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• FFMPEG in Java (runtime error)

  4 juillet 2012, par Eric

  I want to write a program that converts video into frames using FFMPEG. When I use it on the Ubuntu terminal, it works fine. But when I try to put it into the Java code, it gives me a runtime error. Did I make a mistake in my code below ?

  import java.util.*;
  
  import java.awt.*;
  
  import java.lang.*;
  
  import java.lang.Runtime;
  
  import java.io.*;
  
  import java.io.IOException;
  
  
  
  public class ConvertVideoToImage
  
  {
  
      private SingletonServer ss = null;
  
  
  
      public ConvertVideoToImage(SingletonServer ss)
  
      {
  
          this.ss = ss;
  
      }
  
  
  
      public void run()
  
      {
  
          convertVideo();
  
      }
  
  
  
      public void convertVideo()
  
      {
  
          try
  
          {
  
              Runtime rt = Runtime.getRunTime().exec("ffmpeg" + "-i" +         "display.wmv" + "image%d.jpg");
  
          }
  
          catch(Exception e){}
  
      }
  
  
  
  }

  Edit :

  I have changed the code like you suggested, but it also doesn't work. And when I Googled it, I found out that someone put the full path inside the executable and it became like this :

  Runtime.getRuntime().exec("/home/pc3/Documents/ffmpeg_temp/ffmpeg -i display.wmv image%d.jpg")

  BTW, thanks for the reply. I have another question. Is it possible to make a counter for FFMPEG ? I used this command in the Ubuntu terminal to make it convert a video to 30 frames/1seconds :

  ffmpeg -i display.wmv image%d.jpg

  This will automatically generate numbers like image1.jpg, image2.jpg, to image901.jpg. Is it possible to make a counter for this ? Because I need to count the files and control the number.

  Thanks in advance.

• FFMpeg video thumbnail frame extraction

  30 mars 2012, par Simone Margaritelli

  i'm trying to extract a thumbnail from a video with ffmpeg, therefore i'm using the command line :

  ffmpeg -i video.mp4 -vframes 1 -an -f image2 -y thumbmail.png 2>&1

  But in most cases, the first frame is completely black.
  So, what i'm doing is :

  for( $i = 1; $i < MAX_FRAME_CHECKING; $i++ )
  
  {
  
    $cmd = sprintf( 'ffmpeg -i video.mp4 -vframes 1 -an -vf select="eq(n\,%d)"-f image2 -y thumbmail.png 2>&1', $i );
  
  
  
    @exec( $cmd, $aOutput, $iReturnValue );
  
  
  
    if( self::isGoodKeyFrame( 'thumbmail.png' ) )
  
      break;
  
  }

  Where the isGoodKeyFrame method is defined as :

  private static function isGoodKeyFrame( $sImagePath )
  
  {
  
    if( class_exists('Imagick') )
  
    {
  
      $hImagick = new Imagick();
  
  
  
      try
  
      {
  
        if ( $hImagick->readImage($sImagePath) && $hImagick->valid() )
  
        {
  
          $hQuantized = @$hImagick->clone( );
  
          $hQuantized->quantizeImage( 255, Imagick::COLORSPACE_RGB, 0, TRUE, FALSE );
  
  
  
          return count( $hQuantized->getImageHistogram() ) > self::HISTOGRAM_SIZE_THRESHOLD;
  
        }
  
        else
  
          error_log( "'$sImagePath' is not a valid image." );
  
      }
  
      catch( Exception $e )
  
      {
  
        error_log( $e->getMessage() );
  
      }
  
  
  
      $hImagick->clear( );
  
      $hImagick->destroy( );
  
  
  
    }
  
    else
  
      error_log( 'Imagick not installed.' );
  
  
  
    return TRUE;
  
  }

  So basically what i'm doing is capture 1 to MAX_FRAME_CHECKING frames, check their color histogram and when i find something with much colors than my minimum threshold i break the loop and return that frame.

  Is there a way to do this natively with ffmpeg ?

  Thanks

• Image sequence to video stream ?

  22 août 2015, par Hauns TM

  Like many people already seem to have (there are several threads on this subject here) I am looking for ways to create video from a sequence of images.

  I want to implement my functionality in C# !

  Here is what I wan’t to do :

  /*Pseudo code*/
  
  void CreateVideo(List<image> imageSequence, long durationOfEachImageMs, string outputVideoFileName, string outputFormat)
  
  {
  
      // Info: imageSequence.Count will be > 30 000 images
  
      // Info: durationOfEachImageMs will be &lt; 300 ms
  
  
  
      if (outputFormat = "mpeg")
  
      {
  
      }
  
      else if (outputFormat = "avi")
  
      {      
  
      }
  
      else
  
      {
  
      }
  
  
  
      //Save video file do disk
  
  }
  
  </image>

  I know there’s a project called Splicer (http://splicer.codeplex.com/) but I can’t find suitable documentation or clear examples that I can follow (these are the examples that I found).

  The closest I want to do, which I find here on CodePlex is this :
  How can I create a video from a directory of images in C# ?

  I have also read a few threads about ffmpeg (for example this : C# and FFmpeg preferably without shell commands ? and this : convert image sequence using ffmpeg) but I find no one to help me with my problem and I don’t think ffmpeg-command-line-style is the best solution for me (because of the amount of images).

  I believe that I can use the Splicer-project in some way (?).

  In my case, it is about about > 30 000 images where each image should be displayed for about 200 ms (in the videostream that I want to create).

  (What the video is about ? Plants growing ...)

  Can anyone help me complete my function ?