Ad Processor V2 - Trims songs down to the perfect length for a 2 min advert and also updates the metadata. Requires ffmpeg & mp3info

ad-processor-v2.sh

#!/bin/zsh

# (c) Copyright 2018 Charlie Britton (chza.me). All rights reserved.

# PLEASE NOTE: You will need ffmpeg and mp3info for this script to work properly!
# On MacOS, install Homebrew and then run `brew install mp3info` and `brew install ffmpeg`

# This script has only been tested on MacOS, there is no guarantee that it will work on any other OS (especially Windows).

# Set the directory to work from, this should have the child folder ./original/ with all of your music.
WORKINGDIRECTORY="/Users/someone/process-songs"

# Don't process songs shorter than x seconds. Default set to a few more seconds than advert length.
SHORT=125

# Don't process songs longer than x seconds (default of 5 minutes).
# This is because it could be processing a compilation of songs.
LONG=300

# The actual length of the adverts you'll want.
# Default is 2 seconds over default SC advert length for fading with automation software.
LENGTH=122

# Standard streaming bitrate. Also SC won't run ad stitching on some bitrates. Best left at 128k.
BITRATE=128000

# Default title and artist the SC ad server recognises. Probably best left as is.
TITLE="Advert:"
ARTIST="Advert:"

# PLEASE DO NOT EDIT BELOW THIS LINE! ------------------------------------------

CA=$(tput setaf 5)
CB=$(tput setaf 3)
CC=$(tput setaf 242)

# cd to Music Folder
cd $WORKINGDIRECTORY

# Welcome Message
clear
printf $CA"\n %%$CB Welcome to Ad Processor V2\n$CA %% $CB(c) Copyright 2018 Charlie Britton (chza.me)\n\n$CA %%$CB Please set the directory of the folder to process by editing this script, and then place your original media in a subfolder /original/.\n$CA %%$CB If have done that, please$CA press enter to continue$CB, or$CA CTRL+C to stop and set the process folder$CB.\n"

read keypress

# Setup Working Directories
printf $CA" i$CB Creating Folders... "
mkdir long  > /dev/null 2>&1
mkdir short  > /dev/null 2>&1
printf $CA"Done!\n"

# Don't want to be processing anything longet than 5 mins...
printf $CA" i$CB Moving long albums/compilations (>=$LONG seconds)... "
find original/ -name "*mp3" |
  while IFS= read -r f; do
   songlength=$(mp3info -p "%S" "$f");
   if [[ "$songlength" -ge $LONG ]]; then
     mv $f long/;
   fi;
done
printf $CA"Done!\n"

# Don't want to pad a song with silence either!
printf $CA" i$CB Moving short songs (<=$SHORT seconds)..."
find original/ -name "*mp3" |
  while IFS= read -r f; do
   songlength=$(mp3info -p "%S" "$f");
   if [[ "$songlength" -le $SHORT ]]; then
     mv $f short/;
   fi;
done
printf $CA"Done!\n\n"

printf $CA" %%$CB I am just about to begin processing the songs to: \n     $CA|\n     $CA|-$CB Length (s):       $CA$LENGTH\n     $CA|-$CB Bitrate (bits/s): $CA$BITRATE\n     $CA|-$CB Title:            $CA$TITLE\n     $CA\`-$CB Artist:           $CA$ARTIST\n\n$CA %% PLEASE NOTE:$CB This will take a while to process, so please leave your computer running whilst this operation completes.$CA\n %%$CB Please$CA press enter to continue$CB, or$CA CTRL+C to stop$CB.\n"

read keypress

printf $CA" i$CB Clearing out old adverts... "
rm -rf adverts
mkdir adverts
printf $CA"Done!\n"
sleep 0.5

TOTAL=$(find original/*.mp3 | wc -l | tr -d '[:space:]')
COUNTER=0

printf $CA" i$CB Starting processing of $TOTAL songs$CA NOW!\n\n"
cd original
for i in *.mp3; do
  ((COUNTER++))
  printf $CB" ($COUNTER/$TOTAL)$CC Processing $i... ";
  ffmpeg  -loglevel panic -i "$i" -acodec libmp3lame -ab $BITRATE -af 'afade=t=out:st=117:d=5' -metadata title=$TITLE -metadata artist=$ARTIST -write_id3v1 1 -t $LENGTH "../adverts/ADVERT_$i";
  printf $CA"Done!\n"
done

printf $CA"\n i$CB Finished processing songs!\n\n$CA %%$CB Thanks for using Ad Processor V2.\n\n"

exit 0

If you need to pick some random files from a list of music in a directory, cd into it and then use the following command to save 100 random file paths to a text file:

find . | grep -e ".mp3$" | gsort -R | tail -100 > ~/Desktop/process-songs.txt

Then, I use regexr to wrap the filenames in quotes and replace the newlines with spaces. I then copy and paste that into a cp command cp <paste here> ~/Desktop/music/original after making the directories.

Once done, point the script to the ~/Desktop/music and voila!