android - 无法在 OpenCV Android 示例中链接本机库

Question

我有 OpenCV 代码 (c++)，我想在 Android 中使用它。为此，我必须使用Android NDK。我下载了用于 Android 开发的 OpenCV 包（版本 2.4.0）并按照该手册执行了所有步骤。基本示例（仅限 Java API）运行没有问题。示例 #3 （教程 3（高级）- 添加本机 OpenCV）从 ndk-builder 正确构建。但是当我尝试从 eclipse 在设备上运行/调试它时总是出现异常：

Exception Ljava/lang/UnsatisfiedLinkError; thrown while initializing Lorg/opencv/samples/tutorial3/Sample3View;

在这一行：

System.loadLibrary("native_sample");

这是完整的 logcat 日志：

05-31 23:41:45.976: W/ActivityThread(9708): Application org.opencv.samples.tutorial3 is waiting for the debugger on port 8100...
05-31 23:41:45.983: I/System.out(9708): Sending WAIT chunk
05-31 23:41:45.983: I/dalvikvm(9708): Debugger is active
05-31 23:41:46.179: I/System.out(9708): Debugger has connected
05-31 23:41:46.179: I/System.out(9708): waiting for debugger to settle...
05-31 23:41:46.382: I/System.out(9708): waiting for debugger to settle...
05-31 23:41:46.585: I/System.out(9708): waiting for debugger to settle...
05-31 23:41:46.788: I/System.out(9708): waiting for debugger to settle...
05-31 23:41:46.983: I/System.out(9708): waiting for debugger to settle...
05-31 23:41:47.186: I/System.out(9708): waiting for debugger to settle...
05-31 23:41:47.389: I/System.out(9708): waiting for debugger to settle...
05-31 23:41:47.585: I/System.out(9708): waiting for debugger to settle...
05-31 23:41:47.788: I/System.out(9708): debugger has settled (1463)
05-31 23:41:47.819: D/szipinf(9708): Initializing inflate state
05-31 23:41:47.866: I/Sample::Activity(9708): Instantiated new class org.opencv.samples.tutorial3.Sample3Native
05-31 23:41:48.909: D/dalvikvm(9708): threadid=1: still suspended after undo (sc=1 dc=1)
05-31 23:41:51.770: I/Sample::Activity(9708): onCreate
05-31 23:41:59.283: W/dalvikvm(9708): Exception Ljava/lang/UnsatisfiedLinkError; thrown while initializing Lorg/opencv/samples/tutorial3/Sample3View;
05-31 23:42:01.965: D/AndroidRuntime(9708): Shutting down VM
05-31 23:42:01.965: W/dalvikvm(9708): threadid=1: thread exiting with uncaught exception (group=0x40015560)
05-31 23:42:01.999: E/AndroidRuntime(9708): FATAL EXCEPTION: main
05-31 23:42:01.999: E/AndroidRuntime(9708): java.lang.ExceptionInInitializerError
05-31 23:42:01.999: E/AndroidRuntime(9708):     at org.opencv.samples.tutorial3.Sample3Native.onCreate(Sample3Native.java:21)
05-31 23:42:01.999: E/AndroidRuntime(9708):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
05-31 23:42:01.999: E/AndroidRuntime(9708):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1722)
05-31 23:42:01.999: E/AndroidRuntime(9708):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1784)
05-31 23:42:01.999: E/AndroidRuntime(9708):     at android.app.ActivityThread.access$1500(ActivityThread.java:123)
05-31 23:42:01.999: E/AndroidRuntime(9708):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:939)
05-31 23:42:01.999: E/AndroidRuntime(9708):     at android.os.Handler.dispatchMessage(Handler.java:99)
05-31 23:42:01.999: E/AndroidRuntime(9708):     at android.os.Looper.loop(Looper.java:130)
05-31 23:42:01.999: E/AndroidRuntime(9708):     at android.app.ActivityThread.main(ActivityThread.java:3835)
05-31 23:42:01.999: E/AndroidRuntime(9708):     at java.lang.reflect.Method.invokeNative(Native Method)
05-31 23:42:01.999: E/AndroidRuntime(9708):     at java.lang.reflect.Method.invoke(Method.java:507)
05-31 23:42:01.999: E/AndroidRuntime(9708):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:864)
05-31 23:42:01.999: E/AndroidRuntime(9708):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:622)
05-31 23:42:01.999: E/AndroidRuntime(9708):     at dalvik.system.NativeStart.main(Native Method)
05-31 23:42:01.999: E/AndroidRuntime(9708): Caused by: java.lang.UnsatisfiedLinkError: Couldn't load native_sample: findLibrary returned null
05-31 23:42:01.999: E/AndroidRuntime(9708):     at java.lang.Runtime.loadLibrary(Runtime.java:429)
05-31 23:42:01.999: E/AndroidRuntime(9708):     at java.lang.System.loadLibrary(System.java:554)
05-31 23:42:01.999: E/AndroidRuntime(9708):     at org.opencv.samples.tutorial3.Sample3View.<clinit>(Sample3View.java:48)
05-31 23:42:01.999: E/AndroidRuntime(9708):     ... 14 more

我找到了相同问题的解决方案，但没有一个对我没有帮助：

我还在不同的设备和 Android API 版本上对其进行了测试。

我的系统配置：

astor@astor-K42Jv:~$ uname -a
Linux astor-K42Jv 3.2.0-24-generic-pae #39-Ubuntu SMP Mon May 21 18:54:21 UTC 2012 i686 i686 i386 GNU/Linux

我已经尝试解决这个问题 4 晚（这是我的空闲时间:)），但没有运气。我的论文真的需要这个，所以任何帮助都将不胜感激。

更新：我已经在 Windows 7 (64) 上测试了这个样本，但结果是一样的。

看来这是 OpenCV 错误。

更新：构建日志：

astor@astor-K42Jv:/opt/eclipse-android/workspace/OpenCV-2.4.0-samples/tutorial-3-native$ ndk-build 
Install        : libnative_camera_r2.2.0.so => libs/armeabi-v7a/libnative_camera_r2.2.0.so
Install        : libnative_camera_r2.3.3.so => libs/armeabi-v7a/libnative_camera_r2.3.3.so
Install        : libnative_camera_r3.0.1.so => libs/armeabi-v7a/libnative_camera_r3.0.1.so
Install        : libnative_camera_r4.0.0.so => libs/armeabi-v7a/libnative_camera_r4.0.0.so
Install        : libnative_camera_r4.0.3.so => libs/armeabi-v7a/libnative_camera_r4.0.3.so
Install        : libnative_sample.so => libs/armeabi-v7a/libnative_sample.so

score 17 · Accepted Answer

哇哦！

最后我自己找到了解决这个问题的方法！

我决定调试行：

System.loadLibrary("native_sample");

为此，我从 Android-SDK 下载了 android 源代码，然后将源文件夹(/opt/android-sdk-linux/sources/android-15)附加到我的项目中。在此之后，我发现错误是：

Cannot load library: link_image[1936]:    37 could not load needed library 'libopencv_java.so' for 'libhello-jni.so' (load_library[1091]: Library 'libopencv_java.so' not found)

实际上这个库不在lib目录中。我不知道为什么，但ndk-build忽略了它。所以我决定手动复制和加载它。为此，我复制libopencv_java.so并/opt/OpenCV-2.4.0/libs/armeabi-v7a编辑了 java 代码：

static {
    System.loadLibrary("opencv_java"); //load opencv_java lib
    System.loadLibrary("native_sample");
}

实际上类似的问题是：

从第二个解决方案中，我发现我可以使用dlopen加载库，但我还没有尝试过。

因此，我将编写简单的 bash 脚本来为自己完成（只是复制）。

谢谢大家。

score 2 · Accepted Answer

而不是将您的本机库加载为

static{
    System.loadLibrary("YOUR_LIBRARY");
}

在“BaseLoaderCallBack”中的“onManagerConnected”方法连接opencv管理器后加载库。以下是我为我工作的代码片段

public void onManagerConnected(int status) {
                switch(status){
                case LoaderCallbackInterface.SUCCESS:
                    Toast.makeText(getApplicationContext(), "manager connected", Toast.LENGTH_LONG).show();
                    System.loadLibrary("MYNATIVELIB");
                    break;
                default:
                    super.onManagerConnected(status);
                    break;
                }
            }

score 0 · Accepted Answer

您比实际问题处于更高的水平。运行时请参阅“NDK 入门”

    cd <project>
    <ndk>/ndk-build

... 它说什么？（记住使用 cygwin 窗口而不是 dos 提示符）。

android - 无法在 OpenCV Android 示例中链接本机库

3 回答 3

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