FFmpeg

The library and CLI that nearly every other media tool calls underneath.

Homebrew formula Homebrew formula Direct download

What it does

FFmpeg reads and writes essentially every container and codec in use, and exposes a filter graph for scaling, cropping, overlaying, mixing, subtitling and frame-rate conversion. Almost every GUI media tool in this category — HandBrake, LosslessCut, yt-dlp, the DownloadHelper companion — is a front end over it.

# transcode to a widely compatible H.264 file
ffmpeg -i in.mkv -c:v libx264 -crf 20 -c:a aac out.mp4

# hardware encode on Apple Silicon
ffmpeg -i in.mov -c:v hevc_videotoolbox -q:v 60 out.mp4

# extract audio without re-encoding
ffmpeg -i in.mp4 -vn -c:a copy out.m4a

# frames as images, one per second
ffmpeg -i in.mp4 -vf fps=1 frame_%04d.png

Which formula

ffmpeg-full is a Homebrew build with a wider set of optional libraries enabled than the standard ffmpeg formula — extra codecs, filters like frei0r and rubberband, and additional protocols. Bigger install, fewer “unknown encoder” dead ends.

Aliases

FFmpeg’s power is also its problem: the invocation is longer than the job. These wrap the handful of things worth doing repeatedly. Drop the block in ~/.zshrc — or in a file it sources.

# Defined only when ffmpeg is on PATH, so shells without it start clean.
if (( $+commands[ffmpeg] )); then
  # What is this file, really.
  ffinfo() { ffprobe -hide_banner "$@" }
  ffdur()  { ffprobe -v error -show_entries format=duration -of csv=p=0 "$1" }

  # Software H.264 — slower, smaller, and plays on everything. ff264 in [out] [crf]
  ff264() {
    ffmpeg -i "$1" -c:v libx264 -preset slow -crf "${3:-20}" -pix_fmt yuv420p \
      -c:a aac -b:a 192k -movflags +faststart "${2:-${1:r}.mp4}"
  }

  # Hardware HEVC on Apple Silicon — many times faster, slightly larger at equal
  # quality. -tag:v hvc1 is what makes QuickTime and Safari accept the result.
  ffhevc() {
    ffmpeg -i "$1" -c:v hevc_videotoolbox -q:v "${3:-60}" -tag:v hvc1 \
      -c:a aac -b:a 192k -movflags +faststart "${2:-${1:r}-hevc.mp4}"
  }

  # 1080p cap. -2 keeps the aspect ratio and an even height; min() never upscales.
  ff1080() {
    ffmpeg -i "$1" -vf "scale='min(1920,iw)':-2" -c:v libx264 -preset slow -crf 21 \
      -pix_fmt yuv420p -c:a aac -b:a 160k -movflags +faststart "${2:-${1:r}-1080p.mp4}"
  }

  # Audio out. ffaudio keeps the source stream, ffmp3 re-encodes.
  ffaudio() { ffmpeg -i "$1" -vn -c:a copy "${2:-${1:r}.m4a}" }
  ffmp3()   { ffmpeg -i "$1" -vn -c:a libmp3lame -q:a 0 "${2:-${1:r}.mp3}" }

  # Trim without re-encoding. ffcut in.mp4 00:01:20 00:02:45 [out]
  ffcut() {
    (( $# < 3 )) && { print -u2 'usage: ffcut IN START END [OUT]'; return 2 }
    ffmpeg -ss "$2" -to "$3" -i "$1" -c copy "${4:-${1:r}-cut.${1:e}}"
  }

  # Two-pass GIF. Generating a palette first is the whole difference in quality.
  # ffgif in.mp4 [out.gif] [fps] [width]
  ffgif() {
    local dir=$(mktemp -d -t ffgif)
    ffmpeg -v warning -i "$1" \
      -vf "fps=${3:-15},scale=${4:-800}:-1:flags=lanczos,palettegen" -y "$dir/p.png" &&
    ffmpeg -v warning -i "$1" -i "$dir/p.png" \
      -lavfi "fps=${3:-15},scale=${4:-800}:-1:flags=lanczos[x];[x][1:v]paletteuse" \
      -y "${2:-${1:r}.gif}"
    rm -rf "$dir"
  }

  # Stills. ffframes in.mp4 [fps]
  ffframes() { ffmpeg -i "$1" -vf "fps=${2:-1}" "${1:r}-%04d.png" }

  # Join files that already share a codec, no re-encode. ffcat a.mp4 b.mp4 out.mp4
  ffcat() {
    local list=$(mktemp -t ffcat)
    local f; for f in "${@[1,-2]}"; do printf "file '%s'\n" "${f:A}" >> "$list"; done
    ffmpeg -f concat -safe 0 -i "$list" -c copy "${@[-1]}"
    rm -f "$list"
  }
fi

Alias	Does
`ffinfo in.mkv`	Streams, codecs and container, from `ffprobe`
`ffdur in.mkv`	Duration in seconds, for scripting
`ff264 in.mkv`	H.264 + AAC mp4, `faststart` so it streams before it finishes downloading
`ffhevc in.mov`	The same job on the hardware encoder, when speed matters more than size
`ff1080 in.mkv`	Capped at 1920 wide, never upscaled
`ffaudio` / `ffmp3`	Audio only — copied out, or re-encoded for players that only speak mp3
`ffcut in.mp4 1:20 2:45`	That section, no re-encode
`ffgif in.mp4`	A GIF worth looking at, via a generated palette
`ffframes in.mp4 2`	Two stills a second as PNGs
`ffcat a.mp4 b.mp4 out.mp4`	Join, no re-encode

Two things to know before relying on them. ffcut and ffcat copy streams rather than re-encoding, so cuts land on the nearest keyframe and joining only works when every input shares a codec and resolution — add -c:v libx264 -crf 20 to either when that is not true. And the syntax is zsh: ${1:r} and ${1:e} (path without extension, and extension) and ${@[1,-2]} have no bash equivalent, so under bash use ${1%.*}, ${1##*.} and "${@:1:$#-1}".

Notes

ffprobe ships with it and is the faster way to answer “what actually is this file”: ffprobe -hide_banner in.mkv.

Alternative to

Alternative	Type	Trade-off
GStreamer	Open source	Pipeline-based, aimed at applications rather than one-off commands
Shutter Encoder or HandBrake	Free / Open source	Graphical front ends when the invocation is the hard part
AVFoundation and `avconvert`	Built in	Apple’s own, limited but already present

Install

brew install ffmpeg-full    # wider codec and filter set
brew install ffmpeg         # standard build

Links

Homepage

Official site

Homebrew formula

Formula definition and versions

Documentation

The (very long) manual

Filter reference

Every filter and its options

This post is licensed under CC BY 4.0 by the author.

Last updated on September 27, 2026

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