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• Extracting klm data from mp2 stream using C++ and ffmpeg

  25 mars 2019, par Douglas

  I have an mp2 stream that has klv metadata. I stored the klv in a file using ffmpeg command line :

  ffmpeg -i input.mpg -map data-re -codec copy -f data output.klv

  I now want to do this in c++. So, I have

  FFMPEG setup …..

  Then the main loop

  // Read frames
  
  while(av_read_frame(pFormatCtx, &packet) >= 0)
  
  {
  
      // Is this a packet from the video stream?
  
      if(packet.stream_index == videoStream)
  
      {
  
          // Decode video frame
  
          avcodec_decode_video2(pCodecCtx, pFrame, &frameFinished, &packet);
  
  
  
          // Did we get a video frame?
  
          if(frameFinished)
  
          {
  
              // Convert the image from its native format to RGB
  
              sws_scale(sws_ctx, (uint8_t const * const *)pFrame->data,
  
                                  pFrame->linesize, 0, pCodecCtx->height,
  
                                  pFrameRGB->data, pFrameRGB->linesize);
  
  
  
              QImage myImage(pFrameRGB->data[0], pCodecCtx->width, pCodecCtx->height, QImage::Format_RGB888);
  
  
  
              QPixmap img(QPixmap::fromImage(myImage.scaled(ui->label->width(),ui->label->height(),Qt::KeepAspectRatio)));
  
  
  
              ui->label->setPixmap(img);
  
              QCoreApplication::processEvents();
  
          }
  
      }
  
      else // klv stream
  
      {
  
          // Decode klv data
  
          qDebug() << packet.buf->size;
  
          for(int i=0; isize; i++)
  
          {
  
              qDebug() << packet.buf->data[i];
  
          }
  
      }

  The resulting klv output is different - I must be doing something wrong processing the packet. The frames are good and I’m viewing it in a qt label - so my ffmpeg setup is working on images but not the klv data.

• Extract MXF file data using python

  28 juin 2022, par Rex

  Is there any way to extract MXF file data using python ?

  


  All I want to do is get data like video duration, actual video stream and if possible the voice in mp3 or any audio format from an MXF file.

  


• How to load/dump a raw video data into AvFrame structure pointer by using ffmpeg api function

  4 octobre 2016, par Harikrishna

  I want to write an application for encoding raw (yuv) video file data by using ffmpeg api functions instead of using a command.

  So for this, I need to use avcodec_encode_video2 function to encode raw video data and before calling this function all required configurations and video data should be fill on the AVCodecContext and AvFrame structure pointers.

  Can anyone guide me that how can I load this raw video data on AvFrame by using ffmpeg api function ?

  Thank you in advance.