1. "Digital Media Primer" Yue-Ling Wong, Copyright (c)2013 by Pearson Education, Inc. All rights reserved.

2. Chapter 6 Fundamentals of Digital Video
Part 1
The Properties of Broadcast Video

3. In this lecture, you will learn:
the basic terminology of broadcast standards that will prepare you to learn digital video terminology and standards

4. Video
motion
a sequence of pictures

5. Video
motion
a sequence of pictures
frames

6. Frame Rate How fast the pictures are captured
How fast the frames are played back is determined by
Frames per second (fps)

7. Broadcast Standards Digital video resolution Color spaces Frame rate
Influenced by analog TV broadcast standards

8. Standards for Analog Color TV
NTSC:
designated by U.S.'s National Television Systems Committee
U.S., Japan, Taiwan, parts of the Carribean, South America
PAL:
Phase Alternating Line
Australia, New Zealand, Western Europe, Asian
SECAM:
Séquentiel Couleur avec Mémoire
France, former Soviet Union, Eastern Europe

9. Frame Rates of Different Broadcast Standards
Video Type
Frame Rate (frames per second)
NTSC (black-and-white) 30
NTSC (color)
29.97
PAL 25
SECAM
Motion-picture film 24

10. How CRT Monitors and TVs Display Pictures
Picture displayed on CRT is made up of horizontal lines
NTSC: 525 lines (about 480 lines are picture)
PAL and SECAM: 625 lines (about 576 lines are picture)
Lines are traced across the screen
one line at a time
from top to bottom

11. Ways of Tracing Lines From Top to Bottom
Progressive scan:
from top to bottom in one pass
Interlaced scan:
in two passes:
even-numbered lines
odd-numbered lines

12. Video Display: Interlaced Scan versus Progressive Scan
Also see the interactive tutorial:
Video Display: Interlaced Scan versus Progressive Scan
An interactive animation that illustrates two-pass scanning in interlaced scan and one-pass scanning in progressive scan.

13. Field Set of lines in the same pass 2 fields in interlaced scan:
even-numbered lines
odd-numbered lines
Upper field: the field that contains the topmost scan line
Lower field:
the other field

14. Undesirable Side Effects of Interlaced Scan
The two fields in a frame are captured at a slightly different moment in time
Discontinuities will become apparent for fast moving objects in video shot in the interlaced mode
Comb-like artifacts

15. Comb-like Artifacts

16. Upper Field

17. Lower Field

18. Video Recording: Interlaced Mode versus Progressive Mode
Also see the interactive tutorial:
Video Recording: Interlaced Mode versus Progressive Mode
An interactive animation that illustrates how the interlace artifact may be produced in fast-action videos.

19. Upper Field and Lower Field
Also see the interactive tutorial:
Upper Field and Lower Field
An interactive demo shows the upper field and the lower field of a video frame.

20. Fast-Action Digital Video Showing the Interlace Artifact
Also check out the video:
Fast-Action Digital Video Showing the Interlace Artifact
The soccer practice video clip from which the example is using here to show the comb-like interlace artifact.

21. Interlace Artifacts
Not visible during normal playback of most videos

22. Deinterlace To remove the interlace artifact Common method:
discard one field
fill in the gaps by duplicating or interpolating the other field

23. Deinterlaced Result

24. Color Format for Videos
Luminance-chrominance color models
Luminance: brightness Chrominance: color or hue

25. Luminance-chrominance Color Model Examples
YUV:
Y: luminance component
U and V: chrominance components
used for PAL
YIQ:
I and Q: chrominance components
used for NTSC

26. Review Questions Note to instructor:
Depending on your preference, you may want to go over the review questions at the end of this lecture as an instant review or at the beginning of next lecture to refresh students' memory of this lecture.

27. Review Question
Which of the following is the television broadcast standard for the U.S. and Japan?
NTSC
PAL
SECAM A

28. Review Question
Which of the following is the television broadcast standard for most of the Asian countries?
NTSC
PAL
SECAM B

29. Review Question
In the YUV color model, the Y-component is ___, the U-component is ___, and V-component is ___.
luminance; luminance; chrominance
luminance; chrominance; luminance
luminance; chrominance; chrominance
chrominance; chrominance; luminance
chrominance; luminance; luminance C

30. Review Question The frame rate for the NTSC system is ___ fps. 24 25
28.9
29.97 30 D

31. Review Question The frame rate for the PAL system is ___ fps. 24 25
28.9
29.97 30 B

32. Review Question
The frame rate for the the motion-picture film is ___ fps. 24 25
28.9
29.97 30 A

33. Review Question The scan mode of a CRT computer monitor is ___.
interlaced
progressive A

34. Review Question The scan mode of a CRT television set is ___.
interlaced
progressive A

35. Review Question
Interlaced scan displays the frame by scanning the lines of a frame ___.
in one pass from top to bottom
in two passes: even-numbered lines in one pass and odd-numbered lines in the second B

36. Review Question
Progressive scan displays the frame by scanning the lines of a frame ___.
in one pass from top to bottom
in two passes: even-numbered lines in one pass and odd-numbered lines in the second A

37. Review Question
The comb-like artifact in a digital video, as shown here, occurs in the ___ video.
interlaced
progressive
both A and B A