ffmpeg is the powerhouse for simple processing of videos. You can use simple commands to resample, resize, cut, append, and combine videos. You can also break a video into frames or create a video from multiple images. Here are some basic useful commands to get started.

Converting frame rate of videos.

import subprocess
command = f"ffmpeg -i {input_video} -r 30 -c:v libx264 -preset ultrafast -crf 0 {output_video}"
subprocess.call(command, shell=True)

Extracting frames from a video.

Using the fps to skip frames and scaling the screenshot

import subprocess
command = f"ffmpeg -i {input_video} -vf fps=.5 -vf scale=320:-1 screenshot_%04d.png"
subprocess.call(command, shell=True)

Create a video based on images

import subprocess
command = f"ffmpeg -r 30 -start_number 0 -i screenshot_%04d.png -pix_fmt yuv420p -y {output_video}"
subprocess.call(command, shell=True)

Trim video

Trimming videos are tricky if you want to be super accurate, see these references: https://stackoverflow.com/questions/12208639/ffmpeg-convert-video-from-specified-time-period-slowly/12208967#12208967 https://superuser.com/questions/499380/accurate-cutting-of-video-audio-with-ffmpeg

# More accurate but slower
ffmpeg -i Input.mp4 -ss 00:17:00 -t 15 -async 1 TrimmedVideo.mp4

# Less accurate but faster
ffmpeg -ss 00:00:02 -i Input.mp4 -t 00:00:30 TrimmedVideo.mp4

Stitch videos side-by-side

ffmpeg -i LeftVideo.mp4 -i RightVideo.mp4 \
  -r 24 \
  -crf 30 \
  -filter_complex hstack \
  -preset ultrafast \
  CombinedVideo.mp4

Concatenate videos together

ffmpeg -i FirstVideo.mp4 -c copy -bsf:v h264_mp4toannexb -f mpegts intermediate1.ts
ffmpeg -i SecondVideo.mp4 -c copy -bsf:v h264_mp4toannexb -f mpegts intermediate2.ts
ffmpeg -i "concat:intermediate1.ts|intermediate2.ts" -c copy -bsf:a aac_adtstoasc CombinedVideo.mp4

Convert video to standard MP4 format - to read in jupyter notebook

ffmpeg -i Input.mov Output.mp4