Slides to accompany a talk I gave in June 2012. These are an updated version of my H.264/video compression slides.

1. An introduction to
Video Compression
Iain Richardson
20 June 2012
Slide 1

2. Agenda
• 1. What is Video Compression?
• 2. How does a video codec work?
– - prediction
– - transform + quantization
– - coding
– - examples
• 3. Video compression standards
– - H.264
– - HEVC
• 4. Video compression patents
• 5. Going further
Slide 2

3. Agenda
• 1. What is Video Compression?
• 2. How does a video codec work?
– - prediction
– - transform + quantization
– - coding
– - examples
• 3. Video compression standards
– - H.264
– - HEVC
• 4. Video compression patents
• 5. Going further
Slide 3

4. Video compression
MPEG-2 H.264 HEVC ……
Broadcast DVD / IPTV Web Mobile
Digital TV Blu-Ray Video Video
……
Slide 4

5. The need for video compression
Original 2 hour movie: 1,800,000,000,000 bits
=53 DVD disks
COMPRESS
=1 DVD disk
Slide 5

6. Video Source Video Display
Compress Transmi Decompress
(Encode) t or (Decode)
Store
Slide 6

7. Slide 7

8. Slide 8

9. Slide 9

10. Agenda
• 1. What is Video Compression?
• 2. How does a video codec work?
– - prediction
– - transform + quantization
– - coding
– - examples
• 3. Video compression standards
– - H.264
– - HEVC
• 4. Video compression patents
• 5. Going deeper
Slide 10

11. Digital video
Luma (Y)
Displayed frame
Chroma (Cr) Chroma (Cb)
Slide 11

12. Macroblock
Slide 12

13. Video Encoder
Slide 13

14. Video decoder
Slide 14

15. Prediction
Slide 15

16. Prediction
Slide 16

17. Intra prediction
Slide 17

18. Slide 18

19. Inter prediction
Slide 19

20. Slide 20

21. Types of predicted picture
I : Intra prediction only
P : Inter prediction (one reference frame) or Intra prediction
B : Biprediction (two reference frames), Inter (one reference) or Intra prediction
Slide 21

22. Transform + Quantization
Slide 22

23. Video Encoder
Slide 23

24. Forward Transform
Slide 24

25. Inverse Transform
Slide 25

26. Forward Quantize
Slide 26

27. Forward Transform + Quantize
58 64 51 58 961 -41 15 -48 48 -1 0 -1
52 64 56 66 -34 72 -30 -104 -1 1 -1 -2
62 63 61 64 -15 3 15 24 0 0 0 0
59 51 63 69 13 81 -5 8 0 1 0 0
Block of samples After transform Quantized, QP=18
Slide 27

28. Inverse Quantize
Slide 28

29. Inverse Transform
Slide 29

30. 58 64 51 58 48 -1 0 -1 55 66 54 58
52 64 56 66 -1 1 -1 -2 54 62 58 63
62 63 61 64 0 0 0 0 61 59 61 62
59 51 63 69 0 1 0 0 60 55 65 67
Block of samples Quantized, QP=18 Rescaled +
inverse
transformed
Slide 30

31. Entropy coding
Slide 31

32. Video Encoder
Slide 32

33. Entropy coding
Fixed length
codes
Variable length
Headers codes
Prediction parameters
Context Adaptive
Quantized coefficients Variable Length
Codes
Context Adaptive
Binary Arithmetic
Codes
Slide 33

34. Slide 34

35. Slide 35

36. Slide 36

37. Examples
Slide 37

38. Slide 38

39. Slide 39

40. Slide 40

41. Slide 41

42. ……etc
Slide 42

43. Agenda
• 1. What is Video Compression?
• 2. How does a video codec work?
– - prediction
– - transform + quantization
– - coding
– - examples
• 3. Video compression standards
– - H.264
– - HEVC
• 4. Video compression patents
• 5. Going deeper
Slide 43

44. H.264 Advanced Video Compression
Slide 44

45. H.264/AVC
• First released in 2003
• Published by ISO MPEG and ITU-T VCEG
• Roughly 2x compression efficiency of MPEG-2
• Used for:
– Blu-Ray Disks
– High Definition TV broadcasting
– Internet video
– ……
Slide 45

46. Slide 46

47. High Efficiency Video Compression
(HEVC)
Slide 47

48. HEVC
• Under development by ISO MPEG and ITU-T VCEG
• Roughly 2x compression efficiency of H.264
• Due for publication in 2013
Slide 48

49. Slide 49

50. Agenda
• 1. What is Video Compression?
• 2. How does a video codec work?
– - prediction
– - transform + quantization
– - coding
– - examples
• 3. Video compression standards
– - H.264
– - HEVC
• 4. Video compression patents
• 5. Going deeper
Slide 50

51. Source: USPTO database
Slide 51

52. Types of video compression patent
• Encoder
• Decoder
• Transport
Slide 52

53. Patent Pools
• E.g. MPEG-LA, H.264/AVC patent pool:
– Licenses patents on behalf of patent holders
– Unrelated to ISO/IEC MPEG
– Accepts patents based on determination of “essentiality”
– 250+ US patents
– 900+ licensees
Slide 53

54. Agenda
• 1. What is Video Compression?
• 2. How does a video codec work?
– - prediction
– - transform + quantization
– - coding
– - examples
• 3. Video compression standards
– - H.264
– - HEVC
• 4. Video compression patents
• 5. Going further
Slide 54

55. To find out more
• http://www.itu.int - Download the H.264 standard
• http://www.vcodex.com - Free tutorials
• Follow me on Twitter: @onecodec
Slide 55