App is not working.

[shaileshmulange]

I have used your code as it is, but I am getting an error
java.lang.UnsatisfiedLinkError: dalvik.system.PathClassLoader[DexPathList[[zip file "/data/app/fr.enoent.videokit-2/base.apk"],nativeLibraryDirectories=[/vendor/lib, /system/lib]]] couldn't find "libvideokit.so".
How to solve this issue.

[Kernald]

Did you compile the JNI part? You should have a libvideokit.so file in your libs folder. Check the compagnon article for an how-to.

[shaileshmulange]

Hi Kernald,
I have checked the above article, but I am unable to create JNI part can you give me a simple example for it or step by step process. I have windows operating system with android-ndk-r10e and ffmpeg-2.7.

[shaileshmulange]

I have successfully build ffmpeg as per "compagnon article" and find ffmpeg header and .so library in ffmpeg/android/arm directory.
1:- I have created Android.mk file using .a files and put this file in ffmpeg/android/arm directory.
2:- Add Android.mk file in my project jni folder.

but didn't get any videokit folder or libvideokit.so file with this compilation. I have seen System.loadLibrary("videokit"); code in this project but not sure how to create videokit.so file.

So please can you tell me how to create videokit part in my project?

[Kernald]

Running ndk-build on this project should generate, as indicated in the jni/Android.mk file (LOCAL_MODULE := videokit), the videokit.so (or maybe libvideokit.so) file you're looking for.

[shaileshmulange]

Thanks Kernald,
I am able to run ndk-build on my project and generate .so file for my project i.e.libFileName.so.

I have used following code for Android.mk file and generate five .so files i.e. libavformat.so libavcodec.so libswscale.so libavutil.so and libFileName.so.

LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := FileName
LOCAL_C_INCLUDES := $(ANDROID_NDK)/sources/ffmpeg
LOCAL_LDLIBS := -llog -ljnigraphics -lz -landroid
LOCAL_SHARED_LIBRARIES := libavformat libavcodec libswscale libavutil
include $(BUILD_SHARED_LIBRARY)
$(call import-module,ffmpeg/android/arm)

but I have seen run() (private native boolean run(String[] args);) in your Videokit class. I think you have used this method using this file fr_enoent_videokit_Videokit.c.

So please let me know how to create run() method or use in my project with above Android.mk file.

[Kernald]

The run native method is indeed in the fr_enoent_videokit_Videokit.c file: https://github.com/Kernald/ffmpeg-android/blob/master/jni/videokit/fr_enoent_videokit_Videokit.c#L17 - just compile it in your libFileName.so, and it will be available via JNI in your Java code.

[shaileshmulange]

I tried to compile fr_enoent_videokit_Videokit.c file with my libFileName.so but getting the following error.
D:\Android\MyFFMPEGDEMO1\app\jni>ndk-build
[armeabi-v7a] Compile thumb : FileName <= fr_enoent_videokit_Videokit.c
[armeabi-v7a] Prebuilt : libavformat.so <= /sources/ffmpeg/android/arm/lib/
[armeabi-v7a] Prebuilt : libavcodec.so <= /sources/ffmpeg/android/arm/lib/
[armeabi-v7a] Prebuilt : libswscale.so <= /sources/ffmpeg/android/arm/lib/
[armeabi-v7a] Prebuilt : libavutil.so <= /sources/ffmpeg/android/arm/lib/
[armeabi-v7a] SharedLibrary : libFileName.so
D:/Android/MyFFMPEGDEMO1/app/jni/fr_enoent_videokit_Videokit.c:36: error: undefined reference to 'main'
collect2.exe: error: ld returned 1 exit status
make: *** [D:/Android/MyFFMPEGDEMO1/app/obj/local/armeabi-v7a/libFileName.so] Error 1

Please also tell me I have seen other .c and .h (ffmpeg.c ffmpeg_filter.c ffmpeg_opt.c) files in your "vidoekit" directory all these files are necessary or without this file able to execute my ffmpeg code.

[Kernald]

The error is telling you that on line 36 of fr_enoent_videokit_Videokit.c, a call to a function named main is made. You can see it here: https://github.com/Kernald/ffmpeg-android/blob/master/jni/videokit/fr_enoent_videokit_Videokit.c#L36

This function is defined in the ffmpeg.c file: https://github.com/Kernald/ffmpeg-android/blob/master/jni/videokit/ffmpeg.c#L3568 So yes, you have to include these files in your libFileName.so to make it work ;-)

[josydeleon]

I already compile everyhting fine, but when I run the app works and then close automatically. When I comment /** **/ the method process, the app runs normally. The Log, does not show any error.

[Kernald]

The process method is the one responsible for calling the C library. If this one is causing trouble, you probably made a mistake while either compiling or packaging the C library.

[josydeleon]

@Kernald Thanks for your answer. The problem is in the main(argc, argv); when I comment this line and compile the library again. Works. I am trying to execute a single line to convert mp4 to mp3 but is not working. Can you help me with that?

[Kernald]

@zoedevelopers The call to main() is doing pretty much everything. It seems that you have the wrapper code, but not ffmpeg's actual code. I didn't use ffmpeg in three years, so my ability to help will be really limited…