Codec Overview

A codec (coder/decoder) compresses and decompresses audio and video data. FFmpeg supports hundreds of codecs natively.

Listing Codecs

# List all codecs
ffmpeg -codecs

# List only encoders
ffmpeg -encoders

# List only decoders
ffmpeg -decoders

# Search for specific codec
ffmpeg -encoders | grep h264

Video Codec Categories

Category	Description	Codecs
H.264 family	Most widely compatible	libx264, h264_nvenc, h264_videotoolbox
H.265 family	Better compression, less compatibility	libx265, hevc_nvenc, hevc_videotoolbox
VPx	Royalty-free web codecs	libvpx-vp8, libvpx-vp9
AV1	Newest, best compression	libaom-av1, libsvtav1
ProRes	Professional editing	prores, prores_ks
DNxHD	Professional editing	dnxhd
GIF	Animation	gif
PNG/JPEG	Image	mjpeg, png

Audio Codec Categories

Category	Description	Codecs
AAC	Most common, web streaming	aac, libfdk_aac, aac_fixed
MP3	Universal compatibility	libmp3lame
Opus	Low latency, voice/music	libopus
Vorbis	Open, web	libvorbis
FLAC	Lossless	flac
PCM	Uncompressed	pcm_s16le, pcm_s24le
AC3	DVD/Blu-ray	ac3
E-AC3	Blu-ray, streaming	eac3

Copy Mode

The fastest way to transcode is copying streams when the codec doesn't need to change:

# Copy all streams (container conversion only)
ffmpeg -i input.mkv -c copy output.mp4

# Copy video, re-encode audio
ffmpeg -i input.mkv -c:v copy -c:a aac output.mp4

# Copy audio, re-encode video
ffmpeg -i input.mkv -c:v libx264 -preset fast -crf 22 -c:a copy output.mp4

Copy-Specific Options

# Copy with stream selection
ffmpeg -i input.mkv \
  -map 0:v:0 -map 0:a:1 -map 0:s \
  -c:v copy -c:a copy -c:s copy \
  output.mp4

Choosing a Codec

Use Case	Recommended Video	Recommended Audio
Web (MP4)	libx264	aac
Web (WebM)	libvpx-vp9	libopus
Archival	FFV1	FLAC
Editing	ProRes 422 HQ / DNxHD	PCM
Streaming	libx264 / h264_nvenc	aac / libopus
Mobile	libx264	aac
GIF	gif / palettegen	—
Ultra-low latency	h264_nvenc	libopus