split audio files into same length parts

_split.ps1

# Split MP3/M4A/M4B files into 5 min parts
# Known Issues:
# recursive folders don't work. seperate files I also screwed up. Just give it 1 folder, or use _splitAll.ps1 for multiple folders.
# afterwards you can search in the folder with everything (https://www.voidtools.com/support/everything/) 
#    like this : "D:\!!Downloads\!audiobook\" !_ to find everything without an underscore (_) which should most likely only be the 
#    original files and delete them

# if windows refuses to execute the scripts try something like this in an admin powershell (Win+X A): 
#    Set-ExecutionPolicy Unrestricted
for ($i = 0; $i -lt $args.Count; $i++) {
    # iterate through all given parameters
    if (Test-Path -Path $args[$i] -PathType Container) {
        # check if fodler
        $folderFiles = Get-ChildItem $args[$i]
        for ($j = 0; $j -lt $folderFiles.Count; $j++) {
            $path = Get-Location                            #  save current fodler
            Set-Location $args[$i]                          # change to working dir
            $base = (Get-Item $folderFiles[$j]).BaseName    # filename w/o extension
            $ext = (Get-Item $folderFiles[$j]).Extension    # extension with period i.e. .mp3
            
            # m4b is for single file audio books, m4a for single files both use aac codec
            if ($ext -eq ".m4b") {
                $ext = ".m4a"
            }
            ffmpeg -i $folderFiles[$j] -f segment -segment_time 300 -c copy "$base""_%03d$ext"  #  split into 5 minute parts
            Set-Location $path  # go to starting folder
        }
    }
    else {
        #  for files instead of folders
        $path = Get-Location                            #  save current fodler
        Set-Location $args[$i]                          # change to working dir
        $base = (Get-Item $folderFiles[$j]).BaseName    # filename w/o extension
        $ext = (Get-Item $folderFiles[$j]).Extension    # extension with period i.e. .mp3
        # m4b is for single file audio books, m4a for single files both use aac codec
        if ($ext -eq ".m4b") {
            $ext = ".m4a"
        }
        ffmpeg -i $args[$i] -f segment -segment_time 300 -c copy "$base""_%03d$ext"    #  split into 5 minute parts
        Set-Location $path # go to starting folder
    }
}

_splitAll.ps1

# use Everything (https://www.voidtools.com/support/everything/) to copy list of folder names
$vals = @(
    "D:\!!Downloads\!audio\The Witcher\Andrzej Sapkowski - Baptism of Fire The Witcher, Book 3 (Unabridged)"
    "D:\!!Downloads\!audio\The Witcher\Andrzej Sapkowski - Blood of Elves The Witcher, Book 1 (Unabridged)"
    "D:\!!Downloads\!audio\The Witcher\Andrzej Sapkowski - Lady of the Lake The Witcher, Book 5 (Unabridged)"
    "D:\!!Downloads\!audio\The Witcher\Andrzej Sapkowski - Season of Storms (Unabridged)"
    "D:\!!Downloads\!audio\The Witcher\Andrzej Sapkowski - Sword of Destiny (Unabridged)"
    "D:\!!Downloads\!audio\The Witcher\Andrzej Sapkowski - The Last Wish (Unabridged)"
    "D:\!!Downloads\!audio\The Witcher\Andrzej Sapkowski - The Tower of the Swallow The Witcher, Book 4 (Unabridged)"
    "D:\!!Downloads\!audio\The Witcher\Andrzej Sapkowski - Time of Contempt The Witcher, Book 2 (Unabridged)"
    "D:\!!Downloads\!audio\Robert Jordan - The Wheel of Time Series\Book 0 -  New Spring (Unabridged)"
    "D:\!!Downloads\!audio\Robert Jordan - The Wheel of Time Series\Book 1 -  The Eye of the World (Unabridged)"
    "D:\!!Downloads\!audio\Robert Jordan - The Wheel of Time Series\Book 10 -  Crossroads of Twilight (Unabridged)"
    "D:\!!Downloads\!audio\Robert Jordan - The Wheel of Time Series\Book 11 -  Knife of Dreams (Unabridged)"
    "D:\!!Downloads\!audio\Robert Jordan - The Wheel of Time Series\Book 12 -  The Gathering Storm (Unabridged)"
    "D:\!!Downloads\!audio\Robert Jordan - The Wheel of Time Series\Book 13 -  Towers of Midnight (Unabridged)"
    "D:\!!Downloads\!audio\Robert Jordan - The Wheel of Time Series\Book 14 -  A Memory of Light (Unabridged)"
    "D:\!!Downloads\!audio\Robert Jordan - The Wheel of Time Series\Book 2 -  The Great Hunt (Unabridged)"
    "D:\!!Downloads\!audio\Robert Jordan - The Wheel of Time Series\Book 3 -  The Dragon Reborn (Unabridged)"
    "D:\!!Downloads\!audio\Robert Jordan - The Wheel of Time Series\Book 4 -  The Shadow Rising (Unabridged)"
    "D:\!!Downloads\!audio\Robert Jordan - The Wheel of Time Series\Book 5 -  The Fires of Heaven (Unabridged)"
    "D:\!!Downloads\!audio\Robert Jordan - The Wheel of Time Series\Book 6 -  Lord of Chaos (Unabridged)"
    "D:\!!Downloads\!audio\Robert Jordan - The Wheel of Time Series\Book 7 -  A Crown of Swords (Unabridged)"
    "D:\!!Downloads\!audio\Robert Jordan - The Wheel of Time Series\Book 8 -  The Path of Daggers (Unabridged)"
    "D:\!!Downloads\!audio\Robert Jordan - The Wheel of Time Series\Book 9 -  Winter's Heart (Unabridged)"
    "D:\!!Downloads\!audio\Mistborn\Brandon Sanderson - The Final Empire Mistborn, Book 1 (Unabridged)"
    "D:\!!Downloads\!audio\Mistborn\Brandon Sanderson - The Hero of Ages Mistborn, Book 3 (Unabridged)"
    "D:\!!Downloads\!audio\Mistborn\Brandon Sanderson - The Well of Ascension Mistborn, Book 2 (Unabridged)"
)

foreach ($val in $vals) {
    Invoke-Expression -Command ".\_split.ps1 '$val'"    
}