This paper presents two novel methods to encode HD (High Definition) video at low bitrates (~5 Mbps) using the MPEG-2 Main Profile@Main Level standard (be compatible with current digital video devices; e.g., DVD players, digital video recorders, etc.) with the embedded HD-relevant information (E-data) in the bitstream. Due to the low bitrate constraint, traditional coding based approaches (e.g., MPEG-2 layered coding or scalable coding) cannot satisfy this requirement. Therefore, we developed our system from the video-enhancement point of view. At first, the HD video is down converted to SD (Standard Definition). During the down-conversion, extra data (E-data) is saved. This E-data is used to re-create HD effects when the encoded SD is upconverted prior to the display. For HD re-creation, we developed a novel multilevel resolution-enhancement method that makes an upconverted image emulate the quality of the original HD picture. Further, we designed a visual-based fine detail injection method to add more details into the picture to achieve near HD quality. Based on several test video sequences, we conclude that our approaches have the potential to create HD visual effect on the upconverted SD video.