Rate control model adaptation based on slice dependencies for video coding

摘要

Statistics for estimating quantization factors of a coding-unit type (e.g., B-coded or I-coded) pictures are determined from other, possibly different (e.g., P-coded) pictures, or previously coded coding-units. Bit rate and quality relationships between such coding-unit types may be used with the quantization parameters. Estimating bit rate and quality relationships between coding-unit types enables accurate rate control for pictures regardless of their coding-unit type. Bit rate and quality relationships between coding-unit types can be used with multiple rate control models to increase compression. Rate control parameters may be adjusted with statistics generated by a motion estimation and compensation framework. Rate control performance may be controlled in transcoding compressed bit streams.

主权项

1. A method, comprising:
maintaining, at a video encoder, a first number of rate control models for the first number of coding-unit types in a second number of coding-unit types, each coding-unit type in the first number of coding-unit types corresponding to a respective rate control model in the first number of rate control models, the second number of coding-unit types further comprising one or more coding-unit types not corresponding to any rate control model in the video encoder; the first number being an integer greater than zero, the second number being an integer greater than the first number; wherein a rate control model in the first number of rate control model comprises one or more coding parameters for coding pictures of a coding unit type to which the rate control model corresponds; wherein one or more coding parameters for coding pictures of a coding-unit type in the one or more coding-unit types not corresponding to rate control models in the video encoder are derived from one or more coding parameters in a rate control model in the first number of rate control model; receiving a current picture at the video encoder, wherein the current picture is characterized by a specific coding-unit type in the one or more coding-unit types not corresponding to any rate control model in the video encoder; translating one or more coding parameters from a first rate control model in the first number of rate control models to generate a first set of translated parameters, to code pictures of the specific coding unit type, using at least one scaling parameter or translation parameter that is based at least in part on a bit rate relationship between at least two different coding-unit types; coding the current picture using the first set of translated parameters.