Tung-Hsing Wu

18.6 A 0.5nJ/pixel 4K H.265/HEVC codec LSI for multi-format smartphone applications

A 4K×2K H.265/HEVC video codec chip is fabricated in a 28nm CMOS process with a core area of 2.16mm2. This LSI chip integrates a dual-standard (H.265 and H.264) video codec and a series of prevalent (VC-1, WMV-7/8/9, VP-6/8, AVS, RM-8/9/10, MPEG-2/4) decoders into a single chip. It contains 3,558K logic gates and 308KB of internal SRAM. Moreover, it simplifies intra/inter-rate-distortion optimization (RDO) processes and reduces external bandwidth via line-store SRAM pool (LSSP) and data-bus translation (DBT) techniques. For smartphone applications, it completes real-time HEVC encoding and decoding with 4096×2160 resolution and 30fps, and consumes 126.73mW (0.5nJ/pixel) of core power dissipation at 0.9V, at 494MHz (encoding) and 350MHz (decoding). 1080HD and 720HD resolutions are reported as well. The chip features are summarized in Fig. 18.6.1.

A 0.5 nJ/Pixel 4 K H.265/HEVC Codec LSI for Multi-Format Smartphone Applications

A 4 K × 2 K H.265/HEVC video codec chip supporting 14 video standard formats is implemented on a 1.49 × 1.45 mm 2 die in a 28 nm CMOS process. Several HEVC fast algorithms reduce the coding modes by analyzing the content features leading to over 68.5% and 83% of complexity reduction in intra and inter coding, respectively. A fully parallel processing element (PE) array is adopted in SAO and IP/ME, which reduce number of accesses to SRAM by 48.7% and 78.4%, respectively. A shared memory management unit (MMU) including line-store SRAM pool (LSSP) and data bus translation (DBT) techniques efficiently reuses and packs the neighboring pixels which contribute 71.6% of external bandwidth reduction. This chip achieves 4096 × 2160@30 fps HEVC encoding/decoding and consumes 126.73 mW, 0.5 nJ/pixel of energy efficiency, under 494 MHz and 350 MHz of clock frequency, enabling 4 K video services for smart-phone applications.

A 1.94mm 2 , 38.17mW dual VP8/H.264 Full-HD encoder/decoder LSI for Social Network Services (SNS) over smart-phones

A first dual-standard video encoder and decoder LSI providing VP8 (i.e. video format of WebM project for use of webs video) or H.264/AVC video recording and playback simultaneously is implemented with 28nm CMOS and occupies 1.94mm2 of core area. Several area-efficient techniques are realized, leading to 43.6% of area reduction. A new rate control is designed to facilitate the adaptation of video data and frame rates for network services. Two fast algorithms and new bool encoder/decoder are proposed to enhance power efficiency. This chip consumes 28.15mW and 10.02mW of VP8 encoder and decoder average power for 1080p@30fps at 0.9V, respectively.