SYSTEM UND VERFAHREN ZUR ERZEUGUNG VON TRICKWIEDERGABE-VIDEODATENSTRÖMEN AUS EINEM KOMPRIMIERTEN NORMALWIEDERGABE-VIDEODATENSTROM

摘要

A system and method for generating trick play video streams, such as fast forward and fast reverse video streams, from an MPEG compressed normal play bitstream. The system receives a compressed normal play bitstream and filters the bitstream by extracting and saving only portions of the bitstream. The system preferably extracts I-frames and sequence headers, including all weighting matrices, from the MPEG bitstream and stores this information in a new file. The system then assembles or collates the filtered data into the proper order to generate a single assembled bitstream. The system also ensures that the weighting matrixes properly correspond to the respective I-frames. This produces a bitstream comprised of a plurality of sequence headers and I-frames. This assembled bitstream is MPEG-2 decoded to produce a new video sequence which comprises only one out of every X pictures of the original, uncompressed normal play bitstream. This output picture stream is then re-encoded with respective MPEG parameters desired for the trickplay stream, thus producing a trickplay stream that is a valid MPEG encoded stream, but which includes only one of every X frames. The present invention thus generates compressed trick play video streams which require reduced storage and reduced data transfer bandwidth requirements.