Video transcoder with bitstream look ahead for rate control and statistical multiplexing

摘要

A method is provided for transcoding, i.e., decoding, and re-encoding, a previously encoded video signal, to a second encoded representation. A number k1 of previously encoded pictures of the previously encoded video signal are received in a buffer. Each of the k previously encoded pictures in the buffer is scanned to gather information on each of the k previously encoded pictures. An encoding parameter is allocated to a first one of the k previously encoded pictures which precedes each other one of the k previously encoded pictures in encoded order of the previously encoded video signal. The encoding parameter is allocated based on the information gathered for each of the k previously encoded pictures. The first previously encoded picture is decoded to produce a decoded picture. The decoded picture is re-encoded to generate a re-encoded picture in a second encoded representation of the video signal. The re-encoding is performed in a fashion which depends on the encoding parameter allocated thereto. An apparatus is also disclosed for carrying out the method including a buffer, a scanner (for performing the scanning and allocating steps), a decoder and an encoder.