在Android Studio上的JNI编译错误2.3.2

Question

我正在向YouTube频道播放手机视频。我发现这个链接https://github.com/youtube/yt-watchme。

在编写我的代码，我得到错误

libavutil not found in file avecode.h at code #include "libavutil/samplefmt.h

我也改变＃包括“../libavutil/samplefmt.h”还是同样的错误。

也许建议任何一个好的rtmp库来向youtube频道播放手机视频。

Error:FAILURE: Build failed with an exception. * What went wrong:
Execution failed for task ':app:externalNativeBuildDebug'.
Build command failed.
Error while executing process

/Users/nomankhan/Library/Android/sdk/cmake/3.6.4111459/bin/cmake with arguments {--build /Clients/Ankur/JniDemo/app/.externalNativeBuild/cmake/debug/mips64 --target native-lib}
[1/2] Building CXX object CMakeFiles/native-lib.dir/src/main/cpp/native-lib.cpp.o
FAILED: /Users/nomankhan/Library/Android/sdk/ndk-bundle/toolchains/llvm/prebuilt/darwin-x86_64/bin/clang++ --target=mips64el-none-linux-android --gcc-toolchain=/Users/nomankhan/Library/Android/sdk/ndk-bundle/toolchains/mips64el-linux-android-4.9/prebuilt/darwin-x86_64 --sysroot=/Users/nomankhan/Library/Android/sdk/ndk-bundle/sysroot -Dnative_lib_EXPORTS -I../../../../src/main/cpp/include/libavcodec -I../../../../src/main/cpp/include/libavformat -I../../../../src/main/cpp/include/libavutil -isystem /Users/nomankhan/Library/Android/sdk/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include -isystem /Users/nomankhan/Library/Android/sdk/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/libs/mips64/include -isystem /Users/nomankhan/Library/Android/sdk/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/backward -isystem /Users/nomankhan/Library/Android/sdk/ndk-bundle/sysroot/usr/include/mips64el-linux-android -D__ANDROID_API__=21 -g -DANDROID -ffunction-sections -funwind-tables -fstack-protector-strong -no-canonical-prefixes -fintegrated-as -Wa,--noexecstack -Wformat -Werror=format-security -O0 -fno-limit-debug-info -fPIC -MD -MT CMakeFiles/native-lib.dir/src/main/cpp/native-lib.cpp.o -MF CMakeFiles/native-lib.dir/src/main/cpp/native-lib.cpp.o.d -o CMakeFiles/native-lib.dir/src/main/cpp/native-lib.cpp.o -c /Clients/Ankur/JniDemo/app/src/main/cpp/native-lib.cpp

In file included from /Clients/Ankur/JniDemo/app/src/main/cpp/native-lib.cpp:4: /Clients/Ankur/JniDemo/app/src/main/cpp/libavcodec/avcodec.h:31:10: fatal error: 'libavutil/samplefmt.h' file not found #include "libavutil/samplefmt.h" ^~~~~~~~~~~~~~~~~~~~~~~

我的CMakeLists.txt

cmake_minimum_required(VERSION 3.4.1) 

add_library(# Sets the name of the library. 
      native-lib 

      # Sets the library as a shared library. 
      SHARED 

      # Provides a relative path to your source file(s). 
      src/main/cpp/native-lib.cpp) 

find_library(# Sets the name of the path variable. 
       log-lib 

       # Specifies the name of the NDK library that 
       # you want CMake to locate. 
       log) 


target_link_libraries(# Specifies the target library. 
         native-lib 

         # Links the target library to the log library 
         # included in the NDK. 
         ${log-lib}) 

include_directories(src/main/cpp/include/libavcodec) 

include_directories(src/main/cpp/include/libavformat) 

include_directories(src/main/cpp/include/libavutil) 

Answer 1

答案下面是假定内cpp的文件夹中包含C++代码/ src目录文件。如果没有，那么你可能有代码和库结构问题。

简单地调用include_directories将不得到CMake编译它们，我相信这只会帮助IDE在某些“语法高亮”和编码相关的东西，但它是非常重要的。

相反，您需要在add_library调用中包含代码文件。由于这是很明显的，你有很多的文件，遍历代码，这样将有助于：

cmake_minimum_required(VERSION 3.4.1) 

include_directories(src/main/cpp/include/libavcodec)   

# Traverses through the directories recursively 
# and append matching files to variable my_lib_SRC 
file(GLOB_RECURSE my_lib_SRC 
    "src/main/cpp/*.h" 
    "src/main/cpp/*.cpp" 
) 

add_library(# Sets the name of the library. 
     native-lib 

     # Sets the library as a shared library. 
     SHARED 

     # Provides a relative path to your source file(s). 
     ${my_lib_SRC}) 

target_link_libraries(# Specifies the target library. 
         native-lib 

         # Links the target library to the log library 
         # included in the NDK. 
         ${log-lib}) 

注意：每次添加一个新的源/代码文件，你需要清洁和再次构建适当构建二进制文件的项目。进一步的解释可以在这里找到：https://stackoverflow.com/a/17655165/2949966