Proceedings Article | 1 August 2021
KEYWORDS: Video, Forward error correction, Video surveillance, Signal to noise ratio, Wireless communications, Error analysis, Defense and security, Software development, Signal attenuation, Distortion
Wireless video communications are a growing segment of communications in both commercial and defense domains. Due to the lossy nature of wireless channels, they require powerful error correction for successful communications. In the commercial domain, ever more people worldwide use video chat, and watch videos on portable wireless devices, while in defense domains, surveillance assets are growing rapidly in numbers, providing real-time motion imagery intelligence. In both domains, the transmission of high-quality video is of vital importance, and a variety of both source and channel codecs have been developed, separately for each domain, and application. Throw in tight bandwidth constraints (e.g., < 1 Mbs), and the challenge intensifies. In this paper, we outline an effort to explore the space of video codecs, channel codecs, and channel models, to find the best practices within this large search space. After some preliminary material, we focus attention on the two most common video codecs in use: H.264/AVC, and H.265/HEVC, ask which is better to use in lossy comms, and in some cases limit bandwidth to just 750 kbs. We perform simulations in both additive white gaussian noise as well as Rayleigh fading channel models, use signal-to-noise ratios that stress transmissions, and use powerful Low-Density Parity-Check (LDPC) and Polar codes to correct errors. Since the channel varies with time (as does our simulation), we aggregate over multiple simulations. Without channel errors, H.265 would be preferred due to its superior coding efficiency. With errors, this is still true in our simulations, but is more subtle. H.264 is in fact more resilient when there are high errors, but as quality improves to usable levels, H.265 takes over.
