System and method for using a High-Definition MPEG decoder to extract multiple Standard Definition frames from a High-Definition frame

摘要

The system and method extracts a predetermined number of Standard Definition television frames from an MPEG-encoded High Definition video frame. The MPEG-encoded High Definition frame is decoded to recover the High Definition scan lines. Scan lines are alternately output from the decoder from the top and bottom of the High Definition frame (or from a frame buffer, after parsing, if the decoder is not capable of this operation). The pixel data in the alternate scan lines is separated into the predetermined number of Standard Definition frames, Standard Definition timing signals are then generated for each Standard Definition frame, and the Standard Definition data is output to a video encoder.