Graphics Reference
In-Depth Information
The image sequences are encoded with the three encoding configurations based on the ex-
isting video coding standards, MPEG-4 MAC, H.264/AVC (using the scalable H.264/AVC
single layer coding) and the scalable extension of H.264/AVC. The base layer encoder of
the scalable H.264/AVC (i.e. encode using the single layer configuration) is utilized to
obtain H.264/AVC coding results as the base layer bit-stream is backward compatible for
H.264/AVC, and to avoid differences arising from the different softwareimplementations
ofH.264/AVCandthescalableextensionofH.264/AVC.Thebasicencoding parametersused
are shown in Table 3.1. The Quantisation Parameter (QP) in the configuration file is varied
to obtain the bitrate range shown in the R-D curves. The same QP is used for encoding
both baseandenhancementlayersofscalableH.264/AVC.TheR-Dcurvesshowtheimage
qualitymeasured inPSNR againstthe resultingaverage bitrate. Experiment 1comparesthe
codingperformanceofthe stereoscopicvideocodingarchitectures.Thecodingperformance
ofcolouranddepthvideovs.leftandrightvideowiththeproposedSVCcodingconfiguration
isdiscussedinExperiment2.
Encoding Parameter
Value
Test sequences
Orbi, Interview
No. of frames
300
Sequence format
IPPP…
Reference frames
1
Searchrange
16 pixels
Entropycoding
VLC(VariableLengthCoding)
Table 3.2:
Encodingparameters
3.5.1 Experiment 1: Comparison of Stereoscopic Video Encoding Configurations
The R-D performance of Orbi and Interview colour and depth sequences using
MPEG-4-MAC (layered encoding), H.264/AVC (frame packing, side-by-side format) and
scalable H.264/AVC coding (layered encoding) configurations are shown in Figures 3.16
and 3.17 respectively. All of the results are plotted against the overall bitrate (output bitrate
of the SVC codec), which includes all of the overhead, texture, colour, motion vector bits
of both colour and depth map video. In order to highlight the R-D performance at a range
of bitrates, the final bitrate is shown from 0 Kbits/s to 2Mbits/s. The H.264/AVC coded
