An NSA (NullSoft Streaming Audio) file is a streaming audio format developed by NullSoft for streaming audio over the internet. NullSoft also developed Winamp media player for streaming and playback of audio and video files. The NSA file format uses audio compression algorithms introduced and developed by NullSoft. NullSoft also has developed the NSV file format for streaming videos over the internet.
NSA File Format
NSA files are streamed online using the NullSoft audio container file format. NSA files are used to stream audio data and music via internet using the Winamp application. NSA files are usually affixed with .nsa extension.