FFmpeg Reference
Filter Syntax
Video Filters (-vf)
# Chain filters with comma
-vf "scale=1920:1080,fps=30,crop=1280:720"
# Complex filters with labels
-filter_complex "[0:v]scale=1920:1080[scaled];[scaled]fps=30[out]" -map "[out]"
Common Video Filters
| Filter |
Syntax |
Example |
| scale |
scale=w:h |
scale=1920:1080 or scale=1280:-1 (auto height) |
| crop |
crop=w:h:x:y |
crop=1280:720:320:180 |
| fps |
fps=N |
fps=30 |
| pad |
pad=w:h:x:y:color |
pad=1920:1080:(ow-iw)/2:(oh-ih)/2:black |
| fade |
fade=t=in/out:st=N:d=N |
fade=t=in:st=0:d=1 |
| setpts |
setpts=N*PTS |
setpts=0.5*PTS (2x speed) |
| drawtext |
drawtext=text='Hi':fontsize=24 |
Add text overlay |
| overlay |
overlay=x:y |
Combine videos |
Common Audio Filters (-af)
| Filter |
Syntax |
Example |
| volume |
volume=N |
volume=1.5 or volume=0.5 |
| afade |
afade=t=in/out:st=N:d=N |
afade=t=in:st=0:d=1 |
| atempo |
atempo=N |
atempo=2.0 (2x speed, range 0.5-2.0) |
| loudnorm |
loudnorm |
Normalize audio levels |
Codec Options
Video Codecs (-c:v)
| Codec |
Use Case |
Notes |
| libx264 |
Universal H.264 |
Best compatibility |
| libx265 |
H.265/HEVC |
Better compression, less compatible |
| libvpx-vp9 |
WebM |
Good for web |
| prores |
ProRes |
Professional editing |
| copy |
Stream copy |
No re-encoding, fastest |
Audio Codecs (-c:a)
| Codec |
Use Case |
Notes |
| aac |
MP4 container |
Most compatible |
| libmp3lame |
MP3 |
Universal |
| libvorbis |
WebM/OGG |
Open source |
| pcm_s16le |
WAV |
Uncompressed |
| copy |
Stream copy |
No re-encoding |
Quality Settings
CRF (Constant Rate Factor) for x264/x265
| CRF |
Quality |
Use Case |
| 0 |
Lossless |
Archive |
| 17-18 |
Visually lossless |
Master |
| 19-22 |
High quality |
Production |
| 23 |
Default |
General use |
| 24-27 |
Medium |
Web delivery |
| 28+ |
Low |
Preview/draft |
Presets (-preset)
Faster presets = larger files, quicker encoding
ultrafast → superfast → veryfast → faster → fast → medium → slow → slower → veryslow
Container Formats
| Format |
Extension |
Best For |
| MP4 |
.mp4 |
Universal, web, mobile |
| MOV |
.mov |
Apple ecosystem, ProRes |
| WebM |
.webm |
Web (VP9) |
| MKV |
.mkv |
Archive, multiple streams |
| GIF |
.gif |
Short animations (no audio) |
Input/Output Options
Input Options (before -i)
| Option |
Purpose |
Example |
| -ss |
Seek to time |
-ss 00:01:30 |
| -t |
Duration limit |
-t 00:00:30 |
| -r |
Input framerate |
-r 30 |
| -f |
Force format |
-f gif |
Output Options (after -i)
| Option |
Purpose |
Example |
| -y |
Overwrite output |
-y |
| -n |
Never overwrite |
-n |
| -movflags faststart |
Web streaming |
-movflags faststart |
| -pix_fmt |
Pixel format |
-pix_fmt yuv420p |
| -an |
No audio |
-an |
| -vn |
No video |
-vn |
Useful Patterns
Get Duration in Seconds
ffprobe -v error -show_entries format=duration -of csv=p=0 input.mp4
Get Resolution
ffprobe -v error -select_streams v:0 -show_entries stream=width,height -of csv=p=0 input.mp4
Get Frame Count
ffprobe -v error -select_streams v:0 -count_frames -show_entries stream=nb_read_frames -of csv=p=0 input.mp4
Create Thumbnail
# At specific time
ffmpeg -i input.mp4 -ss 00:00:05 -vframes 1 thumbnail.jpg
# Best quality
ffmpeg -i input.mp4 -ss 00:00:05 -vframes 1 -q:v 2 thumbnail.jpg
Create GIF from Video
# Simple (large file)
ffmpeg -i input.mp4 -vf "fps=10,scale=480:-1" output.gif
# With palette (better quality, smaller)
ffmpeg -i input.mp4 -vf "fps=10,scale=480:-1,split[s0][s1];[s0]palettegen[p];[s1][p]paletteuse" output.gif
Picture-in-Picture
# Overlay small video in corner
ffmpeg -i main.mp4 -i overlay.mp4 \
-filter_complex "[1:v]scale=320:-1[pip];[0:v][pip]overlay=W-w-20:H-h-20" \
-c:a copy output.mp4
Side-by-Side Videos
ffmpeg -i left.mp4 -i right.mp4 \
-filter_complex "[0:v][1:v]hstack=inputs=2[v]" \
-map "[v]" -c:v libx264 output.mp4
Remotion Integration Notes
- Remotion uses
<OffthreadVideo> which handles most formats
- Prefer H.264 (libx264) in MP4 container
- Always use
-movflags faststart for web playback
- Match fps to composition (usually 30fps)
- Resolution should match composition (1920x1080 typical)
