Blanking Area

Incorrect Active Area

Active

Lines

Active Area

Active Pixels

Figure 3-16 — Incorrect active area setting

Similarly, if the number of active image lines that the scaler is set to scale is set to less than the amount of actual active lines that are input, the IN1404XT only scales the set active area and will skip some of the input lines. This early end to the scaling process results in an output with fewer lines than it should, and looks as if the image is stretched vertically.

Depending on the RGB source, the input sampling rates in the following table may have the same horizontal scan rate and vertical refresh rate. The scaler does not detect pixel space differences (you can have different numbers of pixels in the same horizontal & vertical rates) between input rates. The scaler applies the default capture rate to the specified input frequency. It then maintains the aspect ratio based on the difference between the input active area and the output resolution (active area) by inserting blank borders around the images. If, however, you want to fill the entire monitor, you can adjust the input aspect ratio by tweaking the number of active pixels and active lines to stretch the image. You may also need to adjust the number of total pixels.

Active pixels

Active lines

Aspect ratio

Total pixels

Comment

 

Horizontal rate = 31.5 kHz, vertical rate 60 Hz

640

480

4:3

780

Progressive NTSC

 

 

 

 

 

640

350

64:35

800

 

 

 

 

 

 

640

400

8:5

800

 

 

 

 

 

 

640

480

4:3

800

Factory default

 

 

 

 

 

720

350

72:35

900

 

 

 

 

 

 

720

400

9:5

900

 

 

Horizontal rate = 15.7 kHz, vertical rate 60 Hz

768

480

8:5

910

NTSC 14.3

720

480

3:2

858

NTSC 13.5

640

480

4:3

780

NTSC 12.3 (default)

 

 

 

 

 

IN1404XT Video Scaler and Switcher • Operation 3-27

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Extron electronic IN1404XT manual Incorrect active area setting