Methods and apparatus for reducing the total amount of memory required to implement a video decoder and to perform a scan conversion operation on decoded video are described. In accordance with the present invention this is accomplished by having an interlaced to progressive (I-P) conversion circuit utilize the same frame memory used to decode the images upon which a conversion operation is performed. In this manner, the images, e.g., frames, which are buffered in the decoder are utilized by both the decoder and I-P conversion circuit thereby eliminating the need for the I-P conversion circuit to be supported with an independent frame memory. Data included in a decoder's frame memories is used to detect moving image areas for purposes of the I-P conversion process. In a specific exemplary embodiment, one of three frames, which is nearest to a present frame, is referred for calculating frame difference signals. Both subsequent and preceding frames are used to detect motion for I-P conversion purposes. This approach eliminates the need for a separate frame memory for motion detection purposes. Using the above discussed memory saving techniques, I-P conversion can be performed in accordance with the present invention by sharing the anchor frame memories and B-frame buffer present in a conventional decoder for both decoding and I-P conversion.