Need help with running a command string recursively

S1NN3R · 08-20-2015, 03:12 PM

I'm still little new with bash commands and I've hit a brick wall. Recently I found you don't have to re-encode MKV's if you want to turn them into MP4's, you just simply change the container. I'm using the program FFMpeg to accomplish this. The below command looks in the current folder for any MKV and changes the container to MP4, it then goes through and renames the files.

Code:

for i in *mkv; do ffmpeg -i "$i" -codec copy "$i".mp4; rename 's/\.mkv\.mp4$/\.mp4/' *mkv.mp4;done

It works great, however what this means is I have to navigate into each TV show, then each season, and run the string. As it takes a little time to run it's becoming quite tedious to babysit the progress, then when it finishes change to the next folder, rinse and repeat. This is repetitive task I know that can be scripted to save time.

My file hierarchy looks like this:

Code:

-TV
 --Seinfeld
 --Star Trek TNG
    ---Season 01
    ---Season 02
            Episode 01
            Episode 02
            Episode 03
            ...
    ---Season 03
    ---Season 04
    ...
 --Star Wars Clone Wars

What I want is to run the command from the root TV folder and it recursively to go through each subfolder and run it's conversion operation. Whether there's some code I can add to the original string to do this, or if I have to write a little script file, whatever is more effective. I know this is probably a simple answer for someone with experience. Any help would be appreciated, thanks!

schneidz · 08-20-2015, 03:19 PM

Code:

find . -type f -name "*.mkv" -exec ffmpeg -i '{}' -codec copy '{}'.mp4 \;

dimonic · 08-20-2015, 03:32 PM

So what you want to do could be done in a couple of ways (curse you Linux with your many ways to skin a cat).

One way is to use find

Code:

$ find . -name "*.mkv" -exec ffmpeg -i {} -codec copy `basename {} .mkv`.mp4 \;

Another would be to parse your command line for files and then test if directories and recurse using a shell function

Code:

#!/bin/sh

function parse_dir()
{
    for file in $*
    do
        if [ -d "$file" ]
        then
            cd "$file"
            parse_dir *
        else
          ffmpeg -i "$file" -codec copy `basename "$file" .mkv`.mp4
        fi
    done
}

parse_dir $*

Note that I am using basename to save the rename after each ffmpeg.

grail · 08-21-2015, 07:16 AM

You could also augment your current script:

Code:

shopt -s globstar
shopt -s nullglob

for i in /TV/**/*.mkv; do
  ffmpeg -i "$i" -codec copy "$i".mp4

  rename 's/\.mkv\.mp4$/\.mp4/' *mkv.mp4
done

Untested but you should get the idea. It also assumes TV is at the root level, so obviously put in the appropriate path