Abstract: In this paper, a load balancing algorithm based on multi-band HEVC parallel encoder is proposed to solve the problem of load imbalance in HEVC parallel video encoder with uniform strip division. By analyzing the relationship between the encoding efficiency and several encoding parameters, such as the GOP, the quantization parameter and the number of reference frames, an Encoding Time Prediction Model（ETPM） is proposed for the Coding Tree Units（CTU）. And based on the proposed model, a load-balancing algorithm is further proposed for multi-slice HEVC parallel encoder. This algorithm uses both the previously coded frame on the same temporal layer and the located previously coded frame, and based on the actual encoding parameters, this paper predicts every CTU’s encoding time of the current frame. Then, the load balancing operation of the parallel encoder is carried out based on that. Experimental results show that the proposed method can improve the acceleration ratio of about 9.23% compared with the existing uniform strip division method, and the performance loss of the coding is almost negligible.

Key words: video coding, High Efficiency Video Coding（HEVC）, encoding time prediction model, encoder optimization, load balancing, slice parallel

摘要： 针对在均匀条带划分的HEVC并行视频编码器中出现的负载失衡问题，提出了一种基于多条带HEVC并行编码器的负载均衡算法。从编码参数入手，通过分析量化参数、参考帧数目和图像组等因素与编码耗时之间的关系，提出了一种基于编码参数的编码时间预测模型。以位置上和时间层上相邻已编码帧的编码信息为基础，以实际编码参数为依据，根据编码时间预测模型进行当前帧编码时间的预测，从而以当前帧的预测时间为依据，进行多条带HEVC并行编码器的负载均衡操作。实验结果表明，与现有均匀条带划分方法相比，提出的方法能够提升加速比9.23%左右，而编码的性能损失几乎可以忽略不计。

关键词: 视频编码, 高效视频编码（HEVC）, 编码时间预测模型, 编码器优化, 负载均衡, slice级并行