Introduction

Do you know that funny video on the Internet? Or the movie in the theatre? If you've watched any digital video over the last 15 years, there's a good chance that FFmpeg was involved at some point, whether for editing, playback, or distribution.

FFmpeg is a video and audio transformation software that is used by multimedia companies like YouTube, TikTok, Vimeo, and many others.

In this article, we'll learn how to use it through practical examples.

FFmpeg installation

Linux

Debian / Ubuntu:

sudo apt update
sudo apt install ffmpeg
ffmpeg -version

Fedora:

sudo dnf install https://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-$(rpm -E %fedora).noarch.rpm
sudo dnf install https://download1.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-$(rpm -E %fedora).noarch.rpm
sudo dnf upgrade --refresh
sudo dnf install ffmpeg --allowerasing
sudo dnf install ffmpeg-devel --allowerasing
ffmpeg -version

Arch Linux:

sudo pacman -Sy 
sudo pacman -S ffmpeg 
ffmpeg -version

macOS

Install Brew.
Execute on Terminal:

brew update
brew install ffmpeg
ffmpeg -version

Windows

You can install via Winget (available for Windows 11, Windows Server 2025):

winget install --id=Gyan.FFmpeg -e

Or install manually:

Download the latest FFMpeg for Windows release (link). The essentials version is the most appropriate for most users.
Unzip the file.
Add the bin folder to PATH. For that:
- On Windows Explorer, mouse right-click on This Computer > Properties.
- On the next window, click on Advanced system configurations.
- On System Properties, click on Environment Variables....
- On User Variables for X, select the line with Path and click on Edit....
- Add the bin folder path to the list. It will be something like: C:\Users\user\Downloads\ffmpeg-7.0.1-essentials_build\bin (change for the path in your machine).
- Click OK on the windows to save the changes.

How to use

FFmpeg is used via Terminal, Command Prompt, or PowerShell. In your computer, open one of those programs.
In the examples below, the file paths are specified without their folders, which implies the current folder in the command line. To change the current directory:

cd C:\Users\user\Videos\

If the files are (or will be generated) in other folders, the full file path is required:

ffmpeg -i "C:\Videos\input.mov" -c copy "C:\Videos\output.mp4"

Operations

Change file format

Video file formats usually are just transport containers, whereas their content is determined by the codecs. Some video formats: MP4, AVI, MKV, MOV, WebM.

The most popular video codecs are:

H.264, it's one of the oldest and is widely supported.
H.265, more recent and has up to 50% smaller file sizes than H.264. However, some browsers and players do not support it.
AV1 is a newer codec. It has a royalty-free license and promises better compression than H.265, but FFmpeg doesn't support it very well yet (01/06/2025).
VP9, used by YouTube and in .webm videos.

The main audio codecs are:

MP3, widely supported, lossy, good compression, good quality.
AAC, used in MP4, compression and quality a bit better than MP3.
Opus, lossy with good quality.
FLAC, lossless, but with compression.

File conversion keeping the codecs:

ffmpeg -i input.mov -c copy output.mp4

File and codec conversion (transcoding):

-c:v: video codec
-c:a: audio codec
-b:a: audio bitrate

ffmpeg -i input.mov -c:v h264 -c:a libopus -b:a 96k output.mp4

Extract audio from a video

Full extraction, keeping the codec:

MP4 -> AAC or M4A
MKV -> many codecs
WebM -> Opus or Ogg Vorbis
MOV -> ALAC

ffmpeg -i input.mp4 -vn -c:a copy output.m4a

Extraction with transcoding. -q:a is the quality, from 0 to 9; lower means better.

ffmpeg -i input.mp4 -vn -c:a libmp3lame -q:a 2 output.mp3

Audio extraction from part of the video. -ss is the beginning, -to is the end.

ffmpeg -i input.mp4 -ss 00:00:07 -to 00:00:10.7 -vn -c:a libmp3lame -q:a 2 output.mp3

Reduce file size

There are many ways to reduce the file size of a video. In this section, we'll cover compression.

To fully understand how it works, I recommend reading the codec official docs (such as: H.264 and H.265).

Limit with CRF. The -crf flag, Constant Rate Factor, controls quality. Lower value means less compression and higher quality. The scale goes from 0 to 51, default value is 23.

ffmpeg -i input.mp4 -c:v libx264 -crf 23 -pix_fmt yuv420p -c:a copy output.mp4

-pix_fmt yuv420p is necessary for compatibility with Apple QuickTime and some other players.

Limit bitrate. You can limit the bitrate, making the file size more predictable. This option can be combined with CRF. In the example below, the encoder aims to limit the maximum bitrate in 1Mbit/s.

ffmpeg -i input.mp4 -c:v libx264 -crf 23 -maxrate 1M -bufsize 2M -pix_fmt yuv420p -c:a copy output.mp4

Transcode to more modern codecs. H.265, for example, generates lower files sizes than H.264. CRF scale goes from 0 to 51, default value is 28.

Keep in mind that not every player and browser supports H.265.

ffmpeg -i input.mp4 -c:v libx265 -crf 28 -tag:v hvc1 -c:a copy output.mp4

-tag:v hvc1 is for compatibility with Apple QuickTime.

Cut part of a video

ffmpeg -ss 00:00:19.4 -to 00:03:50 -i input.mp4 -c copy output.mp4

Increase and decrease audio volume

The example below increases the audio volume by 2.4 times.

To reduce it by half, use 0.5.

ffmpeg -i input.mp4 -af "volume=2.4" output.mp4

Resize frames

Fixed dimensions, width x height:

ffmpeg -i input.mp4 -lavfi "scale='720:480'" output.mp4

One fixed dimension and the other proportional, to maintain the aspect ratio:

ffmpeg -i input.mp4 -lavfi "scale='720:-2'" output.mp4

Proportional reduction:

ffmpeg -i input.mp4 -lavfi "scale='floor(iw/4)*2:floor(ih/4)*2'" output.mp4

In the example above, the function floor(d/4) * 2 was used to calculate half, because some codecs require dimensions to always be even numbers (divisible by 2).

Insert subtitles

Optional subtitles

Also known as soft subtitles, they are visible on the player with mouse right-click and selecting the subtitle.

More than one subtitle can be added, for example, for more than one language.

ffmpeg -i input.mp4 -i subtitles.srt -c copy -c:s mov_text -metadata:s:s:0 language=eng output.mp4

Burned subtitles

Hard or burned subtitles are imprinted over the video.

subtitles.srt is the subtitles file. Alignment=2 means bottom center position.

ffmpeg -i input.mp4 -lavfi "subtitles=subtitles.srt:force_style='Alignment=2,OutlineColour=&H100000000,BorderStyle=3,Outline=1,Shadow=0,Fontsize=18,MarginL=5,MarginV=25'" -crf 1 -c:a copy output.mp4

Example of result:

Add text on top of the video

We will use pad and drawtext.

pad adds a layer around the video; in the example below, we'll make it black above the video. For that, we'll extend the frame height by 100 pixels and draw the layer between 0 and 100 on the vertical direction:

# ih = input height
"pad=width=iw:height=(ih+100):x=0:y=100:color=black"

drawtext renders the text on the layer. Our text will have two lines, so we'll use it twice.

x=(w-text_w)/2 centers the text horizontally. The y coordinate determines the line's vertical position.

"drawtext=:font='Arial':text='Men′s Volleyball 2016 Olympics':fontsize=24:fontcolor=white:x=(w-text_w)/2:y=25"

"drawtext=:font='Arial':text='BRA 3 - 0 ITA':fontsize=24:fontcolor=white:x=(w-text_w)/2:y=54"

Command:

ffmpeg -i input.mp4 -lavfi "format=yuv420p,pad=width=iw:height=(ih+100):x=0:y=100:color=black, drawtext=:font='Arial':text='Men′s Volleyball 2016 Olympics':fontsize=24:fontcolor=white:x=(w-text_w)/2:y=25, drawtext=:font='Arial':text='BRA 3 - 0 ITA':fontsize=24:fontcolor=white:x=(w-text_w)/2:y=54" -c:v libx264 -crf 25 output.mp4

format=yuv420p is necessary for compatibility with Apple QuickTime and some other players.

Example of result:

Inspect metadata

Details which codecs were used; video and audio resolution and bitrate; and other information.

ffprobe video.mp4