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I am working on ffmpeg and i want to write Jni wrapper for ffmpeg to i can call decode_video method of ffmpeg avcodec class.

Swap:SwapFfmpeg swap$ ndk-build
Android NDK: WARNING: APP_PLATFORM android-14 is larger than android:minSdkVersion 8 in   ./AndroidManifest.xml    
 Compile thumb  : com_example_swapffmpeg_Jffmpeg <= com_example_swapffmpeg_Jffmpeg.c
 SharedLibrary  : libcom_example_swapffmpeg_Jffmpeg.so
/Users/swap/android-ndk-r9/toolchains/arm-linux-androideabi-4.6/prebuilt/darwin-     x86_64/bin/../lib/gcc/arm-linux-androideabi/4.6/../../../../arm-linux-androideabi/bin/ld: ./obj/local/armeabi/objs/com_example_swapffmpeg_Jffmpeg/com_example_swapffmpeg_Jffmpeg.o: in function Java_com_example_swapffmpeg_Jffmpeg_videoinfo:jni/com_example_swapffmpeg_Jffmpeg.c:14: error: undefined reference to 'avcodec_register_all'
collect2: ld returned 1 exit status
make: *** [obj/local/armeabi/libcom_example_swapffmpeg_Jffmpeg.so] Error 1

I created android.mk file and into that i link to c wrapper class and libffmpeg.so file. But when i try to build it display error on avcodec_register_all

i search on google and i found 2 solution

1) one is extern C {} but i am using .C files not C++ so i dont think so i need to use extern {}

2) second is to add 

LOCAL_LDLIBS := -L/Users/swap/android-ndk-r9/platforms/arch-arm/usr/lib -L$(LOCAL_PATH) -lavformat -lavcodec -lavdevice -lavfilter -lavutil -lswscale  -lz -ldl -lgcc

I have added this into my android.mk and i got this error.anybody can tell me what should i write infornt of Local_LDLIBS and why to write that?

/Users/swap/android-ndk-r9/toolchains/arm-linux-androideabi-4.6/prebuilt/darwin-x86_64/bin/../lib/gcc/arm-linux-androideabi/4.6/../../../../arm-linux-androideabi/bin/ld: ./obj/local/armeabi/objs/com_example_swapffmpeg_Jffmpeg/com_example_swapffmpeg_Jffmpeg.o: in function Java_com_example_swapffmpeg_Jffmpeg_videoinfo:jni/com_example_swapffmpeg_Jffmpeg.c:14: error: undefined reference to 'avcodec_register_all'collect2: ld returned 1 exit status

In this error why it always goes to toolchains? but in android.mk i have provided hardcore path of platform/arch-arm/

Here is my android.mk 

 LOCAL_PATH:=$(call my-dir)
 #declare the prebuilt library
 include $(CLEAR_VARS)
 LOCAL_MODULE := ffmpeg-prebuilt
 LOCAL_SRC_FILES := ffmpeg/$(TARGET_ARCH_ABI)/libffmpeg.so
 LOCAL_EXPORT_C_INCLUDES := ffmpeg/$(TARGET_ARCH_ABI)/include
 LOCAL_LDLIBS := -L/Users/swap/android-ndk-r9/platforms/arch-arm/usr/lib -        L$(LOCAL_PATH) -lavformat -lavcodec -lavdevice -lavfilter -lavutil -lswscale  -lz -ldl -lgcc
 LOCAL_PRELINK_MODULE := true
 include $(PREBUILT_SHARED_LIBRARY)

 include $(CLEAR_VARS) 
 LOCAL_MODULE:=com_example_swapffmpeg_Jffmpeg      
 LOCAL_SRC_FILES:=com_example_swapffmpeg_Jffmpeg.c 
 LOCAL_SHARED_LIBRARY := ffmpeg-prebuilt 
 include $(BUILD_SHARED_LIBRARY)
4

1 回答 1

1

I am not sure this will work or not but you can try this

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)
LOCAL_MODULE := libavcodec
LOCAL_SRC_FILES := ffmpeg/$(TARGET_ARCH_ABI)/lib/$(LOCAL_MODULE).so
LOCAL_EXPORT_C_INCLUDES := ffmpeg/$(TARGET_ARCH_ABI)/include
include $(PREBUILT_SHARED_LIBRARY)


include $(CLEAR_VARS)
LOCAL_MODULE := libavdevice
LOCAL_SRC_FILES := ffmpeg/$(TARGET_ARCH_ABI)/lib/$(LOCAL_MODULE).so
LOCAL_EXPORT_C_INCLUDES := ffmpeg/$(TARGET_ARCH_ABI)/include
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := libavfilter
LOCAL_SRC_FILES := ffmpeg/$(TARGET_ARCH_ABI)/lib/$(LOCAL_MODULE).so
LOCAL_EXPORT_C_INCLUDES := ffmpeg/$(TARGET_ARCH_ABI)/include
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := libavformat
LOCAL_SRC_FILES := ffmpeg/$(TARGET_ARCH_ABI)/lib/$(LOCAL_MODULE).so
LOCAL_EXPORT_C_INCLUDES := ffmpeg/$(TARGET_ARCH_ABI)/include
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := libavutil
LOCAL_SRC_FILES := ffmpeg/$(TARGET_ARCH_ABI)/lib/$(LOCAL_MODULE).so
LOCAL_EXPORT_C_INCLUDES := ffmpeg/$(TARGET_ARCH_ABI)/include
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := libswscale
LOCAL_SRC_FILES := ffmpeg/$(TARGET_ARCH_ABI)/lib/$(LOCAL_MODULE).so
LOCAL_EXPORT_C_INCLUDES := ffmpeg/$(TARGET_ARCH_ABI)/include
include $(PREBUILT_SHARED_LIBRARY)


include $(CLEAR_VARS)
LOCAL_MODULE:=com_example_swapffmpeg_Jffmpeg      
LOCAL_SRC_FILES:=com_example_swapffmpeg_Jffmpeg.c 
LOCAL_SHARED_LIBRARY := ffmpeg-prebuilt
include $(BUILD_SHARED_LIBRARY)


include $(CLEAR_VARS)

LOCAL_MODULE    := com_example_swapffmpeg_Jffmpeg
LOCAL_SRC_FILES := com_example_swapffmpeg_Jffmpeg.c
LOCAL_SHARED_LIBRARIES := libavdevice libavfilter libavutil libswscale libavformat
LOCAL_LDLIBS := -L/Users/swapnil/android-ndk-r9/platforms/$(TARGET_PLATFORM)/arch-arm/usr/lib \
            -L$(LOCAL_PATH)/lib/ffmpeg/$(TARGET_ARCH_ABI)/lib \
            -lavformat \
            -lavcodec \
            -lavdevice \
            -lavfilter \
            -lavutil \
            -lswscale \
            -llog \
            -lz \
            -ldl \
            -lgcc

include $(BUILD_SHARED_LIBRARY)
于 2013-08-30T16:53:57.443 回答