FFmpeg Cookbook

I always end up searching online on how to do the same things over-and-over, decided to just jot them down here so I don’t have to do that anymore.

libvpx-vp9

Two-Pass Video Encoding

1. First pass (generates log file for the second pass)

ffmpeg -i input.mp4 -c:v libvpx-vp9 -b:v 2M -pass 1 -an -f null /dev/null

- `-an` is to disable audio
- `-b:v 2M` sets average bit-rate
    - Can use a constant bit-rate by doing `-b:v 0 -crf 30` *(but why do that?)*

2. Second pass

ffmpeg -i input.mp4 -c:v libvpx-vp9 -b:v 2M -pass 2 -c:a libopus -row-mt 1 output.webm

Deadline

-deadline flag can be set to realtime, good, or best (default is good)

Row-Based Multi-Threading

-row-mt 1 flag activates multithreading, which is off by default.

• (Has a bigger performance boost on higher-resolution videos.)

Universal Audio and Video

Some Video Filter (-vf) Options

Examples:

# Resize to 480 width, -1 means FFmpeg will set height automatically.
scale=480:-1
# Change FPS to 20
fps=20

Mono Audio

-ac 1

Audio Bitrate (-b:a)

e.g.,

-b:a 32K

Stereo and Mono Audio Rates (-ar)

Source: Opus Recommended Settings, xiph.org

Note: Stereo unless specified otherwise

Audio Bands in Telephony:

Name	Range (Hz)
Narrowband	300—3,400
Wideband	50—7,000
Superwideband	50—14,000
Fullband	20—20,000

Source: Wideband audio, Wikipedia