Method for selecting prediction mode of HEVC lossless video coding and corresponding coding method

Abstract

The invention provides a method for selecting a prediction mode of HEVC lossless video coding and a corresponding coding method. The method for selecting the prediction mode of the HEVC lossless video coding comprises the steps that firstly, the Lagrange multiplier, for RDO, of intra-frame prediction and the Lagrange multiplier, for RDO, of inter-frame prediction of each LCU of a video frame are initialized, intra-frame prediction and inter-frame prediction are conducted, an optimal mode is selected and used for coding, and the bit rate needed by coding of the frame is calculated and is used as a reference bit rate of initialization; secondly, the multipliers of the K LCUs of the frame are changed, the optimal mode is then selected and used for coding, the current bit rate is calculated, the difference value between the current bit rate and the reference bit rate is calculated, according to a preset rule, the changed multipliers are accepted or rejected, the current bit rate is used as the reference bit rate when the changed multipliers are accepted, whether the multipliers need to be changed again or not is judged, if not, the steps are ended, and if yes, the second step is executed again and iteration is conducted. According to the method for selecting the prediction mode of the HEVC lossless video coding, the original coding structure of the HEVC is changed slightly, the adverse influence of the QP in a primary standard on the lossless-mode coding efficiency is eliminated, and the coding bit rate is greatly reduced.

Description

technical field [0001] The present invention relates to the field of video coding, and more specifically, to a prediction mode selection method of HEVC lossless video coding and a video coding method based on the method. Background technique [0002] In recent years, with the continuous development of communication technology and multimedia technology, people's demand for multimedia communication such as video is also increasing. However, the amount of video data is huge, and video data that has not been encoded and compressed cannot be transmitted in existing channels. In order to meet the above various requirements, various video coding schemes have been proposed in the world. Since the 1990s, ITU.T and ISO have jointly formulated a series of international standards and recommendations on video compression codecs. Among them, the H.26X series video proposed by ITU Compression standards and the MPEG series of international standards introduced by ISO / IEC JTC have the grea...

AI Technical Summary

Problems solved by technology

However, in lossless compression, there is no quantization anymore, and QP actually has no other role except for adjusting λ.

figure 2 is the curve diagram of the sequence Racehorse bit rate changing with QP (HM 10.0) in lossless compression coding, by figure 2 It can be found that in lossless compression, the bit rate of the encoded code stream has a non-monotonic relationship with QP, whether it is the smallest QP (0 when the encoded video is 8 bits, -12 when the encoded video is 10 bits) or the largest (the encoded video is 51 at 8-bit, 39 at 10-bit), neither of which can reach the minimum bitrate

Images