fix process check, scoop install & ffmpeg check

install/pre.ps1

@@ -1,25 +1,36 @@
 if (Get-Command sm  -Ea Ignore){
-"@
+@"
+
 A Smoothie installation has been detected, what would you like to do?
 
 Press R to Reinstall Smoothie (clean install)
 Press V to update Smoothie to a newer version
 Press U to uninstall Smoothie
+"@
 
-@"
+function CheckProcesses{
+    if (Get-Process -Name sm,vspipe,ffmpeg -ErrorAction SilentlyContinue){
+        Write-Warning "One of the following processes are still running and may cause uninstallation issues, make sure these processes are not tied to Smoothie:"
+        Get-Process -Name sm,vspipe,ffmpeg -ErrorAction SilentlyContinue
+    }     
+
+}
 switch (choice.exe /C RVU /N | Out-Null){
     1{
+        CheckProcesses
         scoop.cmd uninstall smoothie
         scoop.cmd install smoothie
         pause
         exit
     }
     2{
+        CheckProcesses
         scoop.cmd update smoothie
         pause
         exit
     }
     3{
+        CheckProcesses
         scoop.cmd uninstall smoothie
         pause
         exit
@@ -28,6 +39,7 @@ switch (choice.exe /C RVU /N | Out-Null){
 }
 
 if (-Not(Get-Command scoop.cmd -Ea Ignore)){
+    Set-ExecutionPolicy Bypass -Scope Process -Force
     Invoke-RestMethod -Uri http://get.scoop.sh | Invoke-Expression
 }
 
@@ -39,8 +51,28 @@ if ('utils' -NotIn (scoop.cmd bucket list)){
     scoop.cmd bucket add utils https://github.com/couleur-tweak-tips/utils
 }
 
+$IsFFmpegScoop = (Get-Command ffmpeg -Ea Ignore).Source -Like "*\shims\*"
+
 if(Get-Command ffmpeg -Ea Ignore){
+
+    $IsFFmpeg5 = (ffmpeg -hide_banner -h filter=libplacebo)
+
+    if (-Not($IsFFmpeg5)){
+
+        if ($IsFFmpegScoop){
             scoop.cmd update ffmpeg
+        }else{
+            Write-Warning @"
+An FFmpeg installation was detected, but it is not version 5.0 or higher.
+If you installed FFmpeg yourself, you can remove it and use the following command to install ffmpeg and add it to the path:
+
+scoop.cmd install ffmpeg
+"@
+
+        }
+
+    }
+
 }else{
     scoop.cmd install ffmpeg
 }