編譯FFmpeg4.0.1並移植到Android app中使用(最詳細的FFmpeg-Android編譯教程)
1.搭建編譯環境
1.安裝ubuntu14.04,安裝完成後執行以下命令
apt-get update
apt-get install yasm
apt-get install pkg-config
2.下載ndk
我用的是ndk r14b,附上下載地址:https://dl.google.com/android/repository/android-ndk-r14b-linux-x86_64.zip
將ndk下載到 /home/ndk/目錄下,下載完成後執行tar -zxvf android-ndk-r14b-linux-x86_64.zip
解壓
3.下載FFmpeg4.0.1
下載地址:
下載完成後執行tar -zxvf n4.0.1
解壓
2.編譯FFmpeg
1.修改configure
進入原始碼根目錄,用vim開啟configure,找到
SLIBNAME_WITH_MAJOR='$(SLIBNAME).$(LIBMAJOR)' LIB_INSTALL_EXTRA_CMD='$$(RANLIB)"$(LIBDIR)/$(LIBNAME)"' SLIB_INSTALL_NAME='$(SLIBNAME_WITH_VERSION)' SLIB_INSTALL_LINKS='$(SLIBNAME_WITH_MAJOR)$(SLIBNAME)'
將其修改為
SLIBNAME_WITH_MAJOR='$(SLIBPREF)$(FULLNAME)-$(LIBMAJOR)$(SLIBSUF)'
LIB_INSTALL_EXTRA_CMD='$$(RANLIB)"$(LIBDIR)/$(LIBNAME)"'
SLIB_INSTALL_NAME='$(SLIBNAME_WITH_MAJOR)'
SLIB_INSTALL_LINKS='$(SLIBNAME)'
2.配置編譯指令碼
在原始碼根目錄新建build.sh,內容如下:
#!/bin/bash NDK=/home/ndk/android-ndk-r14b SYSROOT=$NDK/platforms/android-21/arch-arm/ CPU=armv7-a TOOLCHAIN=$NDK/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64 PREFIX=$(pwd)/android/$CPU OPTIMIZE_CFLAGS="-mfloat-abi=softfp -mfpu=vfp -marm -march=$CPU " function build_android { ./configure \ --prefix=$PREFIX \ --enable-neon \ --enable-hwaccels \ --enable-shared \ --enable-jni \ --enable-mediacodec \ --enable-decoder=h264_mediacodec \ --disable-static \ --disable-doc \ --enable-ffmpeg \ --disable-ffplay \ --disable-ffprobe \ --enable-avdevice \ --disable-doc \ --disable-symver \ --cross-prefix=$TOOLCHAIN/bin/arm-linux-androideabi- \ --target-os=android \ --arch=arm \ --cpu=armv7-a \ --enable-cross-compile \ --sysroot=$SYSROOT \ --extra-cflags="-Os -fpic $OPTIMIZE_CFLAGS" \ --extra-ldflags="$ADDI_LDFLAGS" \ $ADDITIONAL_CONFIGURE_FLAG } build_android
賦予指令碼執行許可權:chmod +x build.sh
執行指令碼:./build.sh
編譯:make -j4
(-j<改成你的CPU核心數量>)
生成動態連結庫:make install
如果一切順利就可以在原始碼更目錄下的android/armv7-a下找到我們需要的.so檔案了
3.移植到Android App中
1.JNI編譯
(1)將編譯後的FFmpeg原始碼目錄打包並複製到Windows中,在任意目錄下新建jni資料夾,在解壓後的 …\FFmpeg-n4.0.1\android\armv7-a\lib目錄下有7個.so檔案,將所有的.so檔案放到 …\jni\prebuilt\目錄下;
將 …\FFmpeg-n4.0.1\android\armv7-a\include目錄下的所有資料夾複製到 …\jni\目錄下;
將 …\FFmpeg-n4.0.1\fftools\目錄下的以下檔案複製到 …\jni\目錄下
cmdutils.h
ffmpeg.h
ffmpeg.c
ffmpeg_opt.c
config.h
ffmpeg_filter.c
cmdutils.c
ffmpeg_hw.c
(2)修改cmdutils
開啟cmdutils.h,將
void show_help_children(const AVClass *class, int flags);
改為
void show_help_children(const AVClass *clazz, int flags);
否則和C++一起編譯會出問題
開啟cmdutils.c
將void exit_program(int ret)
中的退出函式註釋掉,否則命令執行完會導致APP退出:
void exit_program(int ret)
{
//if (program_exit)
// program_exit(ret);
//exit(ret);
}
(3)修改ffmpeg.c
找到入口函式int main(int argc, char **argv)
將其修改為int ffmpeg_exec(int argc, char **argv)
並將該函式末尾此行程式碼註釋掉:
//exit_program(received_nb_signals ? 255 : main_return_code);
同時在ffmpeg.h中新增函式申明:
int ffmpeg_exec(int argc, char **argv);
在函式static void ffmpeg_cleanup(int ret)
末尾加上以下程式碼:
nb_filtergraphs = 0;
nb_output_files = 0;
nb_output_streams = 0;
nb_input_files = 0;
nb_input_streams = 0;
(4)輸出ADB日誌
在ffmpeg.c中引入標頭檔案
#include "android/log.h"
#define LOGD(...) __android_log_print(ANDROID_LOG_DEBUG , "ffmpeg.c", __VA_ARGS__)
#define LOGE(...) __android_log_print(ANDROID_LOG_ERROR , "ffmpeg.c", __VA_ARGS__)
實現log_callback_null
函式
static void log_callback_null(void *ptr, int level, const char *fmt, va_list vl)
{
static int print_prefix = 1;
static int count;
static char prev[1024];
char line[1024];
static int is_atty;
av_log_format_line(ptr, level, fmt, vl, line, sizeof(line), &print_prefix);
strcpy(prev, line);
//sanitize((uint8_t *)line);
if (level <= AV_LOG_WARNING) {
LOGE("%s", line);
} else {
LOGD("%s", line);
}
}
(5)實現JNI介面
編寫ffmpeg-invoke.cpp並放到 …\jni\目錄下:
#include <jni.h>
#include <string>
#include "android/log.h"
extern "C"{
#include "ffmpeg.h"
}
#define LOGD(...) __android_log_print(ANDROID_LOG_DEBUG , "ffmpeg-invoke", __VA_ARGS__)
extern "C"
JNIEXPORT jstring JNICALL
Java_com_gamepp_ffmpegtest_jni_FFmpegInvoke_test(JNIEnv *env, jclass type) {
std::string retValue = "FFmpeg invoke test";
return env->NewStringUTF(retValue.c_str());
}
extern "C"
JNIEXPORT jint JNICALL
Java_com_gamepp_ffmpegtest_jni_FFmpegInvoke_run(JNIEnv *env, jclass type, jint cmdLen,
jobjectArray cmd) {
char *argCmd[cmdLen] ;
jstring buf[cmdLen];
LOGD("length=%d",cmdLen);
for (int i = 0; i < cmdLen; ++i) {
buf[i] = static_cast<jstring>(env->GetObjectArrayElement(cmd, i));
char *string = const_cast<char *>(env->GetStringUTFChars(buf[i], JNI_FALSE));
argCmd[i] = string;
LOGD("argCmd=%s",argCmd[i]);
}
ffmpeg_exec(cmdLen, argCmd);
return 0;
}
注意:將com_gamepp_ffmpegtest_jni_FFmpegInvoke改為自己工程中的JAVA檔案對應的包名和路徑
(6)編寫.mk檔案
編寫Android.mk檔案並放到 …\jni\目錄
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := libavutil
LOCAL_SRC_FILES := prebuilt/libavutil.so
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := libswresample
LOCAL_SRC_FILES := prebuilt/libswresample.so
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := libswscale
LOCAL_SRC_FILES := prebuilt/libswscale.so
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := libavcodec
LOCAL_SRC_FILES := prebuilt/libavcodec.so
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := libavformat
LOCAL_SRC_FILES := prebuilt/libavformat.so
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := libavfilter
LOCAL_SRC_FILES := prebuilt/libavfilter.so
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := libavdevice
LOCAL_SRC_FILES := prebuilt/libavdevice.so
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := ffmpeg-invoke
LOCAL_SRC_FILES :=ffmpeg-invoke.cpp \
cmdutils.c \
ffmpeg_filter.c \
ffmpeg_opt.c \
ffmpeg_hw.c \
ffmpeg.c
LOCAL_C_INCLUDES := D:\libs\FFmpeg-n4.0.1
LOCAL_LDLIBS := -llog -ljnigraphics -lz -landroid -lm -pthread -L$(SYSROOT)/usr/lib
LOCAL_SHARED_LIBRARIES := libavcodec libavfilter libavformat libavutil libswresample libswscale libavdevice
include $(BUILD_SHARED_LIBRARY)
注意:將LOCAL_C_INCLUDES改為自己電腦中FFmpeg原始碼所在目錄
編寫Application.mk並放到 …\jni\目錄下
APP_ABI := armeabi-v7a
APP_PLATFORM=android-21
APP_OPTIM := release
APP_STL := stlport_static
(7)編譯
確認所需檔案都準備就緒:
開啟CMD,進入該目錄,執行ndk-build
(確保ndk路徑已經配置到環境變數中)
編譯成功:
編譯成功後可以再jni同級目錄下找到libs目錄,libs\armeabi-v7a目錄下的.so檔案就是我們最終需要的動態連結庫:
2.新建Android Studio測試工程 FFmpegTest
(1)在FFmpegTest\app\src\main\目錄下新建jniLibs目錄,將上一步編譯生成的 \libs\armeabi-v7a資料夾複製到jniLibs目錄下;
在com.gamepp.ffmpegtest.jni路徑下新建FFmpegInvoke.java
public class FFmpegInvoke {
static {
System.loadLibrary("avutil");
System.loadLibrary("avcodec");
System.loadLibrary("swresample");
System.loadLibrary("avformat");
System.loadLibrary("swscale");
System.loadLibrary("avfilter");
System.loadLibrary("avdevice");
System.loadLibrary("ffmpeg-invoke");
}
private static native int run(int cmdLen, String[] cmd);
public static native String test();
public static int run(String[] cmd){
return run(cmd.length,cmd);
}
}
(2)呼叫測試
測試是否能夠成功呼叫動態連結庫函式
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
TextView tvMessage = findViewById(R.id.tv_message);
tvMessage.setText(FFmpegInvoke.test());
}
}
正是ffmpeg-invoke.cpp中Java_com_gamepp_ffmpegtest_jni_FFmpegInvoke_test(JNIEnv *env, jclass type)
函式返回的字串,說明java呼叫C++函式成功。
(3)測試FFmpeg命令
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE)
!= PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},
100);
}
TextView tvMessage = findViewById(R.id.tv_message);
tvMessage.setText(FFmpegInvoke.test());
ffmpegTest();
}
private void ffmpegTest() {
new Thread(){
@Override
public void run() {
long startTime = System.currentTimeMillis();
String input = "/sdcard/Movies/Replay_2018.05.08-13.46.mp4";
String output = "/sdcard/Movies/output.mp4";
//剪下視訊從00:20-00:28的片段
String cmd = "ffmpeg -d -ss 00:00:20 -t 00:00:08 -i %s -vcodec copy -acodec copy %s";
cmd = String.format(cmd,input,output);
FFmpegInvoke.run(cmd.split(" "));
Log.d("FFmpegTest", "run: 耗時:"+(System.currentTimeMillis()-startTime));
}
}.start();
}
}
執行完畢後再/sdcard/Movies/目錄下找到output.mp4,開啟播放確實是我們想要的結果,說明FFmpeg的命令成功執行了。