Bitstream decoding processor for fast entropy decoding of variable length coding–based multiformat videos

Abstract

We present a bitstream decoding processor for entropy decoding of variable length coding-based multiformat videos. Since most of the computational complexity of entropy decoders comes from bitstream accesses and table look-up process, the developed bitstream processing unit (BsPU) has several designated instructions to access bitstreams and to minimize branch operations in the table look-up process. In addition, the instruction for bitstream access has the capability to remove emulation prevention bytes (EPBs) of H.264/AVC without initial delay, repeated memory accesses, and additional buffer. Experimental results show that the proposed method for EPB removal achieves a speed-up of 1.23 times compared to the conventional EPB removal method. In addition, the BsPU achieves speed-ups of 5.6 and 3.5 times in entropy decoding of H.264/AVC and MPEG-4 Visual bitstreams, respectively, compared to an existing processor without designated instructions and a new table mapping algorithm. The BsPU is implemented on a Xilinx Virtex5 LX330 field-programmable gate array. The MPEG-4 Visual (ASP, Level 5) and H.264/AVC (Main Profile, Level 4) are processed using the developed BsPU with a core clock speed of under 250 MHz in real time.

Perceptual Adaptive Quantization Parameter Selection Using Deep Convolutional Features for HEVC Encoder

“…High-efficiency video coding (HEVC) standard has been widely accepted to achieve better compression performance over H.264/Advanced Video Coding (AVC) by maintaining similar visual quality [1]. It has encompassed various video media services and applies not only to full high definition (FHD) but also to 4K/8K ultra-HD (UHD) [2]- [4]. Since the standard was released, many studies have been conducted for the sake of its advantages of visual quality improvement [5]- [7], computational complexity reduction [8]- [16], bitrate reduction [17], [18], and prospects as a future video coding standard [19]- [26].…”