i listened an introduction of Nvidia (2018) on new features of GPU
The author reports that if the middle frame in a triple of successive B-frames is used for reference by its immediate neighboring B-frames (i.e. the cadence … P b B b P … ). Then the improvement in BD-PSNR is 0.3 dB against ordinary cadence (… P b b b P …).
i didn’t understand whether these results related to HEVC or AVC or to both. i would be glad if someone elaborate.
It’s worth mentioning that B-reference is not allowed in BluRay specification.