7
PEVQ™ Analyzer
PEVQ MOS Results for H.264
1
1,5
2
2,5
3
3,5
4
4,5
5
64kbit
64kbit
128kbit
128kbit
320kbit
704kbit
Bitrate
P
E
V
Q
M
O
S
Shuttle
Calendar
Football
MOS = 3.3
MOS = 3.3
MOS = 2,5
MOS = 2,5
MOS = 1.6
MOS = 1.6
The image quality of advanced video
codecs, like H.264, does very much depend
on the content material and in particular at
lower bitrates significant performance
deviations can be observed for various
programme material. In the diagram one
and same H.264 encoding was applied to
three test sequences of differing, individ-
ual complexity. As a result, the measured
MOS scores vary between 3,3 and 1,6, a
significant content depending difference
which outlines why NGNs carrying IPTV
and multimedia services need to be ana-
lyzed by true perceptual signal analysis
like PEVQ. An example that clearly shows
why packet-loss analysis based E-model
estimates simply can't tackle this level of
performance issue.
Headend/Aggregator
Core Network
Metro Network
Home
Content
Provider/
Studio
Home
Mobile
PDA
Cell
PEVQ
Analyzer
IP
Access Network
Stream
Stream
Stream
Decode/
Transcode/
Reformat
Decode/
Transcode/
Reformat
Decode/
Transcode/
Reformat
Encrypt/
Server
Encrypt/
Server
Encrypt/
Server
STB/TV
PC
VoIP
STB/TV
PC
VoIP
Reference 1
Reference 2
Test 1
Test 2
Test 3
Regional Service Provider
VOD File
VOD File
VOD File
Legacy
Cable Network
IP (IPTV)
Core Network
IMS
Ecosystem
SD/HDTV
SD/HDTV
Mobile TV
Dish
Farm
Application to IPTV and IMS Architectures
Product Differentiator
PEVQ is a full reference video quality measure that compares the original signal from the
satellite downlink (reference1) or a stored reference from the studio (reference2) with the
test signal, degraded by transmission artefacts. Test Signals can be acquired e.g. after
transcoding at the headend (test1), at the edge of the core (test2) or the metro (test3)
network, i.e. at the subscriber broadband tools (STB or Mobile TV). The application to
network segments represents a very useful toolset for service
assurance and SLA compliance testing.
