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• Would compressing the extracted source images of a video and reconstructing it make the video smaller ? [closed]

  9 septembre 2022, par tawfikboujeh

  I discovered squoosh and found out that it does crazy compression on images,

  


  Squoosh only works on images and i wanted to scale it to work on videos.

  


  I then wrote this script to convert the video to a set of images that I'll squoosh and then reconstitute to a video again using the almighty ffmpeg.

  


  mkdir out ; rm -rf ./out/*
ffmpeg -i input.mp4 -r 25 buffer.mp4 # for a reason, i needed to create a buffer, this is hacky, but whatever.
ffmpeg -i buffer.mp4 -vf fps=25 out/out%d.png # convert the image into images
squoosh-cli --mozjpeg '{quality: 75}' out/*.png # compress
FRAMERATE=$(ffmpeg -i buffer.mp4 2>&1 | sed -n "s/.*, \(.*\) fp.*/\1/p") # get the framerate from buffer video
ffmpeg -framerate $FRAMERATE -i out/out%d.jpg output.mp4 # reconstitute the video knowing the framerate and having the compressed images


  


  the images are 90% smaller but the video has a bigger size than the original one.

  


  benchmarks :

  


  for the images :

  


  1.jpeg : 98 KB on disk
1.png : 1,7 MB on disk 


  


  for the videos :

  


  input.mp4 : 20 Mb on disk
buffer.mp4 : 21 Mb on disk
output.mp4 : 19 Mb on disk


  


  Any idea compressing the source images would make the video smaller ?

  


• resize and crop HD video into square video using ffmpeg

  7 mai 2021, par Ahmet Cetin

  I want to scale and crop HD video (1920x1080) into square one while adding watermark. I tried

  


  ffmpeg
  
-i video.mp4
  
-i watermark.png
  
-filter_complex "[0]scale=720:720,crop=720:720[a] ;[1]scale=720:720[b] ;[a][b]overlay=(W-w)/2 :(H-h)/2"
  
output.mp4

  


  but it produces output with 889x500. Can anyone help me ? What I'm doing wrong ?

  


• ffmpeg remove multiple segments from a video rotate and crop video

  2 novembre 2017, par 1234567

  ffmpeg remove multiple segments from a video rotate and crop video

  I have a video of 2 min 25 seconds , i want to remove part from 10 second to 16 second and 20 second to 26 second and rotate video and crop it

  I am trying this command

   "-y", "-i", j,
  
                        "-filter_complex",
  
                          "[0:v]trim=start=10:end=16,setpts=PTS-STARTPTS[a];  " +
  
                                  "[0:v]trim=start=20:end=26,setpts=PTS-STARTPTS[b]; " +
  
                                  "[0:a]atrim=start=10:end=16,asetpts=PTS-STARTPTS[c]; " +
  
                                  "[0:a]atrim=start=20:end=26,asetpts=PTS-STARTPTS[d]; " +
  
                                  "[a][c][b][d]concat=n=2:v=1:a=1[e][f],"+
  
                                  "crop=" + 40 + ":" + 20 + ":" + 100 + ":" + 100,"+
  
                                  "transpose=1", "-map", "'[e]'" ,"-map",
  
                          "'[f]'", "-preset", "ultrafast",out

  what is the correct command to do it