Adaptive loop filtering based interview video coding in an hybrid video codec with MPEG-2 and HEVC for stereosopic video coding

In this paper, a hybrid stereoscopic video codec is proposed based on MPEG-2 and an extended HEVC with an interview coding scheme for stereoscopic TV services through heterogeneous networks. The left-view sequences are encoded in an MPEG-2 video encoder for conventional 2D TV services via the traditional terrestrial broadcasting networks. On the other hand, the right-view sequences are encoded by an extended HEVC with a proposed interview coding scheme and the resulting bitstreams are transmitted over Internet. So, a 3D TV terminal to support the hybrid stereoscopic video streams receives the MPEG-2 data for the left-view sequences via the terrestrial broadcasting networks, and receives the right-view sequence streams of an extended HEVC data over Internet. The proposed interview coding scheme in an extended HEVC utilizes as reference frames the reconstructed MPEG-2 frames of the left-view sequences to perform predictive coding for the current frames of the right-view sequences. To enhance the texture qualities of the reference frames, an ALF tool is applied for the reconstructed MPEG-2 frames and HEVC as well. The ALF ON/OFF signaling map and ALF coefficients for the MPEG-2 reconstructed frames are transmitted in conjunction with HEVC bitstreams via Internet. The experimental results show that the proposed hybrid stereoscopic codec with ALF-based interview coding improves the coding efficiency with average 16.81% BD-rate gain, compared to a hybrid stereoscopic codec of independent MPEG-2 and HEVC codec without interview coding.