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Section 3.5. The MPEG-4 Standard 73
Video Session VS VS
(VS) 0 1
Video Object VO VO
(VO) 0 1
Video Object Layer
VOL VOL
(VOL) 0 1
Group of VOPs
GOV GOV
(GOV) 0 1
Video
Object Plane VOP VOP VOP VOP
0 k 0 1
(VOP)
Layer 0 Layer 1
Figure 3.7: MPEG-4 video bitstream structure
VO 0 VO 0
Coding Decoding
Bitstream
VO 1 VO 1
Coding Decoding
Video VO DEMULTIPLEX VO Video
Input Formation MULTIPLEX Composition Output
VO N
VO N
Coding Decoding
User interaction
Figure 3.8: An MPEG-4 codec
generated using segmentation techniques. Each VO is encoded individually,
and the resulting bitstreams are multiplexed to a single bitstream. At the de-
coder, the received bitstream is /rst demultiplexed to the individual bitstreams.
Each bitstream is then decoded, and the decoded VOs are composited to
