opencv编译随笔

编译目标

本文将记录在Linux下编译Opencv及其扩展contrib，并记录在这过程中发生的问题。

环境需求

操作系统: Ubuntu 20.04
CMake: 3.22.1及以上
Make: 4.2.1
gcc/g++: 9.4.0
联网需求: 是

准备

1. 拉取OpenCV和opencv_contrib代码，得到两个代码文件夹opencv和opencv_contrib

https://github.com/opencv/opencv.git
https://github.com/opencv/opencv_contrib.git

编译

进入opencv中，执行编译命令，编译命令如下：

mkdir build && cd build

cmake -DOPENCV_EXTRA_MODULES_PATH=../../opencv_contrib/modules ..

可选编译参数：
-DOPENCV_EXTRA_MODULES_PATH: 指定扩展contrib文件模块所在路径
-DBUILD_EXAMPLES: 编译官方示例
-DCMAKE_BUILD_TYPE: 编译版本类型
-DUSE_O3: 使用O3优化级别
-DENABLE_CXX11: 使用C++11特性
-DBUILD_DOCS: 构建文档
-DBUILD_TESTS: 构建测试用例
-GUnix: 指定使用Make进行编译，也可以是-GNinja使用Ninja进行编译
ENABLE_GNU_STL_DEBUG(default: OFF) 启用C++库的调试模式，进行更多的代码检查，但会降低编译速度和运行速度。
OPENCV_GENERATE_PKGCONFIG(default: OFF) 选项启用生成.pc文件，并与标准的CMake包一起使用。由于配置过程的复杂性，生成的.pc文件可能包含不完整的第三方依赖列表，并且在某些配置下可能无法正常工作，尤其是在静态构建的情况下。自4.x版本以来，这个功能不再被官方支持，并且默认是禁用的。由于opencv需要的链接选项较多，建议开启该功能方便编译。
BUILD_TESTS(default: ON) 构建准确性测试
BUILD_PERF_TESTS(default: ON) 构建性能测试
BUILD_EXAMPLES(default: OFF) 构建示例程序
BUILD_opencv_apps
OPENCV_ENABLE_NONFREE(default: OFF) 选项用于启用受专利保护的功能，如SURF。(可用性存疑)

完毕之后再执行：

cmake --build .

--build: 指定构建目录

问题记录

1. VideoCapture 无法读取视频文件？

解决方案：删除原有的build目录，重新构建opencv。
原因：
可能在cmake下载依赖时由于网络问题没有下载完全，导致即使有部分文件没下载成功，编译也不会出现问题，要多注意输出日志。

一份正常的生成记录

General configuration for OpenCV 4.10.0 =====================================
  Version control:               unknown

  Extra modules:
    Location (extra):            /home/user/Desktop/opencv-4.10.0/opencv_contrib/modules
    Version control (extra):     unknown

  Platform:
    Timestamp:                   2024-12-12T20:30:45Z
    Host:                        Linux 5.15.0-126-generic x86_64
    CMake:                       3.31.0
    CMake generator:             Unix Makefiles
    CMake build tool:            /usr/bin/make
    Configuration:               Release

  CPU/HW features:
    Baseline:                    SSE SSE2 SSE3
      requested:                 SSE3
    Dispatched code generation:  SSE4_1 SSE4_2 FP16 AVX AVX2 AVX512_SKX
      requested:                 SSE4_1 SSE4_2 AVX FP16 AVX2 AVX512_SKX
      SSE4_1 (18 files):         + SSSE3 SSE4_1
      SSE4_2 (2 files):          + SSSE3 SSE4_1 POPCNT SSE4_2
      FP16 (1 files):            + SSSE3 SSE4_1 POPCNT SSE4_2 FP16 AVX
      AVX (9 files):             + SSSE3 SSE4_1 POPCNT SSE4_2 AVX
      AVX2 (38 files):           + SSSE3 SSE4_1 POPCNT SSE4_2 FP16 FMA3 AVX AVX2
      AVX512_SKX (8 files):      + SSSE3 SSE4_1 POPCNT SSE4_2 FP16 FMA3 AVX AVX2 AVX_512F AVX512_COMMON AVX512_SKX

  C/C++:
    Built as dynamic libs?:      YES
    C++ standard:                11
    C++ Compiler:                /usr/bin/c++  (ver 9.4.0)
    C++ flags (Release):         -fsigned-char -W -Wall -Wreturn-type -Wnon-virtual-dtor -Waddress -Wsequence-point -Wformat -Wformat-security -Wmissing-declarations -Wundef -Winit-self -Wpointer-arith -Wshadow -Wsign-promo -Wuninitialized -Wsuggest-override -Wno-delete-non-virtual-dtor -Wno-comment -Wimplicit-fallthrough=3 -Wno-strict-overflow -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -ffunction-sections -fdata-sections  -msse -msse2 -msse3 -fvisibility=hidden -fvisibility-inlines-hidden -O3 -DNDEBUG  -DNDEBUG
    C++ flags (Debug):           -fsigned-char -W -Wall -Wreturn-type -Wnon-virtual-dtor -Waddress -Wsequence-point -Wformat -Wformat-security -Wmissing-declarations -Wundef -Winit-self -Wpointer-arith -Wshadow -Wsign-promo -Wuninitialized -Wsuggest-override -Wno-delete-non-virtual-dtor -Wno-comment -Wimplicit-fallthrough=3 -Wno-strict-overflow -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -ffunction-sections -fdata-sections  -msse -msse2 -msse3 -fvisibility=hidden -fvisibility-inlines-hidden -g  -O0 -DDEBUG -D_DEBUG
    C Compiler:                  /usr/bin/cc
    C flags (Release):           -fsigned-char -W -Wall -Wreturn-type -Waddress -Wsequence-point -Wformat -Wformat-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Winit-self -Wpointer-arith -Wshadow -Wuninitialized -Wno-comment -Wimplicit-fallthrough=3 -Wno-strict-overflow -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -ffunction-sections -fdata-sections  -msse -msse2 -msse3 -fvisibility=hidden -O3 -DNDEBUG  -DNDEBUG
    C flags (Debug):             -fsigned-char -W -Wall -Wreturn-type -Waddress -Wsequence-point -Wformat -Wformat-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Winit-self -Wpointer-arith -Wshadow -Wuninitialized -Wno-comment -Wimplicit-fallthrough=3 -Wno-strict-overflow -fdiagnostics-show-option -Wno-long-long -pthread -fomit-frame-pointer -ffunction-sections -fdata-sections  -msse -msse2 -msse3 -fvisibility=hidden -g  -O0 -DDEBUG -D_DEBUG
    Linker flags (Release):      -Wl,--exclude-libs,libippicv.a -Wl,--exclude-libs,libippiw.a   -Wl,--gc-sections -Wl,--as-needed -Wl,--no-undefined  
    Linker flags (Debug):        -Wl,--exclude-libs,libippicv.a -Wl,--exclude-libs,libippiw.a   -Wl,--gc-sections -Wl,--as-needed -Wl,--no-undefined  
    ccache:                      NO
    Precompiled headers:         NO
    Extra dependencies:          dl m pthread rt
    3rdparty dependencies:

  OpenCV modules:
    To be built:                 aruco bgsegm bioinspired calib3d ccalib core datasets dnn dnn_objdetect dnn_superres dpm face features2d flann fuzzy gapi hdf hfs highgui img_hash imgcodecs imgproc intensity_transform line_descriptor mcc ml objdetect optflow phase_unwrapping photo plot quality rapid reg rgbd saliency shape signal stereo stitching structured_light superres surface_matching text tracking ts video videoio videostab wechat_qrcode xfeatures2d ximgproc xobjdetect xphoto
    Disabled:                    world
    Disabled by dependency:      -
    Unavailable:                 alphamat cannops cudaarithm cudabgsegm cudacodec cudafeatures2d cudafilters cudaimgproc cudalegacy cudaobjdetect cudaoptflow cudastereo cudawarping cudev cvv freetype java julia matlab ovis python2 python3 sfm viz
    Applications:                tests perf_tests examples apps
    Documentation:               NO
    Non-free algorithms:         NO

  GUI:                           NONE
    GTK+:                        NO
    VTK support:                 NO

  Media I/O: 
    ZLib:                        /usr/lib/x86_64-linux-gnu/libz.so (ver 1.2.11)
    JPEG:                        /usr/lib/x86_64-linux-gnu/libjpeg.so (ver 80)
    WEBP:                        build (ver encoder: 0x020f)
    PNG:                         build (ver 1.6.43)
    TIFF:                        /usr/lib/x86_64-linux-gnu/libtiff.so (ver 42 / 4.1.0)
    JPEG 2000:                   build (ver 2.5.0)
    OpenEXR:                     build (ver 2.3.0)
    HDR:                         YES
    SUNRASTER:                   YES
    PXM:                         YES
    PFM:                         YES

  Video I/O:
    DC1394:                      NO
    FFMPEG:                      YES
      avcodec:                   YES (58.54.100)
      avformat:                  YES (58.29.100)
      avutil:                    YES (56.31.100)
      swscale:                   YES (5.5.100)
      avresample:                NO
    GStreamer:                   NO
    v4l/v4l2:                    YES (linux/videodev2.h)

  Parallel framework:            pthreads

  Trace:                         YES (with Intel ITT)

  Other third-party libraries:
    Intel IPP:                   2021.11.0 [2021.11.0]
           at:                   /home/user/Desktop/opencv-4.10.0/build/3rdparty/ippicv/ippicv_lnx/icv
    Intel IPP IW:                sources (2021.11.0)
              at:                /home/user/Desktop/opencv-4.10.0/build/3rdparty/ippicv/ippicv_lnx/iw
    VA:                          NO
    Lapack:                      NO
    Eigen:                       NO
    Custom HAL:                  NO
    Protobuf:                    build (3.19.1)
    Flatbuffers:                 builtin/3rdparty (23.5.9)

  OpenCL:                        YES (no extra features)
    Include path:                /home/user/Desktop/opencv-4.10.0/3rdparty/include/opencl/1.2
    Link libraries:              Dynamic load

  Python (for build):            /usr/bin/python3

  Java:                          
    ant:                         NO
    Java:                        NO
    JNI:                         NO
    Java wrappers:               NO
    Java tests:                  NO

  Install to:                    /usr/local
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参考文档

OpenCV配置选项文档