【贪吃蛇python源码】【源码代表数字】【科技模板源码】jni源码编译-皮皮网

【贪吃蛇python源码】【源码代表数字】【科技模板源码】jni源码编译

2024-11-29 22:32:41 来源：电脑网站源码分类：知识

1.å¦ä½å¨Androidä¸ä½¿ç¨JNI
2.ç¨jniåçå®ååºç¨è½è¢«åç¼è¯å
3.音视频探索(5)：JPEG格式与Libjpeg库编译移植
4.Android开发中的源译NDK到底是什么？(详细解析+案例)

jni源码编译

å¦ä½å¨Androidä¸ä½¿ç¨JNI

ãã1.å¼è¨

ãã2.ç¯å¢éç½®

ãã2.1.å®è£jdk1.6

ããï¼1ï¼ä»jdkå®æ¹ç½ç«ä¸è½½jdk-6u-linux-i.binæä»¶ã

ããï¼2ï¼æ§è¡jdkå®è£æä»¶

ãã[html] view plaincopyprint?

ãã.$chmod a+x jdk-6u-linux-i.bin

ãã.$jdk-6u-linux-i.bin

ãã$chmod a+x jdk-6u-linux-i.bin

ãã$jdk-6u-linux-i.bin

ãã(3)éç½®jdkç¯å¢åé

ãã[html] view plaincopyprint?

ãã.$sudo vim /etc/profile

ãã.#JAVAEVIRENMENT

ãã.exportJAVA_HOME=/usr/lib/java/jdk1.6.0_

ãã.exportJRE_HOME=$JAVA_HOME/jre

ãã.exportCLASSPATH=$JAVA_HOME/lib:$JRE_HOME/lib:$CLASSPATH

ãã.exportPATH=$JAVA_HOME/bin:$JRE_HOME/bin:$PATH

ãã$sudo vim /etc/profile

ãã#JAVAEVIRENMENT

ããexportJAVA_HOME=/usr/lib/java/jdk1.6.0_

ããexportJRE_HOME=$JAVA_HOME/jre

ããexportCLASSPATH=$JAVA_HOME/lib:$JRE_HOME/lib:$CLASSPATH

ããexportPATH=$JAVA_HOME/bin:$JRE_HOME/bin:$PATH

ããä¿ååéåºç¼è¾ï¼å¹¶éå¯ç³»ç»ã

ããï¼4ï¼éªè¯å®è£

ãã[html] view plaincopyprint?

ãã.$java -version

ãã.javaversion "1.6.0_"

ãã.Java(TM)SE Runtime Environment (build 1.6.0_-b)

ãã.JavaHotSpot(TM) Server VM (build .4-b, mixed mode)

ãã.$javah

ãã.ç¨æ³ï¼javah[éé¡¹]<ç±»>

ãã.å¶ä¸[éé¡¹]åæ¬ï¼

ãã.-helpè¾åºæ¤å¸®å©æ¶æ¯å¹¶éåº

ãã.-classpath<è·¯å¾>ç¨äºè£å¥ç±»çè·¯å¾

ãã.-bootclasspath<è·¯å¾>ç¨äºè£å¥å¼å¯¼ç±»çè·¯å¾

ãã.-d<ç®å½>è¾åºç®å½

ãã.-o<æä»¶>è¾åºæä»¶ï¼åªè½ä½¿ç¨-dæ-oä¸çä¸ä¸ªï¼

ãã.-jniçæJNIæ ·å¼çå¤´æä»¶ï¼é»è®¤ï¼

ãã.-versionè¾åºçæ¬ä¿¡æ¯

ãã.-verboseå¯ç¨è¯¦ç»è¾åº

ãã.-forceå§ç»åå¥è¾åºæä»¶

ãã.ä½¿ç¨å¨éå®åç§°æå®<ç±»>ï¼ä¾

ãã.å¦ï¼java.lang.Objectï¼ã

ãã$java -version

ããjavaversion "1.6.0_"

ããJava(TM)SE Runtime Environment (build 1.6.0_-b)

ããJavaHotSpot(TM) Server VM (build .4-b, mixed mode)

ãã$javah

ããç¨æ³ï¼javah[éé¡¹]<ç±»>

ããå¶ä¸[éé¡¹]åæ¬ï¼

ãã-helpè¾åºæ¤å¸®å©æ¶æ¯å¹¶éåº

ãã-classpath<è·¯å¾>ç¨äºè£å¥ç±»çè·¯å¾

ãã-bootclasspath<è·¯å¾>ç¨äºè£å¥å¼å¯¼ç±»çè·¯å¾

ãã-d<ç®å½>è¾åºç®å½

ãã-o<æä»¶>è¾åºæä»¶ï¼åªè½ä½¿ç¨-dæ-oä¸çä¸ä¸ªï¼

ãã-jniçæJNIæ ·å¼çå¤´æä»¶ï¼é»è®¤ï¼

ãã-versionè¾åºçæ¬ä¿¡æ¯

ãã-verboseå¯ç¨è¯¦ç»è¾åº

ãã-forceå§ç»åå¥è¾åºæä»¶

ããä½¿ç¨å¨éå®åç§°æå®<ç±»>ï¼ä¾

ããå¦ï¼java.lang.Objectï¼ã2.2.å®è£androidåºç¨ç¨åºå¼åç¯å¢

ããï¼1ï¼Eclipse

ããï¼2ï¼ADT

ããï¼3ï¼AndroidSDK

ããæemulatoræå¨ç®å½android-sdk-linux/toolsä»¥åadbæå¨ç®å½android-sdk-linux/platform-toolsæ·»å å°ç¯å¢åéä¸ï¼android-sdk-linuxæandroidsdkå®è£åandroid-sdk_rxx-linuxçè§£åç®å½ã

ãã[plain] view plaincopyprint?

ãã.$sudo vim /etc/profile

ãã.exportPATH=~/software/android/android-sdk-linux/tools:$PATH

ãã. exportPATH=~/software/android/android-sdk-linux/platform-tools:$PATH

ãã$sudo vim /etc/profile

ããexportPATH=~/software/android/android-sdk-linux/tools:$PATH

ããexportPATH=~/software/android/android-sdk-linux/platform-tools:$PATH

ããç¼è¾å®æ¯åéåºï¼å¹¶éå¯çæã

ãã2.3.å®è£NDK

ããNDKæ¯ç±androidæä¾çç¼è¯androidæ¬å°ä»£ç çä¸ä¸ªå·¥å·ã

ããï¼1ï¼ä»androidndkå®ç½/sdk/ndk/index.htmlä¸è½½ndkï¼ç®åææ°çæ¬ä¸ºandroid-ndk-r6b-linux-x.tar.bz2.

ããï¼2ï¼è§£åndkå°å·¥ä½ç®å½ï¼

ãã[plain] view plaincopyprint?

ãã.$tar -xvf android-ndk-r6b-linux-x.tar.bz2

ãã.$sudo mv android-ndk-r6b /usr/local/ndk

ãã$tar -xvf android-ndk-r6b-linux-x.tar.bz2

ãã$sudo mv android-ndk-r6b /usr/local/ndk

ããï¼3ï¼è®¾ç½®ndkç¯å¢åé

ãã[plain] view plaincopyprint?

ãã.$sudo vim /etc/profile

ãã.exportPATH=/usr/local/ndk:$PATH

ãã$sudo vim /etc/profile

ããexportPATH=/usr/local/ndk:$PATH

ããç¼è¾å®æ¯åä¿åéåºï¼å¹¶éå¯çæ

ããï¼4ï¼éªè¯å®è£

ãã[plain] view plaincopyprint?

ãã.$ cd/usr/local/ndk/samples/hello-jni/

ãã.$ ndk-build

ãã.Gdbserver : [arm-linux-androideabi-4.4.3] libs/armeabi/gdbserver

ãã.Gdbsetup : libs/armeabi/gdb.setup

ãã.Install : libhello-jni.so => libs/armeabi/libhello-jni.so

ãã$ cd/usr/local/ndk/samples/hello-jni/

ãã$ ndk-build

ããGdbserver : [arm-linux-androideabi-4.4.3] libs/armeabi/gdbserver

ããGdbsetup : libs/armeabi/gdb.setup

ããInstall : libhello-jni.so => libs/armeabi/libhello-jni.so

ãã3.JNIå®ç°

ãã3.1.ç¼åJavaåºç¨ç¨åºä»£ç

ããï¼1ï¼å¯å¨Eclipseï¼æ°å»ºandroidå·¥ç¨

ããProjectï¼JNITest

ããPackageï¼org.tonny.jni

ããActivityï¼JNITest

ããï¼2ï¼ç¼è¾èµæºæä»¶

ããç¼è¾res/values/strings.xmlæä»¶å¦ä¸ï¼

ãã

ããç¼è¾res/layout/main.xmlæä»¶

ããï¼3ï¼ç¼è¾JNITest.javaæä»¶

ããåçè¿ä¸æ®µï¼

ãã[java] view plaincopyprint?

ãã.privatenativeString GetReply();

ããprivatenativeString GetReply();

ãã[java] view plaincopyprint?

ãã.publicvoidonClick(View arg0) {

ãã.edtName.setText(reply);

ãã.}

ããpublicvoidonClick(View arg0) {

ããedtName.setText(reply);

ãã}

ããï¼4ï¼ç¼è¯å·¥ç¨ï¼çæ.classæä»¶ã

ãã3.2.ç¨javahå·¥å·çæç¬¦åJNIè§èçcè¯è¨å¤´æä»¶

ããå¨ç»ç«¯ä¸ï¼è¿å¥androidå·¥ç¨æå¨çbinç®å½

ãã[plain] view plaincopyprint?

ãã.$cd ~/project/Android/JNITest/bin

ãã$cd ~/project/Android/JNITest/bin

ããæä»¬ç¨lså½ä»¤æ¥çï¼å¯ä»¥çå°binç®å½ä¸æä¸ªclassesç®å½ï¼å¶ç®å½ç»æä¸ºclasses/org/tonny/jniï¼å³classesçåç®å½ç»ææ¯androidå·¥ç¨çååorg.tonny.jniãè¯·æ³¨æï¼ä¸é¢æä»¬åå¤æ§è¡javahå½ä»¤çæ¶åï¼å¿é¡»è¿å¥å°org/tonny/jniçä¸çº§ç®å½ï¼å³classesç®å½ï¼å¦åjavahä¼æç¤ºæ¾ä¸å°ç¸å³çjavaç±»ã

ããä¸é¢ç»§ç»ï¼

ãã[plain] view plaincopyprint?

ãã.$cd classes

ãã.$javah org.tonny.jni.JNITest

ãã.$ls

ãã.org org_tonny_jni_JNITest.h

ãã$cd classes

ãã$javah org.tonny.jni.JNITest

ãã$ls

ããorg org_tonny_jni_JNITest.h

ããæ§è¡javahorg.tonny.jni.JNITestå½ä»¤ï¼å¨classesç®å½ä¸ä¼çæorg_tonny_jni_JNITest.hå¤´æä»¶ãå¦æä¸è¿å¥å°classesç®å½ä¸çè¯ï¼ä¹å¯ä»¥è¿æ ·ï¼

ãã[plain] view plaincopyprint?

ãã.$javah -classpath ~/project/Android/JNITest/bin/classesorg.tonny.jni.JNITest

ãã$javah -classpath ~/project/Android/JNITest/bin/classesorg.tonny.jni.JNITest

ãã-classpath åæ°è¡¨ç¤ºè£è½½ç±»çç®å½ã

ãã3.3.ç¼åc/c++ä»£ç

ããçæorg_tonny_jni_JNITest.hå¤´æä»¶åï¼æä»¬å°±å¯ä»¥ç¼åç¸åºçå½æ°ä»£ç äºãä¸é¢å¨androidå·¥ç¨ç®å½ä¸æ°å»ºjniç®å½ï¼å³~/project/Android/JNITest/jniï¼æorg_tonny_jni_JNITest.hå¤´æä»¶æ·è´å°jniç®å½ä¸ï¼å¹¶å¨jniç®å½ä¸æ°å»ºorg_tonny_jni_JNITest.cæä»¶ï¼ç¼è¾ä»£ç å¦ä¸ï¼

ãã[cpp] view plaincopyprint?

ãã.#include<jni.h>

ãã.#include<string.h>

ãã.#include"org_tonny_jni_JNITest.h"

ãã.

ãã.JNIEXPORTjstring JNICALLJava_org_tonny_jni_JNITest_GetReply

ãã.(JNIEnv *env, jobject obj){

ãã.return(*env)->NewStringUTF(env,(char*)"Hello,JNITest");

ãã.}

ãã#include<jni.h>

ãã#include<string.h>

ãã#include"org_tonny_jni_JNITest.h"

ããJNIEXPORTjstring JNICALLJava_org_tonny_jni_JNITest_GetReply

ãã(JNIEnv *env, jobject obj){

ããreturn(*env)->NewStringUTF(env,(char*)"Hello,JNITest");

ãã}

ãã3.4.ç¼åAndroid.mkæä»¶

ããå¨~/project/Android/JNITest/jniç®å½ä¸æ°å»ºAndroid.mkæä»¶ï¼androidå¯ä»¥æ ¹æ®è¿ä¸ªæä»¶çç¼è¯åæ°ç¼è¯æ¨¡åãç¼è¾Android.mkæä»¶å¦ä¸ï¼

ãã[plain] view plaincopyprint?

ãã.LOCAL_PATH:= $(call my-dir)

ãã.include$(CLEAR_VARS)

ãã.LOCAL_MODULE := libJNITest

ãã.LOCAL_SRC_FILES:= org_tonny_jni_JNITest.c

ãã.include$(BUILD_SHARED_LIBRARY)

ããLOCAL_PATH:= $(call my-dir)

ããinclude$(CLEAR_VARS)

ããLOCAL_MODULE := libJNITest

ããLOCAL_SRC_FILES:= org_tonny_jni_JNITest.c

ããinclude$(BUILD_SHARED_LIBRARY)

ããLOCAL_MODULEè¡¨ç¤ºç¼è¯çå¨æåºåç§°

ããLOCAL_SRC_FILES è¡¨ç¤ºæºä»£ç æä»¶

ãã3.5.ç¨ndkå·¥å·ç¼è¯å¹¶çæ.soæä»¶

ããè¿å¥å°JNITestçå·¥ç¨ç®å½ï¼æ§è¡ndk-buildå½ä»¤å³å¯çælibJNITest.soæä»¶ã

ãã[plain] view plaincopyprint?

ãã.$cd ~/project/Android/JNITest/

ãã.$ndk-build

ãã.Invalidattribute name:

ãã.package

ãã.Install : libJNITest.so => libs/armeabi/libJNITest.so

ãã$cd ~/project/Android/JNITest/

ãã$ndk-build

ããInvalidattribute name:

ããpackage

ããInstall : libJNITest.so => libs/armeabi/libJNITest.so

ããå¯ä»¥çå°ï¼å¨å·¥ç¨ç®å½çlibs/armeabiç®å½ä¸çæäºlibJNITest.soæä»¶ã

ãã3.6.å¨æ¨¡æå¨ä¸è¿è¡

ãã[plain] view plaincopyprint?

ãã.$cd ~/software/android/android-sdk-linux/tools

ãã.$./emulator @AVD-2.3.3-V -partition-size

ãã$cd ~/software/android/android-sdk-linux/tools

ãã$./emulator @AVD-2.3.3-V -partition-size

ããAVD-2.3.3-Vè¡¨ç¤ºä½ çæ¨¡æå¨åç§°ï¼ä¸å¨Eclipse->AVDManagerä¸çAVDNameå¯¹åºï¼-partition-sizeè¡¨ç¤ºæ¨¡æå¨çåå¨è®¾å¤å®¹éã

ãã[plain] view plaincopyprint?

ãã.$cd ~/project/Android/JNITest/libs/armeabi/

ãã.$adb remount

ãã.$adb push libJNITest.so /system/lib

ãã. KB/s ( bytes in 0.s)

ãã$cd ~/project/Android/JNITest/libs/armeabi/

ãã$adb remount

ãã$adb push libJNITest.so /system/lib

ãã KB/s ( bytes in 0.s)

ããå½å¨ç»ç«¯ä¸çå°æ KB/s ( bytes in 0.s)ä¼ è¾éåº¦çä¿¡æ¯çæ¶åï¼è¯´ææ·è´æåã

ç¨jniåçå®ååºç¨è½è¢«åç¼è¯å

音视频探索(5)：JPEG格式与Libjpeg库编译移植

libJPEG-turbo是一个强大的JPEG图像处理库，它支持JPEG格式的码编编码和解码，尤其对于Android平台，源译其底层压缩常采用libJPEG。码编然而，源译Android系统为适应低版本设备，码编贪吃蛇python源码压缩算法非标准，源译可能导致图像质量和压缩性能的码编权衡。因此，源译本篇将介绍如何利用AS的码编Cmake工具编译libJPEG-turbo，并通过JNI/NDK技术引入哈夫曼编码以优化Android中的源译压缩质量。

哈夫曼编码是码编一种无损压缩方法，年由Huffman提出。源译它依据字符出现概率构造编码，码编概率高的源译信息编码较短。在图像压缩中，通过计算像素概率生成Huffman码表，源码代表数字编码后的图像数据记录每个像素的码字，与码表对应。例如，通过构建赫夫曼树，字符集中的字符对应树的路径，形成编码。

libJPEG-turbo中的JPEG编码与解码过程包括：分配压缩对象，设置输出和参数，科技模板源码逐行处理数据，以及解压时分配和初始化解压对象、读取数据等。其核心结构体如jpeg_compress_struct和jpeg_decompress_struct，分别用于压缩和解压缩操作。

为了在Android上实现优化，我们需要从libjpeg-turbo源码开始，首先在CmakeLists.txt中配置项目，spark中文源码然后在Java层编写JNI方法，将C++的哈夫曼编码逻辑与Java代码连接。编译后，会生成libjpegtil.so文件，将其与libjpeg.so一同引入目标项目。

Android开发中的NDK到底是什么？(详细解析+案例)

在Android开发中，Native Development Kit (NDK)扮演着关键角色，它是魔鬼资金源码一个用于快速开发C和C++动态库的工具包。NDK的主要目标是将编译后的.so文件与应用一起打包成APK，尤其适合需要JNI（Java Native Interface）技术的场景。

NDK使用步骤如下：

首先，配置Android NDK环境。这包括下载并解压NDK工具包到指定路径，如：/Users/Carson_Ho/Library/Android/sdk/ndk-bundle。Android Studio会自动检测并集成，无需额外手动关联。

关联项目与NDK：在Gradle配置文件中添加必要的配置，包括local.properties、gradle.properties和build.gradle中的ndk节点，确保项目每次都能正确使用NDK。

创建本地C++代码文件，如test.cpp。注意文件命名规则，确保Java和C++接口的兼容性。

接着，编写Android.mk和Application.mk文件，分别指定源码编译配置和平台相关配置，放在jni文件夹中。

执行编译命令，生成.so库文件，一般会在src/main/jniLibs目录下找到。

在MainActivity.java和对应的布局文件中，集成并调用NDK编写的C++代码。

对于Android Studio 2.2及以上版本，NDK的集成更为方便，只需在创建工程时按照提示配置即可，无需额外安装和配置。

【贪吃蛇python源码】【源码代表数字】【科技模板源码】jni源码编译

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