Encoding method and device, and decoding method and device

Abstract

An embodiment of the invention discloses an encoding method and a device, a decoding method and a device and an encoding and decoding system. The encoding method includes that an encoding terminal obtains data to be encoded, and the data to be encoded are at least one largest coding unit (LCU); the encoding terminal 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 encoded; the encoding terminal determines quantization parameters (QPs) of coding units (CUs) according to the size of a minimum image block and the size of CUs contained in the LCU; the encoding terminal calculates QP differences of CUs according to the QPs of the CUs and QP predicated values of the CUs; the encoding terminal carries the QP difference of the CU in the CU for each CU which meets preset conditions; and the encoding terminal encodes the quantization depth parameter, the QP differences of the CUs which meet the preset conditions and the CUs to obtain code streams. The embodiment of the invention further provides a decoding method and an encoding and decoding device. According to the embodiment of the encoding method and the device, and the decoding method and the device, the code rate control accuracy and the 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

[0015] 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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