Low Quality for High Quality: Exploiting 2K Frames for Supporting Efficient 4K-Quality Pervasive Video Streaming Applications

Emerging cloud-based video streaming applications suggest limitations on current video streaming systems and emphasize the need to preserve and exchange high-quality contents while minimizing processing latency, given that both are critical in perpetuating a high user-perceived quality. This article presents 4KODEC, a codec for supporting real-time high-quality videos for cloud-based video streaming. 4KODEC is designed to induce minimal latency when encoding and decoding 4K video frames, by exploiting the fact that many regions (tiles) of a 4K frame can be recovered from their 2K counterparts given the low-complexity embedded in most tiles. Furthermore, 4KODEC is designed to effectively identify complex tiles, so that original 4K representations can be selectively exchanged to maintain high quality. We present evaluations using four different 4K-quality online games to show that 4KODEC reduces the processing latency by nearly half while improving perceptual quality when compared to widely used H.264/265 codec-based 4K video streaming implementations.