安卓开发者万里长城又走了一步，真是痛快
昨天生成了动态库，动态库生请看这里，今天就新建了一个项目，测试了一下库的使用如下
目录结构如下图：
首先新建一个c++项目，新建完了会有一个cpp的文件夹，新建项目的Mainactivity要用java不要用kotlin，这个很坑的，kotlin目前好像不行，不知道是不是我没找到方法，卡这里至少掉了十根头发
这个CMakeLists.txt也很坑的，开始看的网上的Adroid.mk和Application.mk,技不如人，看着人家一步一步搞的，自己的有问题，最后发现CMakeLists.txt就是替换Adroid.mk和Application.mk这两个东西的
还有include这个文件夹，开始放到cpp下面，native-lib可以引入头文件，放到jniLibs目录下就无法引入了，这个最后写的绝对路径"./../jniLibs/include/libavcodec/avcodec.h"这样的，然后include头文件的.h文件很挫有错误的，就改，原本#include "libavutil/rational.h"修改为#include "../libavutil/rational.h",有十来个文件把一个一个改*
# For more information about using CMake with Android Studio, read the
# documentation: https://d.android.com/studio/projects/add-native-code.html
# Sets the minimum version of CMake required to build the native library.
cmake_minimum_required(VERSION 3.4.1)
# Creates and names a library, sets it as either STATIC
# or SHARED, and provides the relative paths to its source code.
# You can define multiple libraries, and CMake builds them for you.
# Gradle automatically packages shared libraries with your APK.
#add_library( # Sets the name of the library.
# native-lib
#
# # Sets the library as a shared library.
# SHARED
#
# # Provides a relative path to your source file(s).
# src/main/cpp/native-lib.cpp)
# Searches for a specified prebuilt library and stores the path as a
# variable. Because CMake includes system libraries in the search path by
# default, you only need to specify the name of the public NDK library
# you want to add. CMake verifies that the library exists before
# completing its build.
find_library( # Sets the name of the path variable.
log-lib
# Specifies the name of the NDK library that
# you want CMake to locate.
log)
# Specifies libraries CMake should link to your target library. You
# can link multiple libraries, such as libraries you define in this
# build script, prebuilt third-party libraries, or system libraries.
#target_link_libraries( # Specifies the target library.
# native-lib
#
# # Links the target library to the log library
# # included in the NDK.
# ${log-lib})
set(distribution_DIR ${CMAKE_SOURCE_DIR}/src/main/jniLibs/${ANDROID_ABI})
include_directories(/src/main/jniLibs/include)
add_library( avutil-55
SHARED
IMPORTED )
set_target_properties( avutil-55
PROPERTIES IMPORTED_LOCATION
${distribution_DIR}/libavutil-55.so)
add_library( swresample-2
SHARED
IMPORTED )
set_target_properties( swresample-2
PROPERTIES IMPORTED_LOCATION
${distribution_DIR}/libswresample-2.so)
add_library( avcodec-57
SHARED
IMPORTED )
set_target_properties( avcodec-57
PROPERTIES IMPORTED_LOCATION
${distribution_DIR}/libavcodec-57.so)
add_library( avfilter-6
SHARED
IMPORTED )
set_target_properties( avfilter-6
PROPERTIES IMPORTED_LOCATION
${distribution_DIR}/libavfilter-6.so)
add_library( swscale-4
SHARED
IMPORTED )
set_target_properties( swscale-4
PROPERTIES IMPORTED_LOCATION
${distribution_DIR}/libswscale-4.so)
add_library( avdevice-57
SHARED
IMPORTED)
set_target_properties( avdevice-57
PROPERTIES IMPORTED_LOCATION
${distribution_DIR}/libavdevice-57.so )
add_library( avformat-57
SHARED
IMPORTED )
set_target_properties( avformat-57
PROPERTIES IMPORTED_LOCATION
${distribution_DIR}/libavformat-57.so)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=gnu++11")
add_library( native-lib
SHARED
src/main/cpp/native-lib.cpp)
target_link_libraries(native-lib swresample-2 avcodec-57 avfilter-6 swscale-4 avdevice-57 avformat-57 avutil-55
${log-lib})
native-lib.cpp原码
#include <jni.h>
#include <string>
extern "C" {
#include "./../jniLibs/include/libavutil/avutil.h"
#include "./../jniLibs/include/libavfilter/avfilter.h"
#include "./../jniLibs/include/libavformat/avformat.h"
#include "./../jniLibs/include/libavcodec/avcodec.h"
jstring
Java_com_ffmpeg_myffmpeg_MainActivity1_stringFromJNI(
JNIEnv *env,
jobject /* this */) {
std::string hello = "Hello from C++";
return env->NewStringUTF(hello.c_str());
}
jstring
Java_com_ffmpeg_myffmpeg_MainActivity1_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);
}
jstring
Java_com_ffmpeg_myffmpeg_MainActivity1_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_ffmpeg_myffmpeg_MainActivity1_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_ffmpeg_myffmpeg_MainActivity1_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);
}
}
MainActivity原码，这里开始是Mainactivity.kt,最后修改为Mainactivity.java,报错，又修改为了MainActivity1.java的
package com.ffmpeg.myffmpeg;
import android.os.Bundle;
import android.widget.TextView;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
public class MainActivity1 extends AppCompatActivity {
private TextView textView;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textView=findViewById(R.id.sample_text);
textView.setText(stringFromJNI()+
urlprotocolinfo()+
avformatinfo()+
avfilterinfo());
}
public native String stringFromJNI();
public native String urlprotocolinfo();
public native String avformatinfo();
public native String avfilterinfo();
static {
System.loadLibrary("native-lib");
System.loadLibrary("avcodec-57");
System.loadLibrary("avdevice-57");
System.loadLibrary("avfilter-6");
System.loadLibrary("avformat-57");
System.loadLibrary("avutil-55");
System.loadLibrary("postproc-54");
System.loadLibrary("swresample-2");
System.loadLibrary("swscale-4");
}
}
最后上传代码一份： 别忘点个赞哈 https://github.com/gethub-json/myffmpeg