c++ - 使用CMake的ffmpeg链接问题

Question

我正在编写一个包含 2 个内部库并依赖于更多 2 个外部库(ffmpeg 和 opencv)的应用程序。我还使用 CMake 生成 UNIX 生成文件。问题是当我尝试构建源时，它编译但根本不与 ffmpeg 链接，链接器给出的下一个输出:

../../Decoder/libDecoder.a(ConverterAVFrameToRGB.cpp.o): In function `FaceVideo::ConverterAVFrameToRGB::to_rgb_conversion(std::vector<AVFrame*, std::allocator<AVFrame*> >&, int, int, int)':
ConverterAVFrameToRGB.cpp:(.text+0x990): undefined reference to `av_frame_free'
../../Decoder/libDecoder.a(FfmpegDecoder.cpp.o): In function `FaceVideo::FfmpegDecoder::destroy()':
FfmpegDecoder.cpp:(.text+0xa30): undefined reference to `av_frame_free'
../../Decoder/libDecoder.a(FfmpegDecoder.cpp.o): In function `FaceVideo::FfmpegDecoder::decode_next_chunk(int)':
FfmpegDecoder.cpp:(.text+0xb6b): undefined reference to `av_frame_clone'
FfmpegDecoder.cpp:(.text+0xc13): undefined reference to `av_frame_free'
../../Decoder/libDecoder.a(FfmpegEncoder.cpp.o): In function `FaceVideo::FfmpegEncoder::destroy()':
FfmpegEncoder.cpp:(.text+0x132): undefined reference to `avcodec_free_frame'
../../Decoder/libDecoder.a(FfmpegEncoder.cpp.o): In function `FaceVideo::FfmpegEncoder::encode()':
FfmpegEncoder.cpp:(.text+0x4c4): undefined reference to `avcodec_encode_video2'
FfmpegEncoder.cpp:(.text+0x592): undefined reference to `avcodec_encode_video2'
../../Decoder/libDecoder.a(FrameSaver.cpp.o): In function `FaceVideo::FrameSaver::saver(std::vector<AVFrame*, std::allocator<AVFrame*> >&, int, int, int)':
FrameSaver.cpp:(.text+0x869): undefined reference to `av_frame_free'
collect2: ld returned 1 exit status

这正是我不想看到的。

一共有三个 Cmake 文件:两个用于内部库(使用

add_library(Decoder ${SOURCES_DECODER})
             and 
add_library(Detector ${SOURCES_DETECTOR})

在其中)和一个用于主要可执行文件(使用

add_executable(Tool ${SOURCES_TOOL})
             and
target_link_libraries (Tool Decoder avutil avcodec swscale avformat Detector ${OpenCV_LIBS})

在其中)。

据我从 CMake 手册和示例中了解到，这应该使链接器将这些库链接在一起，但没有效果。

我一直在尝试很多事情，例如:
1) 在任何可能的地方添加带有库路径的 link_directories()(对我来说是/usr/lib/x86_64-linux-gnu/)，没有任何改变。
2) 分别链接每个库，我的意思是我尝试在我的内部库 CMake 文件中做这样的事情:target_link_libraries (Decoder avutil avcodec swscale avformat)。然后将库链接到我的工具 CMake 文件中:target_link_libraries (Tool Decoder Detector)。
3) 编辑输出 makefile。
4)编译简单的单文件应用程序只是为了测试我是否可以做到。我可以。 g++ -lavcodec -o out mysource.cpp 完美运行。
5) 手动编译ffmpeg并安装。

事实是我真的不知道我该怎么办。我不知道。我将非常感谢您的每一个回答。

UPD1:设置 CMAKE_VERBOSE_MAKEFILE 时的输出

! /usr/bin/c++ -march=x86-64 -Wall -fPIC -pthread -std=c++0x -D__STDC_CONSTANT_MACROS -march=x86-64 -fPIC CMakeFiles/FaceDetectorTool.dir/home/anton/Programming/facevideo/branches/Stream_Prototype/src/tools/FaceDetectorTool/facedetector.cpp.o -o FaceDetectorTool -rdynamic ../../Detector/libDetector.a ../../Decoder/libDecoder.a -lavutil -lavcodec -lswscale -lavformat /usr/local/lib/libopencv_videostab.so.2.4.7 /usr/local/lib/libopencv_video.so.2.4.7 /usr/local/lib/libopencv_ts.a /usr/local/lib/libopencv_superres.so.2.4.7 /usr/local/lib/libopencv_stitching.so.2.4.7 /usr/local/lib/libopencv_photo.so.2.4.7 /usr/local/lib/libopencv_ocl.so.2.4.7 /usr/local/lib/libopencv_objdetect.so.2.4.7 /usr/local/lib/libopencv_nonfree.so.2.4.7 /usr/local/lib/libopencv_ml.so.2.4.7 /usr/local/lib/libopencv_legacy.so.2.4.7 /usr/local/lib/libopencv_imgproc.so.2.4.7 /usr/local/lib/libopencv_highgui.so.2.4.7 /usr/local/lib/libopencv_gpu.so.2.4.7 /usr/local/lib/libopencv_flann.so.2.4.7 /usr/local/lib/libopencv_features2d.so.2.4.7 /usr/local/lib/libopencv_core.so.2.4.7 /usr/local/lib/libopencv_contrib.so.2.4.7 /usr/local/lib/libopencv_calib3d.so.2.4.7 -ldl -lm -lpthread -lrt /usr/local/lib/libopencv_nonfree.so.2.4.7 /usr/local/lib/libopencv_ocl.so.2.4.7 /usr/local/lib/libopencv_gpu.so.2.4.7 /usr/local/lib/libopencv_photo.so.2.4.7 /usr/local/lib/libopencv_objdetect.so.2.4.7 /usr/local/lib/libopencv_legacy.so.2.4.7 /usr/local/lib/libopencv_video.so.2.4.7 /usr/local/lib/libopencv_ml.so.2.4.7 /usr/local/lib/libopencv_calib3d.so.2.4.7 /usr/local/lib/libopencv_features2d.so.2.4.7 /usr/local/lib/libopencv_highgui.so.2.4.7 /usr/local/lib/libopencv_imgproc.so.2.4.7 /usr/local/lib/libopencv_flann.so.2.4.7 /usr/local/lib/libopencv_core.so.2.4.7 -Wl,-rpath,/usr/local/lib

UPD2Cmake 示例看起来像那样。

cmake_minimum_required (VERSION 2.8)
project (Decoder)
include(../CMakeInit.cmake)
include_directories(${FFMPEG_INCLUDE_DIR})
include_directories(${Stream_Facevideo_SOURCE_DIR}/../src/kernel/decoder/)
include_directories(${Stream_Facevideo_SOURCE_DIR}/../src/kernel/stuff/)
set(SOURCES_VIDEODECODER
            *sources*
  )

if(WINDOWS)
    set(SOURCES_VIDEODECODER    ${SOURCES_VIDEODECODER} 
            *headers*                           
    )
endif(WINDOWS)

set (SOURCES_DECODER
    ${SOURCES_VIDEODECODER}
)

add_library(Decoder ${SOURCES_DECODER})
link_directories("/usr/lib/x86_64-linux-gnu/")
target_link_libraries(Decoder swscale avformat avcodec avutil)

Answer 1

似乎这个解决方案应该有效:Findavutil.cmake & CMakeLists.txt