MPEG-4 Book, The

9.1. SNHC Overview

The work scope of SNHC includes both audio and visual information. Synthetic audio coding tools include text-to-speech (TTS) and structured audio, notably a structured audio orchestra language (SAOL; see Chapter 12). Synthetic audio tools are useful when they are combined with synthetic visual tools, but also as stand-alone. For example, TTS can be used with facial animation to generate the so-called talking heads for electronic commerce and entertainment applications. Synthetic visual tools are FBA, 2D and 3D mesh coding, and view-dependent scalability.

Visual texture coding (VTC) was developed by the SNHC group because its need was related to the mapping of textures on top of 2D and 3D mesh models. However, because the visual ...