Video Basics

Introduction ---- video industry

Video Imaging ---- video scan, aspect ratio

Color and Composite & component systems

From Analog To Digital Video

Spatial Conversions ---- video formats

Temporal Conversions

Mixing And Keying

Onde temos vídeo?

C a b le N e tw o rk

D V B - S d o w n s t r e a m ( m a x 9 0 M b p s )D S S

D V B - C d o w n s t r e a m ( m a x 4 0 M b p s )O p e n C a b le

1 . S a t e l li te ( f a s t P S T N / I S D N2 . C a b l e M o d e m ( Q P S K , T C P / I P ™ f o r P S T N / I S D N m o d e m3 . S D S L / A D S L / V D S L … ..

I E E E 1 3 9 4 / U S BE t h e r n e t 1 0 M b p s …..

S a te llit e

In ter a c tio n C h a n n e l

H o m e C o n n e ct io n

T e rre s tr ia l ( P l u g & P l a y , h i g h - d a t a - r a t e )

( 1 - w a y / 2 - w a y )

DTV set

DV B - T / A T S C

DS TB

Cab l e M o dem

Di recP C /Di recDuo

Provedores de vídeo

Service P rov is ion

TC P / IP

D V B - TD V B - S

(h igh speed BB )D V B - C

(C ab le M odem )

H FC(Fu ll S erv ice

Netw ork)

PO T S(xD SL access)

Residen tia l LAN(IR, RF, W ired)

Hybrid Services

D S T B

W ireless C able(M M D S)

Aplicações de vídeo digital‚

’ ' ˆ ¯

¯

* Ì - - ‚ ‘ •

. .

.

… e )

…

. . .. . .

S e t - T o p B o xR C

Surfar, email, homebanking

Pay-per-view

Video telefoniaMultimídia sob demanda

Vantagens de vídeo digitalOpen Architecture video systems, meaning the existence of video at multiple spatial, temporal, and SNR resolution within a single scalable bitstream

Interactivity

Variable-rate transmission on demand

Easy software conversion from one standard to another

Integration of various video applications

Editing capabilities, such as cutting and pasting, zooming

removal of noise and blur

Robustness to channel noise and ease of encryption

…...

Sistema de vídeo do futuro

De s c ra m b le r OSD

T ran s p ort

N T SC / PALEnc od e r

CP U

M PEG - 2Vi deo

T ra fficC on t rol ler

M PEG - 2Au di o

D i g i t a l D e c o d e r C h i p

T u ner

T u ner

T u ner

Sa te l l i te

Ca b l e

T e rr estr ia l

QP SKDe m o d

QAMDe m o d

CO F D MDe m o d

FE C

FE C

FE C

SD R A M

F las h /EPR OM

SD R A M VC X O

P1 3 9 4I R B u ffe r& Am p R S 2 3 2 I rD A Po rt

M od emV- Ser i es

Sma rt Ca rdB u ff er P1 2 8 4 SC S I

I 2 C

R FM odul ator

SEC AMEnc od e r

(o p ti on al )

DA C s+ F ilte rs

L

R

AV

Sw itc h

R G B or Y/ Can d C VBS

Gra ph i c s

AN D/ OR

AD C

AN D/ OR

I F

I F

QP SKM o d

FEC

AD C

D u alAD C

Imagens e vídeo - definições

Imaging: normal photography, X-rays, electronic documents, electronic still pictures, motion pictures, TV

Video: a sequence of still pictures of a scene taken at various subsequent intervals in time

Scanning: a form of sampling of a continuously varying two-dimensional signal

Resolução de vídeoViewing Ratio (VR):

VR = d /PH d= viewer’s distance from the screenPH= picture height

Visible pixels = 3440 /VR

Pixel (Pel) : the smallest detail that can be reproduced in a picture is about the size of a picture element

System Line or pixels/PH VR

NTSC television 483 7.2

HDTV 1080 3.2

Computer display 768 <4.5

Minimum viewing rates

Taxa de refresh e flickerPersistence of vision, causes the visual system responds slowly to

rapid changes of illumination

Flicker: if the illumination varies cyclically at a low frequency, the eye may perceive an annoying effect

Refresh Rate: the light output of display devices decays after a short time, and therefore must be refreshed periodically to maintain the effect of steady illumination

System Refresh rate (Hz) VR

NTSC television 60(59.94) 7

Computer display 72 1-2

Motion picture theater 48 5-10

Display refresh rates

scanear uma imagem de vídeonão entrelaçado

scanear uma imagem de vídeoentrelaçado

Relação largura/altura

IAR (Image Aspect Ratio )is defined as the ratio of picture width to height

• IAR = w / h• PAR (pel aspect ratio) =

IAR * vertical_size / horizontal_sizewhere horizontal_size is the width of the image in terms of pels and vertical_size is the height of the image in linesex. Display IAR = 4:3

Image size = 720 pels * 486 linesPAR = 4/3 x 486/720 = 0.9or IAR * display_vertical_size / display_horizontal_size