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• How can I create a c++ console application which makes use of an open source c project

  2 octobre 2018, par Bogdan Daniel

  I’ve been playing around with a compiled version of https://github.com/FFmpeg/FFmpeg. But it has some problems, during the closing of an opened stream using avio_close(it takes a really long time to close it).

  I’ve been trying to understand what could go wrong by reading through the implementation, but couldn’t find anything.

  What I would like to do, is to actually have a C++ console application which uses the c files and to debug them while running the code(using breakpoints and so on).

  Unfortunately I cannot find any information on how to set it up. Simply copying the files in a new console application is not enough.

  Thanks in advance for any suggestions.

  Edit : I can already see a closing vote. If this question is not appropriate for this website, I will delete it. But please point me in the right direction of where to post it.Although it is quite a general question, I believe that it is clear and enough information has been provided.

  Edit2 : Yes, I was a bit unclear about what I’m using.

  I’m using Visual Studio Community 2017 on Windows 10 for creating the C++ console application.

  Edit3 :

  Steps that I’ve taken into using the source files into my console application which was using the DLLs.

  1. Copy all of the contents of the FFmpeg-master to my console application
  2. Include all of them in the c++ console application project
  3. Run a build - takes forever and has infinite build errors( > 1000) - probably compiler related

  Edit4 :

  I have no actual errors with avio_close, it just takes too long to close the stream. What I found out when playing around with the settings is that when the fifo_size parameter is set, closing the stream is a lot faster depending on how small the set value is. And it sort of makes sense since fifo_size is related to the packet size, but I haven’t found out where in the code this size has an impact.

  fifo_size=units
  Set the UDP receiving circular buffer size, expressed as a number of packets with size of 188 bytes. If not specified defaults to 7*4096.

  Edit5 : I still haven’t found a way to compile the open source ffmpeg project into libs, dlls and pdbs. Am I the first one needing such files(seems unrealistic) ?
  The only tool capable of delivering those so far is vcpkg. The only problem is that it compiles the 3.3.3 version and the latest is 4.0.2 .

  I tried to modify the vcpkg\ports\ffmpeg\portfile.cmake file to include the latest version of ffmpeg, but it doesn’t build it.

  Are there any other suggestions ?

• video editing using FFMPEG in android project [closed]

  1er mai 2012, par Pankaj Mehra

  Possible Duplicate :
  Use FFMPEG on Android

  i want to create a android app which can merge audio images to form video i am prefering ffmpeg for that ,please guide me how can i use ffmpeg functions and libraries to do so

• Unknown reason of an error while debugging an Opencv project using opencv2 functions

  30 mars 2013, par Animesh Pandey

  I have openCV 2.3 and I am using Visual Studio 2010.

      ...
  
  VideoCapture cap;
  
  cap.open("Video.avi");
  
  if( !cap.isOpened() )
  
  {
  
  
  
      puts("***Could not initialize capturing...***\n");
  
      system("Pause");
  
      return 0;
  
  } ...

  This is a code snippet of the while program.
  I added a system command in order to hold the output window. I got no errors while building the project but when I began debugging, the output window had this output :

  warning: Error opening file (../../modules/highgui/src/cap_ffmpeg_impl.hpp:477)
  
  ***Could not initialize capturing...***
  
  
  
  Press any key to continue . . .

  I checked this directory, the file is available but then why is it that it doesn't open ?
  I even have the opencv_ffmpeg.dll in the bin folder with its path added to System Paths.
  Still I get this same error ....
  I even checked first 3 pages of google search I did but could not find an answer.
  So please help !

  ---

  The error which I mentioned is because, there has been an error in opening the .avi file ...
  This is the part of code in cap_ffmpeg_impl.hpp -

  int err = av_open_input_file(&ic, _filename, NULL, 0, NULL);
  
  if (err < 0) {
  
      CV_WARN("Error opening file"); //Error part
  
      goto exit_func;
  
  }

  This file is available at D :\OpenCV2.3\opencv\modules\highgui\src. When I make any changes in this file, they do not reflect on the output window and when I removed this file, even then it did not give any error !:O
  I am not able to understand what is happening ....??