`ffmpeg` simple cheatsheet

Nov 6, 2024 • 2 min read

Personal reference for basic CLI commands.

Geese hanging out in The King's Garden, Copenhagen. I don't think they like me.

Now and then I'll want to upload a video to my pull request to make it easier to review, but the file size is over the limit. I pull up ffmpeg in my terminal to compress it, only to realize I forgot how it works.

I decided to write down some notes on how to use it. Then I thought I should just share them. And here we are. Hope this is useful to somebody besides myself.

`man ffmpeg` but you don't need a PhD


NAME
    ffmpeg - ffmpeg media converter

EXAMPLE
    ffmpeg -i input.mp4 -c:v libx265 -preset medium output.mp4

OPTIONS
    -i [path] Input file path.

    -c:v [libx264|libx265|libvpx] Video codec.
       '[libx264|libx265]' are mp4.
       '[libx265]' has better compression but worse compatibility.
       '[libvpx]' is webm.

    -c:a [aac|ac3|libmp3lame|copy] Audio codec.
       'copy' means to skip re-encoding audio.

    -an Discard audio.

    -preset [ultrafast|superfast|veryfast|faster|fast|
       medium|slow|slower|veryslow]
       Settings preset, to be used with [libx264|libx265].
       Each option has diminishing returns over the next.

    -crf [0 <= number <= 51] Compression quality (Constant Rate Factor).
         Default is '23'. Lower gives better quality. '0' is lossless.
         Valid range depends on specified video codec.
         Range given here is for '[libx264|libx265]'.
         Range for '[libvpx]' is '[4 <= number <= 63]'.

    -b:v Video bitrate. To be used with '[libvpx]'.
         Examples:
         360p  ->  -b:v 1M
         480p  ->  -b:v 2M
         720p  ->  -b:v 5M
         1080p ->  -b:v 8M
         2K    ->  -b:v 16M
         4K    ->  -b:v 40M

    -vf  Filtering tools. Use for scaling a video.
         Examples:
         360p  ->  -vf scale=640:360
         480p  ->  -vf scale=854:480
         720p  ->  -vf scale=1280:720
         1080p ->  -vf scale=1920:1080
         2K    ->  -vf scale=2048:1080
         4K    ->  -vf scale=3840:2160
         For a vertical video, you'll probably want to
         flip values around.

Example

Here's some jellyfish 🪼

ffmpeg -i jellyfish.mov -c:v libvpx -an -crf 4 -b:v 1.5M jellyfish.webm
# before 44.5 MB
# after   4.3 MB

Found in Berlin's aquarium

`ffmpeg` simple cheatsheet

`man ffmpeg` but you don't need a PhD

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