The H.263 Recommendation specifies a coded representation that can be used for compressing the moving picture components of audio-visual services at low bit rates. Detailed specifications of the first generation of this codec under the test model (TM) to verify the performance and compliance of this codec were finalised in 1995. The basic configuration of the video source algorithm in this codec is based on ITU-T Recommendation H.261, which is a hybrid of interpicture prediction to utilise temporal redundancy and transform coding of the residual signal to reduce spatial redundancy. However, during the course of the development of H.261 and the subsequent advances on video coding in MPEG-1 and MPEG-2 video codecs, substantial experience was gained, which has been exploited to make H.263 an efficient encoder. In this chapter those parts of the H.263 standard that make this codec more efficient than its predecessors will be explained.

Inspec keywords: data compression; transform coding; code standards; audio-visual systems; video coding

Other keywords: H.263 Recommendation; spatial redundancy reduction; audio-visual services; video source algorithm; moving picture component compression; interpicture prediction; bit-rate communications; MPEG-1 video codec; MPEG-2 video codec; video coding; transform coding; temporal redundancy; ITU-T Recommendation H.261; residual signal

Subjects: Image and video coding