A METHOD AND APPARATUS FOR ALLOCATING BITS FOR CODING PICTURES AND A SEQUENCE OF PICTURES IN A BITSTREAM RECEIVED AT A DIGITAL VIDEO TRANSCODER

摘要

Rate control system of the present invention is suitable for use in a digital video transcoder for MPEG standard. In addition, the rate control system of the present invention by starting the coding in accordance with any appropriate set of estimated GOP parameters, and avoid a processing delay of about one GOP without extracting the complete GOP structure information from a pre-compressed bitstream. In addition, the system since it is not necessary to store the data corresponding to the GOP, the memory required for transcoding is reduced. Start the first picture of the GOP, or the encoding of the next sequence without a priori knowledge of the picture type of the picture. The appropriate set of GOP parameters is assumed to determine an encoding bit budget. Bit budget is a continuous picture coding according to the picture type is gradually corrected. Changes in the GOP structure of pre-compressed bitstreams, for example, may be addressed to the case of switching channels, inserting commercials. A target rate according to an incorrect starting GOP parameters can be concentrated in a small number of GOP.