The current range value causes an underflow
when negated and pushes anything less than zero
to the minimum.

For now force everything to int16_t, except
for variables used as index

If everything works fine for 16-bit streams,
the current code could be extended to do 24-bit.

Not sure if this is correct. But looks like
it was giving us off-by-one's when used to index
buffers.

(Resolves some conflicts)

Size should be determined from bits per sample.
The current code only accepts 16-bit streams.