公开(公告)号：EP0931417B1

公开(公告)日：2005-12-07

申请号：EP97910970.9

申请日：1997-10-09

申请人： QUALCOMM INCORPORATED

发明人： PIAN, Donald, T. ,  LEE, Chong, U.

IPC分类号： H04N7/30

CPC分类号： H04N19/152 ,  H04N19/115 ,  H04N19/126 ,  H04N19/146 ,  H04N19/149 ,  H04N19/15 ,  H04N19/176 ,  H04N19/186 ,  H04N19/60 ,  H04N19/61

公开(公告)号：EP0931417A1

公开(公告)日：1999-07-28

申请号：EP97910970.0

申请日：1997-10-09

申请人： QUALCOMM INCORPORATED

发明人： PIAN, Donald, T. ,  LEE, Chong, U.

IPC分类号： G06T9 ,  H04N7

CPC分类号： H04N19/152 ,  H04N19/115 ,  H04N19/126 ,  H04N19/146 ,  H04N19/149 ,  H04N19/15 ,  H04N19/176 ,  H04N19/186 ,  H04N19/60 ,  H04N19/61

摘要： A system and method for adaptively controlling the encoded data rate in a data compression system. The system and method sets up alternative encoded bit streams for each segment of data and selects the alternative that would produce the bit rate closest to a predetermined target bit rate for transmission. Each segment of the video input is quantized by a set of quantizers (20a-20c) to produce a plurality of quantized segments. Each quantized segment is variable rate encoded by a variable-length encoder (22a-22c) based on a quantization index to produce an alternative encoded bit stream. A set of rate measurers (24a-24c) measure the data rate that would be required to transmit each alternative encoded bit stream, and comparator (30) compares the measured rates with a predetermined target bit rate. The encoded bit stream having a rate closest to the target bit rate is provided to a rate buffer (34) in preparation for transmission. Having processed one segment of data, the system and method then updates its parameters for processing the next segment of data. A target bit rate update element (38) determines an updated target bit rate based on the rate buffer status. In addition, a quantization index update element (36) generates new quantization indices for processing the next segment of data.