Streaming codes offer reliable recovery under decoding-delay constraint $\tau $ , of packets transmitted over a burst-and-random-erasure channel. Prior rate-optimal code constructions had field size quadratic in $\tau $ and employed diagonal embedding of a scalar block code of length $n$ within the packet stream. It is shown here that staggered diagonal embedding (SDE) under which the $n$ code symbols are dispersed across a span of $N \ge n$ successive packets leads to a simpler, low-complexity construction of rate-optimal streaming codes having linear field size. The limits of the SDE approach under the restriction $N \leq \tau +1$ are explored. Some binary streaming codes that are rate-optimal under this restriction are identified. © 1997-2012 IEEE.