burndvd.sh

#!/bin/sh

# Prerequisites (on MacOS with Homebrew installed)
# brew install dvdauthor dvdrtools ffmpeg

# Usage:
# chmod +x burndvd.sh
# ./burndvd.sh path/to/input_video.ext

input_file="$1"
if [ -f "$input_file" ]
then
  temp_path="$(mktemp -d)/out"
  # Convert input file to MPEG-2
  ffmpeg -i "$input_file" -threads 16 -aspect 16:9 -target ntsc-dvd "$temp_path.mpg"
  # Demux into VIDEO_TS/AUDIO_TS structure
  VIDEO_FORMAT=NTSC dvdauthor -o "$temp_path" -t "$temp_path.mpg"
  # Create table of contents IFO
  VIDEO_FORMAT=NTSC dvdauthor -o "$temp_path" -T
  # Create ISO
  mkisofs -dvd-video -V VOLUME -o "$temp_path.iso" "$temp_path/"
  # Burn to DVD
  hdiutil burn "$temp_path.iso"
else
  echo "No (existing) input file provided (run script with ./burndvd.sh path/to/input_video.ext)."
  exit 1
fi

You might want to add ffmpeg to the brew install list

You might want to add ffmpeg to the brew install list

Ah sure thanks :) In fact I just took this from a reddit post and wanted to share my adjustments to it as well with this gist.
(so there might be some more things not working out of the box for other people as I didn't have a more generic use case in mind)