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• Need help finding a way to use avconv or ffmpeg to convert any video to an exact size and shape

  29 octobre 2013, par mikecole79

  This is for work. We have a system that supports streaming video, but we support multiple players. I have multiple systems that I COULD use for this. Currently, I've been using the media server that we use to stream the video, which has ffmpeg on it (running Red Hat 4). On that system, I've used :

   ffmpeg -i INPUT_FILE.mp4 -c:v libx264 -crf 23 -maxrate 3000k -bufsize 30000k -c:a aac -strict experimental -b:a 192k -filter:v "scale=iw*min($width/iw\,$height/ih):ih*min($width/iw\,$height/ih), pad=$width:$height:($width-iw*min($width/iw\,$height/ih))/2:($height-ih*min($width/iw\,$height/ih))/2" -f OUTPUT_FILE.mp4

  And I thought that it worked well. On one file I used to test, it seemed to display properly on both player types. On a different file, it did not appear properly. The input files are also in varying formats (mostly mp4, with a few m4g files) and different aspect ratios.

  We also have many desktop/laptop machines that are running Ubuntu 13.04 (comes with avconv) that I'd like to be able to use to format video as well. If I can get at least one of these systems to properly format video, that would be great, but ideally I'd like to figure out how to do this with both avconv AND ffmpeg so I can use any system.

  The problem that we're trying to solve is that one player is an Android DMP device, which will play a video of varying sizes properly by adding black bars at the sides or top/bottom as needed to keep the video sized properly. The other player is a Samsung Smart TV, which is SO Smart that it can reformat videos to fit the screen. Which sucks horribly, because if they're not sized to exactly the right format, it will stretch them one direction or another to make them be sized right. The resulting video show's people that appear to be 8 feet tall weighing 130 pounds, or 4 feet tall and 3 feet wide.

  Obviously, this isn't what we desire, but I lack the knowledge of avconv/ffmpeg to do anything to fix it. I need an expert, and I am not he. Nor is anyone I currently work with an expert on this subject. Anyone that is, I'd appreciate your help more than I can express via a web interface.

  Thanks !

• How to extract video clip from larger video based on specific time and duration

  26 juillet 2022, par user19019404

  I have video clips that get created. Each video is recorded for 5 minutes and starts at a time e.g. 10:01:20 to 10:06:19 then the next video from 10:06:20 etc. These videos are recorded at a specific frame rate, be it 5 frames or 30 frames (its dependent on the platform making the recording). The net result is NOT a 5 minute video clip but might be a 2 minute video clip (where everyone moves very quickly in the view as a result of the frame rates). I cannot restrict a 1 to 1 recording as these are generated by external systems.

  


  I need to extract specific portions out of the video. For example I need to extract from 10:03:10 to 10:03:35 (25 seconds). This would equate to 10 seconds into the video up to 14 seconds into the video, in those 4 seconds of video, 25 real world seconds are displayed.

  


  My question is do you have any guidance as to how I can calculate that each second of recording actually means 10 or 12 seconds in real life, therefore go to this frame and record to this frame for example.

  


  I have been looking at cv2.CAP_PROP_FPS to get the video frame rates, CAP_PROP_POS_MSEC and CAP_PROP_FRAME_COUNT and believe the answer might lie there, but not sure.

  


  The thinking being if I work out the frame rate of the video, the total frames then I can divide the one by the other to get to how many frames make up real world seconds (this is where I fail). This way I can run from frame to frame as a result.

  


  Thank you

  


• How to use pathinfo in php ?

  10 juin 2019, par flash

  I am working on a php code as shown below on which Line#A prints the following array (shown below php code). My code doesn’t seems to go inside switch statement. I am not sure why.

  I added print_r($parts) at Line A in order to print the value of $parts.

  php code :

  <?php
  
      if (!empty($_POST['id']))
  
      {
  
      for($i=0; $i / Line A
  
      switch ($parts['extension'])
  
      {
  
      echo "Hello World";                 // Line B
  
      case 'mp4' :
  
      $filePath = $src_dir . DS . $f;
  
      system('ffmpeg -i ' . $filePath . ' -map 0:2 -ac 1 ' . $destination_dir . DS . $parts['filename'] . '.mp3', $result);
  
      }
  
      }
  
      }
  
      }
  
  ?>

  Output (Line#A) :

  Array 
  
  (
  
      [dirname]  => .
  
      [basename] => hello.mp4
  
      [extension] => mp4
  
      [filename] => hello
  
  )

  I have used echo "Hello World" at Line B but for some reasons, its not getting printed and throwing 500 internal server error on console.

  Problem Statement :

  I am wondering what changes I should make in the php code so that it goes inside switch statement.