-1 -2 A bit rate shaping method of MPEG-1 and MPEG-2 video on the comressed domain

摘要

The present invention is compressed to suit the multimedia communication that is necessary to convert the video to be, in particular, the bit rate that meets the bandwidth in real time in response to changes of the communication band on the MPEG-1 and MPEG-2 bit rate bit-rate conversion method of the video in the compressed domain the method is to convert the video to the desired bit rate has the best quality.; The invention converts the bit rate through the re-quantization, which converts a quantization parameter of a macroblock constituting a frame in the compressed domain to a different value. And was used for IACT (Image Activity, video activity), which is a measure of the content of the image to the bit assignment for the macroblock, it obtains a bit allocation function to allocate the bits in the macroblock using the IACT. However, the bit allocation function may be the basis for assigning the bits of the macro block. However, the model in the variation according to the content of the frame and the image can not be applied to all streams. Therefore it devised an adaptive bit allocation model using the proper bit rate allocation function on a macroblock of the input stream according to the type and extent of IACT of the frame to solve this problem, and converts the bit rate on this basis.; The invention has the advantage to be calculated for use in convergence speed and accuracy, the algorithm of the converted bit rate and real time processing as compared to the conventional method.