| 摘要 |
A method of rate control using a picture-based lookahead sliding window in a dual-pass transcoder/encoder compressed video architecture extracts statistics from an input video signal according to a simple compression standard, the input video signal being a compressed video signal for transcoding or an uncompressed video signal for encoding. A trans-factor is calculated for a current picture based on previous pictures in a sliding window to predict the complexity of the current picture, the trans-factor being a ratio of global complexity measures for the simple compression standard versus a sophisticated compression standard. Bits for the current picture are then allocated based on the complexity of future pictures in the sliding window. After encoding the current picture according to the sophisticated compression standard, the target bits of and the picture complexity in the sliding window, as well as the trans-factor, are updated as the window is moved by one picture. The extraction of the statistics is achieved in a transcoder by using a simple compression standard decoder to produce the statistics from the compressed video signal as the input video signal, and in an encoder by using a simple compression encoder to generate the statistics from the uncompressed video signal as the input video signal. |
