HEVC视频编码：快速帧内编码技术

154 浏览量更新于2024-08-27 收藏 809KB PDF 举报

“快速帧内编码实现高效视频编码” 在视频编码领域，高效率视频编码（High Efficiency Video Coding，简称HEVC）是一种先进的标准，旨在显著提高视频压缩效率，同时保持相同的视频质量。HEVC是国际电信联盟（ITU-T）的视频编码专家组与国际标准化组织（ISO）/国际电工委员会（IEC）的运动图像专家组共同制定的新一代视频编码标准。它是在H.264/AVC的基础上发展起来的，提供了大约一倍的压缩比，这对日益增长的高清和超高清视频需求至关重要。快速帧内编码是HEVC编码过程中的核心部分，它涉及到对视频帧的内部预测和优化。帧内编码是指在编码一个视频帧时，仅依赖于同一帧内的像素信息进行预测，而无需参考其他时间上的帧。在HEVC中，帧内预测采用了多种模式，包括平面模式、角度模式以及更复杂的块分割模式，以适应不同场景和图像特征。文章提到的研究工作主要关注如何提高快速帧内编码的效率。作者Han Huang、Yao Zhao、Chunyu Lin和Huihui Bai来自北京交通大学的信息科学研究所和先进信息科学与网络技术北京市重点实验室。他们的研究得到了多项国家自然科学基金的支持，以及973计划、杰出青年学者基金等多个项目的资助。在HEVC中，快速帧内编码的关键在于减少计算复杂度，提高编码速度，同时保持编码质量和压缩效率。研究人员可能采用了优化的算法来快速选择最佳预测模式，例如通过简化搜索过程，利用统计模型预测最佳模式，或者开发新的上下文自适应二进制算术编码（Context-Adaptive Binary Arithmetic Coding，CABAC）策略来减少编码过程中的计算量。论文指出，快速帧内编码的改进对于实时视频传输和存储应用尤其重要，因为这些应用通常需要在有限的计算资源下处理大量的视频数据。通过减少编码时间和计算复杂度，可以实现更快的视频编码和解码，这对于移动设备和云计算环境中的视频服务来说是极其关键的。此外，文章还可能探讨了实际编码性能的评估，如编码效率的提升、编码时间的减少以及在不同视频内容和分辨率下的性能表现。这通常会通过与标准HEVC编码器的比较，或者与其他高级视频编码技术的性能对比来展示其优越性。 "快速帧内编码实现高效视频编码"这篇研究论文专注于提高HEVC编码标准的性能，通过优化帧内编码策略，实现更快、更高效的视频压缩，这对于推动视频编码技术的发展，满足未来高清视频传输和存储需求具有重要意义。

KSII TRANSACTIONS ON INTERNET AND INFORMATION SYSTEMS VOL. 8, NO. 3 Mar. 2014 1095

During the transform and quantization process, a CU can also be recursively split into a

quadtree of transform unit (TU). The intra prediction is applied for each TU sequentially

instead of applying the intra prediction at the PU level [2]. In this way, the nearest neighboring

reference samples from the already reconstructed TU are used for prediction. The HEVC

defines 35 intra prediction modes, namley Intra_DC, Intra_Planar and 33 angular prediction

modes denoded as Intra_Angular[k], k = 2,...,34. In comparison with H.264/AVC, the intra

prediction modes defined in HEVC are able to capture more directional structures.

In the HEVC test mode (HM), a rate-distortion (RD) optimized bottom-up pruning

algorithm [3] is adopted to find the best CU partition of a CTU. Given a CU, the best PU

partition type, prediction mode and TU partition are found by minimizing the Lagrangian cost.

While the flexible block structure and more choices of prediction mode provide better coding

performance, it dramatically increases the encoder complexity. Even for intraframe coding, it

is still far away from real-time application [4]. The computational complexity mainly comes

from two folds. First, an optimal CU partition within a CTU can consist of various sizes of CU

ranging from 8x8 to 64x64. Second, finding an optimal prediction mode requires a RD

optimization process. Therefore, fast algorithms in both aspects are desirable. Research works

regarding fast CU size decision include [5-8]; works targeting fast intra mode decision include

[9-15]. In our previous work [16], a novel fast bottom-up pruning (FBUP) algorithm was

proposed and proved to be efficient. In this paper, three techniques are proposed for fast intra

mode decision and combined with the FBUP algorithm. Starting from the smallest CU size, a

full quadtree is processed in a bottom-up manner. First, we check whether mode decision

process is needed for a current CU node. If the mode decision process is performed, then a set

of intra candidate modes are derived from the coding information obtained from its sub-blocks

(sub-CUs or PART_NXN PUs), followed by a rough decision process to choose a smaller set

of candidates. The number of candidates in the set is adaptively chosen based on the low

complexity RD cost. In this way, we can either skip the mode decision process or reduce the

number of candidate modes. Thus, the computational complexity is reduced.

In Section 2, the previous works in the literature are reviewed. Then the proposed method is

described in Section 3. In Section 4, the experimental results are presented to prove the

efficiency of the proposed algorithm. Compared to the original HM encoder, averaging over

all the test sequences and rate points, 41.39% encoding time saving is achieved while the

bitrate increase is only 0.77%. Finally, the conclusion is given in Section 5.

2. Related Works

2.1 Rate-Distortion Optimized Bottom-up Pruning

In HEVC, the CTU size is 64x64 and the maximum number of depth levels of the quadtree

4D

. The HM encoder adopts the rate-distortion optimized bottom-up pruning algorithm

to obtain the optimal CU quadtree partition. Consider the full quadtree as shown in Fig. 3, we

locate a node by its depth level from top to bottom and its position from left to right. Let

),( ji

be the index of

th node at depth level

, then

j 4

. Denote

as a CU at node

),( ji

without further splitting and

as the optimal tree after rate-distortion optimized pruning.

Let

)(J

be the operation to calculate the best RD cost. The bottom-up pruning algorithm

剩余11页未读，继续阅读

weixin_38725902

粉丝: 4

HEVC视频编码：快速帧内编码技术

视频编码基础：帧内编码技术解析

H.264视频编码技术：一种快速帧内预测算法研究

HEVC帧内编码优化：快速编码树单元决策算法

基于卷积神经网络的高效视频编码快速帧内编码方法研究与实现

自适应快速帧内预测，​​实现高效视频编码

基于x265的高效HEVC多速率编码系统中的快速帧内编码

高效视频编码标准中快速帧内模式决策与CU尺寸决策研究

HEVC平滑区域检测的快速帧内编码算法

基于决策树的HEVC快速帧内编码算法

高效视频编码(HEVC)开源实现Kvazaar 2.0：快速与优化的互帧编码器

最新资源

自适应快速帧内预测，实现高效视频编码