I managed to fix some of the common issues on my fork, leaking Context and non working kill command to be specific.

Steps to install if this doesn't get merged:

1. Edit your project's build.gradle (not app) like this. (important line is jitpack)

allprojects {
    repositories {
        jcenter()
        mavenCentral()

        ...

        maven {
            url 'https://jitpack.io'
        }
    }
}

2. Add below line to your app's build.gradle dependencies.

compile 'com.github.diegoperini:ffmpeg-android-java:v0.4.6'

Link for the fork: https://github.com/diegoperini/ffmpeg-android-java

Changelog:

1. Added whenFFmpegIsReady() to properly wait for ffmpeg state.
2. Fixed killRunningProcesses() to properly kill the execution.
3. Added a FFmpeg.getInstance() overload to work with a ContextProvider instead of a context. It is a fix for a common memory leak caused by storing the context internally. Old factory method is still supported but marked as deprecated.