Develop Reference

OpenCV android NDK build error

I'm using NDK to use C++ native code in OpenCV through Android studio.
Every thing is alright except when I'm running this project to an android device I have the following error
Warning:Native C/C++ source code is found, but it seems that NDK option is not configured. Note that if you have an Android.mk, it is not used for compilation. The recommended workaround is to remove the default jni source code directory by adding:
android {
sourceSets {
main {
jni.srcDirs = []
}
}
}
and also
to build.gradle, manually compile the code with ndk-build, and then place the resulting shared object in src/main/jniLibs.
C:\Users\MALIK\Desktop\ImageJ\app\src\main\jni\com_example_malik_imagej_DetectionBasedTracker.cpp
Error:(2, 10) 'opencv2/opencv.hpp' file not found 1 error generated.
and when I do the workaround and make jni.srcDir empty , I got error that "cannot resolve corresponding JNI function "
so the native code won't run and the app crashes , what should I do in this case?
this is my gradle :
apply plugin: 'com.android.application'
android {
compileSdkVersion 23
buildToolsVersion "23.0.1"
defaultConfig {
applicationId "com.example.malik.haar"
minSdkVersion 16
targetSdkVersion 23
versionCode 1
versionName "1.0"
}
task ndkBuild(type: Exec, description: 'Compile JNI source via NDK') {
commandLine "C:/Android/sdk/ndk-bundle/ndk-build.cmd",
'NDK_PROJECT_PATH=build/intermediates/ndk',
'NDK_LIBS_OUT=src/main/jniLibs',
'APP_BUILD_SCRIPT=src/main/jni/Android.mk',
'NDK_APPLICATION_MK=src/main/jni/Application.mk'
}
tasks.withType(JavaCompile) {
compileTask -> compileTask.dependsOn ndkBuild
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
sourceSets { main { jni.srcDirs = [] } }
}
dependencies {
compile fileTree(include: ['*.jar'], dir: 'libs')
compile 'com.android.support:appcompat-v7:23.1.1'
androidTestCompile files('libs/junit-4.12.jar')
compile project(':openCVLibrary320')
}
and this is my Android.mk file :
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
OPENCVROOT:=C:\OpenCV-android-sdk
OPENCV_INSTALL_MODULES:=on
OPENCV_LIB_TYPE:=SHARED
include $(OPENCVROOT)/sdk/native/jni/OpenCV.mk
LOCAL_SRC_FILES := com_example_malik_imagej_DetectionBasedTracker.cpp
LOCAL_C_INCLUDES += $(LOCAL_PATH)
LOCAL_LDLIBS += -llog -ldl
LOCAL_MODULE := detection_based_tracker
include $(BUILD_SHARED_LIBRARY)
and this is my Header file of native code :
thanks.

GoogleTest building with android NDK (r13b) giving error (C++ headers not found)

I was trying to build GoogleTest with Android NDK but it's getting error , couldn't find c++ headers properly on gTest sources (like- 'limits'/'ostream'/'vector'... file not found , please see given error file). What could be the problem? Your valuable suggestion would be helpful.
Error given by Android Studio
[arm64-v8a] Compile++ : foo <= foo.cpp
make: Entering directory `/media/user/New Volume/Android_live_streaming_test_client/AndroidNDKDemo/app/src/main'
[arm64-v8a] SharedLibrary : libfoo.so
[arm64-v8a] Install : libfoo.so => libs/arm64-v8a/libfoo.so
[arm64-v8a] Compile++ : foo_unittest <= foo_unittest.cpp
Error:(54, 10) 'limits' file not found
/home/user/Android/Sdk/ndk-bundle/sources/third_party/googletest/googletest/include/gtest/gtest.h
1 error generated.
make: *** [obj/local/arm64-v8a/objs/foo_unittest/foo_unittest.o] Error 1
make: Leaving directory `/media/user/New Volume/Android_live_streaming_test_client/AndroidNDKDemo/app/src/main'
:app:ndkBuild FAILED
Error:Execution failed for task ':app:ndkBuild'.
> Process 'command '/home/user/Android/Sdk/ndk-bundle/ndk-build'' finished with non-zero exit value 2
Android.mk file
LOCAL_PATH := $(call my-dir)
APP_STL := gnustl_shared
include $(CLEAR_VARS)
LOCAL_MODULE := foo
LOCAL_SRC_FILES := foo.cpp
include $(BUILD_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := foo_unittest
LOCAL_SRC_FILES := foo_unittest.cpp
LOCAL_SHARED_LIBRARIES := foo
LOCAL_STATIC_LIBRARIES := googletest_main
include $(BUILD_EXECUTABLE)
$(call import-module,third_party/googletest)
Application.mk file
APP_STL := gnustl_shared
Gradle file, from where the ndk-build command has been called
import org.apache.tools.ant.taskdefs.condition.Os
apply plugin: 'com.android.application'
android {
compileSdkVersion 24
buildToolsVersion "24.0.3"
defaultConfig {
applicationId "com.ipvcloud.androidndkdemo"
minSdkVersion 15
targetSdkVersion 24
versionCode 1
versionName "1.0"
}
sourceSets.main {
jniLibs.srcDir 'src/main/libs' //set .so files location to libs
jni.srcDirs = [] //disable automatic ndk-build call
}
// call regular ndk-build(.cmd) script from app directory
task ndkBuild(type: Exec) {
if (Os.isFamily(Os.FAMILY_WINDOWS)) {
commandLine 'ndk-build.cmd', '-C', file('src/main').absolutePath
} else {
commandLine android.ndkDirectory.getAbsolutePath() + '/ndk-build', '-C', file('src/main').absolutePath
}
}
tasks.withType(JavaCompile) {
compileTask -> compileTask.dependsOn ndkBuild
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
testCompile 'junit:junit:4.12'
compile 'com.android.support:appcompat-v7:24.2.1'
// 'command '/home/jumman/Android/Sdk/ndk-bundle/ndk-build'' finished with non-zero exit value 2
}

OpenCV undefined reference to `cv::fastFree(void*)'

I try to build project with OpenCV, i downloaded OpenCV SDK 3.1 from official website, however during building i get error
/Users/Mario/Downloads/OpenCV-android-sdk/sdk/native/jni/include/opencv2/core/mat.inl.hpp
Error:(571) undefined reference to 'cv::fastFree(void*)'
Error:(663) undefined reference to 'cv::Mat::create(int, int const*, int)'
Error:(682) undefined reference to 'cv::Mat::deallocate()'
here is my gradle.build, i use gradle-experimental:0.4.0
apply plugin: 'com.android.model.application'
model {
android {
compileSdkVersion = 23
buildToolsVersion = "23.0.2"
defaultConfig.with {
applicationId = "pl.mariusz.opencv"
minSdkVersion.apiLevel = 17
targetSdkVersion.apiLevel = 23
versionCode = 1
versionName = "1.0"
}
task ndkBuild(type: Exec) {
commandLine '/Users/Mario/Library/Android/android-ndk-r10e/ndk-build', '-C', file('src/main').absolutePath
}
tasks.withType(JavaCompile) {
compileTask -> compileTask.dependsOn ndkBuild
}
}
android.ndk {
moduleName = "source_file"
cppFlags.add("-std=c++11")
cppFlags.add("-fexceptions")
cppFlags.add("-I${file("/Users/Mario/Downloads/OpenCV-android-sdk/sdk/native/jni/include")}".toString())
cppFlags.add("-I${file("/Users/Mario/Downloads/OpenCV-android-sdk/sdk/native/jni/include/opencv")}".toString())
stl = "gnustl_static"//"gnustl_static"//"gnustl_shared"//"stlport_static"
}
android.sources {
main {
jni{
source{
srcDirs = []
}
}
jniLibs {
source {
srcDirs = ['src/main/Libs']
}
}
}
}
android.buildTypes {
release {
minifyEnabled = false
proguardFiles.add(file('proguard-rules.txt'))
}
}
}
Android.mk
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
OPENCVROOT:= /Users/Mario/Downloads/OpenCV-android-sdk
OPENCV_LIB_TYPE=STATIC
include ${OPENCVROOT}/sdk/native/jni/OpenCV.mk
LOCAL_SRC_FILES := source_file.cpp
LOCAL_LDLIBS += -llog -ldl
LOCAL_MODULE := source_file
include $(BUILD_SHARED_LIBRARY)
and Application.mk
APP_STL := gnustl_static
APP_CPPFLAGS := -frtti -fexceptions
APP_ABI := armeabi-v7a
APP_PLATFORM := android-17
i tried mix it with shared,static STL with still same error, how can i fix it?
[EDIT]
[SOLUTION]
its more like compromise not real solution, but i changed gradle-experimental:0.4.0 back to classpath 'com.android.tools.build:gradle:1.5.0' and added file gradle.properties to project root directory with
android.useDeprecatedNdk=true

You have to add opencv libraries to your linker. To do that, you have to do 2 things: 1. add the library files; 2. add the library directory.
Try
LOCAL_LDLIBS += -llog -ldl -LlibPath -lopencv_calib3d -lopencv_core
and so an, add all the opencv libraries (or at least the ones you'll need) in this way. -l will automatically assume the "lib" in the filename and the suffix.
The -L will tell the linker where to find libraries, so instead of libPath please add the absolute path of your opencv library folder. See how to mention path of libraries in Android.mk file or Application.mk file?
Try it and tell me the new error message.

Android NDK Exception failed: dlopen failed: cannot locate symbol "_ZN7Tangram11setPositionEdd" referenced by "libtangram.so"

I am trying to run a demo application of a Library in which android ndk is integrated. I have imported this code in Android studio and also downloaded ndk and linked it with project. Code compiles and build succesfully. It gives crash with exception "exception ljava lang unsatisfiedlinkerror thrown while initializing" "failed: dlopen failed: cannot locate symbol "_ZN7Tangram11setPositionEdd" referenced by "libtangram.so"..."
Application.mk:
APP_STL := c++_shared
APP_CPPFLAGS := -frtti -fexceptions
APP_ABI := armeabi armeabi-v7a x86 mips
APP_PLATFORM := android-19
Android.mk:
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := tangram
LOCAL_SRC_FILES := jniExports.cpp jniGenerated.cpp platform_android.cpp
LOCAL_LDLIBS := -llog
LOCAL_ALLOW_UNDEFINED_SYMBOLS := true
include $(BUILD_SHARED_LIBRARY)
Module Gradle File:
buildscript {
dependencies {
classpath 'com.android.tools.build:gradle:1.2.3'
classpath 'com.github.dcendents:android-maven-plugin:1.2'
}
}
apply plugin: 'com.android.library'
apply plugin: 'com.github.dcendents.android-maven'
group = GROUP
version = VERSION_NAME
android {
compileSdkVersion 22
buildToolsVersion "21.1.2"
defaultConfig {
minSdkVersion 15
targetSdkVersion 22
}
sourceSets.main {
manifest.srcFile 'AndroidManifest.xml'
java.srcDirs = ['src']
jni.srcDirs = []
assets.srcDirs = ['core/resources']
}
task ndkBuild(type: Exec, description: 'Compile JNI source via NDK') {
commandLine "C:/Users/Administrator/AppData/Local/Android/android-ndk-r10e/ndk-build.cmd",
'NDK_PROJECT_PATH=build/intermediates/ndk',
'NDK_LIBS_OUT=jniLibs',
'APP_BUILD_SCRIPT=jni/Android.mk',
'NDK_APPLICATION_MK=jni/Application.mk'
}
tasks.withType(JavaCompile) {
compileTask -> compileTask.dependsOn ndkBuild
}
}
// Add gdb server to apk
afterEvaluate {
Sync packageTask = project.getTasks().findByName("packageReleaseJniLibs")
if (packageTask) { packageTask.include(['**/gdbserver', '**/gdb.setup']) }
packageTask = project.getTasks().findByName("packageDebugJniLibs")
if (packageTask) { packageTask.include(['**/gdbserver', '**/gdb.setup']) }
}
dependencies {
compile 'com.squareup.okhttp:okhttp:2.5.0'
compile 'xmlpull:xmlpull:1.1.3.1'
}
apply from: file('gradle-mvn-push.gradle')
In Java class load libraries:
static {
System.loadLibrary("c++_shared");
System.loadLibrary("tangram");
}
I google this issue and in these posts Link1 Link2 Link3 Link4 it is mentioned that it may be the issue of compiling at api 21 or newer and running it on older devices. But i have mentioend APP_PLATFORM := android-19 in my Application.mk and getting this exception.
Any Help?

It looks like you tried to compile the tangram project from your own custom ndk-build as opposed to their recommended build process (https://github.com/tangrams/tangram-es#android). Use their build process with make to create the libtangram.so file, and then copy that .so file into your native libraries directory for your app.
The reason it can't find those symbols is because you aren't including the appropriate source files that define those functions when building with the ndk. By ingnoring undefined symbols, it will compile but won't be able to resolve them at runtime.
The symbol you are missing is created from Tangram::setPosition(double, double) which is defined at https://github.com/tangrams/tangram-es/blob/master/core/src/tangram.cpp#L318 ; however, your Android.mk file doesn't include that source file.

Android NDK: Are you sure your NDK_MODULE_PATH variable is properly defined ? Error

I got project as Eclipse project, I moved it to Android studio
the build works well now, but when I try to run the app i get error message
this is my project structure:
This is my gradle file:
apply plugin: 'com.android.application'
android {
compileSdkVersion 23
buildToolsVersion "23.0.2"
defaultConfig {
applicationId "com.testProj.test1"
minSdkVersion 10
targetSdkVersion 23
ndk {
moduleName "player_shared"
}
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
}
}
sourceSets {
// jni.srcDirs = [] // This prevents the auto generation of Android.mk
main.jniLibs.srcDirs = ['libs']
test.jniLibs.srcDirs = ['libs']
}
// sourceSets.main {
// jni.srcDirs = [] // This prevents the auto generation of Android.mk
// jniLibs.srcDir 'src/main/libs' // This is not necessary unless you have precompiled libraries in your project.
// }
task buildNative(type: Exec, description: 'Compile JNI source via NDK') {
def ndkDir = android.ndkDirectory
commandLine "$ndkDir/ndk-build",
'-C', file('src/main/jni').absolutePath, // Change src/main/jni the relative path to your jni source
'-j', Runtime.runtime.availableProcessors(),
'all',
'NDK_DEBUG=1'
}
task cleanNative(type: Exec, description: 'Clean JNI object files') {
def ndkDir = android.ndkDirectory
commandLine "$ndkDir/ndk-build",
'-C', file('src/main/jni').absolutePath, // Change src/main/jni the relative path to your jni source
'clean'
}
clean.dependsOn 'cleanNative'
tasks.withType(JavaCompile) {
compileTask -> compileTask.dependsOn buildNative
}
}
dependencies {
compile 'com.google.android.gms:play-services:+'
compile files('libs/PTAdChartboost.jar')
compile files('libs/dagger-1.2.2.jar')
compile files('libs/javax.inject-1.jar')
compile files('libs/nineoldandroids-2.4.0.jar')
compile files('libs/support-v4-19.0.1.jar')
}
This is Android.mk file:
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := player_shared
LOCAL_MODULE_FILENAME := libplayer
LOCAL_SRC_FILES := main.cpp
LOCAL_WHOLE_STATIC_LIBRARIES := core_static cocos2dx_static box2d_static
include $(BUILD_SHARED_LIBRARY)
$(call import-module, core)
$(call import-module, cocos2dx)
$(call import-module, box2D)
The error messages:
Error:(15) *** Android NDK: Aborting. . Stop.
Android NDK: /Users/mylaptop/Documents/Lines/app/src/main/jni/Android.mk: Cannot find module with tag 'core' in import path
Android NDK: Are you sure your NDK_MODULE_PATH variable is properly defined ?
Android NDK: The following directories were searched:
Android NDK:
make: Entering directory `/Users/mylaptop/Documents/Lines/app/src/main/jni'
make: Leaving directory `/Users/mylaptop/Documents/Lines/app/src/main/jni'
:app:buildNative FAILED
Error:Execution failed for task ':app:buildNative'.
> Process 'command '/Users/mylaptop/Documents/android-ndk-r10e/ndk-build'' finished with non-zero exit value 2