Technical Manual

21
O t h e r f a c t o r s t h a t i m p a c t t h e t o t a l a v a i l a b l e b i t r a t e a r e t h e c o d e r a t e
a n d t h e g u a r d i n t e r v a l s e t t i n g s .
C o d i n g R a t e S e t t i n g : T h i s s e t t i n g d e t e r m i n e s t h e a m o u n t o f f o r w a r d
e r r o r c o r r e c t i o n u s e d t o r e d u c e v i d e o d a t a l o s s u n d e r a d v e r s e c o n d i t i o n s .
I f t h e c o d e r a t e i s s e t t o ½ , t h i s m e a n s t h a t h a l f o f t h e a v a i l a b l e d a t a r a t e
i s b e i n g u s e d f o r e r r o r c o r r e c t i o n , w h i l e t h e r e s t i s a v a i l a b l e f o r v i d e o . A
c o d e r a t e o f 1 / 2 u s e s t h e m o s t b a n d w i d t h f o r e r r o r c o r r e c t i o n , b u t
p r o v i d e s t h e h i g h e s t d e g r e e o f p r o t e c t i o n a g a i n s t v i d e o b r e a k u p .
G u a r d I n t e r v a l : T h e p r i m a r y p u r p o s e o f t h e g u a r d i n t e r v a l i s t o p r o v i d e
r e s i s t a n c e t o m u l t i p a t h a n d c o - c h a n n e l i n t e r f e r e n c e . L o n g e r g u a r d
i n t e r v a l s a r e u s e d i n d e n s e m e t r o a r e a s , w h e r e h i g h l e v e l s o f m u l t i p a t h
a r e e x p e c t e d . A g u a r d i n t e r v a l o f 1 / 4 i s t h e l o n g e s t , w h i l e 1 / 3 2 i s t h e
s h o r t e s t .
N O T E : W h e n p r o g r a m m i n g a n H DX - 1 1 0 0 , a g o o d r u l e o f t h u m b i s t o
p r o g r a m s e v e r a l p r e s e t s w i t h v a r y i n g a m o u n t s o f e r r o r c o r r e c t i o n t o b e
a b l e t o q u i c k l y s w i t c h q u i c k l y f r o m a v e r y r o b u s t , l o w d a t a r a t e s e t t i n g , t o
a l e s s r o b u s t b u t h i g h e r - s p e e d s e t t i n g .
6 . 5 V I D E O A N D A U D I O I N P U T S E T U P
The video and audio inputs must be configured for each preset. To initiate this procedure,
click on MPEG-2 or MPEG-4 in the bar at the top of the screen, and then click on Video on
the left side of the screen. Two dialogue boxes will appear: Video In, and, Encryption.
See next graphic for details.
IMPORTANT: When equipped with the MPEG-2 encoding option, HDX-1100 presets
may be programmed all in MPEG-2 mode, all in H.264/MPEG-4 mode, or as a mix of
the two. For example, the first five presets may be programmed for MPEG-2 encoding,
while the remaining four are programmed for H.264/MPEG-4 encoding.
V i d e o S e t t i n g s : Click on Video In and select the desired parameters from the drop
down table. Available parameters include the input configuration, such as composite or SDI,
as well as video resolution. MPEG-2 settings differ from MPEG-4 settings, and require
additional choices to be made, including
NOTE: Input A is the normal video input and must always be set up. When using the
DoubleVision option, Input B must also be set up.