Authors:
Peter Lambert
;
Wesley De Neve
;
Davy De Schrijver
;
Yves Dhondt
and
Rik Van de Walle
Affiliation:
Ghent University – IBBT, Belgium
Keyword(s):
Content adaptation, FMO, H.264/AVC, MPEG-21 BSDL, placeholder slices, ROI, video coding.
Related
Ontology
Subjects/Areas/Topics:
Layered Coding and Transcoding
;
MPEG Standards and Related Issues
;
Multimedia
;
Multimedia and Communications
;
Multimedia Signal Processing
;
Telecommunications
;
Universal Multimedia Adaptation
Abstract:
The concept of Regions of Interest (ROIs) within a video sequence is useful for many application scenarios. This paper concentrates on the exploitation of ROI coding within the H.264/AVC specification by making use of Flexible Macroblock Ordering. It shows how ROIs can be coded in an H.264/AVC compliant bitstream and how the MPE-21 BSDL framework can be used for the extraction of the ROIs. The first type of ROI extraction that is described, is simply dropping the slices that are not part of one of the ROIs. The second type is the replacement of these slices with so-called placeholder slices, the latter being implemented as P slices containing only macroblocks that are marked as ‘skipped’. The exploitation of ROI scalability, as achieved by the presented methodology, illustrates the possibilities that are offered by the single-layered H.264/AVC specification for content adaptation. The results show that the bit rate needed to transmit the adapted bitstreams can be reduced significantl
y. Especially in the case of a static camera and a fixed background, this bit rate reduction has very little impact on the visual quality. Another advantage of the adaptation process is the fact that the execution speed of the receiving decoder fairly increases.
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