Testing with active format description (afd) – Quantum Data 802BT User Manual
Page 172
162
Chapter 9
Testing HDMI Sink Devices
5. Press and release the
Step
key.
The
Step
key illuminates.
6. Using the
Image
knob, select the appropriate InfoFrame type.
The contents of the appropriate InfoFrame output appears on the HDMI display.
7. When finished, press and release the
Step
key.
The light on the
Step
key extinguishes.
Testing with Active Format Description (AFD)
When transporting HDMI video images from a source to a display, different formats may
be used between the content, transmission signal, and display. To provide compatibility
between the different formats, Active Format Description (AFD) is used.
AFD describes the portion of the coded video frame that is "of interest" (or “active”). The
appropriate AFD information is transmitted with the video to the HDMI display as part of
AVI InfoFrame packets. Using AFD information, the display is able to present the image
optimally.
For AFD testing, the generator allows you to apply different AFD cases using the AFDtest
image, which provides 12 different cases (as image versions) for both 4:3 and 16:9
displays. As each image version appears, the appropriate AFD information is sent with the
video to the display.
The following table lists the AFD cases (as specified in the
ETSI TR 101 154 v.1.4.1
standard) that are provided by the generator.
AFD case
Image
Version
(4:3 Format)
Image
Version
(16:9 Format) Aspect Ratio of Active Area
2
8
7
box 16:9 (top)
3
5
4
box 14:9 (top)
4
9-12
9-12
box > 16:9 (center)
8
0
6
Same as the signal format
9
1
1
4:3 (center)
10
7
8
16:9 (center)
11
4
3
14:9 (centered)
13
3
5
4:3 (with shoot and protect 14:9 center)
14
6
2
16:9 (with shoot and protect 14:9 center)
15
2
0
16:9 (with shoot and protect 4:3 center)