Industrial Technology Research Institute

Sunplus Technology Co., Ltd.

Tut Systems, Inc.

Zhi Zhou

Ming-Ting Sun

Charles H Van Dusen

Guoyao Yu

Yuh-Feng Hsu

Shin-Huang Chang

Methods and systems for fast variable block-size motion estimation based on merging and splitting procedures for AVC video encoding are disclosed. The methods take advantage of the correlation of the Motion Vectors (MVs) of the different block-size modes to achieve a good computation reduction. Considering that the smaller the block-size difference between two block-sizes is, the more correlations between their MVs can be expected, the methods use a 8*8 block as an initial processing block to calculate prediction MVs. The prediction MVs are then used in predicting MVs for other block-sizes.

System and method for fast variable-size motion estimation

A method for fast macroblock mode decision is disclosed. The method includes: (A) determining if a motion cost at the origin (0, 0) or a prediction motion vector (PMV) for a 4n*4n macroblock is smaller than a first threshold; (B) if the motion cost is smaller than the first threshold, determining a macroblock mode as 4n*4n and ending the method; (C) if the motion cost is not smaller than the first threshold, using an adaptive diversity search strategy to perform motion estimation on four 2n*2n blocks associated with the 4n*4n macroblock; (D) determining if all motion costs of the four 2n*2n blocks in step (C) are smaller than a second threshold; and (E) if step (D) determines that the motion costs of the four 2n*2n blocks are smaller than the second threshold, determining the macroblock mode as 2n*2n and ending the method.

Method for fast macroblock mode decision based on motion cost of variable block size

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.

Rate control with picture-based lookahead window

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Seattle, WA, United States of America

Zhi Zhou