windows下編譯最新版ffmpeg3.3-android，並通過CMake方式移植到Android studio2.3中
阿新 • • 發佈：2019-02-03
windows下編譯最新版ffmpeg3.3
- 編輯ffmpeg資料夾下面的configure檔案，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) $(SLIBNAME)'
將其修改成：
SLIBNAME_WITH_MAJOR='$(SLIBPREF) ============================================
2.新建一個build_android.sh檔案
注意：要根據環境配置前四項，且每行末尾不能有空格。 export TMPDIR，NDK，SYSROOT，TOOLCHAIN –cross-prefix一定有
#!/bin/bash
export TMPDIR="C:/Users/shuo.wang/Desktop/ff"
NDK=C:/Users/shuo.wang/AppData/Local/Android/sdk/ndk-bundle
SYSROOT=$NDK/platforms/android-21/arch-arm/
TOOLCHAIN=$NDK/toolchains/arm-linux-androideabi-4.9/prebuilt/windows-x86_64
function build_one {
./configure \
--prefix=$PREFIX \
--enable-shared \
然後在MinGW中進入cd進ffmpeg目錄。
命令：
1. chmod 777 ./build_android.sh
2. ./build_android.sh 然後就開始編譯了。
注意因為 NDK和ffmpeg，版本問題。ffmpeg3.1編譯不過。
ffmpeg3.3可以。
編譯完成後這時會發現 FFmpeg下多了一個資料夾android
下面開始移植到Android studio中
需要Android studio版本2.2以上，並安裝CMake。本例中用Android studio2.3
1.新建工程取名為FFmpegAndroid，然後選中include c++ support，然後下一步直到新建完成為止。
2.然後開啟app中build.gradle。
新增如下：
externalNativeBuild {
cmake {
cppFlags ""
}
}
//新增 start
ndk {
abiFilters "armeabi", "armeabi-v7a"
}
//----------------------------------------------
sourceSets.main {
jniLibs.srcDirs = ['libs']
jni.srcDirs = []
}
//新增 end
externalNativeBuild {
cmake {
path "CMakeLists.txt"
}
}3.把之前編譯好的.so庫拷貝進專案libs目錄
如圖：
4.重點 CMakeLists.txt配置
# Sets the minimum version of CMake required to build the native
# library. You should either keep the default value or only pass a
# value of 3.4.0 or lower.
cmake_minimum_required(VERSION 3.4.1)
add_library(
native-lib
SHARED
src/main/cpp/native-lib.cpp )
find_library(
log-lib
log )
set(distribution_DIR ${CMAKE_SOURCE_DIR}/../../../../libs)
add_library( avutil-55
SHARED
IMPORTED )
set_target_properties( avutil-55
PROPERTIES IMPORTED_LOCATION
../../../../libs/armeabi-v7a/libavutil-55.so )
add_library( swresample-2
SHARED
IMPORTED )
set_target_properties( swresample-2
PROPERTIES IMPORTED_LOCATION
../../../../libs/armeabi-v7a/libswresample-2.so )
add_library( avcodec-57
SHARED
IMPORTED )
set_target_properties( avcodec-57
PROPERTIES IMPORTED_LOCATION
../../../../libs/armeabi-v7a/libavcodec-57.so )
add_library( avfilter-6
SHARED
IMPORTED)
set_target_properties( avfilter-6
PROPERTIES IMPORTED_LOCATION
../../../../libs/armeabi-v7a/libavfilter-6.so )
add_library( swscale-4
SHARED
IMPORTED)
set_target_properties( swscale-4
PROPERTIES IMPORTED_LOCATION
../../../../libs/armeabi-v7a/libswscale-4.so )
add_library( avdevice-57
SHARED
IMPORTED)
set_target_properties( avdevice-57
PROPERTIES IMPORTED_LOCATION
../../../../libs/armeabi-v7a/libavdevice-57.so )
add_library( avformat-57
SHARED
IMPORTED)
set_target_properties( avformat-57
PROPERTIES IMPORTED_LOCATION
../../../../libs/armeabi-v7a/libavformat-57.so )
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=gnu++11")
include_directories(libs/include)
#target_include_directories(native-lib PRIVATE libs/include)
target_link_libraries( native-lib swresample-2 avcodec-57 avfilter-6 swscale-4 avdevice-57 avformat-57
${log-lib} )
cmake_minimum_required(VERSION 3.4.1):表示cmake的最低版本是3.4.1。
add_library():新增庫，分為兩種，一種是需要編譯為庫的程式碼，一種是已經編譯好的庫檔案。
比如上面編譯好的ffmpeg的庫
這裡用到的需要生產的.so檔案
add_library( native-lib
SHARED
src/main/cpp/native-lib.cpp )最後的引數是原始碼的路徑，如果有更多的原始碼就接下去寫上。
add_library( avutil-55
SHARED
IMPORTED )這裡avutil-55表示庫的名稱，SHARED表示是共享庫，一般.so檔案，還有STATIC，一般.a檔案。IMPORTED表示引用的不是生成的。
set_target_properties：對於已經編譯好的so檔案需要引入，所以需要設定。
set_target_properties( avutil-55
PROPERTIES IMPORTED_LOCATION
../../../../libs/armeabi-v7a/libavutil-55.so ) 這裡avutil-55是名字，然後是PROPERTIES IMPORTED_LOCATION加上庫的路徑。
include_directories：一般外面引入的庫檔案需要標頭檔案，所以可以通過這個來引入：
include_directories(libs/include)target_link_libraries：連結，把需要的so檔案連結起來，這裡native-lib需要連結ffmpeg的庫檔案。
5.修改native-lib.cpp
#include <jni.h>
#include <string>
extern "C"
{
#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <libavfilter/avfilter.h>
jstring
Java_com_ws_ffmpeg_ffmpegandroid_MainActivity_stringFromJNI(
JNIEnv *env,
jobject /* this */) {
std::string hello = "Hello from C++";
return env->NewStringUTF(hello.c_str());
}
jstring
Java_com_ws_ffmpeg_ffmpegandroid_MainActivity_urlprotocolinfo(
JNIEnv *env, jobject) {
char info[40000] = {0};
av_register_all();
struct URLProtocol *pup = NULL;
struct URLProtocol **p_temp = &pup;
avio_enum_protocols((void **) p_temp, 0);
while ((*p_temp) != NULL) {
sprintf(info, "%sInput: %s\n", info, avio_enum_protocols((void **) p_temp, 0));
}
pup = NULL;
avio_enum_protocols((void **) p_temp, 1);
while ((*p_temp) != NULL) {
sprintf(info, "%sInput: %s\n", info, avio_enum_protocols((void **) p_temp, 1));
}
return env->NewStringUTF(info);
}
jstring
Java_com_ws_ffmpeg_ffmpegandroid_MainActivity_avformatinfo(
JNIEnv *env, jobject) {
char info[40000] = {0};
av_register_all();
AVInputFormat *if_temp = av_iformat_next(NULL);
AVOutputFormat *of_temp = av_oformat_next(NULL);
while (if_temp != NULL) {
sprintf(info, "%sInput: %s\n", info, if_temp->name);
if_temp = if_temp->next;
}
while (of_temp != NULL) {
sprintf(info, "%sOutput: %s\n", info, of_temp->name);
of_temp = of_temp->next;
}
return env->NewStringUTF(info);
}
jstring
Java_com_ws_ffmpeg_ffmpegandroid_MainActivity_avcodecinfo(
JNIEnv *env, jobject) {
char info[40000] = {0};
av_register_all();
AVCodec *c_temp = av_codec_next(NULL);
while (c_temp != NULL) {
if (c_temp->decode != NULL) {
sprintf(info, "%sdecode:", info);
} else {
sprintf(info, "%sencode:", info);
}
switch (c_temp->type) {
case AVMEDIA_TYPE_VIDEO:
sprintf(info, "%s(video):", info);
break;
case AVMEDIA_TYPE_AUDIO:
sprintf(info, "%s(audio):", info);
break;
default:
sprintf(info, "%s(other):", info);
break;
}
sprintf(info, "%s[%10s]\n", info, c_temp->name);
c_temp = c_temp->next;
}
return env->NewStringUTF(info);
}
jstring
Java_com_ws_ffmpeg_ffmpegandroid_MainActivity_avfilterinfo(
JNIEnv *env, jobject) {
char info[40000] = {0};
avfilter_register_all();
AVFilter *f_temp = (AVFilter *) avfilter_next(NULL);
while (f_temp != NULL) {
sprintf(info, "%s%s\n", info, f_temp->name);
f_temp = f_temp->next;
}
return env->NewStringUTF(info);
}
}
6.呼叫native方法
package com.ws.ffmpeg.ffmpegandroid;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity implements View.OnClickListener {
// Used to load the 'native-lib' library on application startup.
static {
System.loadLibrary("native-lib");
}
private Button protocol,format,codec,filter;
private TextView tv_info;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
init();
}
private void init() {
protocol = (Button) findViewById(R.id.btn_protocol);
format = (Button) findViewById(R.id.btn_format);
codec = (Button) findViewById(R.id.btn_codec);
filter = (Button) findViewById(R.id.btn_filter);
tv_info = (TextView) findViewById(R.id.tv_info);
protocol.setOnClickListener(this);
format.setOnClickListener(this);
codec.setOnClickListener(this);
filter.setOnClickListener(this);
}
@Override
public void onClick(View view) {
switch (view.getId()) {
case R.id.btn_protocol:
tv_info.setText(urlprotocolinfo());
break;
case R.id.btn_format:
tv_info.setText(avformatinfo());
break;
case R.id.btn_codec:
tv_info.setText(avcodecinfo());
break;
case R.id.btn_filter:
tv_info.setText(avfilterinfo());
break;
default:
break;
}
}
public native String stringFromJNI();
public native String urlprotocolinfo();
public native String avformatinfo();
public native String avcodecinfo();
public native String avfilterinfo();
}
ok ! 效果如圖：
