android - 'imported-lib - NOTFOUND' 在为 android studio 2.2 构建 ffmpeg 3.2

Question

我正在尝试为 Android 构建和使用 ffmpeg。我的Andoid Studio版本是2.2.2，ffmpeg是3.2。按照有关如何导入重建库的 Android 文档，我认为我的设置正确但一直出现此错误

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}
                        )

如果我指定完整的库名称 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知道为什么编译会这样。

Answer 1

根据 Tsyvarev 的输入，我在此处编译和链接的内容。

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}
                        )

注意以下重要区别:

• set_target_properties 中的路径必须是绝对路径。这里是使用"../../../../"四层到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，但找不到包含文件。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为 IMPORTED_LOCATION。