Question

I am having an issue trying to build my program, which is using a C++ class to dela with FFmpeg objects:

    Undefined symbols for architecture armv7:
  "__Z13avcodec_open2P14AVCodecContextP7AVCodecPP12AVDictionary", referenced from:
      __Z10openStreamPKcb in RTPReader.o
  "__Z21avcodec_decode_audio4P14AVCodecContextP7AVFramePiP8AVPacket", referenced from:
      __Z13getStreamDataRPhRi in RTPReader.o
  "__Z20avformat_close_inputPP15AVFormatContext", referenced from:
      __Z11closeStreamv in RTPReader.o
  "__Z21avformat_network_initv", referenced from:
      __Z10openStreamPKcb in RTPReader.o
  "__Z26avcodec_get_frame_defaultsP7AVFrame", referenced from:
      __Z13getStreamDataRPhRi in RTPReader.o
  "__Z15av_register_allv", referenced from:
      __Z10openStreamPKcb in RTPReader.o
  "__Z19av_find_best_streamP15AVFormatContext11AVMediaTypeiiPP7AVCodeci", referenced from:
      __Z10openStreamPKcb in RTPReader.o
  "__Z14av_free_packetP8AVPacket", referenced from:
      __Z13getStreamDataRPhRi in RTPReader.o
      __Z11closeStreamv in RTPReader.o
  "__Z6av_logPviPKcz", referenced from:
      __Z10openStreamPKcb in RTPReader.o
      __Z13getStreamDataRPhRi in RTPReader.o
  "__Z19avformat_open_inputPP15AVFormatContextPKcP13AVInputFormatPP12AVDictionary", referenced from:
      __Z10openStreamPKcb in RTPReader.o
  "__Z26av_samples_get_buffer_sizePiii14AVSampleFormati", referenced from:
      __Z13getStreamDataRPhRi in RTPReader.o
  "__Z19avcodec_alloc_framev", referenced from:
      __Z13getStreamDataRPhRi in RTPReader.o
  "__Z25avformat_find_stream_infoP15AVFormatContextPP12AVDictionary", referenced from:
      __Z10openStreamPKcb in RTPReader.o
  "__Z13av_read_frameP15AVFormatContextP8AVPacket", referenced from:
      __Z13getStreamDataRPhRi in RTPReader.o
ld: symbol(s) not found for architecture armv7
clang: error: linker command failed with exit code 1 (use -v to see invocation)

在我的C++方法中,它增加了一个预设标准——Z#,我不知道为什么。

问题是什么?

Answer 1

你们看到的“......Z#”是正常的。 http://en.wikipedia.org/wiki/Name_mangling”rel=“nofollow”http://en.wikipedia.org/wiki/Name_mangling 。说明理由。

我不得不在这里做一 couple,缺乏更详细的信息(但我不能评论,只能回答)。看一看刺.,看来FFmpeg有一个CLAN而不是C++。如果情况确实如此,你的解决办法可能是把FFmpeg的所有档案都包含在“C”之外(见 )。解释:

extern "C" {
    #include <someffmpegheader.h>
}

由于链接失败的原因,你是否与设计前的刺-图书馆连接,或者你是否将刺 source来源档案列入你的项目? 如果你与图书馆重新连接,它可能没有正确的架构。如果你在终端窗户上运行以下指挥系统,它将告诉你图书馆有哪些建筑:

file libffmpeg.a

Answer 2

在我看来,这间图书馆与“C”外人有联系,但你试图在没有这一条款的情况下建立联系。 Maybe 您。 H 档案来自一个版本和......。业余公司从完成另一卷档案。

在C++中,当你试图从C++法典中获取C功能时,使用关于进口职能的“C”条款。您应使用这一条款。

友情链接