1. Overview of the H.264/AVC Video Coding Standard
T. Wiegand, G.J. Sullivan, G. Bjøntegaard and A. Luthra, IEEE Transaction on Circuits and Systems for Video Technology, Vol. 13, no. 7, Jul
Presented by Peter

2. H.264/AVC Latest Video coding standard
Basic design architecture similar to MPEG-x or H.26x
Better compression efficiency
Up to 50% in bit rate savings
Subjective quality is better
Advance functional element

3. History of H.264/AVC
Initiate by the Video Coding Experts Group (VCEG) in early 1998
Previous name H.26L
Target to double the coding efficiency
First draft was adopted in Oct. of 1999
In Dec. of 2001, VCEF and the Moving Pictures Experts Group (MPEG) formed a Joint Video Team (JVT)
Approved by the ITU-T as H.264 and ISO/IEC as International Standard (MPEG-4 part 10) Advanced Video Codec (AVC) in Mar. 2003

4. Timeline of Video Development

5. Design Features Highlights
Features for enhancement of prediction
Directional spatial prediction for intra coding
Variable block-size motion compensation with small block size
Quarter-sample-accurate motion compensation
Motion vectors over picture boundaries
Multiple reference picture motion compensation
Decoupling of referencing order form display order
Decoupling of picture representation methods from picture referencing capability
Weighted prediction
Improved “skipped” and “direct” motion inference
In-the-loop deblocking filtering

6. Design Features Highlights
Features for improved coding efficiency
Small block-size transform
Exact-match inverse transform
Short word-length transform
Hierarchical block transform
Arithmetic entropy coding
Context-adaptive entropy coding

7. Design Features Highlights
Features for robustness to data errors/losses
Parameter set structure
NAL unit syntax structure
Flexible slice size
Flexible macroblock ordering (FMO)
Arbitrary slice ordering (ASO)
Redundant pictures
Data Partitioning
SP/SI synchronization/switching pictures

8. Directional spatial prediction for intra coding
Intra prediction is to predict the texture in current block using the pixel samples from neighboring blocks
Intra prediction for 44 and 16  16 blocks are supported in H.264
Figs. from [2]

9. Directional spatial prediction for intra coding - 4  4 example
Mode 7 is selected
Figs. from [2]

10. Directional spatial prediction for intra coding – 16  16 example
Mode 3 is selected
Figs. from [2]

11. Variable block-size motion compensation with small block size
Partitioned in 2 stages
In the 1st stage, determine first 4 modes
1616, 168, 816, 88
If mode 4 (88) is chosen, further partition into smaller blocks for every 88 block
84, 48, 44
At most 16 motion vectors may be transmitted for a 1616 macroblock
Large computational complexity to determine the modes
Fig. from [3]

12. Variable block-size motion compensation with small block size

13. Multiple reference picture motion compensation – P Slices
More than one prior coded
picture can be used as reference
for MC prediction
Reference index parameter is
transmitted for each MC 1616, 168, 816 or 88
For smaller blocks within the 88 use 1 reference index
P macroblock can also be coded in P-Skip type
Fig. from [1]

14. Multiple reference picture motion compensation – B Slices
Utilize two distinct lists of reference pictures
Four different types of inter-picture predict
List 0, list 1, bi-predictive, and direct prediction
Bi-predictive
weighted average of MC list 0 and list 1
Direct prediction
Inferred from previously transmitted syntax
Either list 0 or list 1 prediction or bi-predictive
Similar macroblock partitioning as P slices is utilized
B_Skip mode is supported

15. Small block-size transform
Transformation is applied on 44 blocks
Close to 44 DCT transform
Inverse-transform mismatches are avoided
The transform matrix is given as

16. Short word-length transform
Post-scaling matrix in forward transform
Pre-scaling matrix in inverse transform
Only integer operations and shifting are needed in transformation and quantization

17. Hierarchical block transform
For macroblock is coded in 1616 Intra mode and chrominance blocks
DC coefficients are further grouped and transformed
Hadamard transform is used for chrominance block
Intended for coding of smooth areas
Figs. from [4]

18. Some results – Foreman QCIF @ 10 Hz
Fig. from [1]

19. Some results – Foreman CIF @ 30 Hz
Fig. from [1]

20. Profiles 3 profiles - Baseline, Main and Extended Profile 15 levels
Picture size: up to 250M pixels/s
Bit Rate: up to 240M bps

21. Potential Applications
Baseline (low latency)
H.320 conversational video services
3GPP conversational H.324/M services
H.323 with IP/RTP
3GPP using IP/RTP and SIP
3GPP streaming using IP/RTP and RTSP
Main (moderate latency)
Modified H.222.0/MPEG-2
Broadcast via satellite, cable, terrestrial or DSL
DVD and VOD
Extended
Streaming over wired Internet
Any (no requirement on latency)
3GPP MMS
Video mail

22. References
T. Wiegand, G.J. Sullivan, G. Bjøntegaard and A. Luthra, “Overview of the H.264/AVC Video Coding Standard,” IEEE Transaction on Circuits and Systems for Video Technology, Vol. 13, no. 7, Jul
I.E.G. Richardson, “H.264/MPEG4 Part 10: Intra Prediction,” available at
I.E.G. Richardson, “H.264/MPEG4 Part 10: Inter Prediction,” available at
I.E.G. Richardson, “H.264/MPEG4 Part 10: Transform and Quantization,” available at