Quick intraframe prediction algorithm

Abstract

The invention discloses a quick intraframe prediction algorithm, which comprises the following steps of: 1) calculating SADavs of an 8X8 brightness block of a macro block; 2) determining the size of the SADavs, and taking a DC mode into account only if the SADavs is less than T1, or executing step 3) if the SADavs is equal to or more than 1; 3) if the SADavs is more than another threshold value T2, taking a direction mode rather than the DC mode into account only, or if the SADavs is less than or equal to another threshold value T2, taking both the direction mode and the DC mode into account,calculating Lumadiff of four direction modes, and marking the mode, corresponding to the minimum, as a Directionmode; 4) collecting MODEup, MODEleft and the candidates modes obtained by step 2) and step (3) to form a final candidate mode set; 5) calculating RDCost of each mode in the candidate set and selecting the mode, corresponding to the minimal RDCost, as the optimal prediction mode of the current sub-block; and 6) repeating step 1) to step 4) to acquire the optimal intraframe prediction modes of all the sub-blocks of the current macro block.

Description

technical field [0001] The invention belongs to the technical field of audio and video encoding and decoding, and in particular relates to an AVS1-P2 fast intra-frame prediction algorithm. Background technique [0002] AVS1-P2 adopts intra-frame prediction based on 8×8 pixel blocks. There are 4 and 5 modes for luma and chroma intra-frame prediction respectively. The reconstructed pixel values ​​of adjacent decoded blocks before loop filtering are used as the current block. refer to. Intra-frame prediction is a main time-consuming module of AVS1-P2 encoder, so optimizing the intra-frame prediction module is extremely important to improve the encoding speed. Fast intra prediction mode selection algorithm has always been a research hotspot in the video codec industry. [0003] At present, there are two commonly used methods to improve intra-frame prediction: simplifying the cost function and narrowing the selection range of prediction modes. The disadvantages of these two m...

AI Technical Summary

Problems solved by technology

The disadvantages of these two methods of improving intra prediction are that the prediction process is relatively complicated and the encoding time is long. Therefore, optimizing the intra prediction module to improve the encoding and decoding speed is an urgent task to improve the intra prediction method.

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