Cross Compile FFmpeg

Cross compile FFmpeg on MacOS for Android

1. Prepare FFmpeg and Android NDK

FFmpeg

// 1. Download FFMpeg (4.2.2 for this tutotial)
https://ffmpeg.org/releases/

// 2. unzip
tar -jxvf ffmpeg-4.2.2.tar.bz2

// 3. configure
./configure --disable-x86asm

Android NDK

https://developer.android.google.cn/ndk/downloads

2. Build

In the unzipped folder ffmpeg-4.2.2, create a new shell script build_android.sh.

build_android.sh

#!/bin/sh

# NDK path, android studio has downloaded sdk, inside the sdk folder, there are multiple ndk versions. I am using 26.1.10909125 here.
NDK=~/Library/Android/sdk/ndk/26.1.10909125
# Target OS
ARCH=aarch64
CPU=arm64-v8a
# Android API
API=21
# Output path: /android/arm64-v8a
OUTPUT=$(pwd)/android/$CPU
# NDK toolchain path
TOOLCHAIN=$NDK/toolchains/llvm/prebuilt/darwin-x86_64
SYSROOT_L=$TOOLCHAIN/sysroot/usr/lib/aarch64-linux-android
GCC_L=$NDK/toolchains/aarch64-linux-android-4.9/prebuilt/darwin-x86_64/lib/gcc/aarch64-linux-android/4.9.x

build_arm64() {
    echo "\033[32m Compiling FFmpeg for $CPU \033[0m"
  ./configure \
  --target-os=android \
  --prefix=$OUTPUT \
  --arch=$ARCH \
  --sysroot=$TOOLCHAIN/sysroot \
  --enable-neon  \
  --enable-hwaccels  \
  --enable-gpl   \
  --disable-postproc \
  --disable-debug \
  --enable-small \
  --enable-jni \
  --enable-mediacodec \
  --enable-decoder=h264_mediacodec \
  --enable-static \
  --enable-shared \
  --disable-doc \
  --enable-ffmpeg \
  --disable-ffplay \
  --disable-ffprobe \
  --disable-avdevice \
  --disable-doc \
  --disable-symver \
  --enable-cross-compile \
  --cross-prefix=$TOOLCHAIN/bin/aarch64-linux-android- \
  --cc=$TOOLCHAIN/bin/aarch64-linux-android$API-clang \
  --cxx=$TOOLCHAIN/bin/aarch64-linux-android$API-clang++ \
  --extra-cflags="-fpic -I$OUTPUT/include" \
  --extra-ldflags="-lc -ldl -lm -lz -llog -lgcc -L$OUTPUT/lib"

  make clean all
  make -j8
  make install
  echo "\033[32m The Compilation of FFmpeg for $CPU is completed \033[0m"
}

build_arm64

To build

chmod +x build_android.sh
./build_android.sh

After successful build, we will have needed libs and headers under android/arm64-v8a

3. Test FFmpeg on Android

Build a simple demo in Android studio to test if FFmpeg works.

We place the ffmpeg headers under cpp/include and all the libraries under jniLibs/arm64-v8a.

Java client code

MainActivity.java

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        EdgeToEdge.enable(this);
        setContentView(R.layout.activity_main);
        ((TextView)findViewById(R.id.text_view)).setText(FFmpegPlay.getFFmpegVersion());
    }
}

FFmpegplay.java

public class FFmpegPlay {
    static {
        System.loadLibrary("ffmpegtest");
    }

    public static String getFFmpegVersion() {
        return nativeGetFFmpegVersion();
    }

    private static native String nativeGetFFmpegVersion();
}

Native code

ffmpegtest.cpp

#include <jni.h>
#include <cstring>
#include "util/log.h"

extern "C" {
#include <libavcodec/version.h>
#include <libavcodec/avcodec.h>
#include <libavformat/version.h>
#include <libavutil/version.h>
#include <libavfilter/version.h>
#include <libswresample/version.h>
#include <libswscale/version.h>
}

extern "C"
JNIEXPORT jstring JNICALL
Java_com_example_ffmpegtest_FFmpegPlay_nativeGetFFmpegVersion(JNIEnv *env, jclass clazz) {
    char strBuffer[1024 * 4] = {0};
    strcat(strBuffer, "libavcodec : ");
    strcat(strBuffer, AV_STRINGIFY(LIBAVCODEC_VERSION));
    strcat(strBuffer, "\nlibavformat : ");
    strcat(strBuffer, AV_STRINGIFY(LIBAVFORMAT_VERSION));
    strcat(strBuffer, "\nlibavutil : ");
    strcat(strBuffer, AV_STRINGIFY(LIBAVUTIL_VERSION));
    strcat(strBuffer, "\nlibavfilter : ");
    strcat(strBuffer, AV_STRINGIFY(LIBAVFILTER_VERSION));
    strcat(strBuffer, "\nlibswresample : ");
    strcat(strBuffer, AV_STRINGIFY(LIBSWRESAMPLE_VERSION));
    strcat(strBuffer, "\nlibswscale : ");
    strcat(strBuffer, AV_STRINGIFY(LIBSWSCALE_VERSION));
    strcat(strBuffer, "\navcodec_configure : \n");
    strcat(strBuffer, avcodec_configuration());
    strcat(strBuffer, "\navcodec_license : ");
    strcat(strBuffer, avcodec_license());
    LOGCATE("GetFFmpegVersion\n%s", strBuffer);
    return env->NewStringUTF(strBuffer);
}

CMakeLists.txt

# Sets the minimum version of CMake required to build the native library.
cmake_minimum_required(VERSION 3.4.1)

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=gnu++11")

set(jnilibs ${CMAKE_SOURCE_DIR}/../jniLibs)
set(libname ffmpegtest)

include_directories(
        ${CMAKE_SOURCE_DIR}/include
        ${CMAKE_SOURCE_DIR}/util
)

link_directories(
        ${jnilibs}/${ANDROID_ABI})

file(GLOB src-files
        ${CMAKE_SOURCE_DIR}/*.cpp)

add_library(
        ${libname}
        SHARED
        ${src-files}
)

set(third-party-libs
        avformat
        avcodec
        avfilter
        swresample
        swscale
        avutil
)

set(native-libs
        android
        mediandk
        EGL
        GLESv3
        OpenSLES
        log
        m
        z
)

target_link_libraries(
        ${libname}

        ${log-lib}
        ${third-party-libs}
        ${native-libs}
)

Result