add subtitles
You can hardcode subtitles by providing a subtitles files and running the following command
ffmpeg -i input.mp4 -vf subtitles=subs.srt out.mp4
add watermark in any position
The base command for adding watermark looks like this
ffmpeg -i input.mp4 -i watermark.png -filter_complex "POSITION_HERE" out.mp4
You can replace POSITION_HERE with any position you need from the following
Top Right
overlay=main_w-overlay_w-10:10
Top Left
overlay=10:10
Bottom Right
overlay=main_w-overlay_w-10:main_h-overlay_h-10
Bottom Left
overlay=10:main_h-overlay_h-10
Center
overlay=x=(main_w-overlay_w)/2:y=(main_h-overlay_h)/2
extract audio
If you need to extract audio of a video with re-encoding the whole thing then you can run following command
ffmpeg -i input.mp4 -vn -acodec copy out.mp3
extract video waveform
Following command can be used to extract video waveform
ffmpeg -i input.mp4 -filter_complex "compand,showwavespic=s=640x120" -frames:v 1 out.png
flip a video
Horizontally
ffmpeg -i input.mp4 -vf 'hflip' out.mp4
Vertically
ffmpeg -i input.mp4 -vf 'vflip' out.mp4
generate thumbnails
If you are running a video sharing website or a similar service, you might want to extract thumbnails from video. This is helpful to show what video represents. You can run following command for this.
ffmpeg -i input.mp4 -ss 00:00:10 -vframes 12 thumb.png
audio volume
Reduce volume by half
ffmpeg -i input.wav -filter:a "volume=0.5" output.wav
Increase volume to 150%
ffmpeg -i input.wav -filter:a "volume=1.5" output.wav
You can also replace 0.5 with dB
video speed
ffmpeg -i input -filter:v "setpts=0.5*PTS" output
You can adjust speed by changing 0.5
video greyscale
You can make an entire video or a part of it greyscale.
full video greyscale
ffmpeg -i input.mp4 -vf "hue=s=0" out.mp4
part of video greyscale
ffmpeg -i input.mp4 -vf "hue=s=0:enable=\'between(t,3,5)\" out.mp4
mute video
You can remove audio from video with this command
ffmpeg -i input.mp4 -c copy -an out.mp4
reverse video
only reverse video
ffmpeg -i input.mp4 -vf 'reverse' out.mp4
reverse audio and video
ffmpeg -i input.mp4 -vf 'reverse' -af 'areverse' out.mp4
rotate video by x degrees
Following command can be used to rotate videos
ffmpeg -i input.mp4 -c copy -metadata:s:v:0 rotate=360 out.mp4
Here you can replace 360with any values e.g 180
show two videos side by side
If you want to display two videos side by side like mostly done on news channels, it can be done like this
ffmpeg -i left.mp4 -i right.mp4 -filter_complex hstack output.mp4
split video
ffmpeg -i input.mp4 -ss 0 -t 300 -c copy out.mp4
Here 0 is start time in seconds and 300 is end time. This command extracts first 5 minutes of video. You can replace it with any time you need.