Reducing IPTV channel switching time using H.264 scalable video coding

In this paper, we aim to reduce the channel switching time for Internet protocol TV (IPTV) without unduly influencing the picture quality. For this purpose, we propose to adopt the H.264 scalable video coding scheme, for which we allocate a base layer and enhancement layers of each channel to two separate multicast groups. In preview mode, users access the base layers of different channels already stored in a buffer, so they can switch between channels without delay. In watching mode, they use both the base and enhancement layers of the selected channel to achieve full quality. While providing fast channel switching in the preview mode, our approach proves to maintain the picture quality similar to the case of single layer coding. An experimental result, for example, shows that, even with complicated scenes, a 1.5 Mbps scalable video stream for IPTV has achieved a good picture quality with a PSNR of 33.7 dB¹.