1. By Sudeep Gangavati ID 1000717165 EE5359 Spring 2012, UT Arlington
Video Compression Standards : A Comparative Analysis of H.264, Dirac and AVS P2
By Sudeep Gangavati ID
EE5359 Spring 2012,
UT Arlington

2. Objective and motivation
The goal – to compare H.264/AVC, AVS P2 and Dirac
Video quality assessment – MSE, PSNR, SSIM
Ever increasing demand for video compression
Several different video coding standards have been developed to address the needs efficient video coding for multitude of applications like video streaming, TV broadcasting, 3D TV, Free-viewpoint TV etc. [24].
1.The main motive behind the project is to compare for performance and analyze video compression standards : H.264/AVC , AVS China Part 2 and Dirac Pro.
2. During the course of the project, several video test sequences will be coded using standard coding software like JM 18.2, Schrodinger ( for Dirac Pro)
and AVS Software for AVS video coding. The quality of the video will be assessed for different performance metrics like MSE, PSNR, SSIM, bitrate.
3. Conclusions will be drawn based on the results obtained.

3. H.264/AVC Features The most widely used video coding standard
Fig. 1 Video coding standards evolution [12]
1.By far, H.264 Adv Video Coding std is the most widely used standard for streaming videos, mobile/handheld applications etc. The std was finalized during H.264 provides the best video compression.
2. There are several codecs that encode/decode videos based on the H.264 standard.The Encoder Structure is similar to MPEG 2

4. Features Motion compensated coding structure
Picture  slices  MBs  subMBs  blocks  pixels. This is shown in Figure 3.
Only 4:2:0 chroma format was supported earlier and 4:2:2 , 4:4:4 were added later. This is shown in Figure 2.
I , P and B slices
Derived slices SI and SP

5. Fig 2. 4:4:4, 4:2:2, 4:2:0 sampling patterns

6. Fig 3. H.264 syntax

7. Profiles and levels Main Profile Baseline Profile Extended Profile
High Profile

8. H.264 Profiles
Fig.4 H.264 profiles [1]

9. H.264 Encoder
Fig. 5 Encoder structure for H.264 [2]

10. H.264 Decoder
Fig.6 Decoder structure of H.264 [2]

11. Intra and Inter Predictions
Intra Prediction :
Uses spatial prediction to reduce spatial redundancy.
4 X 4 luma – 9 modes
16 X 16 luma – 4 modes
8 X 8 luma- 9 modes

12. Intra prediction modes for 4X4 luma
Fig.7(a) Intra prediction modes [6]
The samples above and to the left, labelled A-M in Figure 7 have previously been encoded and reconstructed and are therefore available in the encoder and decoder to form a prediction reference.

13. Intra Prediction Modes for 16x16 luma
Again the previously encoded samples directly above and to the left of the macroblock have been reconstructed and are used for the prediction
Fig 7 (b) Intra prediction modes for 16x16 luma [6]

14. Inter prediction Uses motion estimation and motion compensation (MC).
Fig.8 H.264 Inter prediction [5]

15. De-blocking filter[5] Is used to reduce the blocking artifacts.
Since the filter is present in the loop , it prevents the propagation of the blocking artifacts.
Fig. 9 Boundaries in a macroblock to be filtered (luma boundaries shown with solid lines
and chroma boundaries shown with dotted lines) [1]

16. AVS China[7] AVS-Audio Video Standard
Standardization includes system, audio, video and digital copyright management.
Goal – to achieve coding efficiency with reduced complexity.

17. AVS Parts [3]
Fig. 10 AVS China parts [3]

18. AVS P2 Encoder [7]
Fig. 11 AVS part 2 encoder [7]

19. AVS P2 decoder
Fig 11 (a) AVS P2 decoder block diagram [7]

20. Intra Prediction in AVS[7]
Spatial prediction is used in intra coding in AVS part 2.
The Intra prediction is based on 8x8 block
The intra prediction method is derived from the neighboring pixels in left and top blocks

21. Intra Prediction contd.
Fig.12 (a) Five different modes for intra luminance prediction[16]

22. Inter prediction [16]
Inter prediction in AVS is by motion compensation and motion estimation [16].
As shown in the Figure 12 (b), the macroblock can have 16 x 16, 8 x 16, 16 x 8 or 8 x 8 [16].
Fig 12 (b) Macroblock sizes [16]

23. Dirac Dirac is a video codec originally developed by BBC
This technique is used from web streaming of videos to HD TV applications to storage of content.
Dirac can compress any resolution picture
The encoder and decoder diagrams are shown in Figure 13 (a) and (b) respectively.

24. Dirac encoder and decoder :
Figure 13 (a) Dirac encoder[8]
Figure 13 (b) Dirac decoder[8]

25. Dirac pro Features
Dirac pro supports the following technical aspects [9]:
Intra-frame coding only
10 bit 4:2:2
No subsampling
Lossless or visually lossless compression
Low latency on encode/decode
Support for multiple HD image formats and frame rates
Low complexity for decoding

26. Experimental Results Table 1: Parametric values for Dirac video codec
Implementation of DIRAC Software 1.02:
Video sequence: news_qcif.yuv.
Width: 176, Height: 144.
Total number of frames: 300
Number of frames used for encoding: 100.
Frame rate: 25 FPS. File Size: 3713kB.
Quality Factor
Compressed File Size
Bit rate (kBps)
Y-PSNR(dB)
Y-MSE
Y-SSIM
Comrpession Ratio 38
9.573
25.773
187.13
0.79
98:1 5 61
15.571
32.134
39.588
0.95
60:1 10
369
96.301
46.699
1.41
0.98
10:1 15
1278
130.12
51.799
0.743
0.99
2.9:1
Table 1: Parametric values for Dirac video codec

27. Experimental Results contd.
Quality Factor = 0
Quality Factor = 5
Quality Factor = 10
Fig.14 Output of Dirac video codec at different Quality Factors

28. Table 2. Parametric values of Dirac video codec for foreman_qcif video
Video sequence: foreman_qcif.yuv Width: 176; Height: 144. Total number of frames: 300 Number of frames used for encoding: 100. Frame rate: 25 FPS; File Size: 3713kB
Quality Factor (QF)
Compressed File Size (kB)
Bitrate (kBps)
Y-PSNR (dB)
Y-MSE
Y-SSIM
Compressio n Ratio 27
8.991
21.5
301.56
0.6875
138:1 5 58
12.675
28.91
110.12
0.8613
64:1 10
581
43.675
0.827
0.979
6:1 15
1340
49.556
0.667
0.99
2.7:1
Table 2. Parametric values of Dirac video codec for foreman_qcif video

29. QF=0 QF=05
QF=10 QF=15
Fig.15 Output of Dirac video codec at different Quality Factors for foreman_qcif video

30. Implementation of AVS software Video sequence used: news_qcif
Implementation of AVS software Video sequence used: news_qcif.yuv Width: 176;Height: 144 Total number of frames: 300; Number of frames used: 100 Frame rate: 25 FPS; File Size: 3713kB
QP= QP= QP=50
Fig.16 Output of AVS video codec at different Quality Factors for news_qcif video
Fig.17 Output of AVS video codec at different Quality Factors for foreman _qcif video

31. Implementation of AVS software
Quantization Parameter (QP)
Compressed File Size
Bit rate (kBps)
Y-PSNR(dB)
Y-MSE
Y-SSIM
Comrpession Ratio
980
554.19
54.773
0.2587
0.9997
3:1 10
442
219.12
49.72
0.5525
0.9945
9:1 30
64.0
156.49
38.49
9.23
0.9760
58:1 50
12.0
29.26
27.96
104.13
0.8506
309.7
Table 3. Parametric values of AVS video codec for news_qcif video QP
Compressed file size
Bitrate
Y-PSNR
Y-MSE
Y-SSIM
Compressio n Ratio
1123
478.88
52.658
0.2823
0.998
3:1 10
450
278.9
48.775
0.781
0.9903
8.25:1 30 70
79.66
35.231
13.56
0.867
53:1 50 14
24.5
29.780
146.32
0.776
265:1
Table 4. Parametric values of AVS video codec for foreman_qcif video

32. Implementation of H.264 software (JM 18.0)
Quantization Parameter (QP)
Compressed File Size
Bit rate (kBps)
Y-PSNR(dB)
Y-MSE
Y-SSIM
Comrpession Ratio
279
685.19
60.773
0.999
13:1 10
208
410.21
48.545
0.9653
0.9947
17.8:1 30
123
155.62
35.721
0.8626
30:1 50 35
29.49
28.736
224.23
0.7644
27.5:1
Table 5. Parametric values of H.264 video codec for news_qcif video
Quantization Parameter (QP)
Compressed File Size
Bit rate (kBps)
Y-PSNR(dB)
Y-MSE
Y-SSIM
Comrpession Ratio
379
485.19
62.773
0.999
9:1 10
210
340.21
54.67
0.7769
0.9947
18:1 30 98
155.62
34.721
0.8626
39:1 50 25
39.49
27.736
236.23
0.6944
27.5:1
Table 6. Parametric values of H.264 video codec for foreman_qcif video

33. Plots of PSNR (dB) vs. Bitrate (kBps)
Fig18. Plot of PSNR vs. Bitrate for different codecs for news_qcif video

34. Plots of PSNR (dB) vs. Bitrate (kBps) contd..
Fig 19. Plot of PSNR vs. Bitrate for different codecs for foreman_qcif video

35. Plots of MSE vs. Bitrate
Fig 20. Plot of MSE vs. Bitrate for different codecs for news_qcif video

36. Plots of MSE vs. Bitrate contd..
Fig 21. Plot of MSE vs. Bitrate for different codecs for foreman_qcif video

37. Plot of SSIM vs. Bitrate
Fig 22. Plot of SSIM vs. Bitrate for different codecs for news_qcif video

38. Plot of SSIM vs. Bitrate
Fig 23. Plot of SSIM vs. Bitrate for different codecs for foreman_qcif video

39. Computational complexity
Fig 24. Plot of time taken by each codec at QP=30 and QF=10

40. Conclusions
The plots and tabulations show that with the increase in bitrate, there is an increase in PSNR and SSIM and reduction in the MSE.
Therefor from the plots and the tables, it can be concluded that H.264 provides optimum performance with respect to PSNR, MSE and SSIM over AVS part 2 and Dirac.
Regarding the computational complexity, H.264 is more complex than the other two standards viz., AVS part 2 and Dirac. This is due to the fact that H.264 supports several prediction modes and has varied macroblock sizes when compared to AVS and Dirac.

41. References
[1] Soon-kak Kwon, A. Tamhankar and K.R. Rao, “Overview of H.264 / MPEG-4 Part 10 (pp )”, Special issue on “ Emerging H.264/AVC video coding standard”, J. Visual Communication and Image Representation, vol. 17, pp , April 2006.
[2] T. Wiegand, G. Sullivan, G. Bjontegaard and A. Luthra, “Overview of the H.264/AVC video coding standard,” IEEE Trans. on Circuits and Systems for Video Technology, vol. 13, pp , July 2003.
[3] T. Sikora, “Digital video coding standards and their role in video communications”, Signal Processing for Multimedia, J.S. Byrnes (Ed.), IOS press, pp , 1999.
[4] K. R. Rao, and D. N. Kim, “Current video coding standards: H.264/AVC, Dirac, AVS China and VC-1,” IEEE 42nd Southeastern symposium on system theory (SSST), March , pp. 1-8, March 2010.
[5]Z. Wang and A.C. Bovik, “A universal image quality index”, IEEE Signal Processing Letters,Vol.9, pp , March 2002.
[6] Iain Richardson, “ The H.264 advanced video coding standard”, Second Edition,Wiley, 2010
[7] L. Yu et al, “An Overview of AVS-Video: tools, performance and complexity”, Visual Communications and Image Processing, Proc. of SPIE, vol. 5960, pp , July
[8] “ The Dirac web page” :
[9] “Dirac Codec Wiki Page ” at
[10]“Dirac Pro web page” at
[11] “Video on the web “ a
[12] J.Lou “Advanced video codec optimization techniques”, Doctoral Dissertation, Electrical Engineering Department, University of Washington, August 2009

42. References
[13] H.264 AVC JM Software :
[14] H.264 decoder:
 [15] W. Gao et al, “AVS - The Chinese next-generation video coding Standard” NAB, Las
Vegas, 2004.
 [16] X. Wang et al., “Performance comparison of AVS and H.264/AVC video coding standards” J. Comput. Sci. & Technol., vol.21, No.3, pp , May 2006.
 [17] AVS China part 2 video software, password protected : ftp:// /
 [18] S. Swaminathan and K.R. Rao, “Multiplexing and demultiplexing of AVS CHINA video with AAC audio,” TELSIKS 2011, Nis, Serbia, 5-8 Oct
[19] Dirac Pro Software :
 [20] M. Tun, K.K. Loo and J. Cosmas, “Semi-hierarchical motion estimation for the Dirac video codec,” 2008 IEEE International Symposium on Broadband Multimedia Systems and Broadcasting, pp.1–6, March 31-April 2, 2008.
[21] T. Davies, “The Dirac Algorithm”:
2008.
[22] Dirac video codec – A programmer's guide:
[23] A. Ravi and K.R. Rao, “Performance analysis and comparison of the Dirac video codec with H.264 / MPEG-4 Part 10 AVC,”IJWMIP, vol.4, pp , No.4, 2011.
[24] Proceedings of the IEEE Special issue on Frontiers of Audiovisual Communications, vol. 100, No.4, April 2012