sndfile - oscillator for disc files (digital recordings)

sndfile output[b] amplitude[bvpn] increment[bvpn] filename[s] channel[vpn] 
 startframe[bvpn] endframe[bvpn] pos[bvpnd] ptr[d] ;

Repeatedly reads in the specified channel of the file named by the
filename string variable, starting at sample startframe, ending at
sample endframe (if endframe = -1 then the end of the file is used).
The specified increment is applied to the file (this is normally 1.0);
if the end of the specified segment is reached, sndfile starts reading
again from the startframe.  The buffer size used by sndfile can be
controlled with the "set sfbufsize = N;" score statement (the default
value for N is 16KB, and may cause swapping if many simultaneous read
operations are used).
