A hybrid video codec based on extended block sizes, recursive integer transforms, improved interpolation, and flexible motion representation

Abstract

This paper describes video coding technology proposal submitted by Qualcomm Inc. in response to a joint call for proposal (CfP) issued by ITU-T SG16 Q.6 (VCEG) and ISO/IEC JTC1/SC29/WG11 (MPEG) in January 2010. Proposed video codec follows a hybrid coding approach based on temporal prediction, followed by transform, quantization, and entropy coding of the residual. Some of its key features are extended block sizes (up to 64×64), recursive integer transforms, single pass switched interpolation filters with offsets (single pass SIFO), mode dependent directional transform (MDDT) for intra-coding, luma and chroma high precision filtering, geometry motion partitioning, adaptive motion vector resolution. It also incorporates internal bit-depth increase (IBDI), and modified quadtree based adaptive loop filtering (QALF). Simulation results are presented for a variety of bit rates, resolutions and coding configurations to demonstrate the high compression efficiency achieved by the proposed video codec at moderate level of encoding and decoding complexity. For random access hierarchical B configuration (HierB), the proposed video codec achieves an average BD-rate reduction of 30.88℅ compared to the H.264/AVC alpha anchor. For low delay hierarchical P (HierP) configuration, the proposed video codec achieves an average BD-rate reduction of 32.96℅ and 48.57℅, compared to the H.264/AVC beta and gamma anchors, respectively.

Fast computing of discrete cosine and sine transforms of types VI and VII

“…Recently, Han, Saxena, and Rose 17 have shown that Karhunen-Loeve Transform (KLT) for residual signals, such as ones produced by Intra-Prediction process in video coding, 18 can be well approximated by DST-VII. This was further validated in ongoing experimental work on High Efficiency Video Coding (HEVC) standard, 19 resulting in inclusion of DST-VI/VII transforms in the Working Draft of this standard.…”