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8
D: VIDEO TESTS
Due to the automatic selection of video protocols we were unable to carry out the full
suite of tests.
In all tests at H.323 the corresponding audio standard is Siren™ 14, 48kbit/s
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 Tape:
Signals recorded Time on tape
EBU colour bars 1min 30secs
Grey scale 1.40 - 2.40
Blue field 2.50 - 3.50
Medium close up female face, still 4.00 - 5.00
Medium close up female face, talking 5.10 - 6.10
Close up face, nodding 6.20 - 7.20
Close up face, shaking head side to side 7.30 - 8.30
Zoom out slowly to wide angle three people 8.40 - 9.40
Zoom in quickly to close up of centre person 9.50 - 10.50
Turntable speeds: 1, 2, 3 and 4 11.00 - 15.30
Football sequence 15.40 - 16.40
Zoom in and out of ‘A-to-Z’ map 16.50 - 17.50
Text legibility, font sizes 20 to 12 pt 20.30 - 20.50
Cut tests, scenes various with camera movements 21.00 - 22.00
Man teaching at whiteboard 22.10 - 23.23
To ensure accuracy of measurement at the remote site, all signals are to be monitored
prior to transmission.