ئەز   Khalid Abdullah M. Salih

particularly when using User Datagram Protocol (UDP), which lacks inherent error correction mechanisms. This study provides a comprehensive framework for selecting HEVC encoding configurations based on motion content and network condition. The paper evaluates the packet loss resilience of various HEVC encoding configurations across video content with high-motion, intermediate-motion, and low-motion activity. Utilizing UDP streaming in conjunction with the MPEG Transport Stream (MPEG-TS) container, video quality was quantified using the Peak Signal-to-Noise Ratio (PSNR) and Structural Similarity Index Measure (SSIM) under packet loss rates of up to 1.0%. Three HEVC encoding configurations IPPP, periodic I, and periodic IDR were assessed. The results indicate that periodic IDR, with its closed GOP structure, achieves the highest resilience to packet loss, rendering it ideal for unreliable networks. Specifically, for high-motion video content, periodic IDR limited PSNR degradation to 6.97 dB (from 28.78 dB to 21.87 dB) under a 0.5% packet loss rate. For intermediate-motion content (Mobcal), PSNR decreased by 9.26 dB (from 34.85 dB to 25.23 dB), and for low-motion content (FourPeople), PSNR degraded by 6.96 dB (from 40.87 dB to 33.91 dB), consistently outperforming the other configurations. In contrast, periodic I demonstrated moderate resilience, with PSNR degradation of 9.6 dB for high-motion content, up to 14.36 dB for intermediate-motion content, and approximately 11.46 dB for low-motion content. The IPPP configuration exhibited the greatest vulnerability, with PSNR degradations of 12.66 dB, 18.7 dB, and 11.95 dB for Crowd_run, Mobcal, and FourPeople, respectively, due to extensive error propagation inherent in its open GOP structure. The findings advance the understanding of error resilience in video compression and offer practical guidelines for maximizing video quality in real-world streaming scenarios over lossy IP networks.

Abstract: Digital video coding aims to reduce the bitrate and keep the integrity of visual presentation. High-Efficiency Video Coding (HEVC) can effectively compress video content to be suitable for delivery over various networks and platforms. Finding the optimal coding configuration is challenging as the compression performance highly depends on the complexity of the encoded video sequence. This paper evaluates the effects of motion content on coding performance and suggests an adaptive encoding scheme based on the motion content of encoded video. To evaluate the effects of motion content on the compression performance of HEVC, we tested three coding configurations with different Group of Pictures (GOP) structures and intra refresh mechanisms. Namely, open GOP IPPP, open GOP Periodic-I, and closed GOP periodic-IDR coding structures were tested using several test sequences with a range of resolutions and motion activity. All sequences were first tested to check their motion activity. The rate–distortion curves were produced for all the test sequences and coding configurations. Our results show that the performance of IPPP coding configuration is significantly better (up to 4 dB) than periodic-I and periodic-IDR configurations for sequences with low motion activity. For test sequences with intermediate motion activity, IPPP configuration can still achieve a reasonable quality improvement over periodic-I and periodic-IDR configurations. However, for test sequences with high motion activity, IPPP configuration has a very small performance advantage over periodic-I and periodic-IDR configurations. Our results indicate the importance of selecting the appropriate coding structure according to the motion activity of the video being encoded. Keywords: HEVC; video; motion vectors; periodic-I; periodic-IDR