ffmpeg

Universal media converter for audio/video transcoding, filtering, and format conversion.

$ ffmpeg -i input.mp4 -c:v libx264 -crf 28 -preset medium -c:a aac -b:a 128k output.mp4

Input file (-i)Output file

Overwrite output (-y)

Video codec (-c:v)

H.264

H.265

VP9

AV1

Audio codec (-c:a)

AAC

MP3

Opus

Copy

Quality (CRF, 0-51)Encoder preset (-preset)

Ultrafast

Fast

Medium

Slow

Veryslow

Audio bitrate (-b:a)

Examples

# CRF 28 compression (good quality)
ffmpeg -i input.mp4 -c:v libx264 -crf 28 -c:a aac output.mp4

# CRF 35 (smaller file)
ffmpeg -i input.mp4 -c:v libx265 -crf 35 -c:a aac -b:a 128k output.mp4

# 2-pass quality
ffmpeg -i input.mp4 -c:v libx264 -b:v 1M -maxrate 2M -bufsize 4M -c:a aac output.mp4