selected papers from icip 2004 presented by peter

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Selected Papers from ICIP 2004 Presented by Peter

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Page 1: Selected Papers from ICIP 2004 Presented by Peter

Selected Papers from ICIP 2004

Presented by Peter

Page 2: Selected Papers from ICIP 2004 Presented by Peter

Secure Media Streaming & Secure Adaptation for Non-scalable Video (Invited Paper)John G.Apostolopoulos

Hewlett-Packard Labs, Palo Alto, CA

Page 3: Selected Papers from ICIP 2004 Presented by Peter

Summary

Targets Adapting the media for the time-varying available

network bandwidth for non-scalable video Protect the security of the media

Media data is encrypted while R-D information is unencrypted

Each P-frame is encoded into one packet Some P-frame is more important than others

that give less distortion for when being dropped

Page 4: Selected Papers from ICIP 2004 Presented by Peter

Total Distortion

Left: Carphone, Foreman Right: MrthrDhtr, Salesman

Page 5: Selected Papers from ICIP 2004 Presented by Peter

Secure Adaptive Streaming using a Secure-Media Rate-Distortion Hint Track (SM-RDHT) SM-RDHT for untrusted

streaming server RD information

embedded in hint track Media itself is

encrypted

Page 6: Selected Papers from ICIP 2004 Presented by Peter

SM-RDHT

Page 7: Selected Papers from ICIP 2004 Presented by Peter

Secure Transcoding at a Mid-Network Node using Secure Scalable Packets H.264 video is packetized into secure

scalable packets Unencrypted packet headers provide R-D

information – the importance of each packet Mid-network transcoder can perform R-D

optimized adaptation across multiple packets of a single stream or across packets of multiple different strems

1 byte R-D information for each packet (one frame)

Page 8: Selected Papers from ICIP 2004 Presented by Peter

Secure Transcoding at a Mid-Network Node using Secure Scalable Packets

Page 9: Selected Papers from ICIP 2004 Presented by Peter

Comments

Packet size is limited to one frame that reduce the flexibility

Distortion highly depends on method of error concealment methods used at the decoder that is unknown at the streaming server and Mid-Network nodes

Page 10: Selected Papers from ICIP 2004 Presented by Peter

Discussions

Page 11: Selected Papers from ICIP 2004 Presented by Peter

Simple AVC-Based Codecs with Spatial Scalability

R. Lange, Ł. Błaszak and M. Domański

Poznań University of Tachnology, Poland

Page 12: Selected Papers from ICIP 2004 Presented by Peter

Summary

Spatial scalability for AVC-Based Codecs Base layer is fully AVC-compliant Prediction using the interpolation based layer

and previous frame of enhancement layer Improved motion vector encoding Codec complexity is comparable to the

complexity of a pair of codec used for simulcast coding of two layer

Proposed to the AVC standard

Page 13: Selected Papers from ICIP 2004 Presented by Peter

To Layers Structure

Page 14: Selected Papers from ICIP 2004 Presented by Peter

Improved Encoding of Motion Vectors in the Enhancement Layer Optimum motion vectors are used in both layers Previous proposals used motion vectors in the same

layer to predict the current MV Improved version includes up-scaled base layer MV

to predict current MV Prediction residuals are encoded using CABAC Directional prediction is used as AVC standard for

8x16 blocks

Page 15: Selected Papers from ICIP 2004 Presented by Peter
Page 16: Selected Papers from ICIP 2004 Presented by Peter

Improved results from MV Predcition

Page 17: Selected Papers from ICIP 2004 Presented by Peter

Prediction in the Enhancement Layer Two additional reference frames

Interpolated from decoded current base-layer frame

Average of latter and last temporal reference frame

Scalable coding is efficient if temporal prediction and base layer prediction are mixed with substantial prob. For each mode.

Edge-adaptive interpolation technique is used that improve the performance by 1dB

Page 18: Selected Papers from ICIP 2004 Presented by Peter

Experimental Results

Page 19: Selected Papers from ICIP 2004 Presented by Peter

Comments

The proposed scalable codec is not compliant with AVC

Only 2 layers are presented, Not Finegranularity scalable in spatial resolution

Coding efficiency improvement is small comparing to simulcast

Page 20: Selected Papers from ICIP 2004 Presented by Peter

Discussions

Page 21: Selected Papers from ICIP 2004 Presented by Peter

Mode Mapping Method for H.264/AVC Spatial Downscaling TranscodingP. Zhang, Y. Lu, Q. Huang and W. Gao

Chinese Academy of Science,

Microsoft Research Asia

Page 22: Selected Papers from ICIP 2004 Presented by Peter

Summary

Focused only on mode decision part Cascaded Pixel-Domain transcoder (CPDT) Mode mapping only for 16x16 predict mode for I

frames and 8x8 prediction mode for P frames Save about 50% time cost High correlation between the four modes of original

MB and the corresponding MB at half resolution Two modes are proposed:

Simple Mode (SimMap) Use motion vectors information (MapMV)

Page 23: Selected Papers from ICIP 2004 Presented by Peter
Page 24: Selected Papers from ICIP 2004 Presented by Peter
Page 25: Selected Papers from ICIP 2004 Presented by Peter

Simple Mode Mapping Method (SimMap) For I frames

If more than 1 MB use I4x4 mode => use I4x4 in downsized frame

Otherwise use I16x16 For P frames

If all MB are I16x16 => I16x16 If more than 1MB are intra mode => I4x4 If all are P16x16 or skip mode => P16x16,

otherwise P8x8 is selected 4 sub-modes are decided by direct mapping

Page 26: Selected Papers from ICIP 2004 Presented by Peter
Page 27: Selected Papers from ICIP 2004 Presented by Peter

Mode Mapping with Motion Vector (MapMV) For the SimMap, the P16x8 and P8x16 are

not utilized When P8x8 is selected from SimMap:

Compute the distance between all MVs If all distance < Th, => P16x16 If D(MV1, MV3) and D(MV2,MV4) <Th, => P16x8 If D(MV1, MV2) and D(MV3,MV4) <Th => P8x16 Else P8x8

Page 28: Selected Papers from ICIP 2004 Presented by Peter

Experimental Results

Page 29: Selected Papers from ICIP 2004 Presented by Peter

Comments

PSNR loss more than 2dB at low bit rate

Page 30: Selected Papers from ICIP 2004 Presented by Peter

Discussions

Page 31: Selected Papers from ICIP 2004 Presented by Peter

A New Rate Control Scheme for H.264 Video Coding

P. Yin and J. Boyce

Corporate Research, Thomson Inc. Princeton

Page 32: Selected Papers from ICIP 2004 Presented by Peter

Summary

A new constant bit rate control method based on TMN8

Use simple preprocessing to achieve the target bit rate

Better target bit rate, bit allocation, buffer management

Adoption of virtual frame skipping Frame level and MB level rate control Simulations show that the method meet the target

bitrate even for scene changes and scene transitions

Page 33: Selected Papers from ICIP 2004 Presented by Peter

Preprocessing Stage

Chicken and egg problem in RDO: Quantization parameter QP is needed for RDO such as

mode decision Residue signal is needed to determine the QP, i.e. mode

has to be decided to obtain the QP For I frames, residue signals are estimated using

original pixels For P frames, rate constrained 16x16, 1 reference

frame ME is performed to obtain the estimated residue

Average QP of previously coded picture is used the determine the

Page 34: Selected Papers from ICIP 2004 Presented by Peter

Frame-layer rate control

Determine the frame QPf

Use GOP layer rate control GOP length = 1s Constraint the number of bit allocated for GOP to

prevent buffer overflow Unused bits are distributed over several following

GOPs Allocate more target bits for P pictures at the

beginning of GOP for better references Virtual buffer level is used to prevent QP deceases

very quickly

Page 35: Selected Papers from ICIP 2004 Presented by Peter

MB-layer Rate Control

For I picture, a higher distortion is given to MBs with less detail

For P picture, a higher distortion is given to the MBs with more residue errors

Better perceptual quality is maintained for I picture and can be propagated to following P pictures

QP variation within a frame is limited to QPf

2

Page 36: Selected Papers from ICIP 2004 Presented by Peter

Virtual Frame Skipping

After a frame is encoded, if buffer level > 90% of total buffer, next frame is virtual skipped until buffer level is less than 90%

Virtual skipped is achieved by code every MB in P picture to skip mode

Increase the frame QP by 2 after a frame is skipped

Page 37: Selected Papers from ICIP 2004 Presented by Peter

Experimental Results

Page 38: Selected Papers from ICIP 2004 Presented by Peter
Page 39: Selected Papers from ICIP 2004 Presented by Peter

Comments

An implemented rate control system

Page 40: Selected Papers from ICIP 2004 Presented by Peter

Discussions

Page 41: Selected Papers from ICIP 2004 Presented by Peter

Video Encoder Complexity Reduction by Estimating Skip Mode Distortion

I. Richardson and Y. Zhao

The Robert Gordon University

Page 42: Selected Papers from ICIP 2004 Presented by Peter

Summary

Predicts MBs that are likely to be skipped by the encoder

By estimating the increase in distortion due not skipping

Complexity reduced as motion estimation, FDCT, quantization and VLC is skipped for a skipped MB

Page 43: Selected Papers from ICIP 2004 Presented by Peter

Macroblock Distortion and Skip Prediction SAE is used as distortion measure:

The difference between the SAEskip and SAEnoskip is used to determine whether a MB will be skipped ot not

SAEnoskip is not available at the encoder, estimated by SAEnoskip of previous frames

Page 44: Selected Papers from ICIP 2004 Presented by Peter

Experimental Results

Page 45: Selected Papers from ICIP 2004 Presented by Peter

Experimental Results

Page 46: Selected Papers from ICIP 2004 Presented by Peter

Experimental Results

Page 47: Selected Papers from ICIP 2004 Presented by Peter

Comments

Page 48: Selected Papers from ICIP 2004 Presented by Peter

Discussions

Page 49: Selected Papers from ICIP 2004 Presented by Peter

An Improved Rate-Quantization Model for Rate Control in Real-Time Video EncodingB. Xie and W. Zeng

PacketVideo Corporation, San Diego

University of Missouri-Columbia

Page 50: Selected Papers from ICIP 2004 Presented by Peter

Rate-Distortion Optimized Video Coding with Stopping Rules: Quality and Complexity

M. Moecke and R. Seara

Federal University of Santa Catarina

Page 51: Selected Papers from ICIP 2004 Presented by Peter

Adaptive Rate Control for H.264

Z.G. Li, F. Pan, K.P. Lim, X. Lin and S. Rahardja

Institute for Infocomm Research, Singapore

Page 52: Selected Papers from ICIP 2004 Presented by Peter

On Resizing Images in the DCT Domain

C.L. Salazar and T.D. Tran

The John Hopkins University

Page 53: Selected Papers from ICIP 2004 Presented by Peter

Resizing of Images in the DCT Space by Arbitrary Factors

J. Mukhopadhyay and S.K. Mitra

Indian Institute of Technology, India

University of California, Santa Barbara

Page 54: Selected Papers from ICIP 2004 Presented by Peter

Video Multicast Over Channels Based on Distributed Source CodingA. Majumdar and K. Ramchandran

University of California, Berkeley

Page 55: Selected Papers from ICIP 2004 Presented by Peter

Peer-to-Peer Multipoint Videoconferencing

M.R. Civanlar, Ö. Özkasap and T. Çelebi

Koç University, Turkey

Page 56: Selected Papers from ICIP 2004 Presented by Peter

Low-Complexity Rate-Distortion Optimized Video StreamingJ. Chakareski, J, Apostolopoulos and B. Girod

Hewlett-Packard Labs,

Stanford University

Page 57: Selected Papers from ICIP 2004 Presented by Peter

Rate-Distortion-Complexity Adaptive Video Compression and StreamingM. Schaar, D. Turaga and V. Akella

University of California, Davis

Sony Electronics, San Jose

Page 58: Selected Papers from ICIP 2004 Presented by Peter

A Compressed-domain Heterogeneous Video Transcoder

W.C. Siu, K.T. Fung and Y.L. Chan

The Hong Kong Polytechnic University

Page 59: Selected Papers from ICIP 2004 Presented by Peter

Rate-Distortion-Complexity Optimization of Fast Motion Estimation in H.264/MPEG4-AVCJ. Støttrup-Andersen, S. Forchhammer and S.M. Aghito

Milestone System, Denmark

Research Center COM, DTU Denmark

Page 60: Selected Papers from ICIP 2004 Presented by Peter

Summary

Optimizing integer motion estimation in real-time H.264 encoding with respect to the trade-off between rate-distortion and complexity

Enhanced implementation on fast EPZS Speed-up factor of 4 compared to EPZS at 1%

increase in rate (speed-up =2000 when comparing with FS)

Complexity is measured by the number of weighted search positions (4x4 block is weighted by1)