libmediainfo：qt5 项目未定义符号错误

Posted 2023-02-16

【中文标题】libmediainfo：qt5 项目未定义符号错误

【英文标题】：libmediainfo: qt5 project undefined symbol errors

【发布时间】：2016-05-30 03:40:45

【问题描述】：

我正在尝试在我的 qt5 项目中使用 libmediainfo，但出现以下错误

Undefined symbols for architecture x86_64:
  "MediaInfoLib::MediaInfo::Open(std::basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> > const&)", referenced from:
      MainWindow::on_dupeslistWidget_itemClicked(QListWidgetItem*) in mainwindow.o
  "MediaInfoLib::MediaInfo::Option(std::basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> > const&, std::basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> > const&)", referenced from:
      MainWindow::on_dupeslistWidget_itemClicked(QListWidgetItem*) in mainwindow.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [VideoTwin.app/Contents/MacOS/VideoTwin] Error 1
19:56:12: The process "/usr/bin/make" exited with code 2.
Error while building/deploying project VideoTwin (kit: default)
When executing step "Make"

我的 .pro 文件

QT       += core gui
QT += sql
QT += concurrent
QT += multimedia multimediawidgets

INCLUDEPATH += /usr/local/include /usr/local/Cellar/opencv3/3.1.0_1/include/ $$[QT_INSTALL_PREFIX]/src/3rdparty/sqlite
LIBS += -L/usr/local/Cellar/opencv3/3.1.0_1/lib -L/usr/local/lib -lmediainfo -lzen -lz -lpthread -lopencv_stitching -lopencv_superres -lopencv_videostab -lopencv_aruco -lopencv_bgsegm -lopencv_bioinspired -lopencv_ccalib -lopencv_cvv -lopencv_dnn -lopencv_dpm -lopencv_fuzzy -lopencv_line_descriptor -lopencv_optflow -lopencv_plot -lopencv_reg -lopencv_saliency -lopencv_stereo -lopencv_structured_light -lopencv_rgbd -lopencv_surface_matching -lopencv_tracking -lopencv_datasets -lopencv_text -lopencv_face -lopencv_xfeatures2d -lopencv_shape -lopencv_video -lopencv_ximgproc -lopencv_calib3d -lopencv_features2d -lopencv_flann -lopencv_xobjdetect -lopencv_objdetect -lopencv_ml -lopencv_xphoto -lopencv_highgui -lopencv_videoio -lopencv_imgcodecs -lopencv_photo -lopencv_imgproc -lopencv_core

QMAKE_CXXFLAGS += -D_UNICODE -DUNICODE
QMAKE_CFLAGS += -D_UNICODE -DUNICODE

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = VideoTwin
TEMPLATE = app


SOURCES += main.cpp\
        mainwindow.cpp \
    preferencsedialog.cpp \
    myqlistwidget.cpp \
    $$[QT_INSTALL_PREFIX]/src/3rdparty/sqlite/sqlite3.c \
    matchpair.cpp

HEADERS  += mainwindow.h \
    preferencsedialog.h \
    myqlistwidget.h \
    matchpair.h

FORMS    += mainwindow.ui \
    preferencsedialog.ui

RESOURCES += \
    resources.qrc

在我的头文件中

#include <MediaInfo/MediaInfo.h>

以及来自 cpp 的相关部分

MediaInfoLib::MediaInfo media_info;
media_info.Option(L"Internet",L"No");
media_info.Open(item->data(Qt::UserRole + FilepathRole).toString().toStdWString());
QString temp = QString::fromWCharArray( media_info.Inform().c_str(),media_info.Inform().length());
ui->video_info->setText(temp);
ui->video_info->show();

我不确定问题出在哪里。我在 /usr/local/lib 目录中有 libmediaplayer.dylib。请帮忙

【参考方案1】：

链接静态库并使用“dll”头文件对我有用：

把它放到你的源代码中

#include "MediaInfoDLL/MediaInfoDLL_Static.h"
using namespace MediaInfoDLL;

这是.pro文件的内容

QT += core
QT -= gui

TARGET = QtTestMediaInfo
CONFIG += console
CONFIG -= app_bundle
TEMPLATE = app
SOURCES += main.cpp

# Adjust this to where you put the source code of MediaInfo
MEDIA_INFO_DIR=~/Downloads/MediaInfo_CLI_GNU_FromSource

#INCLUDEPATH += $$MEDIA_INFO_DIR/ZenLib/Source
INCLUDEPATH += $$MEDIA_INFO_DIR/MediaInfoLib/Source
LIBS += -L$$MEDIA_INFO_DIR/MediaInfoLib/Project/GNU/Library -lmediainfo
LIBS += -L$$MEDIA_INFO_DIR/ZenLib/Project/GNU/Library -lzen -lz

祝你好运！

【参考方案2】：

你没有告诉 Qt libmediainfo.dylib 在哪里，所以 Qt 没有找到它。

您需要将其添加到您的 .pro 文件中，例如：

LIBS += $$system(pkg-config --libs libmediainfo)

您可以拥有more examples about how to configure your .pro file in order to link to libmediainfo.dylib，具体取决于您系统上的 libmediainfo.dylib 的位置。

【讨论】：

哎呀忘了提我在 OS X 上，libmediainfo 也在 /usr/local/lib 中

我看到了（“.dylib”）。示例中的 .pro 也适用于 Mac OS X。您可以执行 LIBS += -lmediainfo（例如，如果没有 pkg​​-config），但它的可移植性较差。

很抱歉，您确实滚动过对吗？这东西没有自动换行代码

糟糕，抱歉，我错过了您的 .pro 文件 -lmediainfo。我不能帮助更多:(。