VIDEO TERMINOLOGYUnderstanding Video

Chapters

Video Formats Progressive vs. Interlaced Video Image Sizes Frame Rates Video Outputs Video as Digital Data Compression Tape Formats

Video Standards

NTSC NTSC-J PAL PAL-M SECAM

aNTSC

525 scanlines to a frame of video Displays at 30 fps Countries using NTSC

North and Central America Philippians Twain

NTSC-J

Same as NTSC but used in Japan 525 scanlines 30 fps

Darker black than NTSC Black setting goes to 0 vs 7.5 IRE

PAL

High resolution – 625 scanlines per frame 25 fps Used in Europe, Scandinavia, the Pacific

and South Africa

PAL - M

Used in Brazil 525 scanlines PAL color palette Runs at 30 fps

SECAM

625 scanlines 25 fps PAL color palette Used in France, Russia, the Middle East

and North Africa

Comparing PAL and NTSC

PAL Sharper Image with 625 scanlines More flicker because it runs at 25 fps

NTSC Less flicker running at 30 fps Poorer resolution only 525 scanlines

Which should you use? Depends on where your video will be viewed. If America – must be NTSC If Europe – must be PAL

Progressive vs. Interlaced

Video is made up of scanlines When you display then from top to

bottom in sequentially first line 1, then 2, 3,4, …….all the way to the bottom of the image. That is called Progressive scan and all computer monitors use this type of scan.

Progressive vs. Interlaced

When television first started they could not display video progressively.

They used fields One field displayed all the even lines (2,4,6,8,

…)and the other all the odd lines ( 1, 3, 5,7,...) First they displayed the the even field and

alternating with the odd field. By weaving these together the could display a

single frame.

Interlaced

Computer use progressive but all televisions both NTSC and PAL use Interlaced display.

Interlacing by its nature photographs the odd numbered scanlines and then the even numbered scanlines.

Called Interlacing Artifacts

Progressive

Film is Progressive. When you take an image with film you

take the entire image at one time. Advantage to progressive is better image

quality. Disadvantage is you can’t broadcast it.

There is no broadcasting of progressive images excluding HD.

Progressive vs. Interlaced

Progressive Entire image Film or Computer

screen Better image

quality

Interlaced Every other line Television Broadcast

compatibility Whether shooting DV

or broadcast the first shot are all the even lined fields and then the odd ones.

Fields = Sam LinesEven and Odd Fields = Upper and Lower Fields

Frame Rates

FILM: 24 fps PAL: 25 fps NTSC: 30 fps

Video Formats

DV Digital Video

SD Standard Definition Video

HD High Definition Video

Video Formats

DV MiniDV DVCPro-25 DVCAM

Image quality of each is the same. Totally digital format

Video Formats

SD DVCPro-50 (digital) Betacam SX (digital) Betacam SP (analog) DigiBetacam (digital)

Video Formats

HD HDV DVCPro-HD (100) HD

Image Size

All video is fixed in size All are bitmapped video –there size is

fixed at the moment they were created. The sized of the screen makes no

difference because the size of the image is fixed.

Image Size

Projected film and computer monitors are variable size.

If you project a film on a large screen or computer monitor you see more detail.

Image Size

Video resolution is fixed at 72 dpi. DV – NTSC

720 x 480 PAL

720 x 576

Image Size

SD NTSC – 720 x 486 PAL – 720 x 576

Image Size

Why? NTSC

SD 720 x 486 DV 720 x 480

Both 720 and 480 are divisible by 4 Video compression requires 4 x 4 pixel

squares called Super Blocks

HD

Comes in both progressive and interlaced formats.

There are three sizes.

HD

HD 480i & p Broadcast image size

HD 720i & p Refers to the number of vertical lines of

information. 1280 x 720

HD 1080i 1920 x 1080

HD

All HD formats are 16:9 (16 units wide by 9 units high)

HDV

1440 x 1080 – native format JVC – 1280 x 720 p Sony – 1920 x 1080i

Image Sizes

Summary HD 1080i = 1920 x 1080 HD 720p = 1280 x 720 Traditional = 720 x 480

Aspect Ratio

Number which describes the relationship of the width of a picture with the height of a picture.

The height is described as the number one and the width describe how much longer than one unit high the picture is wide.

Aspect Ratio

To compete with TV, film started changing the aspect ratio to provide a different viewing experience.

Television invented with a 4 by 3 aspect ratio.

Pre-1950s films were 4:3 (1.33:1)

Aspect Ratio

Disney cartoons became (1.66:1) about 60% wider than high

Movies today are 16:9 (1.78:1) Epic movies are wider 2.35:1

Aspect Ratio

SD = 4:3 HD = 16:9 vs 4:3 Letterboxing

Adding black bars at the top and bottom of the screen to fit a 16:9 image onto a 4:3 screen.

Pillar boxing Adding black to the sides of the screen to fit a

4:3 image to a 16:9 screen.

Video Outputs

Analog Digital

Video Outputs

ANALOG DIGITAL

Composite Single nozzle, RCA plug

or BNC S-Video

4 pin plug that carries the color on different wires

Component Highest analog

connection labeled red, green and blue or Y, CR and CB

Firewire A communications

protocol that moves digital data

SDI Carries digital data but

works for both SD and HD pictures

Digital Audio

EMBEDDED SDI AES/EBU

Most time you will use embedded audio

Be careful not to cross digital an analog audio input

Digital audio on a microphone connector – 3 pins

Tape Formats

VHS Universal Poor quality Analog

Tape Formats

DV DVCPRO-25 (Panasonic format) DVCAM (Sony format) MiniDV (about 20 companies)

Image quality between the three formats is identical.

Tape Formats

DVCPRO-50 Higher quality than DV (6 MB/sec data rate) DVPRO-50 (50 MB/sec data rate) 6 MB/sec data rate Used by most broadcast stations

Tape Formats

DVCPRO-HD (100) HDV

DV tape size and data rate HD picture quality Brand new format

Betacam SX See only in broadcast about the same quality

as HDV

Tape Formats

Betacam SP Industry workhorse for video formats the

broadcast industry Analog Used around the world on daily basis for video

capture and editing

Tape Formats

DigiBetacam SD highest quality 16:9 or 4:3 ratio recording Can shoot 24 fps as well as 30 fps or 25 fps Digital High end of standard definition

Tape Formats

HD D1 & D5

Used specifically when high resolution is necessary

Work at the highest quality you can afford Most people = DV Broadcast industry = DigiBetacam