我试图在Android Studio中将OpenCV与NDK一起使用。您可能已经注意到我正在使用另一个名为GStreamer的本地库。
我的build.gradle:
apply plugin: 'com.android.application'
def getNdkCommandLine(ndkRoot, target) {
def gstRoot
def opencvRoot
gstRoot = 'C:/local/gstreamer-1.0-android-arm-1.8.0'
opencvRoot = 'C:/local/OpenCV-3.1.0-android-sdk/OpenCV-android-sdk'
if (ndkRoot == null)
throw new GradleException('NDK not configured')
return ["$ndkRoot/ndk-build.cmd",
'NDK_PROJECT_PATH=build',
'APP_BUILD_SCRIPT=src/main/jni/Android.mk',
'NDK_APPLICATION_MK=src/main/jni/Application.mk',
'GSTREAMER_JAVA_SRC_DIR=src/main/java',
"GSTREAMER_ROOT_ANDROID=$gstRoot",
"OPENCV_ROOT_ANDROID=$opencvRoot",
"$target"]
}
android {
compileSdkVersion 19
buildToolsVersion "23.0.2"
sourceSets {
main {
// Avoid using the built in JNI generation plugin
jni.srcDirs = []
jniLibs.srcDirs = ['build/libs']
}
}
defaultConfig {
applicationId "com.mytestcom.mytestapp"
minSdkVersion 19
targetSdkVersion 19
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_7
targetCompatibility JavaVersion.VERSION_1_7
}
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
signingConfig signingConfigs.release
}
}
// Before compiling our app, prepare NDK code
tasks.withType(JavaCompile) {
compileTask -> compileTask.dependsOn ndkBuild
}
// Need to call clean on NDK ourselves too
clean.dependsOn 'ndkClean'
// Build native code using mk files like on Eclipse
task ndkBuild(type: Exec, description: 'Compile JNI source via NDK') {
commandLine getNdkCommandLine(android.ndkDirectory, 'TARGET_ARCH_ABI=armeabi-v7a')
}
task ndkClean(type: Exec, description: 'Clean JNI code built via NDK') {
commandLine getNdkCommandLine(android.ndkDirectory, 'clean')
}
//Renames APK to current versionName found in Android Manifest
applicationVariants.all { variant ->
variant.outputs.each { output ->
def outputFile = output.outputFile
if (outputFile != null && outputFile.name.endsWith('.apk')) {
def fileName = "My_Test_App-${versionName}.apk"
output.outputFile = new File(outputFile.parent, fileName)
}
}
}
}
dependencies {
compile 'com.android.support:support-v4:19.1.0'
compile project(':openCVLibrary310')
}
Android.mk:
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := gstplayer
LOCAL_SRC_FILES := player.cpp
LOCAL_C_INCLUDES := $(OPENCV_ROOT_ANDROID)/sdk/native/jni/include
LOCAL_SHARED_LIBRARIES := gstreamer_android
LOCAL_LDLIBS := -llog -landroid
include $(BUILD_SHARED_LIBRARY)
ifeq ($(TARGET_ARCH_ABI),armeabi)
GSTREAMER_ROOT := $(GSTREAMER_ROOT_ARM)
else ifeq ($(TARGET_ARCH_ABI),armeabi-v7a)
GSTREAMER_ROOT := $(GSTREAMER_ROOT_ARMV7)
else ifeq ($(TARGET_ARCH_ABI),arm64-v8a)
GSTREAMER_ROOT := $(GSTREAMER_ROOT_ARM64)
else ifeq ($(TARGET_ARCH_ABI),x86)
GSTREAMER_ROOT := $(GSTREAMER_ROOT_X86)
else ifeq ($(TARGET_ARCH_ABI),x86_64)
GSTREAMER_ROOT := $(GSTREAMER_ROOT_X86_64)
else
$(error Target arch ABI not supported)
endif
ifndef GSTREAMER_ROOT
ifndef GSTREAMER_ROOT_ANDROID
$(error GSTREAMER_ROOT_ANDROID is not defined!)
endif
GSTREAMER_ROOT := $(GSTREAMER_ROOT_ANDROID)
endif
GSTREAMER_NDK_BUILD_PATH := $(GSTREAMER_ROOT)/share/gst-android/ndk-build/
include $(GSTREAMER_NDK_BUILD_PATH)/plugins.mk
GSTREAMER_PLUGINS := $(GSTREAMER_PLUGINS_CORE) $(GSTREAMER_PLUGINS_PLAYBACK) $(GSTREAMER_PLUGINS_CODECS) $(GSTREAMER_PLUGINS_NET) $(GSTREAMER_PLUGINS_SYS) $(GSTREAMER_PLUGINS_CODECS_RESTRICTED) $(GSTREAMER_CODECS_GPL) $(GSTREAMER_PLUGINS_ENCODING) $(GSTREAMER_PLUGINS_VIS) $(GSTREAMER_PLUGINS_EFFECTS) $(GSTREAMER_PLUGINS_NET_RESTRICTED)
GSTREAMER_EXTRA_DEPS := gstreamer-player-1.0 gstreamer-video-1.0 glib-2.0
OPENCV_INSTALL_MODULES:=on
OPENCV_CAMERAMODULES:=off
OPENCV_LIB_TYPE:=STATIC
include $(GSTREAMER_NDK_BUILD_PATH)/gstreamer-1.0.mk
include $(OPENCV_ROOT_ANDROID)/sdk/native/jni/OpenCV.mk
Application.mk:
APP_PLATFORM=android-19
APP_STL := gnustl_static
APP_CPPFLAGS := -frtti -fexceptions
APP_ABI := armeabi-v7a
我使用的是OpenCV-3.1.0-android-sdk,NDK r10e,Android Studio 2.1,Windows。我尝试过使用不同版本的OpenCV(2.4.11),但它没有帮助。
C:\local\OpenCV-3.1.0-android-sdk\OpenCV-android-sdk\sdk\native\jni\include\opencv2\core\cvstd.hpp
Error:(625) undefined reference to 'cv::String::allocate(unsigned int)'
Error:(667) undefined reference to 'cv::String::deallocate()'
Error:(667) undefined reference to 'cv::String::deallocate()'
Error:(667) undefined reference to 'cv::String::deallocate()'
Error:(667) undefined reference to 'cv::String::deallocate()'
C:\local\OpenCV-3.1.0-android-sdk\OpenCV-android-sdk\sdk\native\jni\include\opencv2\core\mat.inl.hpp
Error:(443) undefined reference to 'cv::error(int, cv::String const&, char const*, char const*, int)'
Error:(459) undefined reference to 'cv::error(int, cv::String const&, char const*, char const*, int)'
Error:(682) undefined reference to 'cv::Mat::deallocate()'
Error:(571) undefined reference to 'cv::fastFree(void*)'
Error:(592) undefined reference to 'cv::Mat::copySize(cv::Mat const&)'
答案 0 :(得分:0)
几天前我遇到了类似的问题。 Imo,您应该尝试将LOCAL_LDLIBS := -llog -landroid
替换为LOCAL_LDLIBS += -llog -landroid
。
答案 1 :(得分:0)
对这些错误的解释是,GStreamer中使用的OpenCV代码无法访问库的其余部分,因此无法找到allocate()
和{等基本方法{1}}。
解决方案是在Android.mk中包含一些预构建的静态库,以便定义这些引用。所以在deallocate()
之后我添加了这些行来添加相关的库:
include $(OPENCV_ROOT_ANDROID)/sdk/native/jni/OpenCV.mk
include $(CLEAR_VARS)
LOCAL_MODULE := opencv-tbb
LOCAL_SRC_FILES := opencvLib/3rdparty/libs/$(TARGET_ARCH_ABI)/libtbb.a
include $(PREBUILT_STATIC_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := opencv-core
LOCAL_SRC_FILES := opencvLib/$(TARGET_ARCH_ABI)/libopencv_core.a
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/opencvLib/include/
LOCAL_STATIC_LIBRARIES := opencv-tbb
include $(PREBUILT_STATIC_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := opencv-imgproc
LOCAL_SRC_FILES := opencvLib/$(TARGET_ARCH_ABI)/libopencv_imgproc.a
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/opencvLib/include/
LOCAL_STATIC_LIBRARIES := opencv-core
include $(PREBUILT_STATIC_LIBRARY)
变量设置与该库对应的包含文件。在这种情况下,include文件夹适用于两个库。
现在,为了使GStreamer代码能够使用这些库,我们必须将LOCAL_EXPORT_C_INCLUDES
添加到gstplayer模块,该模块引用了2个添加的OpenCV模块。
编辑:
我忘记提及我在Application.mk中将LOCAL_STATIC_LIBRARIES := opencv-core opencv-imgproc
更改为APP_STL := gnustl_static