android - UnsatisfiedLInkError 使用 NDK 链接到 FFMPEG

Question

我使用 bambuser 的文件为 android 编译了 FFMPEG。编译运行良好。没有错误。我还确保更改了 build.sh 中的包名称。但是，一旦我尝试链接到文件，手机就会抛出 UnsatisfiedLinkError。这是 Androkd.mk 文件:

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)
MY_LIB_PATH := ffmpeg-android/build/ffmpeg/armeabi/lib
LOCAL_MODULE := bambuser-libavcore
LOCAL_SRC_FILES := $(MY_LIB_PATH)/libavcore.so
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := bambuser-libavformat
LOCAL_SRC_FILES := $(MY_LIB_PATH)/libavformat.so
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := bambuser-libavcodec
LOCAL_SRC_FILES := $(MY_LIB_PATH)/libavcodec.so
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := bambuser-libavdevice
LOCAL_SRC_FILES := $(MY_LIB_PATH)/libavdevice.so
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := bambuser-libavfilter
LOCAL_SRC_FILES := $(MY_LIB_PATH)/libavfilter.so
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := bambuser-libavutil
LOCAL_SRC_FILES := $(MY_LIB_PATH)/libavutil.so
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := bambuser-libswscale
LOCAL_SRC_FILES := $(MY_LIB_PATH)/libswscale.so
include $(PREBUILT_SHARED_LIBRARY)


#local_PATH := $(call my-dir)

include $(CLEAR_VARS)

LOCAL_MODULE    := libtest_jni
LOCAL_SRC_FILES := libtest/video.c

LOCAL_C_INCLUDES := \
    $(LOCAL_PATH)/include \
        $(LOCAL_PATH)/ffmpeg-android/ffmpeg 
        LOCAL_LDLIBS := -L$(NDK_PLATFORMS_ROOT)/$(TARGET_PLATFORM)/arch-arm/usr/lib -L$(LOCAL_PATH) -L$(LOCAL_PATH)/ffmpeg-android/build/ffmpeg/armeabi/lib/ -lavformat -lavcodec -lavdevice -lavfilter -lavutil -lswscale -llog -lz -lm
        #dl -lgcc

        include $(BUILD_SHARED_LIBRARY)

Video.c 非常简单:

#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <libswscale/swscale.h>

#include <jni.h>  
#include <string.h>  
#include <stdio.h>
#include <android/log.h>  

void Java_com_bukabros_videolivewallpaper_Opengl2Renderer_loadNthFrame3
       (JNIEnv * env, jobject this, jstring fileName)  {

       jboolean isCopy;  
         const char * szLogThis = (*env)->GetStringUTFChars(env, fileName, &isCopy);  

          __android_log_print(ANDROID_LOG_DEBUG, "NDK: ", "NDK:LC: [%s]", szLogThis); 
          }   

对应的Java代码也很简单:

 private native void loadNthFrame3(String fileName);

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

但是我得到这个错误:

E/AndroidRuntime(11489): FATAL EXCEPTION: main

E/AndroidRuntime(11489): java.lang.ExceptionInInitializerError

E/AndroidRuntime(11489):    at com.bukabros.videolivewallpaper.VideoLiveWallpaper$CubeEngine.<init>(VideoLiveWallpaper.java:147)

E/AndroidRuntime(11489):    at com.bukabros.videolivewallpaper.VideoLiveWallpaper.onCreateEngine(VideoLiveWallpaper.java:120)

E/AndroidRuntime(11489):    at android.service.wallpaper.WallpaperService$IWallpaperEngineWrapper.executeMessage(WallpaperService.java:814)

E/AndroidRuntime(11489):    at com.android.internal.os.HandlerCaller$MyHandler.handleMessage(HandlerCaller.java:61)

E/AndroidRuntime(11489):    at android.os.Handler.dispatchMessage(Handler.java:99)

E/AndroidRuntime(11489):    at android.os.Looper.loop(Looper.java:123)

E/AndroidRuntime(11489):    at android.app.ActivityThread.main(ActivityThread.java:4627)

E/AndroidRuntime(11489):    at java.lang.reflect.Method.invokeNative(Native Method)

E/AndroidRuntime(11489):    at java.lang.reflect.Method.invoke(Method.java:521)

E/AndroidRuntime(11489):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:878)

E/AndroidRuntime(11489):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:636)

E/AndroidRuntime(11489):    at dalvik.system.NativeStart.main(Native Method)

E/AndroidRuntime(11489): Caused by: java.lang.UnsatisfiedLinkError: Library libtest_jni not found

E/AndroidRuntime(11489):    at java.lang.Runtime.loadLibrary(Runtime.java:461)

E/AndroidRuntime(11489):    at java.lang.System.loadLibrary(System.java:557)

E/AndroidRuntime(11489):    at com.bukabros.videolivewallpaper.Opengl2Renderer.<clinit>(Opengl2Renderer.java:389)

E/AndroidRuntime(11489):    ... 12 more

我尝试在 Java 中手动加载预构建的共享库(bambuser 文件)(使用 System.loadLibrary)，但它告诉我找不到文件。

如果有帮助，这是 readelf 的输出:

 0x00000001 (NEEDED)                     Shared library: [libc.so]
  0x00000001 (NEEDED)                     Shared library: [libstdc++.so]
   0x00000001 (NEEDED)                     Shared library: [libm.so]
    0x00000001 (NEEDED)                     Shared library: [/data/data/com.bukabros.videolivewallpaper/lib/libavformat.so]
     0x00000001 (NEEDED)                     Shared library: [/data/data/com.bukabros.videolivewallpaper/lib/libavcodec.so]
      0x00000001 (NEEDED)                     Shared library: [/data/data/com.bukabros.videolivewallpaper/lib/libavdevice.so]
       0x00000001 (NEEDED)                     Shared library: [/data/data/com.bukabros.videolivewallpaper/lib/libavfilter.so]
        0x00000001 (NEEDED)                     Shared library: [/data/data/com.bukabros.videolivewallpaper/lib/libavutil.so]
     0x00000001 (NEEDED)                     Shared library: [/data/data/com.bukabros.videolivewallpaper/lib/libswscale.so]
      0x00000001 (NEEDED)                     Shared library: [liblog.so]
       0x00000001 (NEEDED)                     Shared library: [libz.so]
        0x00000001 (NEEDED)                     Shared library: [libdl.so]
         0x0000000e (SONAME)                     Library soname: [libtest_jni.so]
          0x00000010 (SYMBOLIC)                   0x0
           0x00000004 (HASH)                       0xd4
            0x00000005 (STRTAB)                     0x250
         0x00000006 (SYMTAB)                     0x130
          0x0000000a (STRSZ)                      712 (bytes)
           0x0000000b (SYMENT)                     16 (bytes)
            0x00000003 (PLTGOT)                     0x174c
             0x00000002 (PLTRELSZ)                   32 (bytes)
              0x00000014 (PLTREL)                     REL
               0x00000017 (JMPREL)                     0x55c
                0x6ffffffe (VERNEED)                    0x53c
             0x6fffffff (VERNEEDNUM)                 1
              0x6ffffff0 (VERSYM)                     0x518
               0x00000000 (NULL)                       0x0

哦对了。我正在使用 ndk r5。

Answer 1

看来我找到了答案。问题是当您在 Java (System.loadLibrary) 中加载库时，您不能使用“lib”前缀。我还必须手动加载 Java 中的 ffmpeg 库。这个故事的寓意是您应该始终阅读文档并且不要放弃:-)这是正确的代码:

 static {  
System.loadLibrary("avcore");
System.loadLibrary("avformat");
System.loadLibrary("avcodec");
System.loadLibrary("avdevice");
System.loadLibrary("avfilter");
System.loadLibrary("avutil");
System.loadLibrary("swscale");
System.loadLibrary("test_jni");  
 }