17
Appendix 2
Detailed Video Tests
During all video tests the audio protocol negotiated was G.719. When the system
was forced to H.263 video protocol, image material connected to the DVI input
was restricted to 8fps at XGA resolution. This has a serious impact on many of
the rating scores as motion and lip synchronisation were significantly affected by
this reduction in frame rate.
Objective Video Tests:
Signal measurements
1.
75% EBU bars
2.
Grey scale
Subjective Video Impairments Tested:
Lip synchronisation
LS
Block distortion (tiling)
BLK
Blurring
(reduced edge sharpness and spatial detail)
BLR
Colour errors
CLR
Jerkiness (distortion of smooth motion)
JRK
Object persistence
(lagging images from previous frames as faded or outline images)
OP
Scene cut response (i.e. time to build up the new image)
SCR
Scale of impairments:
Imperceptible
1
Perceptible
2
Slightly annoying
3
Annoying
4
Very annoying
5
Test DVD:
Signals recorded
Time on tape
1.
EBU colour bars
1min 30secs
2.
Grey scale
1.40 - 2.40
3.
Blue field
2.50 - 3.50
4.
Medium close up female face, still
4.00 - 5.00
5.
Medium close up female face, talking
5.10 - 6.10
6.
Close up face, nodding
6.20 - 7.20
7.
Close up face, shaking head side to side
7.30 - 8.30
8.
Zoom out slowly to wide angle three people
8.40 - 9.40
9.
Zoom in quickly to close up of centre person
9.50 - 10.50
10.Turntable speeds: 1,2,3 and 4
11.00 - 15.30
11.Football sequence
15.40 - 16.40
12.Zoom in and out of “A to Z” map
16.50 - 17.50
13.Text legibility, font sizes 20 to 12 pt
20.30 - 20.50
14.Cut tests, scenes various with camera movements
21.00 - 22.00
15.Man teaching at whiteboard
22.10 - 23.23
(Insert 75% EBU bars at local site, measure at remote site)
