Shunichi Sekiguchi

A low-cost video frame-rate up conversion using compressed-domain information

A new low-cost video frame-rate up conversion (FRC) technique that exploits compressed-domain information is proposed in this paper. Recent worldwide growth of digital video applications such as home AV network or mobile multimedia have been demanding higher video compression ratio in order to meet system requirements due to limited bandwidth or storage capacity. Enhancement of temporal resolution using FRC at decoder side is attractive in a sense that the R-D performance can be maintained even at low bitrates by dropping frames during encoding process and recovering them at the decoder. The proposed FRC aims to provide accurate estimates of motion vectors for recovered frames based on compressed-domain information. The goal of our study is to realize a decoder design with robust FRC over a variety of implementation platforms from mobile to consumer set-top.

Real-time hardware implementation of HEVC video encoder for 1080p HD video

This paper describes a hardware implementation of HEVC (High Efficiency Video Coding) video encoder for exploring performance of HEVC in real-time applications. By optimizing hardware architecture and developing fast mode decision algorithms, our FPGA-based prototype can encode 1080p, 10-bit video at 60fps in real-time. Both objective and subjective evaluations clearly demonstrate that the developed HEVC encoder achieves significant coding gain relative to professional-use AVC/H.264 encoder available on the market. This paper also refers to the development of a real-time HEVC encoder for much higher resolution video such as SHV (Super Hi-Vision, 8K) using the HD encoder in parallel.

On Separate Color-Plane Prediction for Direct 4:4:4 Video Coding

In this paper, we propose a video coding scheme supporting direct 4:4:4 source format, which is designed as a straight-forward extension of MPEG-4 AVC/H.264 high profile coding. In the proposed scheme, each color component is encoded with independent spatio-temporal prediction using coding tools supported by MPEG-4 AVC/H.264 high profile, which is now regarded as the most powerful video compression standard in the world. We discuss the performance of the proposed method in comparison with several candidate schemes, and will show that the proposed scheme achieves coding performance improvement in terms of signal representation fidelity (PSNR) around higher bitrate range that is valuable for high quality applications. The presented scheme has been proposed to the MPEG-4 AVC/H.264 standardization body as a candidate technique for the new 4:4:4 video coding standard.

New Video Coding Scheme Optimized for High-Resolution Video Sources

This paper presents a design of new video coding scheme targeting substantial compression performance with reasonable complexity for next-generation high-resolution video sources. While it takes a conventional block-based MC+DCT hybrid coding approach that is suitable for hardware implementation of a high-resolution video codec, the proposed scheme achieved significant improvement of coding efficiency by introducing various technical optimizations in each functional block, especially allowing the use of larger blocks for motion compensation and transform than conventional standards. According to our experimental analysis, the proposed scheme achieves approximately 26% bit-rate savings on average compared to the state-of-the-art standard AVC/H.264 high profile. We also study the tradeoff between complexity and performance of the codec towards its standardization and implementation.

Block boundary filtering for intra prediction samples

This paper presents a new intra prediction technique for HEVC, which is next-generation video coding standard that has collaboratively been developed by ISO/MPEG and ITU-T/VCEG. On intra coding for HEVC, extension of MPEG4-AVC/H.264-like intra prediction scheme has been studied. In this conventional scheme, the prediction block is generated by simply copying adjacent reference samples, interpolating the reference samples toward prediction direction or averaging the reference samples. Thus, signal discontinuity between prediction block and adjacent reconstructed blocks could occur, which causes loss of coding efficiency of residual signal. In this paper, we propose an adaptive filtering scheme for intra prediction samples generated by either DC or directional prediction that solves the above issue. According to our evaluation, the proposed scheme achieves approximately 0.6% bitrate savings on average compared to the conventional AVC-style intra coding.