Sur d’autres sites (13108)

• Using ffmpeg showwaves as circle. Is it possible ?

  14 décembre 2020, par Tudor-Radu Barbu

  Showwaves are normally used in a horizontal manner.
Is it possible to display the waveform in a circle ?

  


  Something like this ?

  


  

  


• How to create ffmpeg mosaic with empty cells ?

  7 septembre 2020, par DenVebber

  I try to create video mosaic with ffmpeg.

  


  Two videos with horizontal stack :

  


  ffmpeg -i vid1.mp4 -i vid2.mp4 -filter_complex "[0]scale=-1:1080[v0];[1]scale=-1:1080[v1];[v0][v1]hstack=inputs=2[vmap]" -map "[vmap]" output.mp4

  


  How can I replace vid1.mp4 with black background and save the stack with 2 elements ?
I can add blackvideo.mp4, but it should be easier, right ?

  


• FFMPEG, Blur an area of a video using Image Select Areas Plugin

  12 juillet 2016, par Drupalist

  I am building an online video editor. I need to allow the users to blur an area of movies. This must be done graphically, I mean user should be able to select an area of a video, using an screenshot, then the selected area must be blurred. Some thing like this

  

  Is there anyway to map this selected area dimension and its distance from borders to the real values that must be applied to the video ?

  I mean four numbers, width, length, top, left will be provided using this plug in and I need to use these numbers to blur an area of videos.

  I take an screenshot of video. In order to keep the aspect ratio, I will fix the width to 800px and let the height to be scaled up/down. It is clear that the width, length, top, left of the selected area of the screenshot is a factor of the width, length, top, left of the area that must be blurred in video. but I don’t know how to get this factor. Besides that I don’t know how to get the video resolution.

  Thanks in advance.

  ---

  Update

  This is my PHP code that gets the selected area dimensions and offsets

  $iLeft = $_POST['left'];
  
  $iTop = $_POST['top'];
  
  $iWidth = $_POST['width'];
  
  $iHeight = $_POST['height'];
  
  exec('ffmpeg -i '.$url.' -filter_complex "[0:v]scale=iw*sar:ih,setsar=1,split[bg][bb];[bb]crop='.$iWidth.'*iw/800:iw*'.$iHeight.'/800:'.$iWidth.'*iw/800:'.$iHeight.'*iw/800,boxblur=10[b0];[bg][b0]overlay='.$iLeft.'*W/800:'.$iTop.'*W/800"" '.$name.' > block.txt 2>&1');

  $iLeft, $iTop, $iWidth, $iHeight are the left, top, width and height of the selected area via the image plugin.

  It blurs many selected areas very well, but areas like this

  

  The Image Left, Top, Width, Height is 257,  39.26666259765625,  10,  391

  don’t get blurred. Also a video with Dimension 207x207 didn’t get blurred as well.