Coding method and device, and decoding method and device

Abstract

The embodiment of the invention discloses a coding method, a coding device, a decoding method, a decoding device, a coding system and a decoding system. The coding method comprises the following steps that: a coder acquires data to be coded, wherein the data to be coded is at least one largest coding unit (LCU); the coder determines a quantization depth parameter of the LCU according to a code rate control algorithm, and writes the quantization depth parameter into the data to be coded; the coder determines a quantization parameter (QP) of each CU according to a minimum image block dimension and the dimension of each CU in the LCU; the coder calculates a QP difference of each CU according to the QP and a QP predicted value of the CU; for each CU consistent with a preset condition, the coder carries the QP difference of the CU into the CU; and the coder codes the quantization depth parameter, the QP difference of the CU consistent with the preset condition and each CU to obtain a code stream. The embodiment of the invention also provides the decoding method, the coding device and the decoding device. By the embodiment of the invention, code rate control accuracy and compression efficiency can be effectively improved.

Description

technical field [0001] The present invention relates to the field of data processing, in particular to an encoding method and device, and a decoding method and device. Background technique [0002] In the existing video image encoding process, the encoder needs to perform spatial transformation on the original image block data or the predicted image block difference data, quantize the transformation coefficients, and then perform entropy encoding on the quantized coefficients. The decoding end performs an inverse quantization operation on the coefficients obtained by entropy decoding, reconstructs the transformation coefficients, and then performs an inverse transformation operation to obtain the original image block data or image block difference data. [0003] In order to perform inverse quantization at the decoder, the decoder needs to obtain the quantization step size (QStep) used in the quantization process at the encoder. Therefore, the encoder needs to write the adop...

AI Technical Summary

Problems solved by technology

[0019] However, in this prior art, since the smallest CU can be set to 8*8, if the qp_delta information of the CU is carried in each CU, a large amount of coding overhead will be added, thereby affecting the overall compression efficiency of image coding

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