Top Banner

Click here to load reader

Digital Video Compression Fundamentals and Standards Web Technology

Dec 28, 2015

ReportDownload

Documents

  • Digital Video Compression Fundamentals and StandardsWeb Technology

    Digital Video Compression Fundamentals and Standards

  • OutlineIntroductionVideo Compression StandardsSimulation Reference SoftwareFuture Work and Conclusions

    Digital Video Compression Fundamentals and Standards

  • OutlineIntroductionVideo Compression StandardsSimulation Reference SoftwareFuture Work and Conclusions

    Digital Video Compression Fundamentals and Standards

  • Introduction (1/2)Why video compression technique is important ?One movie video without compression720 x 480 pixels per frame30 frames per secondTotal 90 minutesFull colorThe total quantity of data = 167.96 G Bytes !!

    Digital Video Compression Fundamentals and Standards

  • Introduction (2/2)What is the difference between video compression and image compression?Temporal RedundancyCoding method to remove redundancyIntraframe CodingRemove spatial redundancyInterframe CodingRemove temporal redundancy

    Digital Video Compression Fundamentals and Standards

  • The most intuitive method to remove Spatiotemporal redundancy

    3-Dimensional DCTRemove spatiotemporal correlationGood for low motion videoBad for high motion video

    Digital Video Compression Fundamentals and Standards

  • The most popular method to remove temporal redundancyThe Block-Matching Algorithm

    Digital Video Compression Fundamentals and Standards

  • Matching FunctionThe dissimilarity between two blocks and

    The matching criteriaMean square error (MSE) High precision is neededMean absolute difference (MAD) Low precision is enough

    Digital Video Compression Fundamentals and Standards

  • The Exhaustive Block-Matching AlgorithmReference FrameCurrent FrameSearch RangeMotionVector11 22 33 44 55 66 77 8811 22 33 44 55 66 77 8811 22 33 44 55 66 77 8811 22 33 44 55 66 77 8811 22 33 44 55 66 77 8811 22 33 44 55 66 77 8811 22 33 44 55 66 77 8811 22 33 44 55 66 77 8812 22 33 44 55 66 77 8812 22 33 44 55 66 77 8812 22 33 44 55 66 77 8812 22 33 44 55 66 77 8811 23 34 44 55 66 77 8811 23 34 44 55 66 77 8811 23 34 44 55 66 77 8811 23 34 44 55 66 77 881 0 0 0 0 0 0 01 0 0 0 0 0 0 01 0 0 0 0 0 0 01 0 0 0 0 0 0 00 1 1 0 0 0 0 00 1 1 0 0 0 0 00 1 1 0 0 0 0 00 1 1 0 0 0 0 0|A|=12

    Digital Video Compression Fundamentals and Standards

  • Fast Block-Matching AlgorithmsEBMA needs Intensive computation Fast Algorithm is neededFind the possible local optimalReference FrameCurrent Frame

    Digital Video Compression Fundamentals and Standards

  • Fast Block-Matching Algorithms The characteristics of fast algorithmNot accurate as EBMASave large computationTwo famous fast algorithm2-D logarithm Search MethodThree Steps Search Method

    Digital Video Compression Fundamentals and Standards

  • 2-D logarithm Search Method1111122233444441234

    Digital Video Compression Fundamentals and Standards

  • Three Step Search Method1111122221111222233333333123

    Digital Video Compression Fundamentals and Standards

  • Multiresolution Motion Estimation (1/3)The number of levels is Ll-th level images of the target frames

    where is set of pixels at level L At the l-th level, the MV is At the l-th level, the estimated MV isDetermine update such that error is minimized

    The new motion vector is

    Digital Video Compression Fundamentals and Standards

  • Multiresolution Motion Estimation (2/3) Variable block size method

    Digital Video Compression Fundamentals and Standards

  • Multiresolution Motion Estimation (3/3)

    Digital Video Compression Fundamentals and Standards

  • OutlineIntroductionVideo Compression StandardsSimulation Reference SoftwareFuture Work and Conclusions

    Digital Video Compression Fundamentals and Standards

  • The Development of Video Compression Standards

    Digital Video Compression Fundamentals and Standards

    5-point 1D DCT

    6-point 1D DCT

    5-point 1D DCT

    6-point 1D DCT

  • The MPEG-1 StandardGroup of Pictures Motion EstimationMotion CompensationDifferential CodingDCTQuantizationEntropy Coding

    Digital Video Compression Fundamentals and Standards

  • Group of Pictures (1/2)I-frame (Intracoded Frame)Coded in one frame such as DCT. This type of frame do not need previous frame

    P-frame (Predictive Frame)One directional motion prediction from a previous frameThe reference can be either I-frame or P-frameGenerally referred to as inter-frame

    B-frame (Bi-directional predictive frame)Bi-directional motion prediction from a previous or future frameThe reference can be either I-frame or P-frameGenerally referred to as inter-frame

    Digital Video Compression Fundamentals and Standards

  • Group of Pictures (2/2)The distance between two nearest P-frame or P-frame and I-framedenoted by MThe distance between two nearest I-framesdenoted by N

    Digital Video Compression Fundamentals and Standards

  • The MPEG-1 Encoder (1/4)DCTQEntropyCodingQ-1IDCTMotionCompensationFrameMemoryMotionEstimationDCTQEntropyCodingDCTQQ-1IDCTMotionCompensationFrameMemoryMotionEstimationIntra-frameEntropyCodingResidueMotion VectorInter-frame

    Digital Video Compression Fundamentals and Standards

  • The MPEG-1 Encoder (2/4)Differential Coding is the input image is the predictive imageDCT

    Digital Video Compression Fundamentals and Standards

  • The MPEG-1 Encoder (3/4)QuantizationIntra quantization matrixInter quantization matrix

    Digital Video Compression Fundamentals and Standards

  • The MPEG-1 Encoder (4/4)Motion CompensationExploit motion vector and the previous reconstructed frame to generate the predictive frame is the compensated image is the previous image is the motion vectorReference frameTarget frame

    Digital Video Compression Fundamentals and Standards

  • The MPEG-2 StandardField/Frame DCT CodingField/Frame Prediction Mode SelectionAlternative Scan Order Various Picture Sampling FormatsUser Defined Quantization Matrix

    Digital Video Compression Fundamentals and Standards

  • Progressive Scan and Interlaced ScanProgressive ScanInterlaced Scan

    Digital Video Compression Fundamentals and Standards

  • Field/Frame DCT CodingThe field type DCT Fast motion videoThe frame type DCT Slow motion video

    Digital Video Compression Fundamentals and Standards

  • Alternative Scan OrderZigzag scan orderFrame DCTAlternative scan orderField DCT

    Digital Video Compression Fundamentals and Standards

  • The MPEG-2 Encoder (2/2)QuantizationUser can change the quantization if necessaryIntra quantization matrixInter quantization matrix

    Various picture sampling formats4:4:44:2:2 4:2:0

    Digital Video Compression Fundamentals and Standards

  • The MPEG-2 Encoder (1/2)Base LayerBasic quality requirementFor SDTVEnhanced LayerHigh quality serviceFor HDTVDCTQEntropyCodingQ-1IDCTMotionCompensationFrameMemoryMotionEstimationQEntropyCodingQ-1+++++Q-1Bits EnhanceSNR Enhanced Layer+Base LayerBits Base

    Digital Video Compression Fundamentals and Standards

  • H.264/AVCVariable Block SizeMultiple Reference FramesInteger TransformIntra PredictionIn-loop Deblocking Filtering1/4-pel Resolution Motion Estimation CAVLC

    Digital Video Compression Fundamentals and Standards

  • Variable Block SizeThe fixed block size may not be suitable for all motion objectsImprove the flexibility of comparisonReduce the error of comparison7 types of blocks for selection

    Digital Video Compression Fundamentals and Standards

  • Multiple Reference FramesThe neighboring frames are not the most similar in some casesThe B-frame can be reference frameB-frame is close to the target frame in many situations

    Digital Video Compression Fundamentals and Standards

  • Integer Transform for Reducing The Spatial Redundancy (1/2)The transform matrix C

    44 Block SizeSeparable Integer TransformThe transform coefficients are CXCT

    Digital Video Compression Fundamentals and Standards

  • Integer Transform for Reducing The Spatial Redundancy (2/2)CXCTE

    Digital Video Compression Fundamentals and Standards

  • Intra PredictionPredict the similarity between the neighboring pixels in one frame in advance, and exploit differential coding transform coding to remove the redundancy. Vertical right

    Digital Video Compression Fundamentals and Standards

  • Remove Perceptual RedundancyIn-loop deblocking filteringRemove blocking artifactResult from block based motion compensationResult from block based transform codingQP

    Digital Video Compression Fundamentals and Standards

  • 1/4-pel Resolution Motion Estimation

    Digital Video Compression Fundamentals and Standards

  • The H.264/AVC EncoderTransform/QuantizationEntropyCodingInverseTransform/De-QuantizationMotionCompensationDe-blockingFilterMotionEstimationResidueMotion VectorIntra-framePredictionCoderControllerControl Data

    Digital Video Compression Fundamentals and Standards

  • OutlineIntroductionVideo Compression StandardsSimulation Reference SoftwareFuture Work and Conclusions

    Digital Video Compression Fundamentals and Standards

  • H.264 Reference SoftwareJMCurrent software version: JM 15Benchmarkhttp://iphome.hhi.de/suehring/tml/

    Digital Video Compression Fundamentals and Standards

  • Reference Software Demo

    Digital Video Compression Fundamentals and Standards

  • OutlineIntroductionVideo

Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.