Note in Figure 17. 5 that the transcoding function can be located in the end-
point PC if no human is required to perform the transcoding function. Early
research and prototype PC-based transcoding functions have the following
properties:
■■ Voice is a trivial application on all consumer-grade PCs.
■■ ToIP applications have very small processing and memory requirements.
■■ Voice-text conversion and voice recognition are common PC applications.
■■ Avatars for lip reading are superior to video for the following reasons:
■■ Lip reading is difficult when the speaker turns the head.
■■ Lips can be obscured by beards and moustaches.
■■ Low articulation by the speaker may make lip reading hard to follow.
■■ Greater confidentiality, since no human intermediary is involved.Figure 17.6 shows an Avatar implementation in the Synface [6] project.Figure 17.6 Avatar implementation on a laptop for a hearing-impaired person.
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