Effects of MGS fragmentation, slice mode and extraction strategies on the performance of SVC with medium-grained scalability

Abstract

This paper presents a comparison of a wide set of MGS fragmentation configurations of SVC in terms of their PSNR performance, with the slice mode on or off, using multiple extraction methods. We also propose a priority-based hierarchical extraction method which outperforms other extraction schemes for most MGS configurations. Experimental results show that splitting the MGS layer into more than five fragments, when the slice mode is on, may result in noticeable decrease in the average PSNR. It is also observed that for videos with large key frame enhancement NAL units, MGS fragmentation and/or slice mode have positive impact on the PSNR of the extracted video at low bitrates. While using slice mode without MGS fragmentation may improve the PSNR performance at low rates, it may result in uneven video quality within frames due to varying quality of slices. Therefore, we recommend combined use of up to five MGS fragments and slice mode, especially for low bitrate video applications.