用android编译dlib和opencv

Question

我是一名android开发人员，但我对Android并不熟悉，请帮助我，或者告诉我您还需要什么/如何解决这类问题。

我在安卓示例中使用了这 dlib，官方的用于android库的opencv和我希望将两者集成到一个应用程序中。当我试图构建项目时，我会得到以下错误：

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':openCVSamplefacedetection:externalNativeBuildDebug'.
> Build command failed.
  Error while executing process /home/feli/Android/Sdk/ndk-bundle/ndk-build with arguments {NDK_PROJECT_PATH=null APP_BUILD_SCRIPT=/home/feli/Development/android/test/face-detection/openCVSamplefacedetection/src/main/jni/Android.mk NDK_APPLICATION_MK=/home/feli/Development/android/test/face-detection/openCVSamplefacedetection/src/main/jni/Application.mk APP_ABI=mips64 NDK_ALL_ABIS=mips64 NDK_DEBUG=1 APP_PLATFORM=android-21 NDK_OUT=/home/feli/Development/android/test/face-detection/openCVSamplefacedetection/build/intermediates/ndkBuild/debug/obj NDK_LIBS_OUT=/home/feli/Development/android/test/face-detection/openCVSamplefacedetection/build/intermediates/ndkBuild/debug/lib /home/feli/Development/android/test/face-detection/openCVSamplefacedetection/build/intermediates/ndkBuild/debug/obj/local/mips64/libdetection_based_tracker.so}
  [mips64] Compile++      : detection_based_tracker <= DetectionBasedTracker_jni.cpp
  [mips64] Prebuilt       : libopencv_java3.so <= /home/feli/Android/openCV/OpenCV-android-sdk/sdk/native/jni/../libs/mips64/
  [mips64] SharedLibrary  : libdetection_based_tracker.so
  /home/feli/Development/android/test/face-detection/openCVSamplefacedetection/build/intermediates/ndkBuild/debug/obj/local/mips64/objs-debug/detection_based_tracker/DetectionBasedTracker_jni.o: In function `dlib_check_consistent_assert_usage':
  /home/feli/Development/android/test/face-detection/openCVSamplefacedetection/src/main/jni/dlib/dlib/threads/threads_kernel_shared.h:44: undefined reference to `USER_ERROR__missing_dlib_all_source_cpp_file__OR__inconsistent_use_of_DEBUG_or_ENABLE_ASSERTS_preprocessor_directives_'
  clang++: error: linker command failed with exit code 1 (use -v to see invocation)
  make: *** [/home/feli/Development/android/test/face-detection/openCVSamplefacedetection/build/intermediates/ndkBuild/debug/obj/local/mips64/libdetection_based_tracker.so] Error 1


* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

我最初的猜测是，我还没有将source.cpp包含在我的Android.mk中，但是将它放在src文件中并不能解决这个问题。这是我的Android.mk：

LOCAL_PATH := $(call my-dir)

## Build dlib to static library
include $(CLEAR_VARS)
LOCAL_MODULE := dlib
LOCAL_C_INCLUDES := $(LOCAL_PATH)/dlib

LOCAL_SRC_FILES += \
                $(LOCAL_PATH)/dlib/dlib/all/source.cpp \
                $(LOCAL_PATH)/dlib//dlib/threads/threads_kernel_shared.cpp \
                $(LOCAL_PATH)/dlib/dlib/entropy_decoder/entropy_decoder_kernel_2.cpp \
                $(LOCAL_PATH)/dlib/dlib/base64/base64_kernel_1.cpp \
                $(LOCAL_PATH)/dlib/dlib/threads/threads_kernel_1.cpp \
                $(LOCAL_PATH)/dlib/dlib/threads/threads_kernel_2.cpp

LOCAL_EXPORT_C_INCLUDES := $(LOCAL_C_INCLUDES)
include $(BUILD_STATIC_LIBRARY)

# Build opencv
include $(CLEAR_VARS)
OPENCVROOT := ~/Android/openCV/OpenCV-android-sdk
OPENCV_CAMERA_MODULES:=on
OPENCV_INSTALL_MODULES:=on
OPENCV_LIB_TYPE := SHARED
include ${OPENCVROOT}/sdk/native/jni/OpenCV.mk

LOCAL_MODULE     := detection_based_tracker
LOCAL_C_INCLUDES += $(LOCAL_PATH)
LOCAL_SRC_FILES  := DetectionBasedTracker_jni.cpp

LOCAL_LDLIBS     += -lm -llog -ldl -lz -ljnigraphics
LOCAL_CPPFLAGS += -fexceptions -frtti -std=c++11

# LOCAL_STATIC_LIBRARIES += dlib

include $(BUILD_SHARED_LIBRARY)

也许NDK_PROJECT_PATH=null才是问题所在？为什么这两个图书馆要分开建呢？或者还有什么问题？我试过很多次修改Android.mk，但它的工作对我来说是个谜。任何帮助或意见都是有用的。

编辑：

当我注释掉LOCAL_STATIC_LIBRARIES += dlib行时，我得到了以下异常：

Build command failed.
  Error while executing process /home/feli/Android/Sdk/ndk-bundle/ndk-build with arguments {NDK_PROJECT_PATH=null APP_BUILD_SCRIPT=/home/feli/Development/android/test/face-detection/openCVSamplefacedetection/src/main/jni/Android.mk NDK_APPLICATION_MK=/home/feli/Development/android/test/face-detection/openCVSamplefacedetection/src/main/jni/Application.mk APP_ABI=mips64 NDK_ALL_ABIS=mips64 NDK_DEBUG=1 APP_PLATFORM=android-21 NDK_OUT=/home/feli/Development/android/test/face-detection/openCVSamplefacedetection/build/intermediates/ndkBuild/debug/obj NDK_LIBS_OUT=/home/feli/Development/android/test/face-detection/openCVSamplefacedetection/build/intermediates/ndkBuild/debug/lib /home/feli/Development/android/test/face-detection/openCVSamplefacedetection/build/intermediates/ndkBuild/debug/obj/local/mips64/libdetection_based_tracker.so}
  [mips64] Compile++      : detection_based_tracker <= DetectionBasedTracker_jni.cpp
  [mips64] Compile++      : dlib <= source.cpp
  In file included from /home/feli/Development/android/test/face-detection/openCVSamplefacedetection/src/main/jni/dlib/dlib/all/source.cpp:76:
  In file included from /home/feli/Development/android/test/face-detection/openCVSamplefacedetection/src/main/jni/dlib/dlib/all/../gui_widgets/fonts.cpp:14:
  /home/feli/Development/android/test/face-detection/openCVSamplefacedetection/src/main/jni/dlib/dlib/all/../gui_widgets/nativefont.h:27:10: fatal error: 'X11/Xlib.h' file not found
  #include <X11/Xlib.h>
           ^~~~~~~~~~~~
  1 error generated.
  make: *** [/home/feli/Development/android/test/face-detection/openCVSamplefacedetection/build/intermediates/ndkBuild/debug/obj/local/mips64/objs-debug/dlib//home/feli/Development/android/test/face-detection/openCVSamplefacedetection/src/main/jni/dlib/dlib/all/source.o] Error 1

Answer 1

dlib使用cmake，它不是一个简单的设置。专业人员可能需要很长时间才能为这个库准备ndk构建脚本。

我建议您使用cmake构建您的本机库，而不是使用ndk构建。您可以找到一个使用OpenCv 论GitHub的本机库示例。

另外，我建议您从abiFilters开始，将其设置为一个最相关的ABI，并且只有当您看到一切都适合您时，您才能为其他ABI构建您的项目。请记住，对于某些库来说，移植到所有ABI可能是很棘手的。而且，如果你没有一个平台来对某些ABI进行至少一个简短的理智检查，那么构建它是没有意义的。