New-Item -ItemType directory -Path \\192.168.1.100\Media\CamRec\scriptbackup
# Create a new temp folder

copy-item \\192.168.1.100\Media\CamRec\Photos\* \\192.168.1.100\Media\CamRec\scriptbackup
# Copy each item from source folder to new temp one

cd \\192.168.1.100\Media\CamRec\scriptbackup
$i = 1
Get-ChildItem *.jpg | %{Rename-Item $_ -NewName ('pic{0:D4}.jpg' -f $i++)}
# Move to the temp and rename them all sequentially (From 1 to infinity) starting with 'pic'

cmd.exe /c "ffmpeg -r 100 -f image2 -s 1920x1800 -i \\192.168.1.100\Media\CamRec\scriptbackup\pic%04d.jpg -vcodec libx264 \\192.168.1.100\Media\CamRec\Movies\Timelapse.mp4 -y"
# encode sequential shots into a .mp4 video, overwriting if one is currently there to keep it up to date with new film

Remove-Item  -Path \\192.168.1.100\Media\CamRec\scriptbackup -Force -Recurse
# remove the temp directory because there is no need to keep renamed copies of source images