It has been demonstrated recently that 3-D wavelet coding with motion-compensated temporal filtering (MCTF) provides a wide range of spatio-temporal-SNR scalability with state-of-the-art coding performance. However, the coding system is very different from the already standardized motion-compensated DCT (MC-DCT) video coders such as MPEG-2, MPEG-4, or H.26L. Nonetheless, the market acceptance of the new scalable technology will come much easier if backward compatibility to such previous standards would exist. In this paper, we present a new coder architecture where the base layer can be a standard MC-DCT coder, while the enhancement layer is an in-band MCTF codec operating in the overcomplete wavelet domain. First, we propose a simple extension of the scalable 3-D wavelet codec with a standard MC-DCT base layer. As a second step, to improve the performance of the proposed scalable coder over a wide range of bit-rates, we describe several small extensions to the standardized MC-DCT codec structure that can be applied for the base layer coding.