UNIVERSITY OF TEXAS AT ARLINGTON EE5359 FALL 2009 Project report Study and comparison of H 264 MPEG4 part10 AVC main profile with AVS P2 Jizhun profile Instructor Dr K R Rao Submitted By Naveen Siddaraju Student ID 1000621672 Email naveen siddaraju mavs uta edu Page 2 ACKNOWLEDGEMENT I would like to thank Dr K R Rao for all his guidance support and motivation which led to successful completion of the assigned project Also I would like to thank all my friends in the multimedia lab for helping me throughout the project EE5359 Fall 2009 Page 3 Abstract H 264 MPEG4 part 10 developed by JVT is the latest and widely used video coding standard today H 264 performs the best among all its predecessors like MPEG2 MPEG4 part 2 The Audio video coding standard of China AVS is an emerging standard and also it has been adapted as the national standard of China The basic part of AVS AVS P2 targets standard definition SD and high definition HD video format and aims to achieve similar coding efficiency as that of H 264 The objective of this project is to study the tools of both AVS part 2 jizhun profiles and H 264 Main profile in detail and compare them based on various performance parameters like Y psnrs encoding times and compression JM Joint model software will be used for H 264 9 and AVS reference software 10 will be used for AVS EE5359 Fall 2009 Page 4 Introduction The demand for digital video applications such as HDTV video conferencing internet video streaming etc has led to the development of various video codecs H 261 was the first major video codec to arrive in the market 1990 developed by the International telecommunications union ITU It was primarily developed for videoconferencing applications over the ISDN networks MPEG 1 part 2 12 developed by MPEG 11 of ISO IEC was approved as a standard in 1991 it was designed to take the VHS quality video and squeeze it down to a bit rate of about 1 5 Mbps It is the standard used in all VCDs The next standard to arrive was MPEG 2 P2 H 262 13 which was approved in 1994 was jointly developed by ISO and ITU T 8 Although in most applications like digital television it is being replaced by MPEG 4 MPEG 2 is still the standard used in DVDs MPEG 4 is a much broader standard it is also the latest standard today There are two parts of MPEG 4 which deal with video compression MPEG 4 Part 2 14 and MPEG 4 Part 10 Although they are part of MPEG 4 they are completely different from each other DivX XviD or 3viX are all essentially different implementations of MPEG 4 Part2 MPEG 4 Part 10 which is also referred to as H 264 and advanced video codec AVC was jointly developed by MPEG and ITU T 2 It is more efficient than MPEG 4 Part2 Its applications include HD DVD Blu ray IPTV etc AVS 3 is the new audio video coding standard of China AVS part2 which is the video part of the codec was adapted as the national standard for China in April 2005 The main goal of AVS was to achieve coding efficiency very close to that of H 264 but with reduced complexity The Architecture model of AVS is very similar to that of H 264 EE5359 Fall 2009 Page 5 The figures 1 and 2 show the time line for the development of the various video standards Fig1 developments of ITU and ISO video standards Fig2 Developments of AVS standards Before going in to the details of actual codecs it is important to know a little bit about the workings of different parts of a codec EE5359 Fall 2009 Page 6 Color spaces the two most commonly used color spaces are RGB red green and blue and YCrCb Luminance red chrominance and blue chrominance RGB is not the most efficient representation of colour The HVS is less sensitive to color than luminance Hence YCrCb which takes in to account the luminance factor is the more popular colour format used in video coding There is basically 3 popular patterns for subsampling Cr and Cb 4 4 4 4 2 2 4 2 0 4 4 4 means that the 3 components Y Cr and Cb have the same resolution hence a sample of each is present at every pixel location I e for every 4 luma samples there will be 4 Cr and Cb samples In 4 4 4 each pixel is represented by 24bits 4 4 4 sampling preserves the full fidelity of the chrominance components In 4 2 2 sampling there will be 2 Cr and 2 Cb components for every 4 luma samples In 4 2 2 each pixel is represented by 16bits 4 2 2 sampling is used for high quality color reproduction 4 2 0 means that Cr and Cb each have half the resolution of Y for every 4 luma samples there will be one Cr and Cb samples 4 2 0 sampling is popular in mass market digital video applications like tv broad cast and video conferencing 4 2 0 is sometimes described as 12 bits per pixel fig3 shows the macro blocks 16X16 in various sampling modes EE5359 Fall 2009 Page 7 Figure 3 YUV different systems 16 Standards for representing digital video For video coding applications video is often converted to one of number of intermediate formats prior to compression and transmission A set of popular frame resolutions is based around the common intermediate format CIF in which each frame has a resolution of 352X288 pixels The resolutions of these formats are listed in the table Format Luminance resolutions Sub QCIF Quarter CIF QCIF CIF 4CIF 128X96 176X144 352X288 704X576 Table1 intermediate formats EE5359 Fall 2009 Page 8 Video Compression Information carrying signals like video may be compressed I e converted to a representation that requires fewer no of bits than the original signal A device or a program that compresses a signal is called an encoder and a device or a program that decompresses the signal is called a decoder An enCOder DECoder pair is called a CODEC The original signal is encoded by the encoder this is called source coding The source coded signal is then encoded further to add error protection this is called channel coding this is done prior to transmitting the signal over the channel At the receiver the channel decoder detects and corrects the transmission errors and source decoder decompresses the signal If the decompressed signal is identical to the original signal its called lossless compression or else its called lossy compression FIG4 Source CODEC Channel CODEC DPCM Differential pulse code modulation Each sample or pixel is predicted from one or more previously coded samples The actual pixel X is subtracted from the predicted pixel and the error prediction error is transmitted to the receiver The prediction error will be small due to the spatial correlation Compression can be achieved
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