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• change position of image overlay on the fly

  16 août 2012, par user1603231

  I need some help on an issue that I am having overlaying images on a live feed.
  Currently, I am streaming raw data from a device, transcoding that data (i.e. ogg) and then re-streaming using HTTP because I need to view through an HTML page. My problem is that I need to overlay an image on the stream where - when a particular object moves - the image overlay moves as well.

  For example, if you wanted to place an 'X' over a moving object where that object may move left-to-right or top-to-bottom. At this point, I am able to overlay the image at a fixed point using the following command :

  ffmpeg -i rtsp ://[host] :[port] -i x.png -filter_complex 'overlay=10:main_h-overlay_h-10' http://[host] :[post]/output.ogg

  This will give me an 'X' over the object at the start but, once the object moves I need to change the position of that 'X'.

  The only real requirement is that the technologies that I utilize need to be available for Linux.

  Any ideas ?

  Thanks !

• Faster Thumbnail/Image Extraction from Video using FFMPEG ?

  27 août 2012, par mirroredAbstraction

  I am using this command to extract a series of images from a video to express them as a visual time-frame of the video.

  ffmpeg -i inputfile.mp4  -r  1  -t  12  image-%d.jpeg

  Most of my videos are in mp4 format. I am able to extract the images successfully but the time taken for extraction is too long.

  Is there any way I could reduce the time for image extraction ?

  EDIT : It is taking me 60 secs to get 8 thumbnails from a 15 sec long video encoded in MP4 format, I am doing this operation on my Galaxy Nexus(Android Phone) is there any way to improve the speed of operation, ideally I want it be less than  10secs.

• Creating video from image using FFMPEG

  27 août 2012, par yashprit

  I am creating video editing application using JavaScript, ffmpeg and java. Using FFMPEG i have created extract n frame of video, than using canvas.toDataUrl I am replacing new image with existing image frame rate and everything has taken care, but when I use these image to create video, FFMPEG never include newly created PNG image.

  code to save png image from HTML5 canvas

  Base64 decoder = new Base64();
  
      byte[] pic = decoder.decodeBase64(request.getParameter("pic"));
  
      String frameCount = request.getParameter("frame");
  
      InputStream in = new ByteArrayInputStream(pic);
  
      BufferedImage bImageFromConvert = ImageIO.read(in);
  
      String outdir = "output\\"+frameCount;
  
      //Random rand = new Random();
  
      File file = new File(outdir);
  
      if(file.isFile()){
  
          if(file.delete()){
  
              File writefile = new File(outdir);
  
              ImageIO.write(bImageFromConvert, "png", file);
  
          }
  
      }

  Code for creating image from video

  String filePath = "D:\\temp\\some.mpg";
  
      String outdir = "output";
  
      File file = new File(outdir);
  
      file.mkdirs();
  
      Map m = System.getenv();
  
  
  
      /*
  
       * String command[] =
  
       * {"D:\\ffmpeg-win32-static\\bin\\ffmpeg","-i",filePath
  
       * ,"-r 30","-f","image2",outdir,"\\user%03d.jpg"};
  
       * 
  
       * ProcessBuilder pb = new ProcessBuilder(command); pb.start();
  
       */
  
      String commands = "D:\\ffmpeg-win32-static\\bin\\ffmpeg -i " + filePath
  
              + " -r 30  -f image2 " + outdir + "\\image%05d.png";
  
      Process p = Runtime.getRuntime().exec(commands);

  code for creating video from image

  String filePath = "output";
  
      File fileP = new File(filePath);
  
      String commands = "D:\\ffmpeg-win32-static\\bin\\ffmpeg -f image2 -i "
  
              + fileP + "\\image%5d.png " + fileP + "\\video.mp4";
  
      System.out.println(commands);
  
      Runtime.getRuntime().exec(commands);
  
      System.out.println(fileP.getAbsolutePath());