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In the Name of God. Hardware Implementation of Transform & Quantization Blocks in H.264/AVC Video Coding Standard. Custom Implementation of DSP Systems Class Seminar. All materials are copy rights of their respective authors as listed in references. By: Hoda Roodaki Instructor:
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In the Name of God Hardware Implementation of Transform & Quantization Blocks in H.264/AVC Video Coding Standard Custom Implementation of DSP Systems Class Seminar. All materials are copy rights of their respective authors as listed in references By: HodaRoodaki Instructor: Dr. Fakhraei
Outline • Video Coding & Standardization • Video Coding Standards & Application • H.264/AVC (MPEG-10) Standard • H.264 Drawbacks • Proposed Method for 4x4 DCT, 8x8 DCT and Quantization • Concolusion
Video Coding & Standardization • Efficient digital representation of video signals has been the subject of considerable research over the past twenty years. • Availability of digital transmission links • Progress in signal processing • VLSI technology • Video compression research Visual communications has become more feasible Increased commercial interest in video communications Standardization
Video Coding Standards & Application Moving Picture Experts Group (MPEG) • MPEG1 (1988-1992) • Audio and video on storage media such as CDROM • MPEG2 (1993) • Digital TV: SDTV, HDTV • MPEG4 (1994) • A standard for very low bit rate coding of limited complexity audio-visual material ITU-T Video Coding Expert Group (VCEG) • H.261 (1988-1990) • Videoconferencing, video-telephone applications over ISDN telephone lines • H.263 (1996) • mobile network
H.264/AVC (MPEG4-part10) Standard • In 2001 • With the aim of developing a more efficient compression system, VSEG MPEG Joint Video Team (JVT)
H.264/AVC (MPEG-10) Standard • Significant improvement in coding efficiency • Average bit rate reduction of 50% given fixed fidelity compared to any other video standard • Error robustness • Applications • Broadcast over cable, satellite, cable modem, DSL, terrestrial. • Interactive or serial storage on optical and magnetic storage devices, DVD, etc. • Conversational services over ISDN, Ethernet, LAN, DSL, wireless and mobile networks, modems. • Video-on-demand or multimedia streaming services over cable modem, DSL, ISDN, LAN, wireless networks. • Multimedia messaging services over DSL, ISDN. • Broad range of bit rates and picture sizesranging from very low bit rate, low frame rate video for mobile and dial-up devices through to entertainment-quality standard-definition television services, HDTV, and beyond.
H.264 Drawbacks • These aggressive compression techniques increase computational complexity and need an efficient architecture to implement these techniques • Quantization & Transformation blocks are two critical parts of encoder We need some methods that simplifies these blocks Real Time Applications
Proposed Method for 4x4 DCT [1] • The forward 4x4 DCT of a sample block
Proposed Method for 4x4 DCT Evaluation • Synthesized with Xilinx Project Navigator 10.01 for Xilinx Virtex 5 (xc5vlx30).
Proposed Method for 8x8 DCT [2] • Initial H.264 specification adopted an integer approximation of 4×4. • But the 4×4 block is not enough higher resolutions 8x8 DCT Additional Complexity Significant Compression Performance
Proposed Method for 8x8 DCT(Cont.) • The 2-D forward 8x8 • 1-D horizontal (row) transform • 1-D vertical (column) transform
Proposed Method for 8x8 DCT(Cont.) Architecture of Proposed Algorithm [2]
Proposed Method for 8x8 DCT(Cont.) 1-D Transform Block [2]
H.264 Quantization Qstep?
Proposed Method for 8x8 DCT & Quantization - Evaluation • In the architecture • Each input column vector of 8 pixels is input to the 1-D DCT block for 8 cycles => 64 cycles are required to process all pixel elements in one 8×8 block • Without multiplication • The pixel by pixel processing can remove redundant modules processing in integer transform block and quantization block. • Quantization block is designed to cover all multiplication factors without using a real multiplier.
Proposed Method for 8x8 DCT & Quantization - Evaluation • The target device chosen is Xilinx Virtex-II Pro XC2VP30 FPGA. 90% area reduction in Proposed Method [2]
Conclusion • The continuing development of digital video coding has produced H.264/MPEG-4 (Part 10) Advanced Video Coding. • It provides gains in compression efficiency of up to 50% over a wide range of bit rates and video resolutions compared to previous standards • Besides, network friendliness and good video quality at high and low bit rates are important features that distinguish H.264 from other standards. • These advantages are paid with a considerably higher need of computational complexity.
Conclusion • To implement DCT and quantization blocks for H.264, many efforts have been carried out. • 4x4 DCT => a method without any multiplication • less complex and definitely faster than typical method • 8x8 DCT => a pipeline method Without multiplication for DCT & Quantization • Less complex and less area than parallel method but slower
References • [1] Nandi, S.; Rajan, K.; Biswas, P. “Hardware implementation of 4×4 DCT/quantization block using multiplication and error-free algorithm”, TENCON 2009. • [2] Jeoong Sung Park; Ogunfunmi, T. “A New Hardware Implementation Of The H.264 8×8 Transform And Quantization”, IEEE International Conference on Acoustics, Speech and Signal Processing, ICASSP 2009. • [3] Mohammad Norouzi, Karim Mohammadi, Mohammad Mahdy Azadfar,” Multiplication and Error Free Implementation of H.264 like 4x4 DCT/Quan_IQuan/IDCT using Algebraic Integer Encoding”, IJCSNS International Journal of Computer Science and Network Security, VOL.6 No.9B, September 2006. • [4] Iain E G Richardson, “H.264 / MPEG-4 Part 10 White Paper : Transform & Quantization”, vcodex, 2003. • [5] Thomas Wiegand, Gary J. Sullivan, Gisle Bjontegaard, and Ajay Luthra, “Overview of the H.264 / AVC Video Coding Standard”, IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY, JULY 2003. • [6] Thomas Sikora,” Digital Video Coding Standards and Their Role in Video Communications”, Signal Processing for Multimedia. J.S. Byrnes (Ed.) IOS Press, 1999.