Script on Bill Glover

FFmpeg Cheat Sheet

hello@bill.dev (Bill) — Fri, 11 Oct 2024 17:17:25 +0100

Using FFmpeg is more art than science. Every time I reach for it, I find myself trawling the internet for various incantations of the command that result in a playable video. These are commands that have worked for me.

Blu-ray

ffmpeg -i input.mkv -c:v libx265 -crf 18 -c:a aac -b:a 160k -tag:v hvc1 -ac 6 output.mp4

This results in an mp4 container with h265 video and aac sound. The file should be playable on Apple devices. The resulting file will also be significantly smaller than the original.

Replace Environment Variables in a File

hello@bill.dev (Bill) — Mon, 21 Mar 2022 20:17:59 +0000

Every now and again you stumble across a command that solves a problem you didn’t realise you had. Recently, I discovered envsubst.

“Substitutes the values of environment variables.”

I’ve found myself substituting environment variables in configuration files increasingly often (see: Kubernetes). On more than one occasion I’ve tied myself in knots trying to do this with scripts. It turns out that envsubst does most of what I need.

Take the following file, example.yaml: