Input: Input Plugins, also known as Decoders, determine what file types are supported by Winamp. For example, Nullosft MPEG Audio Decoder (in_mp3.dll) is required for Winamp to support mp3 files, Nullsoft Vorbis Decoder (in_vorbis.dll) is required for Ogg Vorbis support, etc. If in_vorbis.dll is not present in the Winamp\Plugins folder, then Winamp will not be able to play files with the .ogg extension. Each individual Input plugin has its own respective configuration. This could include options such as priority class, streaming buffer sizes, file extensions handled by the plugin, and other options specific to the filetypes handled by each respective Input plugin.