The document discusses the H.264/MPEG-4 AVC video compression standard. It provides an overview of the evolution of video coding standards that led to H.264/AVC, describes key features of H.264/AVC such as enhanced motion compensation, transform coding, and entropy coding, and compares H.264/AVC's compression performance to prior standards. The document concludes that H.264/AVC provides up to 50% better compression efficiency than previous standards through improvements like smaller block sizes and an adaptive deblocking filter, though it also increases computational complexity.

1. MPEG 4, H.264 Compression StandardsMPEG 4, H.264 Compression Standards
Presented by Dukhyun Chang
(dhchang@mmlab.snu.ac.kr)

2. ContentsContents
Introduction
Features of the H.264/AVC
Profile & performance of H.264/AVC
Conclusion

3. Evolution of Video coding StandardsEvolution of Video coding Standards
ITU-T
Standard
Joint
ITU-T/MPEG
Standards
MPEG
Standard
1988 1990 1992 1994 1996 1998 2000 2002 2004
H.261
(Version 1)
H.261
(Version 2)
H.263 H.263+ H.263++
H.262/MPEG-2 H.264/MPEG-4 AVC
MPEG-1
MPEG-4
(Version 1)
MPEG-4
(Version 2)

4. Structure of H.264/AVC video encoderStructure of H.264/AVC video encoder
Control
Data
Video Coding Layer
Data Partitioning
Network Abstraction Layer
H.323/IP MPEG-2 etc.H.320 MP4FF
Coded Macroblock
Coded Slice/Partition

5. ApplicationsApplications
Broadcast
Streaming
Content
Server
Internet
Link
Mobile
Communication
Storage
DMB
Multimedia Service
VCL
NAL
Mpeg-2
systems
RTP
payload
ISO media
file format
encapsulation
H.320,
H.324/M
NAL gives VCL network
independent interface

6. Data Structure of MPEGData Structure of MPEG
GOP GOP GOPSH SH SH
I B B P B B P …… BBB P
slice
slice
MB MB MB MB MB MB ….
Y1
Y3
Y2
Y4
Cb Cr
Sequence
GOP
Picture
Slice
Macroblock

7. ContentsContents
Introduction
Features of the H.264/AVC
Profile & Performance of H.264/AVC
Conclusion

8. Basic coding structure of H.264/AVC for a macroblockBasic coding structure of H.264/AVC for a macroblock
Entropy
Coding
Scaling & Inv.
Transform
Motion-
Compensation
Control
Data
Quant.
Transf. coeffs
Motion
Data
Intra/Inter
Coder
Control
Decoder
Motion
Estimation
Transform/
Scal./Quant.
-
Input
Video
Signal
Split into
Macroblocks
16x16 pixels
Intra-frame
Prediction
De-blocking
Filter
Output
Video
Signal
New features of H.264

9. TransformTransform
MPEG-4 AVC
MPEG-2 / MPEG-4
Integer
Transform
Incoming
4x4 Block
transformed
4x4 Block
DCT
Transform
Incoming
8x8 Block
transformed
8x8 Block

10. Intra & Inter Coding StructureIntra & Inter Coding Structure
Intra Coding Structure
– Intra Frame  Motion estimation cannot be exploited
• Eliminate spatial redundancy
– Directional spatial prediction
Motion Compensation
– Various block sizes and shapes for motion compensation
• More precise compensation
0
Sub-macroblock
partitions
0
1
0 1
0 1
2 3
0
0
1
0 1
0
2
1
3
1 macroblock partition of
16*16 luma samples and
associated chroma samples
Macroblock
partitions
2 macroblock partitions of
16*8 luma samples and
associated chroma samples
4 sub-macroblocks of
8*8 luma samples and
associated chroma samples
2 macroblock partitions of
8*16 luma samples and
associated chroma samples
1 sub-macroblock partition
of 8*8 luma samples and
associated chroma samples
2 sub-macroblock partitions
of 8*4 luma samples and
associated chroma samples
4 sub-macroblock partitions
of 4*4 luma samples and
associated chroma samples
2 sub-macroblock partitions
of 4*8 luma samples and
associated chroma samples

11. Motion CompensationMotion Compensation
Multiple reference pictures
– Arbitrary weights
– Regardless of the temporal direction
– Can use B-Slice as reference

12. Adaptive Deblocking FilterAdaptive Deblocking Filter
Deblocking Filter
– There are severe blocking artifacts
• 4*4 transforms and block-based motion compensation
– Result in bit rate savings of around 6~9%
– Improve subjective quality and PSNR of the decoded picture
Without Filter With AVC Deblocking Filter

13. FMO (1/2)FMO (1/2)
FMO (Flexible Macroblock Ordering)
– Slice (composed in FMO)  Enhance Robustness to data loss
Picture
Slice Group
Slice
…
.
.….
Independently-
decodable

14. FMO (2/2)FMO (2/2)
Slice #0
Slice #1
Slice #2
Subdivision of a picture into
slices when not using FMO
Slice Group #0
Slice Group #1
Slice Group #2
Subdivision of a QCIF frame into slices when
utilizing FMO
Slice Group #0
Slice Group #1

15. ASOASO
ASO (Arbitrary Slice Ordering)
– Independently-decoded Slice
• Enables sending and receiving the slice in any order
• Improve end-to-end delay in real-time application
Picture Picture
Internet protocol network
Slice Slice
Start to
decode

16. Entropy CodingEntropy Coding
CAVLC (Context Adaptive Variable Length Coding)
– Context : already coded information of the neighboring
blocks and the coding status of the current block
– Optimized VLC tables are provided for each context to code
the coefficients in different statistical conditions
CABAC (Context Adaptive Binary Arithmetic Codes)
– Use a binary arithmetic coding engine
– Compression improvement is consequence of
• Adaptive probability estimation
• Improved context modeling scheme
– Exploiting symbol correlations by using contexts
– Average bit-rate saving over CAVLC 5~15%

17. ProfilesProfiles

18. Comparison to Previous StandardsComparison to Previous Standards

19. ConclusionConclusion
H.264 is the standard of both ITU-T VCEG and ISO/IEC MPEG
gains in compression efficiency of up to 50% compared to
previous standards
New key features are:
– Enhanced motion compensation
– Small blocks for transform coding
– Integer transform
– Improved deblocking filter
– Enhanced entropy coding
Increased complexity relative to prior standards

20. ReferencesReferences
Ralf Schafer, Thomas Wiegand and Heiko Schwarz, “The emerging H.264/AVC
standard,” in EBU technical review, Jan. 2003.
Jorn Ostermann et al., “Video coding with H.264/AVC: Tools, Performance, and
Complexity,” in IEEE Circuit and systems magazine, first quarter. 2004.
Thomas Wiegand et al., “Overview of the H.264/AVC Video Coding Standard,” in
IEEE transactions on circuits and systems for video technology, Vol. 12, No.7,
July. 2003.
M. Mahdi Ghandi and Mohammad Ghanbari, “The H.264/AVC Video Coding
Standard for the Next Generation Multimedia Communication,” in IAEEE Jounal.