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• Adding outro video to multiple video files using ffmpeg

  31 août 2017, par jasan

  I can successfully merge files using the following command using ffmpeg :

  ffmpeg -f concat -i mylist.txt -c copy output.mp4

  the mylist.txt looks like this :

  file './video.mp4'
  
  file './outro.mp4'

  However what I want to do is the following :

  • I have 100 video files ( video1.mp4, video2.mp4, video3.mp4,...)

  • i have one outro file(outro.mp4)

  I want to concat outro.mp4 to the end of each of the 100 files and save each of concatenated video file with the same filename as the original videofile( i.e video1, video2....)

  I’m on a windows machine. any way I can achieve this ? code snippet would be really helpful.

• How to speed up processing for FFmpeg video overlay on a video source file in Android ?

  28 décembre 2017, par Iffat Fatima

  I am working on an Android application to add a video file as an overlay on another video file, along with adding an audio stream to it, using FFmpeg library for Android.

  I am using the following command to apply the overlay, but for a video of 2 seconds, it takes 55 seconds to process. Is there a way to speed up this process ?

      String[] complexCmd = new String[]{ "-y",    
  
              "-i",               
  
              originalVideoPath,        
  
              "-i",               
  
              overlayVideoPath ,       
  
              "-i",               
  
              audioPath,              
  
              "-filter_complex",  
  
              "[0:v]setpts=PTS-STARTPTS[top];[1:v]setpts=PTS-STARTPTS, scale="+newOverlayWidth+"x"+newOverlayHeight+",format=yuva420p,colorchannelmixer=aa=0.5[bottom];[top][bottom]overlay=shortest=1:x="+left+":y="+top+"" ,
  
              "-c:v",
  
              "libx264",
  
              "-preset",
  
              "ultrafast",
  
              "-crf",
  
              "28",  
  
              "-map",  
  
              "2:a",  
  
              "-shortest",
  
              destVideoPath,
  
      };

• Cut a video in between key frames without re-encoding the full video using ffpmeg ? [closed]

  13 juillet 2024, par bguiz

  I would like to cut a video at the beginning at any particular timestamp, and it need to be precise, so the nearest key frame is not good enough.

  


  Also, these videos are rather long - an hour or longer - so I would like to avoid re-encoding this altogether if possible, or otherwise only re-encode a minimal fraction of the total duration. Thus, would like to maximise the use of -vcodec copy.

  


  How can I accomplish this using ffmpeg ?

  


  NOTE : See scenario, and my own rough idea for a possible solution below.

  


  ---

  


  Scenario :

  


  

  • Original video

    

    • Length of 1:00:00

    


    • Has a key frame every 10s

    


    


  


  • Desired cut :

    

    • From 0:01:35 through till the end

    


    


  


  • Attempt #1 :

    

    • Using -ss 0:01:35 -i blah.mp4 -vcodec copy, what results is a file where :

    


    • audio starts at 0:01:30

    


    • video also starts at 0:01:30

    


    • this starts both the audio and the video too early

    


    


  


  • using -i blah.mp4 -ss 0:01:35 -vcodec copy, what results is a file where :

    

    • audio starts at 0:01:35,

    


    • but the video is blank/ black for the first 5 seconds,

      

      • until 0:01:40, when the video starts

      


      


    


    • this starts the audio on time,
but the video starts too late

    


    


  


  


  ---

  


  Rough idea

  


  

  • (1) cut 0:01:30 to 0:01:40

    

    • re-encode this to have new key frames,
including one at the target time of 0:01:35

    


    • then cut this to get the 5 seconds from 0:01:35 through 0:01:40

    


    


  


  • (2) cut 0:01:40 through till the end

    

    • without re-encoding, using -vcodec copy

    


    


  


  • (3) ffmpeg concat the first short clip (the 5 second one)
with the second long clip

  


  


  I know/ can work out the commands for (2) and (3), but am unsure about what commands are needed for (1).