Quality assessment of MPEG-2 encoded sequences
The Degradation Category Rating (DCR) subjective test methodology has been used
ITU-T P.910 for additional details.
32 pairs of original/impaired sequences
have been presented to each subject (corresponding to 8
different video sequences encoded at 4 different bitrates
23 individuals have participated in this
test. The participants were male and female students with ages in the range from 23 to
25 years old.
The subjects were screened for normal visual acuity
and color blindness. One of them showed color blindness.
Two LCD displays of the same model have been
The display and room
characteristics used in the subjective tests are listed below:
- Height of the picture shown in the
screen: 8 cm
- Viewing distance: 64 cm
- Background room illumination: 13.45
- Peak luminance of the LCD screen:
- Luminance of inactive screen: 2.23
- Luminance of background behind the
display: 10.15 lux
- Ratio of luminance of inactive
screen to peak luminance: 0.023
- Ratio of luminance of background
behind the display to peak of luminance: 0.14
original sequences were encoded using the
MPEG-2 codec developed by the MPEG Software Simulation Group
The main encoder parameters were as follows:
- Main profile, main level
- GOP structure: 15 frames length, with two B frames
inserted between I/P frames
- Intra DC precision set to 9 bits
- Rate control provided by the software
A template for the encoder configuration file can be found
You can get all bitstreams for this test
MOS data is
- Sequence "Australia"
Only the first 250 frames were actually used
(and displayed at 25 frames
- Sequence "Mobile"
A sequence of 900 frames that result from merging Mobile
sequence in the forward direction,
has been encoded.
From the resulting sequence, only the last
part (last 300 frames)
has been used
for subjective quality