Learn FFmpeg from scratch with this beginner-friendly guide. Covers installation, basic commands, video conversion, audio extraction, compression, trimming, and batch processing with practical examples.
FFmpeg is the Swiss Army knife of multimedia. It is a free, open-source command-line tool that can convert, compress, trim, merge, split, and manipulate virtually any audio or video format in existence. Every major tech company uses it -- YouTube, Netflix, Spotify, VLC, OBS, and thousands of other applications are built on FFmpeg's libraries.
Learning FFmpeg gives you complete control over your media files. No subscription fees, no upload limits, no waiting for cloud processing. Everything happens on your machine, at full speed, with pixel-perfect control over every parameter. A single FFmpeg command can replace an entire desktop application.
The learning curve can feel steep at first, but the core concepts are simple. This guide will take you from zero to confidently converting, compressing, and processing media files with FFmpeg.
The easiest method is Homebrew:
# Install Homebrew if you don't have it
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
# Install FFmpeg
brew install ffmpeg
C:\ffmpegC:\ffmpeg\bin to your system PATH:
C:\ffmpeg\binffmpeg -version
sudo apt update
sudo apt install ffmpeg
sudo dnf install ffmpeg
After installation, run:
ffmpeg -version
You should see version information and a list of enabled features. If you see "command not found," the installation did not complete correctly or FFmpeg is not in your PATH.
Every FFmpeg command follows this basic pattern:
ffmpeg [global options] -i input_file [output options] output_file
The key components:
-i input_file -- Specifies the input file (you can have multiple inputs)output_file -- The output filename (FFmpeg infers the format from the extension)Here is the simplest possible conversion:
ffmpeg -i input.mov output.mp4
FFmpeg automatically selects appropriate codecs based on the output format. But you will almost always want to specify settings explicitly for predictable results.
The most common task -- converting between video container formats:
# MOV to MP4 (re-encode with H.264)
ffmpeg -i input.mov -c:v libx264 -c:a aac output.mp4
# MKV to MP4 (stream copy -- no re-encoding, instant)
ffmpeg -i input.mkv -c copy output.mp4
# AVI to MP4
ffmpeg -i input.avi -c:v libx264 -c:a aac output.mp4
# WebM to MP4
ffmpeg -i input.webm -c:v libx264 -c:a aac output.mp4
The difference between -c copy (stream copy) and -c:v libx264 (re-encode) is critical:
| Method | Speed | Quality | File Size Change | When to Use |
|---|---|---|---|---|
-c copy | Near-instant | Identical to original | Minimal | Changing container only (MKV to MP4) |
-c:v libx264 | Slow (CPU-bound) | Depends on settings | Adjustable | Changing codec, compressing, resizing |
-c:v h264_nvenc | Fast (GPU) | Good (slightly lower than libx264) | Adjustable | Speed-critical encoding with NVIDIA GPU |
-c:v h264_videotoolbox | Fast (GPU) | Good | Adjustable | Speed-critical encoding on Apple Silicon |
For detailed format comparisons, the video codecs explained guide covers H.264, H.265, VP9, and AV1 in depth.
# WAV to MP3 (standard quality)
ffmpeg -i input.wav -c:a libmp3lame -b:a 192k output.mp3
# FLAC to MP3
ffmpeg -i input.flac -c:a libmp3lame -b:a 320k output.mp3
# MP4/MOV to MP3 (extract audio)
ffmpeg -i video.mp4 -vn -c:a libmp3lame -b:a 192k output.mp3
# WAV to AAC
ffmpeg -i input.wav -c:a aac -b:a 256k output.m4a
# MP3 to OGG Vorbis
ffmpeg -i input.mp3 -c:a libvorbis -q:a 5 output.ogg
The -vn flag means "no video" -- essential when extracting audio from video files. For more audio extraction techniques, see how to extract audio from video.
CRF lets you set a target quality level. FFmpeg adjusts the bitrate automatically to maintain consistent quality throughout the video:
ffmpeg -i input.mov -c:v libx264 -crf 23 -preset medium -c:a aac -b:a 128k output.mp4
CRF values for H.264 (libx264):
| CRF Value | Quality | Use Case | Approximate File Size (1 min 1080p) |
|---|---|---|---|
| 0 | Lossless | Archiving (huge files) | 1-3 GB |
| 15-17 | Visually lossless | Master copies, editing | 200-400 MB |
| 18-20 | Excellent | High-quality delivery | 80-200 MB |
| 21-23 | Good (default) | General use, streaming | 40-100 MB |
| 24-28 | Acceptable | Web, social media, email | 15-50 MB |
| 29-35 | Low | Previews, thumbnails | 5-20 MB |
| 51 | Worst possible | Never use this | <5 MB |
The -preset flag controls encoding speed. Slower presets produce smaller files at the same quality:
# Fastest encoding (largest file)
ffmpeg -i input.mov -c:v libx264 -crf 23 -preset ultrafast -c:a aac output.mp4
# Best compression (slowest encoding)
ffmpeg -i input.mov -c:v libx264 -crf 23 -preset veryslow -c:a aac output.mp4
Available presets (fastest to slowest): ultrafast, superfast, veryfast, faster, fast, medium (default), slow, slower, veryslow.
For most use cases, medium or slow is the sweet spot. The difference between slow and veryslow is typically only 2-5% file size reduction for 2-4x longer encoding time.
Pro Tip: The CRF value has a much bigger impact on file size than the preset. Changing CRF by 6 roughly doubles or halves the file size. Changing from medium to slow preset only saves about 5-10% at the same CRF. Adjust CRF first, then fine-tune with the preset.
For a complete understanding of bitrate and quality tradeoffs, the video bitrate explained guide goes much deeper.
# Scale to 1080p (maintain aspect ratio)
ffmpeg -i input.mov -vf "scale=1920:1080" -c:v libx264 -crf 23 -c:a aac output.mp4
# Scale to 720p (maintain aspect ratio, auto-calculate height)
ffmpeg -i input.mov -vf "scale=1280:-2" -c:v libx264 -crf 23 -c:a aac output.mp4
# Scale to 50% of original size
ffmpeg -i input.mov -vf "scale=iw/2:ih/2" -c:v libx264 -crf 23 -c:a aac output.mp4
The -2 value means "auto-calculate this dimension while keeping it divisible by 2" (required for H.264).
# Cut from 00:01:30 to 00:03:45
ffmpeg -i input.mp4 -ss 00:01:30 -to 00:03:45 -c copy trimmed.mp4
# Cut first 30 seconds (with re-encoding for frame accuracy)
ffmpeg -ss 00:00:00 -i input.mp4 -t 30 -c:v libx264 -c:a aac first_30s.mp4
# Remove first 10 seconds
ffmpeg -ss 00:00:10 -i input.mp4 -c copy from_10s.mp4
Using -c copy is fast but may have keyframe alignment issues (cut might start a few frames early). Re-encoding with -c:v libx264 gives precise cuts. For GUI-based trimming, use the video trimmer.
# Extract to MP3
ffmpeg -i video.mp4 -vn -c:a libmp3lame -b:a 192k audio.mp3
# Extract to WAV (uncompressed)
ffmpeg -i video.mp4 -vn -c:a pcm_s16le audio.wav
# Extract to AAC (copy without re-encoding, if source is AAC)
ffmpeg -i video.mp4 -vn -c:a copy audio.aac
The extract audio tool provides a drag-and-drop interface for this task.
# Basic GIF (low quality, large file)
ffmpeg -i input.mp4 -vf "fps=10,scale=480:-1" output.gif
# High-quality GIF with optimized palette
ffmpeg -i input.mp4 -vf "fps=15,scale=480:-1:flags=lanczos,split[s0][s1];[s0]palettegen[p];[s1][p]paletteuse" output.gif
The palette optimization method produces significantly better color reproduction. The GIF maker handles this automatically.
# Burn subtitles into video (hardcode)
ffmpeg -i input.mp4 -vf "subtitles=subs.srt" -c:v libx264 -c:a copy output.mp4
# Add subtitles as a separate track (softcode)
ffmpeg -i input.mp4 -i subs.srt -c copy -c:s mov_text output.mp4
# 2x speed (video and audio)
ffmpeg -i input.mp4 -filter_complex "[0:v]setpts=0.5*PTS[v];[0:a]atempo=2.0[a]" -map "[v]" -map "[a]" output.mp4
# 0.5x speed (slow motion)
ffmpeg -i input.mp4 -filter_complex "[0:v]setpts=2.0*PTS[v];[0:a]atempo=0.5[a]" -map "[v]" -map "[a]" output.mp4
Create a text file listing the videos to merge:
# filelist.txt
file 'part1.mp4'
file 'part2.mp4'
file 'part3.mp4'
Then merge:
ffmpeg -f concat -safe 0 -i filelist.txt -c copy merged.mp4
This only works if all files have the same codec, resolution, and frame rate. If they differ, re-encode:
ffmpeg -f concat -safe 0 -i filelist.txt -c:v libx264 -crf 23 -c:a aac merged.mp4
# Convert all MOV files to MP4 (macOS/Linux)
for f in *.mov; do
ffmpeg -i "$f" -c:v libx264 -crf 23 -preset medium -c:a aac "${f%.mov}.mp4"
done
# Convert all WAV files to MP3
for f in *.wav; do
ffmpeg -i "$f" -c:a libmp3lame -b:a 192k "${f%.wav}.mp3"
done
For more batch processing techniques, the batch processing guide covers advanced workflows.
On Windows (PowerShell):
Get-ChildItem *.mov | ForEach-Object {
ffmpeg -i $_.FullName -c:v libx264 -crf 23 -preset medium -c:a aac ($_.BaseName + ".mp4")
}
FFmpeg's filter system is incredibly powerful. Here are the most useful filters:
-vf)# Rotate 90 degrees clockwise
ffmpeg -i input.mp4 -vf "transpose=1" -c:a copy rotated.mp4
# Crop to center 1080x1080 square
ffmpeg -i input.mp4 -vf "crop=1080:1080" -c:a copy cropped.mp4
# Add text overlay
ffmpeg -i input.mp4 -vf "drawtext=text='Hello World':fontsize=48:fontcolor=white:x=50:y=50" output.mp4
# Adjust brightness and contrast
ffmpeg -i input.mp4 -vf "eq=brightness=0.1:contrast=1.2" output.mp4
# Denoise
ffmpeg -i input.mp4 -vf "nlmeans=s=3:p=7:r=15" denoised.mp4
-af)# Normalize audio volume
ffmpeg -i input.mp4 -af "loudnorm=I=-16:TP=-1.5:LRA=11" normalized.mp4
# Fade audio in/out (5-second fade in, 5-second fade out)
ffmpeg -i input.mp4 -af "afade=t=in:st=0:d=5,afade=t=out:st=55:d=5" faded.mp4
# Remove silence
ffmpeg -i input.mp3 -af "silenceremove=start_periods=1:start_silence=0.5:start_threshold=-50dB" no_silence.mp3
| Task | Command |
|---|---|
| Convert MOV to MP4 | ffmpeg -i input.mov -c:v libx264 -crf 23 -c:a aac output.mp4 |
| Compress video | ffmpeg -i input.mp4 -c:v libx264 -crf 28 -preset slow output.mp4 |
| Extract audio | ffmpeg -i video.mp4 -vn -c:a libmp3lame -b:a 192k audio.mp3 |
| Trim video | ffmpeg -i input.mp4 -ss 00:01:00 -to 00:02:00 -c copy trim.mp4 |
| Resize to 720p | ffmpeg -i input.mp4 -vf "scale=1280:-2" -c:v libx264 output.mp4 |
| Create GIF | ffmpeg -i input.mp4 -vf "fps=10,scale=480:-1" output.gif |
| Remove audio | ffmpeg -i input.mp4 -an -c:v copy silent.mp4 |
| Get file info | ffprobe -v quiet -show_format -show_streams input.mp4 |
| Screenshot at timestamp | ffmpeg -i input.mp4 -ss 00:00:30 -frames:v 1 screenshot.jpg |
| Merge videos | ffmpeg -f concat -safe 0 -i filelist.txt -c copy merged.mp4 |
FFmpeg was compiled without H.264 support. Reinstall with full codec support:
# macOS
brew install ffmpeg
# Ubuntu
sudo apt install ffmpeg libavcodec-extra
The input file is corrupted or the format is not recognized. Try:
ffmpeg -err_detect ignore_err -i input.mp4 -c:v libx264 -c:a aac output.mp4
For more on repairing corrupted files, see the corrupted video repair guide.
H.264 requires even dimensions. Use -2 in your scale filter:
ffmpeg -i input.mp4 -vf "scale=1280:-2" output.mp4
Use hardware acceleration or a faster preset:
# Faster preset (larger file but much faster)
ffmpeg -i input.mp4 -c:v libx264 -crf 23 -preset fast -c:a aac output.mp4
# GPU acceleration (NVIDIA)
ffmpeg -i input.mp4 -c:v h264_nvenc -cq 23 -c:a aac output.mp4
FFmpeg is the better choice when you:
Online tools like the MP4 converter or video compressor are better when you:
Pro Tip: You do not have to choose one or the other. Many professionals use FFmpeg for heavy lifting and online tools for quick conversions. Having both in your toolkit makes you more productive.
FFmpeg is the most powerful media conversion tool available, and its basic usage is surprisingly straightforward. The core pattern -- ffmpeg -i input [options] output -- covers 90% of what you need. Start with simple conversions, learn the CRF quality system, and gradually explore filters and batch processing as you grow more comfortable. The investment in learning FFmpeg pays off every time you need to convert, compress, trim, or manipulate a media file without uploading it to a third-party service.
Sarah Chen
Technical writer specializing in multimedia formats and digital workflows. Covers file conversion, video encoding, and document processing.