EE 5359 Low Complexity H 264 encoder for mobile applications Thejaswini Purushotham Student I D 1000 616 811 Date February 18 2010 Fig 1 Basic coding structure for H 264 AVC for a macroblock 1 The high computational complexity of H 264 and real time requirements of video systems represent the main challenge to overcome the development of efficient encoder solutions Fig 2 Various block sizes in H 264 for motion estimation compensation 1 However among H 264 compression modules it is important to emphasize that the most computational expensive process is ME For example assuming FS and M block types N reference frames and a search range for each reference frame and block type equal to W we need to examine N x M x 2W 1 2 positions compared to only 2W 1 2 positions for a single reference block type After the first FS a sup pixel search could also be performed At the end the union of all mode evaluations cost comparisons and exhaustive search inside ME cause a great amount of time spent by the encoder In other words complex and exhaustive ME evaluation is the key to good performance achieved by H 264 but the cost is in the encoding time The evaluation of all Intra Inter modes to select the best coding mode among possible combinations guarantees the smallest distortion under the given bit rate instead of just minimizing the bit rate or the distortion However in order to achieve a better bit rate distortion the complexity is increased making H 264 AVC difficult to apply directly to low complexity devices especially in wireless network environments Machine learning What to do Implement the tree as if else statements This will take lesser encoding time compared to the FS full search method References 1 T Wiegand et al Overview of the H 264 AVC video coding standard IEEE Trans CSVT Vol 13 pp 560 576 July 2003 2 S K Kwon A Tamhankar and K R Rao An overview of H 264 MPEG 4 Part 10 Special issue of Journal of Visual Communication and Image Representation vol 17 pp 186 216 April 2006 3 G Sullivan P Topiwala and A Luthra The H 264 AVC video coding standard overview and introduction to the fidelity range extensions SPIE Conference on Applications of Digital Image Processing XXVII vol 5558 pp 53 74 Aug 2004 4 T Weigand et al Introduction to the Special Issue on Scalable Video Coding Standardization and Beyond IEEE Trans on Circuits and Systems for Video Technology Vol 17 pp 1034 Sept 2007 5 H Kalva and L Christodoulou Using machine learning for fast intra MB coding in H 264 Proc of VCIP 2007 Jan 2007 REFERENCE BOOKS K Sayood Introduction to Data compression III edition Morgan Kauffmann publishers 2006 I E G Richardson H 264 and MPEG 4 video compression video coding for next generation multimedia Wiley 2003 K R Rao and P C Yip The transform and data compression handbook Boca Raton FL CRC press 2001 K R Rao and J J Hwang Techniques and standards for image video and audio coding Prentice Hall 1996 I Richardson The H 264 advanced video compression standard Hoboken NJ May 2010 REFERENCE WEBSITES JM software http iphome hhi de suehring tml n Introduction to Machine learning http ai stanford edu nilsson MLDraftBook MLBOOK pdf ACRONYMS ASO Arbitrary slice ordering AVC Advanced Video Coding B MB Bi predicted MB DCT Discrete Cosine Transform DSP Digital Signal Processing DVD Digital Versatile Disc FMO Flexible macroblock ordering FRExt Fidelity Range Extensions FS Full Search GOP Group Of Pictures I MB Intra Predicted MB IEC International Electrotechnical Commission ISO International Organization for Standardization ITU T International Telecommunication Union Transmission sector JVT P MB IDCT IQ MB MBAFF PicAFF ME MC MV MPEG MSE PSNR Q R D RS SP SI SMPTE SSIM SVC VCEG VLC VLD YUV Joint Video Team Inter Predicted MB Inverse Discrete Cosine Transform Inverse Quantizer Macroblock Macroblock level Adaptive Frame Field Picture level Adaptive Frame Field Motion Estimation Motion Compensation Motion Vector Moving Picture Experts Group Mean Square Error Peak to peak Signal to Noise Ratio Quantizer Rate Distortion Redundant slice Switched P Switched I Society of Motion Picture and Television Engineers Structural Similarity Index Measure Scalable Video Coding Video Coding Experts Group Variable Length Coding Variable Length Decoder Y Luminance and UV Chrominance
View Full Document
Unlocking...