Graduation Semester and Year

2016

Language

English

Document Type

Thesis

Degree Name

Master of Science in Electrical Engineering

Department

Electrical Engineering

First Advisor

Kamisetty R Rao

Abstract

The increasing demand for video and the increase in the number of devices enable of supporting digital media facilitate the enormous demand for video streaming over internet and and Internet Protocol Television (IPTV) applications. The high bit rates that result from the various types of digital video make their transmission through their intended channels very difficult. Hence it becomes necessary to select a good compression scheme to overcome storage and transportation problems of the digital video. High Efficiency Video Coding (HEVC) is an international standard for video compression developed by a working group of ISO/IEC MPEG (Moving Picture Experts Group) and ITU-T VCEG (Video Coding Experts Group). The main goal of HEVC standard is to significantly improve compression performance compared to existing standards (such as H.264/Advanced Video Coding) in the range of 50% bit rate reduction at similar visual quality. HEVC is designed to address existing applications of H.264/MPEG-4 AVC and to focus on two key issues: increased video resolution and increased use of parallel processing architectures. In the case of audio content, the MPEG-4 High Efficiency AAC v2 profile (HE-AAC v2) has proven, in several independent tests, to be the most efficient audio compression scheme available worldwide. High efficiency advanced audio codec version 2 also known as enhanced aacplus is a low bit rate audio codec defined in MPEG4 audio profile belonging to the AAC family. It is specifically designed for low bit rate applications such as streaming. The audio and video codec standards have been chosen based on ATSC-M/H (advanced television systems committee – mobile handheld). The objective of this thesis is to implement a multiplexing scheme for the elementary schemes of HEVC main profile and HE-AAC V2 using MPEG2 systems specifications and demultiplex the transport stream at the receiving end with audio – video synchronization. Since audio and video codecs have frame wise arrangement, frame numbers are used as information to achieve audio-video synchronization. Two layers of packetization of audio and video streams is involved in the multiplexing process where the first layer results in Program Elementary Stream (PES) packets which are of variable size. The synchronization information is embedded in the headers of the first layer of packetization. Since PES packets are not suitable for transport due to their variable size, these are further packetized as Transport Stream (TS) packets of fixed length and 188 bytes long. These packets are decoded by the receiver and the original elementary streams are reconstructed. Playback time is used as criteria for allocating data packets at multiplexer to prevent overflow and underflow of buffers during demultiplexing. The net transport stream bitrates for the sequences obtained are 267.2 kbps, 1095.08 kbps and 1093.44 kbps which can be easily accommodated in systems such as ATSC-M/H, which has an allocated bandwidth of 19.6 Mbps. Encoding video using HEVC and audio based on HE-AAC V2, multiplexing the two coded bit-streams, packetization, de-multiplexing the two coded bit-streams, decoding the video (HEVC) and audio (HE–AAC V2) while maintaining the lip sync are the highlights of this thesis.

Keywords

HEVC, HE-AAC V2, MUX, DEMUX, Lip synch

Disciplines

Electrical and Computer Engineering | Engineering

Comments

Degree granted by The University of Texas at Arlington

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