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• .MKV (Stream #0:0) RGB Video File not playing on Azure Kinect Viewer

  16 juin 2023, par Ashutosh Singla

  I have a recorded video file from Microsoft Kinnect Camera. Using MKVToolNix, I extracted one stream that contains RGB_Original video. This RGB_Original video can be played using Azure Kinect Viewer. However, when I encode RGB_Original video using FFmpeg with the following command

  


  ffmpeg -i .\RGB.mkv -c:v mjpeg -pix_fmt yuvj422p -q:v 5 -r 30 output_video.mkv 


  


  This output_video can not be played using Azure Kinect Viewer. It displays failed to open recording.

  


  Any help would be appreciated.

  


• 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.

• What is legacyNullReferencePolicy ?

  22 février 2014, par Sugrue

  We are getting mysterious SEHExceptions in our C# application which may be coming from some unmanaged code (FFMPEG). Its not being caught by the try-catch blocks - so we are not certain what is causing it, but it is perhaps due to a null reference.

  I found this on MSDN (SEHException MSDN Page) which says :

  The .NET Framework often encounters unmanaged SEH exceptions that are automatically mapped to managed equivalents. There are two common unmanaged SEH exceptions :
  STATUS_NO_MEMORY exceptions are automatically mapped to the OutOfMemoryException class.
  STATUS_ACCESS_VIOLATION exceptions are automatically mapped as follows :

  If legacyNullReferencePolicy is applied, all access violations are mapped to the NullReferenceException class.

  Now, this bit sounds interesting - if we could set this legacyNullReferencePolicy maybe these mysterious NullReferenceExceptions could be caught and we could find out where they are coming from.

  But I can't find any information online about legacyNullReferencePolicy. What is it ? Where do I set it ?