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• Inaccurate sleep using C++11 on Windows

  15 février 2017, par Ashe the human

  I’ve been using C++11 sleep to give the interval between video frames. This method I’ve been using makes playback elongated on Windows.

  #include <iostream>
  
  #include <thread>
  
  #include <sstream>
  
  
  
  
  
  int main(const int argc, const char **args)
  
  {
  
      std::stringstream sb;
  
  
  
      if(argc &lt; 2)
  
          return 1;
  
      int fps = 0;
  
      sb &lt;&lt; args[1];
  
      sb >> fps;
  
  
  
      if(fps &lt;= 0)
  
          return 1;
  
      int i;
  
  
  
  
  
      while(true)
  
      {
  
          std::chrono::high_resolution_clock::time_point start, end;
  
  
  
          start = std::chrono::high_resolution_clock::now();
  
          for(i=0; i fps));
  
          }
  
          end = std::chrono::high_resolution_clock::now();
  
  
  
          auto c = std::chrono::duration_cast(end - start).count();
  
          std::cerr &lt;&lt; c &lt;&lt; std::endl;
  
      }
  
  
  
      return 0;
  
  }
  
  </sstream></thread></iostream>

  Running that program with 60 gives about 1004 1006 on Linux and 1065 1075 on Windows. So, I’m guessing, after playing a 2-hour long video, more than a minute is passed than just 2 hours.

  timeBeginPeriod() has no effect. Is using timer(like this one ?) is the only way to implement media players on Windows ? What about on Linux ? I think it’s the right way considering the fact that ffplay uses av_usleep().

  So sad that there’s no portable way.

• How to user ffmpeg in android app and how to add it to eclipse windows 7 operating system

  18 février 2015, par Prem Tammina

  I have added Android warzone liblary to compress the video (http://androidwarzone.blogspot.in/2011/12/ffmpeg4android.html). But it is not returning the compressing estimated time and size of the output file. So i decided to use the ffmpeg. Can any one give some info or steps to configure the ffmpeg in eclipse which was installed in windows7.

• av_read_frame of ffmpeg in windows always returning packet.stream_index as 0

  17 février 2015, par yanqing lu

  I’m using ffmpeg to demuxer, for some video like the windows’s sample Wildlife.wmv, the av_read_frame is always returning packet.stream_index=0. This leads the video queue very big and memory overflow. I get 15 frames of video, but only 1 frame of audio. Is there some options to control the av_read_frame, so I can read frames like : video-audio-video-audio, in this way it’s easy to sync AV and keep queue balance.

  Thanks in advance.