Synopsis
		sftimerev2d < in.rsf > out.rsf velocity=vel.rsf wave=wave.rsf verb=n abc=n snap=0 depth=0 ngrp=1 cb=0.0f

Parameters
		bool abc=n [y/n] absorbing boundary condition   float cb=0.0f   int depth=0 geophone depth   int ngrp=1 number of groups   int snap=0 wavefield snapshot flag   file velocity= auxiliary input file name   bool verb=n [y/n] verbosity flag   file wave= auxiliary output file name