System requirements and considerations for visual table of contents in PVR

With the introduction of non-tape-based digital video recorders also known as personal video recorders (PVR), consumers can expect alternative navigation methods to the well-known trick-play modes found on analog and digital tape-based systems. In this paper, we explore the system requirements and aspects of a visual table of contents (VTOC). A primary advantage of implementing a VTOC search mode is that it provides a much higher visual performance at high search speeds (50 times or higher) than the conventional search techniques. We present a solution for generating a video signal for visual search that is based on reusing MPEG-2 compressed video data. The video search signal is composed of a set of MPEG-2 compressed subpictures, resulting in a mosaic screen. An efficient strategy is introduced, that allows either full or partial reuse of the compressed sub-pictures via motion compensation of earlier reference sub-pictures to allow the generation of a new mosaic screen.