Native library builder for Android

This repository covers various native library builds for Android, namely:

• lv2 (serd, sord, lv2, sratom, lilv, mda-lv2)
• eigen (well, not really; it's just copying headers)
• guitarix

... as well as dependencies:

• libogg, libvorbis, flac, libsndfile, fftw3
• libffi, glib, mm-common, libsigc++, glibmm

To build those dependencies, we make full use of GStreamer/Cerbero build system - actually a fork of it - which provides comprehensive automated builds for all Android ABI. Unlike Microsoft/vcpkg packages are up to date well and tailored well for Linux, and unlike AOSP ndkports it can resolve complicated dependencies in many build systems (for example, basic Autotools deps).

Although note that our fork is rebased on Android-28 which contains iconv API in bionic libc.

We needed 28 to include certain pthread API for zita-*, but now that they are removed we may bring back the default API level by cerbero (not sure, it is more consistent to not have libiconv for every ABI).

Building for general developers

Run ./build-in-docker.sh to get a release binary zip on Linux.

Notes on pkg-config usage

The resulting binary, especially those on github release page, has *.pc files (for pkg-config) has path specification on the build machine and therefore they won't work as is on your machine.

You are supposed to rewrite those path specifications (like prefix, but not limited to this) with your local path to the specific Android ABI directory in the extracted directory of the (downloaded) archive. For example...

#!/bin/bash

PWD=`pwd`
PWDESC=${PWD//\//\\\/}

echo $PWDESC

for f in `find dependencies/dist/*/lib/pkgconfig -name *.pc` ; do
	sed -e "s/\/home\/runner\/work\/android-native-audio-builders\/android-native-audio-builders\/cerbero-artifacts\/cerbero\/build/$PWDESC\/dependencies/g" $f > $f.1;
	sed -e "s/\/home\/runner\/work\/android-native-audio-builders\/android-native-audio-builders/$PWDESC\/dependencies/g" $f.1 > $f.2 ;
done

Adding packages

You would often like to build more LV2 plugins with this script, and sometimes it's easier to just reuse the build scripts in this repo to resolve complicated set of dependencies like what Guitarix has (glibmm, libsndfile, fftw3).

The Makefile script is already quite complicated, but aap-guitarix build can be still regarded as a reference model to split LV2 core builds from the app build itself. The resulting build outputs can be packaged just by processing dist directory.

Tweak build settings

Ubuntu 20.04 is the expected build machine. We have a CI build based on that.

We do have build-in-docker.sh but it is totally untested nowadays. GitHub Actions workflows provides more precise setup. But note that it is based on their server settings, which already has some software setup.

On some Ubuntu desktop later than 18.04, libpng12 might cause serious package inconsistency and would result in inability to update anything. Try this to avoid such a problem: https://www.linuxuprising.com/2018/05/fix-libpng12-0-missing-in-ubuntu-1804.html

On some Linux desktop (maybe after Ubuntu 18.04) lv2 sample plugins fail to build for unknown reason. In Makefile there is a line that builds lv2 with some options. Add --no-plugins to avoid such build failures.