steven2358

FFmpeg cheat sheet

A list of useful commands for the FFmpeg command line tool.

Download FFmpeg: https://www.ffmpeg.org/download.html

Full documentation: https://www.ffmpeg.org/ffmpeg.html

Basic conversion

asukakenji

Go (Golang) GOOS and GOARCH

All of the following information is based on go version go1.17.1 darwin/amd64.

GOOS Values

GOOS	Out of the Box
aix	✅
android	✅

vt0r

GnuPG 2.2.x Build Instructions

Below are my build instructions for GnuPG 2.2.10, released on August 30th, 2018. These instructions are built for a headless Ubuntu 18.04 LTS server (and have also been tested on Ubuntu 14.04/16.04).

If you prefer, you may use the below install script to install GnuPG 2.2.x by running the following commands:

curl -OL "https://gist.githubusercontent.com/vt0r/a2f8c0bcb1400131ff51/raw/e0d2011d7b89bfe5b83c3f29f21949fb21354dd9/install-gnupg22.sh" && sudo -H bash ./install-gnupg22.sh

Install the needed dependencies

leommoore

File Magic Numbers

Magic numbers are the first bits of a file which uniquely identify the type of file. This makes programming easier because complicated file structures need not be searched in order to identify the file type.

For example, a jpeg file starts with ffd8 ffe0 0010 4a46 4946 0001 0101 0047 ......JFIF.....G ffd8 shows that it's a JPEG file, and ffe0 identify a JFIF type structure. There is an ascii encoding of "JFIF" which comes after a length code, but that is not necessary in order to identify the file. The first 4 bytes do that uniquely.

This gives an ongoing list of file-type magic numbers.

Image Files