Introduction to computer graphics. Chapter 1

Basic of video.

1. UNIT 1
CH.1. INTRODUCTION TO
COMPUTER GRAPHICS

2. VIDEO BASICS
•Video or whole animation is created from sequence of still images called frames.
•By recording and playing back the frames in quick succession, it creates the illusion of
movement.

3. TYPES OF VIDEO FORMATS
•Video format defines how the video is recorded and saved.
•It usually specifies:
1.Codec/ Compressor
2.Frame rate
3.Frame size
4.Frame rate view
5.Pixel Aspect ratio
6.Scanning method

4. TYPES OF VIDEO FORMATS
•Common formats are DV, HDV and AVCHD
•Tape-based formats such as DV and HDV can be transferred to a computer for
editing via firewire.
•File-based formats such as AVCHD are already stored as files and can be
transferred to a computer for USB formatting.

5. CODEC
It is short form of coder-decoder
Most of the video is compressed using codecs
Transcoding is the process of converting one codec to another
Codecs can be lost

6. CODEC
Codec Lossless Use
DV-PAL NO Capture/edit/ output of DV-PAL
video from camera; archive DV-
PAL video
HDV NO Capture/edit/ output of HDV
video from camera; archive HDV
video
H.264 NO Transcode video forweb and
computer playback
MPEG-2 NO Transcodevideo for DVD
Animation YES Output/archive video from after
effects, photoshop

7. FRAME RATE
A frame is a single motionless image within a video clip
the frame contain pixels, each pixel representing the color inside the image
the higher the number of pixels, the better the image can be represented

8. FRAME SIZE
It defines the size of one video frame: width x height, measured
in pixels
FRAME ASPECT RATIO
It describes the relationship between the width and length of a single video
frame
The standard Frame Rate for video is 4:3(normal) and 16:9

9. PAL
it is a TV standard used in the UK and in much of Europe
specifies a frame rate of 25fps and frame size of 720x576 pixels
DV-PAL is a DV video format compatible with PAL specification
NTSC
It is the standard TV used in the USA and Japan
specifies a frame rate of 29.97fps and frame size of 720x480 pixels

10. STANDARD DEFINITION (SD)
•It defines the frame size of a video
•SD video can have a 4:3 or 16:9 frame rate
HIGH DEFINITION (HD)•It defines larger frame size than SD
•Always uses 16:9 frame rate
•Refers to many video formats