While current video quality assessment research predominantly revolves around resolutions of 4K and beyond, targeted at Ultra High-Definition (UHD) displays, effective video quality for mobile video streaming remains primarily within the range of 480p to 1080p. In this study, we conducted a comparative analysis of the Quality of Experience (QoE) for widely implemented video codecs on mobile devices, specifically Advanced Video Coding (AVC), its successor High-Efficiency Video Coding (HEVC), and Google's VP9. Our choice of 720p video sequences from a newly developed database, all with identical bitrates, aimed to maintain a manageable subjective assessment duration, capped at 35-40 minutes. To mimic real-time network conditions, we generated stimuli by streaming original video clips over a controlled emulated setup, subjecting them to eight different packet loss scenarios. We evaluated the quality and structural similarity of the distorted video clips using objective metrics, including Video Quality Metric (VQM), Peak Signal-to-Noise Ratio (PSNR), Video Multi-Method Assessment Fusion (VMAF), and Multi-Scale Structural Similarity Index (MS-SSIM).
Subsequently, we collected subjective ratings through a custom mobile application developed for Android devices. Our findings revealed that VMAF accurately represents the degradation in video quality compared to other metrics. Moreover, in most cases, HEVC exhibits an advantage over both AVC and VP9 under low packet loss scenarios. However, it is noteworthy that in our test cases, AVC outperformed HEVC and VP9 in scenarios with high packet loss, based on both subjective and objective assessments. Our observations further indicate that user preferences for the presented content contribute to video quality ratings, emphasizing the importance of additional factors that influence the perceived video quality of end-users.
