Vlsi Design Of Inverse Transform Inverse Quantization And Deblocking Filter In The H.264Decoder

H.264video coding standard has been paid great attention since published in2003with its effective compression ratio, high-quality video images, and excellentnetwork affinity, it is widely used in video conferencing, monitor, video storage,set-top boxes, Internet field. However, the performance is at the cost of complexityincreasing. According to statistics, the complexity of H.264standard is severaltimes or even over ten times than others. With the increase of video format, it makesa great challenge in hardware design of H.264real-time decoder. This article mainlyfocuses on inverse transformation, rescaling process and deblocking filter unit, thenit also presents a VLSI structure for real-time decoder which supports the1080p.Inverse transform and quantization is very important during reconstruction ofpicture. Its function is to restore the residual which has been transformed and scaledfor the purpose of compression ratio developing. This paper introduce the butterflyoperation to simplify matrix multiplication and add a scaling factor for the input tocombine the three different inverse transform structures. By using the method ofdecomposing the look-up table to simplify the inverse quantization unit to improvethe reuse rate, reduce the area of hardware.Deblocking filter, which aims to reduce blocking distortion during transform,scale, intra and inter predictions to develop the video quality, takes one third of thetotal time of decoding. This paper will optimize boundary strength deciding unit,filter order, memory unit, control unit and filter calculating process and then presenta VLSI structure of high-speed deblocking decoding unit in order to implement thereal-time decoder of HD video.The structure is designed by Verilog HDL and simulated by modelsim. Asimulation workstation will be built after the verification of basic function. Theaccuracy will be further verified by comparing with the output of JM10.1undersame stimulate signal. Finally, this paper synthesize the RTL code of inversetransform, rescale and deblocking filter, and the structure designed can archive1080p real-time decoding by proved with analyzing the performance.