
x86-android-gcc
x86_64-android-gcc

Build

ndk-build NDK_PROJECT_PATH=. APP_BUILD_SCRIPT=./Android.mk \
APP_ABI=arm64-v8a APP_PLATFORM=android-21 APP_OPTIM=release \
APP_STL=c++_static NDK_TOOLCHAIN_VERSION=clang ENABLE_SHARED=0

valid APP_ABI

arm64-v8a
armeabi-v7a
x86
x86_64

Generate Android jni files

using swig

swig -v -java -package your.package.name -outdir your/output/path -o your/jni/wrapper/vp9_svc_encoder_wrap.cpp vp9_svc_encoder.i

Note that it is common to spicify the outdir to app/src/main/java/your/package/name if you spicified the package to your.package.name. The xxx_wrap.cpp and xxx.i are commonly stored in app/src/main/cpp.

For example:

swig -v -java -package io.byteplanet.encoder -outdir src/main/java/io/byteplanet/encoder -o src/main/cpp/vp9_svc_encoder_wrap.cpp src/main/cpp/vp9_svc_encoder.i