website/content/mass-batch-processing-on-the-CLI.md

title	date
Mass batch processing on the CLI	2022-03-19

This post is day 4 of me taking part in the #100DaysToOffload challenge.

Some time ago, I needed to process a lot of video files with vlc. This is usually pretty easy to do, for file in *.mp4 ; do ffmpeg ... ; done is about all you need in most cases. However, sometimes the files you are trying to process are in different folders. And sometimes you want to process some files in a folder but not others. That's the exact situation I was in, and I was wondering if I needed to find some graphical application with batch processing capabilities so I can queue up all the processing I need.

After a bit of thinking though, I realized I could do this very easily with a simple shell script! That shell script lives in my mark-list repository.

The idea is simple, you use the command to mark a bunch of files. Every file you mark is saved into a file for later use.

$ mark-list my-video.mp4  # Choose a file
Marked 1 file.
$ mark-list *.webm  # Choose many files
Marked 3 files.
$ cd Downloadsr
$ mark-list last.mpg  # You can go to other directories and keep marking

You can mark a single file, or a bunch of files, or even navigate to other directories and mark files there.

Once you are done marking, you can recall what you marked with the same tool:

$ mark-list --list
/home/kaan/my-video.mp4
/home/kaan/part-1.webm
/home/kaan/part-2.webm
/home/kaan/part-3.webm
/home/kaan/Downloads/last.mpg

You can then use this in the command line. For example, I was trying to convert everything to mkv files.

for file in `mark-list --list` ; do ffmpeg -i "${file}" "${file}.mkv" ; done

It works! After you are done with it, you then need to clear out your marks:

mark-list --clear

Hopefully this will be useful for someone else as well. It does make it a lot easier to just queue up a lot of videos, and convert all of them overnight.