为android studio 2.2构建ffmpeg 3.2中的“导入-库-NOTFOUND”

Question

我正在尝试为Android构建和使用ffmpeg。我的Andoid版本是2.2.2，ffmpeg是3.2。下面是关于如何导入重新构建库的Android文档，我认为我的设置是正确的，但是我一直在获取这个错误。

ninja: error: 'avcodec-NOTFOUND', needed by '../../../../build/intermediates/cmake/debug/obj/armeabi-v7a/...

这是设置

add_library( avcodec SHARED IMPORTED )
add_library( avdevice SHARED IMPORTED )
add_library( avfilter SHARED IMPORTED )
add_library( avformat SHARED IMPORTED )
add_library( avutil SHARED IMPORTED )
add_library( swscale SHARED IMPORTED )

set_target_properties( avcodec
                        PROPERTIES FFMPEG_LIB_IMPORTED_LOCATION
                        libs/ffmpeg/${ANDROID_ABI}/lib/libavcodec.so
                        )
set_target_properties(  avdevice
                        PROPERTIES FFMPEG_LIB_IMPORTED_LOCATION
                        libs/ffmpeg/${ANDROID_ABI}/lib/libavdevice.so
                        )
set_target_properties( avfilter
                        PROPERTIES FFMPEG_LIB_IMPORTED_LOCATION
                        libs/ffmpeg/${ANDROID_ABI}/lib/libavfilter.so
                        )
set_target_properties( avformat
                        PROPERTIES FFMPEG_LIB_IMPORTED_LOCATION
                        libs/ffmpeg/${ANDROID_ABI}/lib/libavformat.so
                        )
set_target_properties( avutil
                        PROPERTIES FFMPEG_LIB_IMPORTED_LOCATION
                        libs/ffmpeg/${ANDROID_ABI}/lib/libavutil.so
                        )
set_target_properties( swscale
                        PROPERTIES FFMPEG_LIB_IMPORTED_LOCATION
                        libs/ffmpeg/${ANDROID_ABI}/lib/libswscale.so
                        )

# Specifies a path to native header files.
include_directories(
                    libs/ffmpeg/${ANDROID_ABI}/include
                    )

target_link_libraries( # Specifies the target library.
                       native-lib

                       # Links the target library to the log library
                       # included in the NDK.
                       avcodec avdevice avfilter avformat avutil swscale
                       ${log-lib}
                        )

如果我指定了完整的库名libavcodec.so.，错误就会消失。

target_link_libraries( # Specifies the target library.
                       native-lib

                       # Links the target library to the log library
                       # included in the NDK.
                       libavcodec.so libavdevice.so libavfilter.so libavformat.so libavutil.so libswscale.so
                       ${log-lib}
                        )

我想知道是否有人遇到过类似的问题，或者知道为什么编译是这样的。

Answer 1

根据Tsyvarev的输入，我在这里得到的是编译和链接。

add_library( avcodec SHARED IMPORTED )
add_library( avdevice SHARED IMPORTED )
add_library( avfilter SHARED IMPORTED )
add_library( avformat SHARED IMPORTED )
add_library( avutil SHARED IMPORTED )
add_library( swscale SHARED IMPORTED )

set_target_properties( avcodec
                        PROPERTIES IMPORTED_LOCATION
                        ../../../../libs/${ANDROID_ABI}/lib/libavcodec.so
                        )
set_target_properties(  avdevice
                        PROPERTIES IMPORTED_LOCATION
                      ../../../../libs/${ANDROID_ABI}/lib/libavdevice.so
                        )
set_target_properties( avfilter
                        PROPERTIES IMPORTED_LOCATION
                        ../../../..//libs/${ANDROID_ABI}/lib/libavfilter.so
                        )
set_target_properties( avformat
                        PROPERTIES IMPORTED_LOCATION
                        ../../../../libs/${ANDROID_ABI}/lib/libavformat.so
                        )
set_target_properties( avutil
                        PROPERTIES IMPORTED_LOCATION
                        ../../../../libs/${ANDROID_ABI}/lib/libavutil.so
                        )
set_target_properties( swscale
                        PROPERTIES IMPORTED_LOCATION
                        ../../../../libs/${ANDROID_ABI}/lib/libswscale.so
                        )

# Specifies a path to native header files.
include_directories(
                    libs/${ANDROID_ABI}/include
                    )

target_link_libraries( # Specifies the target library.
                       native-lib

                       # Links the target library to the log library
                       # included in the NDK.
                       avcodec avdevice avfilter avformat avutil swscale
                       ${log-lib}
                        )

注:以下是重要的区别：

• set_target_properties中的路径必须是绝对的。下面是使用“.././../”四个级别到libs目录；但是，对于include_directory中的头文件路径，它需要是相对的。我使用了绝对路径，无法找到包含文件。顺便说一下，我删除了“ffmpeg”文件夹。
• set_target_properties中的导入位置属性需要是IMPORTED_LOCATION。