Recherche avancée

Sur d’autres sites (9774)

• How to link libavcodec, libavformat in automake ?

  15 juillet 2014, par user2212461

  I am using the libavcodec and libavformat libraries from ffmpeg in a C++ project. Linking -lavcodec -lavformat with the g++ compiler works fine, but I’m not sure what goes wrong when I try to use the same code compiled in an automake project.

  Working fine :

  g++ -o test -D__STDC_CONSTANT_MACROS -lavcodec -lavformat test.cpp

  Not working Makefile.am :

  binaryname_LDFLAGS= -lavcodec -lavformat

  Error :

  ....
  
  /usr/lib/gcc/i686-linux-gnu/4.6/../../../i386-linux-gnu/libavformat.a(nut.o):function 
  
  ff_nut_add_sp: error: undefined reference to 'av_tree_node_size'
  
  /usr/lib/gcc/i686-linux-gnu/4.6/../../../i386-linux-gnu/libavformat.a(nut.o):function 
  
  ff_nut_add_sp: error: undefined reference to 'av_tree_insert'
  
  /usr/lib/gcc/i686-linux-gnu/4.6/../../../i386-linux-gnu/libavformat.a(nut.o):function 
  
  ff_nut_free_sp: error: undefined reference to 'av_tree_enumerate'
  
  /usr/lib/gcc/i686-linux-gnu/4.6/../../../i386-linux-gnu/libavformat.a(nut.o):function 
  
  ff_nut_free_sp: error: undefined reference to 'av_tree_destroy'
  
  /usr/lib/gcc/i686-linux-gnu/4.6/../../../i386-linux-gnu/libavformat.a(rtp.o):function 
  
  ff_rtp_get_payload_type: error: undefined reference to 'av_opt_get_int'
  
  ...

  also not working :

  LDFLAGS=...-lavcodec -lavformat

  Error :

  src/dsp/audioDecoder.cpp:99: error: undefined reference to 'av_register_all'
  
  src/dsp/audioDecoder.cpp:101: error: undefined reference to 'avcodec_find_decoder'
  
  src/dsp/audioDecoder.cpp:109: error: undefined reference to 'avcodec_alloc_context'
  
  src/dsp/audioDecoder.cpp:120: error: undefined reference to 'avcodec_open2'
  
  src/dsp/audioDecoder.cpp:125: error: undefined reference to 'av_init_packet'
  
  src/dsp/audioDecoder.cpp:188: error: undefined reference to 'avcodec_decode_audio3'

  In the second case, if I don’t set any linker, the include header cannot be found so the linker seems somehow recognized.

  make V=1 returns :

  make  all-am
  
  make[1]: Go to '/path/to/trunk'
  
  /bin/bash ./libtool --tag=CXX   --mode=link g++  -O2 -lrt -D__STDC_CONSTANT_MACROS   -o binaryname progsrc/binaryname/binaryname-binaryname.o    -lm  -lpthread -ldl -lmygeneratedlibrary
  
  libtool: link: g++ -O2 -D__STDC_CONSTANT_MACROS -o binaryname progsrc/binaryname/binaryname-binaryname.o  -lm /path/to//trunk/.libs/lmygeneratedlibrary.a -lrt -lavutil -lavcodec -lavformat -lpthread -ldl
  
  make[1]: Leave '/path/to/trunk'

  What am I doing wrong here ?

• Android Live Streaming based on javaCV + FFMpeg crashes by adding red5 link

  1er octobre 2015, par user1914692

  The Android application code is from :
  Android Live Streaming courtesy of JavaCV and FFMPEG

  It streams the live camera video from the device.

  I follow one comment’s instruction (Yoshio Numai), to use Red5 as the stream server.
  By Red5 itself, I can successfully use simpleBroadcaster and simpleSubscriber to stream and display the live camera (from the computer) steam.

  In the MainActivity.java, I change the code as below :

  private String ffmpeg_link = "rtmp://192.168.1.105/oflaDemo/red5StreamDemo"; 

  And I can start the app in my Android device (Nexus 4).
  after click "start", the app crash, pops out a small window, saying :
  "Unfortunately, JavaCV 0.3 Stream Test has stopped. OK."

  Once I click the OK button, I find the app is still live in the task list.

  But the same thing will happen.
  What’s wrong here ?

• Unable to link QtFFmpegWrapper sample on Win7 with VS 2012

  20 juillet 2014, par mschwarz

  I am trying to incorporate QtFFmpegWrapper in my program, but both my program and the provided sample won’t link with ffmpeg :

  QVideoEncoder.obj:-1: Error: LNK2019: unresolved external symbol _avcodec_init referenced in function "protected: bool __thiscall QVideoEncoder::initCodec(void)" (?initCodec@QVideoEncoder@@IAE_NXZ)
  
  QVideoDecoder.obj:-1: Error: LNK2001: unresolved external symbol _avcodec_init
  
  QVideoEncoder.obj:-1: Error: LNK2019: unresolved external symbol _avcodec_thread_init referenced in function "public: bool __thiscall QVideoEncoder::createFile(class QString,unsigned int,unsigned int,unsigned int,unsigned int,unsigned int)" (?createFile@QVideoEncoder@@QAE_NVQString@@IIIII@Z)
  
  QVideoEncoder.obj:-1: Error: LNK2019: unresolved external symbol _avcodec_open referenced in function "public: bool __thiscall QVideoEncoder::createFile(class QString,unsigned int,unsigned int,unsigned int,unsigned int,unsigned int)" (?createFile@QVideoEncoder@@QAE_NVQString@@IIIII@Z)

  and 10 or so more like these ...

  Why do these pop up when linking ? The libs are all there and found, it just seems like the linker has issues with them ...

  I use the following setup for my project :

  • Latest QtFFmpegWrapper from https://code.google.com/p/qtffmpegwrapper/
  • qt-opensource-windows-x86-msvc2012_opengl-5.3.0
  • Visual Studio 2012 Professional
  • Qt Creator 3.1.2
  • ffmpeg builds from http://ffmpeg.zeranoe.com/builds/ :
  • ffmpeg-20140717-git-fa6716c-win32-dev
  • ffmpeg-20140717-git-fa6716c-win32-shared

  Everything is 32Bit.