Bash alias for combining MP4 files into one file

catmp4.sh

#!/bin/bash
#
# Brett Morrison, June 2022
#
# Below is a script for concatenating multiple mp4 files into one mp4 file.
# This is useful for GoPro camera output. The workflow is:
#   1. Copy files from the GoPro microSD card onto a drive
#   2. Open up a command prompt and CD into the directory you put the MP4 files
#   3. Run the command, catmp4 with the output file name as the one and only parameter
#
# Example:
# $ catmp4 2022-06-23_CAMERA-A.mp4
# 
# To "install" this command
#    1. Install ffmpeg and make sure it's in your path.
#    2. Put this script, catmp4.sh somewhere and make sure it's executable and in your path.
#
rm -f input.txt
for file in `ls -tr *.MP4`
do
  echo file $file >> input.txt
  ffprobe.exe -i $file -print_format json -show_chapters -v quiet | grep start_time >> chapters.txt
done

rm -f $1
ffmpeg.exe -f concat -i input.txt -map_metadata 0 -map_chapters 0 -codec copy $1