Temporal-SNR rate-control for Fine-Granular Scalability
To compensate for the unpredictability and variability in bandwidth between sender and receiver(s) over the Internet, a new scalable coding tool has recently been introduced in MPEG-4: Fine-Granular-Scalability (FGS). The FGS framework is very flexible and can adapt in real-time to the Internet bandwidth variations by supporting both SNR and temporal scalability through a single pre-encoded fine-granular stream. This paper presents a novel Internet video streaming system employing the MPEG-4 FGS temporal-SNR scalability structure. The proposed streaming system performs the trade-off between temporal-resolution and SNR improvements at transmission time, depending on the available bandwidth and possible user preferences, and not at encoding time. An important feature of the proposed system is the temporal-SNR rate-control that ensures a high visual quality for each client, depending on the available bandwidth. The proposed rate-allocation mechanism is based on available compressed-domain information (ie, motion-vectors and texture) and/or pre-stored quality (PSNR) tags determined at encoding time.