FFMPEG cheatsheet

General

• Some common parameters

  -y  Automatically overwrite output file if exists. (Do not ask)
  

Video handling

Extract part of video

Use -ss to set the start time, -t to set the duration:

ffmpeg -ss 00:00:10 -i in.mp4 -t 00:00:20 -c:a copy -c:v copy out.mp4

Reduce video file size (same resolution)

Using H.265 codec (or H.264 if faster encoding time is needed) to significantly reduce video file size without lowering the quality noticeably. Resulting file size should be less than 35% of original file size.

• Reduce file size by using H.265 codec (slower encoding but smaller video than H.254)

  ffmpeg -i in.mp4 -c:v libx265 -pix_fmt yuv420p -crf 24 out.mp4
  

• Reduce file size even more and speed up H.265 encoding with minimal quality reduction:

  ffmpeg -i in.mp4 -c:v libx265 -pix_fmt yuv420p -crf 24 -preset ultrafast out.mp4
  

• Reduce file size by using H.264 codec (faster encoding than H.265 but bigger files)

  ffmpeg -i in.mp4 -c:v libx264 -pix_fmt yuv420p -crf 24 out.mp4
  

Rotate video

• Rotate clockwise:

  ffmpeg -i in.mp4 -vf "transpose=1" out.mp4
  

• Rotate counter clockwise:

  ffmpeg -i in.mp4 -vf "transpose=2" out.mp4
  

Resize video

• Convert to full hd keeping aspect ratio (add black bars if needed). (Source):

  ffmpeg -i in -vf "scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:(ow-iw)/2:(oh-ih)/2,setsar=1" out.mp4
  

Concat several video files

1. Create a file containing all files to concat:

# content of parts.txt
file 'a.mp4'
file 'b.mp4'
file 'c.mp4'

2. Concat video:

ffmpeg -f concat -safe 0 -i parts.txt -c copy output.mp4

Single image handling

• Extract first frame from video as JPG

  ffmpeg -i in.mp4 -vframes 1 -q:v 2 output.jpg
  

• Extract all frames from video as JPG

  ffmpeg -i in.mp4 -q:v 2 output%03d.jpg
  

• Extract frame at given time (in this example after 5 seconds = 00:00:05) from video as JPG

  ffmpeg -ss 00:00:05 -i in.mp4 -vframes 1 -q:v 2 output.jpg
  

• Combine images to movie showing three images per second at a replay framerate of 30 images per second:

  ffmpeg -r 3 -i input%03d.jpg -c:v libx264 -vf fps=30 -pix_fmt yuv420p out.mp4
  

Audio files handling

• concat two MP3 files:

  ffmpeg -i "concat:file1.mp3|file2.mp3" -acodec copy output.mp3
  

360 degree image handling

See next chapter for 360 degree video handling

The samsung_gear_360_in.jpg image is used as example image:

• Extract left fisheye to single image:

  ffmpeg -i samsung_gear_360_in.jpg -filter_complex "crop=ih:iw/2:0:0" samsung_gear_360_left_fisheye.jpg
  

  Result:

  

• Extract right fisheye to single image:

  ffmpeg -i samsung_gear_360_in.jpg -filter_complex "crop=ih:iw/2:0:0" samsung_gear_360_right_fisheye.jpg
  

  Result:

  

• Equirectangular projection of left fisheye projection

  ffmpeg -i samsung_gear_360_in.jpg -filter_complex "crop=ih:iw/2:0:0,v360=input=fisheye:output=e:ih_fov=191.5:iv_fov=191.5" samsung_gear_360_left_equirectangular.jpg
  

  Result:

  

• Equirectangular projection of right fisheye projection

  ffmpeg -i samsung_gear_360_in.jpg -filter_complex "crop=ih:iw/2:iw/2:0,v360=input=fisheye:output=e:ih_fov=191.5:iv_fov=191.5" samsung_gear_360_right_equirectangular.jpg
  

  Result:

  

  For a 180 degree rotation:

  ffmpeg -i samsung_gear_360_in.jpg -filter_complex "crop=ih:iw/2:iw/2:0,v360=input=fisheye:output=e:yaw=180:ih_fov=191.5:iv_fov=191.5" samsung_gear_360_right_equirectangular_yaw180.jpg
  

  

• Equirectangular projection of both fisheye projections:

  ffmpeg -i samsung_gear_360_in.jpg -filter_complex "v360=input=dfisheye:output=e:ih_fov=191.5:iv_fov=191.5" samsung_gear_360_equirectangular.jpg
  

  Results:

  

  For 180 degree yaw rotation use:

  ffmpeg -i samsung_gear_360_in.jpg -filter_complex "v360=input=dfisheye:output=e:ih_fov=191.5:iv_fov=191.5:yaw=180" samsung_gear_360_equirectangular_yaw180.jpg
  

  

• Equirectangular projection of both fisheye projections with mergemap:

  Source: http://www.astro-electronic.de/FFmpeg_Book.pdf

  # Create mergemap
  H=1920 # Height in px
  FOV=191.5 # FieldOfView angle in degrees
  C=11.5 # Overlap degrees
  ffmpeg -f lavfi -i nullsrc=size=${H}x${H} -vf "format=gray8,geq='clip(128-128/${C}*(180-${FOV}/(${H}/2)*hypot(X-${H}/2,Y-${H}/2)),0,255)',v360=input=fisheye:output=e:ih_fov=${FOV}:iv_fov=${FOV}" -frames 1 -y mergemap.png
  
  # Transform image
  ffmpeg -i samsung_gear_360_in.jpg -i mergemap.png -filter_complex \
      "[0]format=bgr24[double_fisheye_in];
      [0]format=bgr24[double_fisheye_inx];
      [double_fisheye_in]crop=ih:iw/2:0:0[right_fisheye_in];
      [double_fisheye_inx]crop=ih:iw/2:iw/2:0[left_fisheye_in];
      [right_fisheye_in]v360=input=fisheye:output=e:ih_fov=${FOV}:iv_fov=${FOV}[right_equirectangular_part];
      [left_fisheye_in]v360=input=fisheye:output=e:ih_fov=${FOV}:iv_fov=${FOV}:yaw=180[left_equirectangular_part];
      [1]format=gbrp[mask];
      [right_equirectangular_part][left_equirectangular_part][mask]maskedmerge" \
      -y samsung_gear_360_equirectangular_mergedmask.jpg
  

  Result:

  

360 degree video handling

See previous chapter for 360 degree image handling

This example video is used (created by a Samsung Gear 360 camera):

• Equirectangular projection of both fisheye projections with mergemap:

  Source: http://www.astro-electronic.de/FFmpeg_Book.pdf

  # Create mergemap
  H=1920 # Height in px
  FOV=191.5 # FieldOfView angle in degrees
  C=11.5 # Overlap degrees
  ffmpeg -f lavfi -i nullsrc=size=${H}x${H} -vf "format=gray8,geq='clip(128-128/${C}*(180-${FOV}/(${H}/2)*hypot(X-${H}/2,Y-${H}/2)),0,255)',v360=input=fisheye:output=e:ih_fov=${FOV}:iv_fov=${FOV}" -frames 1 -y mergemap.png
  
  # Transform image
  ffmpeg -i samsung_gear_360_demo_original.mp4 -i mergemap.png -filter_complex \
      "[0]format=bgr24[double_fisheye_in];
      [0]format=bgr24[double_fisheye_inx];
      [double_fisheye_in]crop=ih:iw/2:0:0[right_fisheye_in];
      [double_fisheye_inx]crop=ih:iw/2:iw/2:0[left_fisheye_in];
      [right_fisheye_in]v360=input=fisheye:output=e:ih_fov=${FOV}:iv_fov=${FOV}[right_equirectangular_part];
      [left_fisheye_in]v360=input=fisheye:output=e:ih_fov=${FOV}:iv_fov=${FOV}:yaw=180[left_equirectangular_part];
      [1]format=gbrp[mask];
      [right_equirectangular_part][left_equirectangular_part][mask]maskedmerge" \
      -c:v libx265  -b:v 40000k -preset ultrafast samsung_gear_360_equirectangular_mergedmask.mp4
  

  Result:

  

  Result as 360 degree video (correct metadata added before uploading to Youtube):

  

DVD

• Rip a dvd:
  1. Use dvdbackup to copy the complete dvd to your local working directory:

  dvdbackup -i /dev/dvd -o . -M

  1. Extract DVD menu as single image:

  ffmpeg -i VTS_07_0.VOB -vframes 1 -q:v 2 dvd-menu.jpg

  1. Use ffmpeg to convert all VOB to a single mp4:

  ffmpeg -i "concat:$(ls VTS_*.VOB | tail -n +2 | xargs echo | sed 's#\ #\|#g')" -vcodec libx264 dvd.mp4

  1. Optional: Split video in chapters:

  ./cut-dvd-by-chapters.py

Audio CD

• Rip audio cd as MP3:
  1. Rip as WAF files:

  cdparanoia -B

  1. Convert to MP3

  ls *.wav | xargs -n1 lame

Sources

• FFMPEG Filters Documentation
• http://www.astro-electronic.de/FFmpeg_Book.pdf