Quick HEVC intra-frame coding unit and pattern decision method

Abstract

The invention relates to a quick high-efficiency video coding (HEVC) intra-frame coding unit and pattern decision method which comprises the following steps: (1) the effective length N of a threshold value is set; (2) a first frame of a video sequence is normally coded, and the final coding depth and the discrete total variation (DTV) value of each largest coding unit (LCU) are stored in a cache region; (3) the DTV values in the cache region are counted, and a threshold value T1 and a threshold value T2 are worked out according to the depth range; (4) a quick pattern search algorithm based on direction gradient is adopted on the remaining N-1 frames according to the current DTV values of the LCUs and the threshold values at each depth search, with low-probability depth skipped; and (5) the (N+1)th frame is set as the first frame, and the steps (1), (2) (3) and (4) are repeated until all the frames are coded. The method adopts adaptive DTV threshold decision, the number of searched macro block units is reduced, the process of pattern search is simplified by adopting features based on direction gradient, and the coding speed is increased.

Description

technical field [0001] The invention relates to a fast HEVC intra-frame coding unit and a mode decision method. Background technique [0002] As a new-generation video coding standard, High Efficiency Video Coding (HEVC) has revolutionized many aspects compared to H.264 / AVC. In HEVC, the size of the macroblock is extended from 16x16 of H.264 / AVC to 64x64 to facilitate the compression of high-resolution video. At the same time, a more flexible coding structure is adopted to improve coding efficiency, including coding unit (Coding Unit, CU), prediction unit (Predict Unit, PU) and transformation unit (Transform Unit, TU). The coding unit is similar to the concept of a macroblock in H.264 / AVC and is used in the encoding process, the prediction unit is a basic unit for prediction, and the transformation unit is a basic unit for transformation and quantization. The separation of these three units makes the processing links of transformation, prediction and encoding more flexible...

AI Technical Summary

Problems solved by technology

If the rate-distortion model is calculated and compared for each mode of the macroblock, not only the content characteristics of the macroblock itself are ignored, but also the calculation amount will be relatively large, so the speed is slow, and the quality of the video after decoding cannot be guaranteed.

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