Method and system for determining differential quantization parameters and video encoder

Abstract

The invention discloses a method and system for determining differential quantization parameters and a video encoder, wherein the method for determining the differential quantization parameters comprises the steps of firstly dividing a discrete cosine transform coefficient block into at least two to-be-encoded areas according to the size of the discrete cosine transform coefficient block; determining a predictive quantization parameter of the to-be-encoded area at an initial position of a preset direction in the at least two to-be-encoded areas according to a preset encoding rule and determining one differential quantization parameter according to the quantization parameter and the predictive quantization parameter of the to-be-encoded area; and sequentially calculating the differential quantization parameters of the remaining to-be-encoded areas according to the quantization parameter of the to-be-encoded area at the initial position of the preset direction in the at least two to-be-encoded areas. Compared with a method for determining one differential quantization parameter of one discrete cosine transform coefficient block in the prior art, the method for determining the differential quantization parameters has the advantage that at least two differential quantization parameters are determined for the discrete cosine transform coefficient block, thereby achieving the aim of improving the video encoding efficiency.

Description

technical field [0001] The present application relates to the technical field of image processing, and more specifically, relates to a method for determining a differential quantization parameter, a system for determining it, and a video encoder. Background technique [0002] Quantization is the operation of reducing the length of image coding and reducing unnecessary information in visual restoration without reducing the visual effect. It is the core step in the video coding process. In today's mainstream discrete cosine transform (DiscreteCosine Transform, DCT) hybrid prediction In a basic video encoder, an image is divided into a plurality of image blocks to be encoded separately. In the process of quantizing the image blocks, the determination of the difference quantization parameters of each image block is the key to determine the video coding efficiency. [0003] In H.264 and earlier coding standards, the image is divided into multiple image blocks during encoding, the...

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Problems solved by technology

[0004] However, the current mainstream video coding methods all have low efficiency problems. How to improve video coding efficiency is one of the directions of researchers' efforts.

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