No abstract

In this paper, we propose a practical synchronization mechanism to achieve synchronized playback of the arrived 4K video bitstreams at different terminal devices based on MMT (MPEG Media Transport) protocol. In addition to the synchronized playback, we achieve the video playback with minimum service latency by estimating the accurate total end-to-end delay between the server and receiver. The conventional synchronization method between multiple clients generally calculates the time difference through communication between each client. Communication between multiple clients increases complexity and consumes network bandwidth. We do not rely on the communication between multiple clients but exploits the timestamp information supported by the MMT protocol.

Recently, as demand for high-quality video and realistic media has increased, High Efficiency Video Coding has been standardized. However, High Efficiency Video Coding requires heavy cost in terms of computational complexity to achieve high coding efficiency, which causes problems in fast coding processing and real-time processing. In particular, High Efficiency Video Coding inter-coding has heavy computational complexity, and the High Efficiency Video Coding inter prediction uses reference pictures to improve coding efficiency. The reference pictures are typically signaled in two independent lists according to the display order, to be used for forward and backward prediction. If an event occurs in the input video, such as a scene change, the inter prediction performs unnecessary computations. Therefore, the reference picture list should be reconfigured to improve the inter prediction performance and reduce computational complexity. To address this problem, this article proposes a method to reduce computational complexity for fast High Efficiency Video Coding encoding using information such as scene changes obtained from the input video through preprocessing. Furthermore, reference picture lists are reconstructed by sorting the reference pictures by similarity to the current coded picture using Angular Second Moment, Contrast, Entropy, and Correlation, which are image texture parameters from the input video. Simulations are used to show that both the encoding time and coding efficiency could be improved simultaneously by applying the proposed algorithms.