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Non-system libraries in linker flags: -lopencv_java3

In the android.mk file I want to include the OpenCV3 library. so the file looks like this:
android.mk
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_EXPORT_C_INCLUDES := D:\path to\OpenCV-android-sdk\sdk\native\jni\include
include D:\path to\OpenCV-android-sdk\sdk\native\jni\OpenCV.mk
LOCAL_MODULE := MyLib
LOCAL_SRC_FILES := file1.cpp
LOCAL_SRC_FILES += file2.cpp
OPENGLES_LIB := -lGLESv1_CM
OPENGLES_DEF := -DUSE_OPENGL_ES_1_1
LOCAL_LDLIBS += -lGLESv1_CM -ldl -llog
include $(BUILD_SHARED_LIBRARY)
But when I build the project, I got this warning message:
Android NDK: WARNING:jni/Android.mk:MyLib: non-system libraries in linker flags: -lopencv_java3
Android NDK: This is likely to result in incorrect builds. Try using LOCAL_STATIC_LIBRARIES
Android NDK: or LOCAL_SHARED_LIBRARIES instead to list the library dependencies of the
Android NDK: current module
How can I solve this issue ?

If you only use OpenCV from your C++ code, you don't need this libopencv_java.so. To indicate this, add
OPENCV_LIB_TYPE=STATIC
Before including OpenCV.mk.
Some explanations can be found at answers.opencv.org.

Try using LOCAL_STATIC_LIBRARIES or LOCAL_SHARED_LIBRARIES instead to list the library dependencies of the current module
Depending on which version you have (static/dylibs), change your LOCAL_LDLIBS to either LOCAL_STATIC_LIBRARIES or LOCAL_SHARED_LIBRARIES
Android.mk is a good reference to variables in the Android makefile

Adding Tesseract and Opencv to Android.mk (Android Studio)

I followed the instructions from here and added OpenCV successfully. But I've been trying to add tesseract to the Android.mk as well, for a few days now, and haven't been able to do it.
I have an android.cpp that uses tesseract so I have to include the dependency in my Android.mk . I found this post that had almost the exact problem and he solved it importing libtess.so and liblept.so files into Android.mk, but didn't explain how to do that, so I looked and found this post that shows how to link prebuilt libraries. So based on that I tried this Android.mk:
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := liblept
LOCAL_SRC_FILES := ../libs/$(TARGET_ARCH_ABI)/liblept.so
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/../../../../tess-two/jni
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := libtess
LOCAL_SRC_FILES := ../libs/$(TARGET_ARCH_ABI)/libtess.so
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/../../../../tess-two/jni
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
OPENCV_PACKAGE_DIR:= /Users/danielsierraf/Documents/OpenCV-2.4.10-android-sdk/sdk
OPENCV_CAMERA_MODULES := off
include $(OPENCV_PACKAGE_DIR)/native/jni/OpenCV.mk
LOCAL_MODULE := run_detection
LOCAL_SHARED_LIBRARIES := libtess
LOCAL_SRC_FILES := text_detect.cpp android.cpp
LOCAL_LDLIBS += -landroid -llog -ldl
include $(BUILD_SHARED_LIBRARY)
And got this output:
[armeabi-v7a] Prebuilt : liblept.so <= src/main/jni/../libs/armeabi-v7a/
[armeabi-v7a] Install : liblept.so => src/main/jniLibs/armeabi-v7a/liblept.so
[armeabi-v7a] Compile++ thumb: run_detection <= text_detect.cpp
In file included from src/main/jni/text_detect.h:4:0,
from src/main/jni/text_detect.cpp:10:
src/main/jni/../../../../tess-two/jni/com_googlecode_tesseract_android/src/api/baseapi.h:32:22: fatal error: platform.h: No such file or directory
#include "platform.h"
^
compilation terminated.
So I guess is not linking libtess correctly, and if you look closely, it doesn't ever install libtess.so, it looks like it installs liblept.so, and then jumps to text_detect.cpp, ignoring this part:
include $(CLEAR_VARS)
LOCAL_MODULE := libtess
LOCAL_SRC_FILES := ../libs/$(TARGET_ARCH_ABI)/libtess.so
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/../../../../tess-two/jni
include $(PREBUILT_SHARED_LIBRARY)
So I tried to force it to install liblept and libtess completely before proceeding by putting it in different files. So I put the last part of the file in a different Android.mk in another folder and tried include $(call all-subdir-makefiles), and then it installs libtess and liblept completely, but ignores the call all-subdir-makefiles.
new jni folder structure:
Android.mk
Application.mk
text_detect/
Android.mk
android.cpp
text_detect.cpp
text_detect.h
Android.mk
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := liblept
LOCAL_SRC_FILES := ../libs/$(TARGET_ARCH_ABI)/liblept.so
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/../../../../tess-two/jni
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := libtess
LOCAL_SRC_FILES := ../libs/$(TARGET_ARCH_ABI)/libtess.so
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/../../../../tess-two/jni
include $(PREBUILT_SHARED_LIBRARY)
include $(call all-subdir-makefiles)
textdetect/Android.mk
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
OPENCV_PACKAGE_DIR:= /Users/danielsierraf/Documents/OpenCV-2.4.10-android-sdk/sdk
OPENCV_CAMERA_MODULES := off
include $(OPENCV_PACKAGE_DIR)/native/jni/OpenCV.mk
LOCAL_MODULE := run_detection
LOCAL_SHARED_LIBRARIES := libtess
LOCAL_SRC_FILES := text_detect.cpp android.cpp
LOCAL_LDLIBS += -landroid -llog -ldl
include $(BUILD_SHARED_LIBRARY)
And this is the output:
[armeabi-v7a] Prebuilt : liblept.so <= src/main/jni/../libs/armeabi-v7a/
[armeabi-v7a] Install : liblept.so => src/main/jniLibs/armeabi-v7a/liblept.so
[armeabi-v7a] Prebuilt : libtess.so <= src/main/jni/../libs/armeabi-v7a/
[armeabi-v7a] Install : libtess.so => src/main/jniLibs/armeabi-v7a/libtess.so
[armeabi] Prebuilt : liblept.so <= src/main/jni/../libs/armeabi/
[armeabi] Install : liblept.so => src/main/jniLibs/armeabi/liblept.so
[armeabi] Prebuilt : libtess.so <= src/main/jni/../libs/armeabi/
[armeabi] Install : libtess.so => src/main/jniLibs/armeabi/libtess.so
[mips] Prebuilt : liblept.so <= src/main/jni/../libs/mips/
[mips] Install : liblept.so => src/main/jniLibs/mips/liblept.so
[mips] Prebuilt : libtess.so <= src/main/jni/../libs/mips/
[mips] Install : libtess.so => src/main/jniLibs/mips/libtess.so
[x86] Prebuilt : liblept.so <= src/main/jni/../libs/x86/
[x86] Install : liblept.so => src/main/jniLibs/x86/liblept.so
[x86] Prebuilt : libtess.so <= src/main/jni/../libs/x86/
[x86] Install : libtess.so => src/main/jniLibs/x86/libtess.so
As you see it installs everything from the first Android.mk perfectly, but it never runs textdetect/Android.mk
So, what I'm I doing wrong? How can I achieve this task that seems so simple? Is there an easier way?
EDIT:
After #ph0b response I went back to my first setup and added the same LOCAL_EXPORT_C_INCLUDES as the original Makefiles (with a couple of variations adapting it to my paths), and that solved it. It couldn't find platform.h because it didn't know where to look for it.
Now, after I did this change I had a different error No such file or directory #include "com_googlecode_tesseract_android/src/api/baseapi.h" and I thought this was because it didn't compile tesseract before run_detection that depends on it. Well that wasn't the problem, it still compiles run_detection before tesseract but that wasn't the issue, it was so much simpler and I feel so stupid for having spent so much time on this error. The problem was it didn't find com_googlecode_tesseract_android/src/api/baseapi.h because I didn't provide the path for that either, so I copied com_googlecode_tesseract_android and com_googlecode_leptonica_android from tess-two and added $(LOCAL_PATH) to LOCAL_EXPORT_C_INCLUDES. This is my final solution:
jni folder structure:
Android.mk
Application.mk
text_detect.cpp
android.cpp
text_detect.h
com_googlecode_leptonica_android
com_googlecode_tesseract_android
Android.mk
LOCAL_PATH := $(call my-dir)
#leptonica
LEPTONICA_LOCAL := $(LOCAL_PATH)/com_googlecode_leptonica_android
LEPTONICA_PATH := $(LEPTONICA_LOCAL)/src
include $(CLEAR_VARS)
LOCAL_MODULE := liblept
LOCAL_SRC_FILES := ../libs/$(TARGET_ARCH_ABI)/liblept.so
LOCAL_EXPORT_C_INCLUDES := \
$(LEPTONICA_LOCAL) \
$(LEPTONICA_PATH)/src
include $(PREBUILT_SHARED_LIBRARY)
#tesseract
TESSERACT_LOCAL := $(LOCAL_PATH)/com_googlecode_tesseract_android
TESSERACT_PATH := $(TESSERACT_LOCAL)/src
include $(CLEAR_VARS)
LOCAL_MODULE := libtess
LOCAL_SRC_FILES := ../libs/$(TARGET_ARCH_ABI)/libtess.so
LOCAL_EXPORT_C_INCLUDES := \
$(LOCAL_PATH) \
$(TESSERACT_PATH)/api \
$(TESSERACT_PATH)/ccmain \
$(TESSERACT_PATH)/ccstruct \
$(TESSERACT_PATH)/ccutil \
$(TESSERACT_PATH)/classify \
$(TESSERACT_PATH)/cube \
$(TESSERACT_PATH)/cutil \
$(TESSERACT_PATH)/dict \
$(TESSERACT_PATH)/opencl \
$(TESSERACT_PATH)/neural_networks/runtime \
$(TESSERACT_PATH)/textord \
$(TESSERACT_PATH)/viewer \
$(TESSERACT_PATH)/wordrec \
$(LEPTONICA_PATH)/src \
$(TESSERACT_LOCAL)
LOCAL_SHARED_LIBRARIES := liblept
include $(PREBUILT_SHARED_LIBRARY)
#opencv
include $(CLEAR_VARS)
OPENCV_PACKAGE_DIR:= /Users/danielsierraf/Documents/OpenCV-2.4.10-android-sdk/sdk
OPENCV_CAMERA_MODULES := off
include $(OPENCV_PACKAGE_DIR)/native/jni/OpenCV.mk
LOCAL_MODULE := run_detection
LOCAL_SRC_FILES := text_detect.cpp android.cpp
LOCAL_LDLIBS += -landroid -llog -ldl
LOCAL_SHARED_LIBRARIES += libtess liblept
include $(BUILD_SHARED_LIBRARY)

Your latest setup is failing in a weird way, ndk-build should at least try to compile your module. Maybe there is a bug in all-subdir-makefiles when there are ndk modules defined before it, and it doesn't find your module's Android.mk. You can try having only include $(call all-subdir-makefiles) inside your top level Android.mk.
Anyway, I think you should go back to your first setup, with your module directly in the jni root folder. Then, your main issue is the proper declaration of includes paths. tess-two/jni doesn't contain any headers ? They're in tess-two/jni/com_googlecode_*_android/src/*. That means you need to list these in your module declarations, by giving all the absolute paths to LOCAL_EXPORT_C_INCLUDES variables (like from the original Makefiles: https://github.com/rmtheis/tess-two/blob/master/tess-two/jni/com_googlecode_tesseract_android/Android.mk#L33)
You also need to add the dependency on liblept for libtess: LOCAL_SHARED_LIBRARIES := liblept inside libtess library declaration.
If it still fails, there is also another possibility: instead of redefining libtess and liblept modules using the generated .so files, you can directly include tess-two/jni/Android.mk and use the same Application.mk than tess-two (copy `tess-two/jni/Application.mk). It will already properly define libtess and liblept modules.

ANDROID: How to properly link against static libraries while creating shared libraries with dependencies on the static ones

I have to use some c++ code in my android application. This code was used successfully in an iOS project.
The code depends on 2 external libraries: zero-mq and protocol buffers.
I compiled the zmq library as an static library like explained here. I added the static (.a) library and the .jar to my project.
I created the protobuf library with the following configurations:
./configure --host=arm-eabi --with-sysroot=x/android-ndk-r10d/platforms/android-21/arch-arm CC="x/android-ndk-r10d/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86/bin/arm-linux-androideabi-gcc --sysroot x/android-ndk-r10d/platforms/android-21/arch-arm" --enable-cross-compile --with-protoc=protoc LIBS=-lc
make
I changed the real directories to x to make them shorter.
In my Android Project(IDE: Android Studio) I prepared everything which is necessary. I created a JNI Folder and deactivated the auto-creation of the makefiles.
Application.mk:
APP_MODULE := proxy
APP_STL := gnustl_shared
APP_CPPFLAGS := -frtti -fexceptions --std=c++11
APP_ABI := armeabi-v7a ##all later
NDK_TOOLCHAIN_VERSION := 4.9
Android.mk:
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := zmq_static
LOCAL_SRC_FILES := zmq/libzmq.a
include $(PREBUILD_STATIC_LIBRARY)
LOCAL_MODULE := protobuf_static1
LOCAL_SRC_FILES := protobuf/libprotobuf.a
LOCAL_EXPORT_C_INCLUDES := google/protobuf protobuf/
include $(PREBUILD_STATIC_LIBRARY)
LOCAL_MODULE := protobuf_static2
LOCAL_SRC_FILES := protobuf/libprotobuf-lite.a
LOCAL_EXPORT_C_INCLUDES := google/protobuf protobuf/
include $(PREBUILD_STATIC_LIBRARY)
LOCAL_MODULE := protobuf_static3
LOCAL_SRC_FILES := protobuf/libprotoc.a
LOCAL_EXPORT_C_INCLUDES := google/protobuf protobuf/
include $(PREBUILD_STATIC_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := proxy
LOCAL_CFLAGS := -I/include -pthread -lpthread -D__GXX_EXPERIMENTAL_CXX0X__ - frtti
LOCAL_CPPFLAGS := -I/include -pthread -lpthread -D__GXX_EXPERIMENTAL_CXX0X__ -frtti
LOCAL_CPP_FEATURES += exceptions
LOCAL_LDLIBS := -llog
LOCAL_SRC_FILES := \
usersession.cpp\
## LOCAL_ALLOW_UNDEFINED_SYMBOLS := true will compile the code but shutdown on runtime
LOCAL_C_INCLUDES += C:\Users\M\Dropbox\Workspace\ndk_swig_test\app\src\main\jni
LOCAL_C_INCLUDES += C:\Users\M\Dropbox\Workspace\ndk_swig_test\app\src\arm\jni
LOCAL_C_INCLUDES += C:\Users\M\Dropbox\Workspace\ndk_swig_test\app\src\debug\jni
LOCAL_C_INCLUDES += C:\Users\M\Dropbox\Workspace\ndk_swig_test\app\src\armDebug\jni
LOCAL_C_INCLUDES += \zmq
LOCAL_C_INCLUDES += \protobuf
LOCAL_STATIC_LIBRARIES := zmq_static protobuf_static1 protobuf_static2 protobuf_static3
LOCAL_WHOLE_STATIC_LIBRARIES := zmq_static protobuf_static1 protobuf_static2 protobuf_static3
include $(BUILD_SHARED_LIBRARY)
The zmq library is in the subdirectory zmq and the protobuf library is in the subfolder protobuf.
Now the linking of the Objects still does not work. The Error Output when I execute ndk-build:
C:\Users\M\Dropbox\Workspace\ndk_swig_test\app\src\main\jni>ndk-build
[armeabi-v7a] SharedLibrary : libproxy.so
C:/Users/M/Documents/ndk/sources/cxx-stl/gnu- libstdc++/4.9/include/ext/new_allocator.h:127: error: undefined reference to 'ControlledInstance::ControlledInstan (std::shared_ptr<protogen::Application>, std:
:shared_ptr<protogen::Role>, std::shared_ptr<protogen::User>)'
C:/Users/M/Documents/ndk/sources/cxx-stl/gnu- libstdc++/4.9/include/bits/shared_ptr_base.h:511: error: undefined reference to 'protogen::User::User()'
C:/Users/M/Documents/ndk/sources/cxx-stl/gnu- libstdc++/4.9/include/bits/shared_ptr_base.h:914: error: undefined reference to 'google::protobuf::internal::empty tring_'
C:/Users/M/Dropbox/Workspace/ndk_swig_test/app/src/main//jni/controlledinstance.h :23: error: undefined reference to 'protogen::MetaGraph::~MetaGraph()'
collect2.exe: error: ld returned 1 exit status
make.exe: *** [C:/Users/M/Dropbox/Workspace/ndk_swig_test/app/src/main//obj/local/armeabi- v7a/libproxy.so] Error 1
I tried many versions of the Android.mk and recreated the library more than once with different options which I found all over the internet.
I also looked at dozens of threads on stackoverflow which did not help me.(I'm not allowed to link them because of low reputation)
Additionally i read most of the doc files from the ndk e.g. PREBUILTS.
I added some other directories to my JNI directory e.g. the directory with the original files and directories (compiler, io, stubs...). I think this directory should offer the export of the necessary methods if the prebuild library was successfully linked to my shared library - which is not the case.
I tried far more than I can explain in few minutes and I think it would be overkill if i added everything I've tried because nothing helped.
Because this is my first question I dont have the reputation to include more than 2 links. Sorry for that.

There may probably be other issues as well, but you at least have got a typo - it should be include $(PREBUILT_STATIC_LIBRARY), as in, BUILT, not BUILD.

Android NDK: Directive not visible to includes of static library

I simply want use a static library for an NDK project. The library works with build systems like automake, but in Android.mk I have a problem with the source files. For some reason, directives don't work over different header files and I get the following error:
error: 'myname' does not name a type
It seems that the directive defined in file1.hpp is not visible in file2.hpp which includes file1.hpp (as I said, this problem does not occur with other build systems like automake.
What am I doing wrong here?
Android.mk:
include $(CLEAR_VARS)
LOCAL_MODULE := libstat
LOCAL_LDLIBS := -lm
LOCAL_SRC_FILES := /home/dir/libstat.a
LOCAL_EXPORT_C_INCLUDES := /home/dir/src
include $(PREBUILT_STATIC_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := hello-jni
LOCAL_CFLAGS := -lm -ldl /home/dir/src
LOCAL_LDFLAGS := -L/home/dir/
LOCAL_C_INCLUDES += /home/dir/src
LOCAL_SRC_FILES := hello-jni.cpp
LOCAL_LDLIBS := -ggdb
LOCAL_STATIC_LIBRARIES := libstat
include $(BUILD_SHARED_LIBRARY)
src includes all header and source files. Any hint would be appreciated.

Build shared library linking to other not standard shared libarary

I have some two shared libraries and header for them.
I want to build third shared library using functions from previous two libs.
Have problem with makefile i think. When i try to build receive this:
Android NDK: /cygdrive/d/.../jni/Android.mk: Cannot find module with tag 'shared1' 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:
/cygdrive/d/.../jni/Android.mk:36: *** Android NDK: Aborting. . Stop.
structure of my project:
jni/
- myfile.c
- Android.mk
jni/dec/
- lot of header files
jni/enc/
- lot of header files
libs/armeabi/
- shared1.so
- shared2.so
also Android.mk sourse:
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_C_INCLUDES := \
$(LOCAL_PATH)/dec \
$(LOCAL_PATH)/enc
LOCAL_SHARED_LIBRARIES := shared1 shared2
LOCAL_MODULE := mylib
LOCAL_SRC_FILES := myfile.c
LOCAL_LDLIBS += -lOpenSLES
LOCAL_LDLIBS += -llog
LOCAL_LDLIBS += -landroid
include $(BUILD_SHARED_LIBRARY)
$(call import-module, shared1)
$(call import-module, shared2)

Take a look to this question: Android JNI APK Packing
You need to give another name for libs/armeabi/ folder to avoid conflicts with NDK build and add the following code before the include $(CLEAR_VARS) statement:
include $(CLEAR_VARS)
LOCAL_MODULE:=shared1
LOCAL_SRC_FILES:=3rdparty_libs/shared1.so
include $(PREBUILT_SHARED_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE:=shared2
LOCAL_SRC_FILES:=3rdparty_libs/shared2.so
include $(PREBUILT_SHARED_LIBRARY)

As I understand it, the correct method is to use ndk-build and not invoking the compiler directly.
In Android.mk you need to specify a module for each static library you want to compile, and then specify that your shared library should use it.
Example of a modified Android.mk file of the hello-jni sample project:
LOCAL_PATH := $(call my-dir)
# Define vars for library that will be build statically.
include $(CLEAR_VARS)
LOCAL_MODULE := <module_name>
LOCAL_C_INCLUDES := <header_files_path>
LOCAL_SRC_FILES := <list_of_src_files>
# Optional compiler flags.
LOCAL_LDLIBS = -lz -lm
LOCAL_CFLAGS = -Wall -pedantic -std=c99 -g
include $(BUILD_STATIC_LIBRARY)
# First lib, which will be built statically.
include $(CLEAR_VARS)
LOCAL_MODULE := hello-jni
LOCAL_STATIC_LIBRARIES := <module_name>
LOCAL_C_INCLUDES := <header_files_path>
LOCAL_SRC_FILES := hello-jni.c
include $(BUILD_SHARED_LIBRARY)
If you want control over which modules to compile when you run ndk-build you can create create a Application.mk file (in the same directory as Android.mk) and list all the modules as in the following example:
APP_MODULES := <module_name_1> <module_name_2> ... <module_name_n>
I think it Helps you