Disable FFmpeg related functions if it's not found
Rename 'Link' column to 'Input'
Shorten automatic conversion variables
Code style
Comment code
Change 'while' loop to 'for' loop
Fix Settings getting wrong value
Use StringBuilder to format title
Move a check into 'IsValidUrl'
Suggest .mp3 filename
Add comment
YoutubeDownloader: Edit summaries
Use 'string.Format' instead of 'String.Format'

- Just to be consistent
Deselect other ListViewItems when adding new item