Tut Systems, Inc.

Arris Enterprises LLC

Guoyao Yu

Charles H Van Dusen

Mayer D Schwartz

Peter A Borgwardt

Zhi Zhou

A method of operating a multi-processor video encoder by determining a target size corresponding to a preferred number of bits to be used when creating an encoded version of a picture in a group of sequential pictures making up a video sequence. The method includes the steps of calculating a first degree of fullness of a coded picture buffer at a first time, operating on the first degree of fullness to return an estimated second degree of fullness of the coded picture buffer at a second time, and operating on the second degree of fullness to return an initial target sized for the picture. The first time corresponds to the most recent time an accurate degree of fullness of the coded picture buffer can be calculated and the second time occurs after the first time.

Parallel rate control for digital video encoder with multi-processor architecture and picture-based look-ahead window

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

A rate and delivery time multiplexing for bandwidth optimization algorithm has an allocation portion and a transrating portion. The allocation portion determines how many bits are available for each group of pictures in each program stream that is to be inserted into an outgoing MPEG Transport Stream (MTS). Based upon the allocated bits the transrating portion, when necessary, further compresses the program streams either in the compressed domain when rate reduction is minimal or in the pixel domain when rate reduction is significant. The result is the ability to transmit more video program streams over a given fixed bandwidth pipe for a given level of acceptable picture degradation.

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Portland, OR, United States of America

Guoyao Yu