[Flac-dev] What is "mid-side coding"?

[Dr. Nick]

Hi all!  I've just gotten into the FLAC world, and have read most of the 
documentation.  I have a question:  Mike Wren's frontend, upon looking at 
the DOS command line it automatically generates, uses the "-m" 
command.  This is for "mid-side coding for each frame".  What is 
this?  Specifically, is this like the mid-side recording technique?  If so, 
that means the audio file is being changed by flac, yes?  An explanation of 
"mid-side coding" would be most appreciated.

Thanks in advance,

Matt