Question

美好的一天，

我是Objective-C和Xcode IDE的初学者。我正在尝试在我的iOS应用程序中使用ffmpeg。我克隆了https://github.com/kewlbear/FFmpeg-iOS-build-script并为arm64和x86_64构建。

当我想构建应用时，它会崩溃

Ld /Users/nikolajpognerebko/Library/Developer/Xcode/DerivedData/CPP3-eowdhpsbeagmxydsrsscofhtuwtl/Build/Products/Debug-iphonesimulator/CPP3.app/CPP3 normal x86_64
cd /Volumes/sedy/xcode/CPP3
export IPHONEOS_DEPLOYMENT_TARGET=9.1
export PATH="/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin:/Applications/Xcode.app/Contents/Developer/usr/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin"
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ -arch x86_64 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator9.1.sdk -L/Users/nikolajpognerebko/Library/Developer/Xcode/DerivedData/CPP3-eowdhpsbeagmxydsrsscofhtuwtl/Build/Products/Debug-iphonesimulator -L/Volumes/sedy/xcode/CPP3/CPP3/ffmpeg/lib -F/Users/nikolajpognerebko/Library/Developer/Xcode/DerivedData/CPP3-eowdhpsbeagmxydsrsscofhtuwtl/Build/Products/Debug-iphonesimulator -filelist /Users/nikolajpognerebko/Library/Developer/Xcode/DerivedData/CPP3-eowdhpsbeagmxydsrsscofhtuwtl/Build/Intermediates/CPP3.build/Debug-iphonesimulator/CPP3.build/Objects-normal/x86_64/CPP3.LinkFileList -Xlinker -rpath -Xlinker @executable_path/Frameworks -mios-simulator-version-min=9.1 -Xlinker -objc_abi_version -Xlinker 2 -stdlib=libc++ -fobjc-arc -fobjc-link-runtime -lavcodec -lavdevice -lavfilter -lavformat -lavutil -lswresample -lswscale -framework AVFoundation -liconv -lbz2 -Xlinker -dependency_info -Xlinker /Users/nikolajpognerebko/Library/Developer/Xcode/DerivedData/CPP3-eowdhpsbeagmxydsrsscofhtuwtl/Build/Intermediates/CPP3.build/Debug-iphonesimulator/CPP3.build/Objects-normal/x86_64/CPP3_dependency_info.dat -o /Users/nikolajpognerebko/Library/Developer/Xcode/DerivedData/CPP3-eowdhpsbeagmxydsrsscofhtuwtl/Build/Products/Debug-iphonesimulator/CPP3.app/CPP3

Undefined symbols for architecture x86_64:
  "av_register_all()", referenced from:
      Decoder::Decoder() in ViewController.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

OneDrive http://1drv.ms/1KkPAia上有压缩项目，因为这是解释我问题的最佳方式。

请帮助我解释一下这个问题出现了什么。

非常感谢。

Answer 1

我猜你没有使用extern“C”（就像这样：

extern "C" {
#include "libavformat/avformat.h"
}

）围绕ffmpeg（libavcodec / libavformat）头文件的每个#include语句？这在访问c代码的c ++代码中是必需的。

未定义的符号av_register_all（）

1 个答案: