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• encode video in reverse ?

  25 juillet 2021, par bob

  Does anyone know if it is possible to encode a video using ffmpeg in reverse ? (So the resulting video plays in reverse ?)

  



  I think I can by generating images for each frame (so a folder of images labelled 1.jpg, 2.jpg etc), then write a script to change the image names, and then re-encode the ivdeo from these files.

  



  Does anyone know of a quicker way ?

  



  This is an FLV video.

  



  Thank you

  


• SOLVED - AVI to MP4 - ffmpeg conversion

  26 mai 2014, par Emmanuel Brunet

  I’m running a debian 7.5 machine with ffmpeg-2.2 installed following these instructions

  Issue

  I’m trying to display a mp4 video inside my browser. The original file has an AVI container format. I can successfully convert it to mp4 and the targetfile is readable (video + sound) with the totem movie player. So I thought everything would be OK displaying the bellow page

  HTML5 web page

      
  
  
  
  
  
  <video width="640" height="480" controls="controls">
  
    <source src="/path/to/output.mp4" type="video/mp4">
  
  <h3>Your browser does not support the video tag</h3>
  
  </source></video>

  Input probe

  $ ffprobe -show_streams input.avi
  
  
  
    Duration: 00:08:22.90, start: 0.000000, bitrate: 1943 kb/s
  
      Stream #0:0: Audio: mp3 (U[0][0][0] / 0x0055), 48000 Hz, stereo, s16p, 64 kb/s
  
      Stream #0:1: Video: mpeg4 (Advanced Simple Profile) (XVID / 0x44495658), yuv420p, 720x540 [SAR 1:1 DAR 4:3], 1870 kb/s, 29.97 fps, 25 tbr, 29.97 tbn, 25 tbc

  Convert

  $ ffmpeg -y -fflags +genpts -i input.avi -acodec copy -vcodec copy ouput.mp4

  Html browser

  Opening the above html file plays sound but no video is displayed.

  When I use other .mp4 files, videos succesfully displayed so I’m sure I face a conversion issue.

  Not : I’ve tryed a lot of other ffmpeg options but without success.

  Any idea ?

  Thanks in advance.

• Turn a video into a sequence of images using GStreamer (not ffmpeg)

  12 août 2021, par Rory

  I have an ogg vorbis video. It plays fine in totem and mplayer. I want to covert it to a sequnces of images, one image per frame. I can do this on ffmpeg with the following command :

  



  ffmpeg -i video.ogv -f image 2 video-frames-%08png


  



  However that doesn't work for this video. Each frame is all grey as if there has been loads of decoding problems. Since it works in totem, I suspect that gstreamer is better able to decode the video than ffmpeg. Is there a gstreamer command that will take in a ogg vorbis video and then create a pile of images, one for each frame ?

  



  I'm using stock Ubuntu Lucid desktop.