Crystal Vision
Appendix A
Aspect ratio
This tab contains the output aspect ratio, active format descriptor (AFD) and output
widescreen signalling (WSS) controls
Output aspect ratio, Vertical bandwidth, AFD and WSS controls
Output aspect ratio
There are four fixed aspect ratios which are Anamorphic, 16:9 Letterbox, 14:9
Letterbox and centre cut. Anamorphic will map the input picture directly to the native
aspect ratio of the viewing display along with the resulting distortion associated with
this. Should it be necessary to view the output on a 4:3 display, setting the aspect
ratio selection to Letterbox will give the correct picture dimensions by adding black
bars to the top and bottom of the picture. Selecting 14:9 Letterbox will crop the picture
to 87.5%, and depending on the aspect ratio of the display will either add black bars
to the top and bottom or both sides of the picture. There will be some loss of picture.
Centre cut will show the central 75% of the 16:9 widescreen picture mapped to the full
monitor height with the corresponding loss of the left and right picture edges.
The LEDs beside the aspect ratio selector radio buttons will show the actual aspect
ratio selected when any of the auto modes are selected. These three auto selections
are also associated with the AFD reader and will automatically set the output WSS
when Widescreen Signalling is set to auto.
Selecting Auto 16:9 for all AFD input codes will give an Anamorphic aspect ratio
conversion and for a 625-line output WSS will be set to 16:9 full frame. When set to
Auto 4:3 the output aspect ratio and WSS data will depend on the input AFD.
Undefined/reserved and full frame codes will produce a Letterbox aspect ratio with
the output WSS set to 16:9 Letterbox. Pillarbox 4:3, Pillarbox 14:9 and Letterbox
greater than 16:9 will give a centre cut conversion and set output WSS to full format
4:3.
Selecting Auto Adaptive for any full frame input will give an Anamorphic aspect ratio
with WSS set to full frame 16:9. Pillarbox 4:3 will give a centre cut conversion and set
output WSS to full format 4:3. Undefined/reserved, Pillarbox 14:9 and Letterbox
greater than16:9 will make no change so the previous conversion will remain. On
power up the default conversion will be Anamorphic.
Q-Down-AG 3G/ATG 3G User Manual R2.1
53
11 July 2019
