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• How to create slideshow from images with ffmpeg ?

  7 novembre 2012, par Arsen Zahray

  I want to create a slideshow from images, where each image would be displayed for some period of time (several seconds).

  How do I do that ?

  Currently I was trying to encode short clips with ffmpeg and then stitch those together with mencoder :

          foreach (var item in filePattern)
  
          {
  
              var otpt = item.Key + ".mpg";
  
              Process.Start("ffmpeg",
  
                  string.Format("-y -r 25 -f image2 -vframes 75 -i {0} {1}", item.Value, otpt)//-loop 1
  
                  ).WaitForExit();
  
          }

  ffmpeg -y -r 25 -f image2 -vframes 75 -i input-pattern output does create a file with 1 frame in it, while ffmpeg -y -loop 1 -r 25 -f image2 -vframes 75 -i input-pattern output on windows never finishes (needs ctrl+c to stop) ; the second command worked on linux for me.

  I need to make this work primary on Windows. Which params should I use ?

• Adding watermark to video

  27 avril 2018, par equallyhero

  I am able to use the moviepy library to add a watermark to a section of video. However when I do this it is taking the watermarked segment, and creating a new file with it. I am trying to figure out if it is possible to simply splice in the edited part back into the original video, as moviepy is EXTREMELY slow writing to the disk, so the smaller the segment the better.

  I was thinking maybe using shutil ?

  video = mp.VideoFileClip("C:\\Users\\admin\\Desktop\\Test\\demovideo.mp4").subclip(10,20)
  
  
  
  logo = (mp.ImageClip("C:\\Users\\admin\\Desktop\\Watermark\\watermarkpic.png")
  
            .set_duration(20)
  
            .resize(height=20) # if you need to resize...
  
            .margin(right=8, bottom=8, opacity=0) # (optional) logo-border padding
  
            .set_pos(("right","bottom")))
  
  
  
  final = mp.CompositeVideoClip([video, logo])
  
  final.write_videofile("C:\\Users\\admin\\Desktop\\output\\demovideo(watermarked).mp4", audio = True, progress_bar = False)

  Is there a way to copy the 10 second watermarked snippet back into the original video file ? Or is there another library that allows me to do this ?

• FFMPEG combining MP4 videos with same encoding not working, only showing first video

  13 avril 2020, par Ayudh

  My mp4 videos have the same encoding : h264

  



  I know because I ran this command on them :

  



  ffprobe -v error -select_streams v:0 -show_entries stream=codec_name -of default=noprint_wrappers=1:nokey=1 a.mp4

  



  Now I combine them using the following command :

  



  ffmpeg -loglevel quiet -f concat -safe 0 -i video-list.txt -c copy video-final.mp4

  



  my video-list.txt file looks like this :

  



  file 'a.mp4'
file 'b.mp4'
file 'c.mp4'


  



  Now the video-final.mp4 which is the combined video actually has duration which is equal to the sum of its' component videos and also is quite larger in size. The issue is that when I play the video, it only plays the first video then stops.

  



  What's going on here ? Any insight would be appreciated.

  



  I've looked at : ffmpeg : Combine/merge multiple mp4 videos not working, output only contains the first video and the answers suggested there are the ones I'm using : specifically, concating from a text file containing the component videos.