A Realtime No Reference Video Quality Analysis...2001/10/03 · A Realtime No Reference Video...

2 MAR | Re | 08/00 | 11 DIGITAL VIDEO QUALITY ANALYZERS DVQ / DVQMRSA | OCT/03/01

A Realtime No ReferenceVideo Quality Analysis

DIGITAL VIDEO QUALITY ANALYZERS DVQ / DVQMRSA | OCT/03/2001 | 2

Overview &Abstracts

Video QualityEvaluation Basics

Theory of the IfN/R&S Algorithm

Single Channel Instrument DVQ

Multi Channel DeviceDVQM

ApplicationExamples

SampleMeasurements

Conclusions

Abstracts of the IfN/R&S Algorithm

Joint Development

u Institute of Telecommunication Technologies (“IfN”) of Technical University

Braunschweig, Germany headed by Prof. Ulrich Reimers

u Rohde & Schwarz Broadcast Division

Real time process

Without reference (NR) or with reduced reference (RR) signal

Analysis of DCT compressed video sequences

u i.e. MPEG2 encoded

Analog distortions cannot be addressed


Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Basic Image Data Analysis (I)Averaged amplitude differences of adjacent pixel pairs relative to their position in the macro block grid

0 8 15

AD(0)AD(1)AD(2)

....AD(i) = AD(5)

....AD(8)

....AD(15)

Macro blockboundaries

Blockboundaries

Relative positionin macro block


Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Basic Image Data Analysis (II)normalized sum of all ADx(i=0) .... ADx(i=15)of all macro blocksin all lines

total 3 * 16 values in x-direction(Y, Cb, Cr)

normalized sum of all ADy(i=0) .... ADy(i=15)of all macro blocksin all columns

total 3 * 16 values in y-direction(Y, Cb, Cr)

u In both directionsu Separately for Y and C’s


Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Analysis Results of non-coded ImagesExample: Flowergarden - original sequence without compression

0 2 4 6 8 10 12 14 16 18 20 22 24 260

2

4

6

8

10

12

14

16A

ve

rag

e D

iffe

ren

ce

Frame number

AD(i=0) AD(i=1) AD(i=2) AD(i=3) AD(i=4) AD(i=5) AD(i=6) AD(i=7) AD(i=8) AD(i=9) AD(i=10) AD(i=11) AD(i=12) AD(i=13) AD(i=14) AD(i=15)


Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Analysis Results of coded ImagesExample: “Flowergarden” - compressed sequence 2 Mbit/s

0 2 4 6 8 10 12 14 16 18 20 22 24 260

2

4

6

8

10

12

14

16A

ve

rag

e D

iffe

ren

ce

Frame number

AD(i=0) AD(i=1) AD(i=2) AD(i=3) AD(i=4) AD(i=5) AD(i=6) AD(i=7) AD(i=8) AD(i=9) AD(i=10) AD(i=11) AD(i=12) AD(i=13) AD(i=14) AD(i=15)

Spatial Activity SA

DVQL-U


Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Involves Parameter “Spatial Activity” (SA)

u Average of amplitude differences of all pixels

u Describes the amount of details within one single frame

SA low SA high

Subjective Weighting (part I)


Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Involves Parameter “Temporal Activity” (TA)

u Average of all amplitude differences of the same pixels in subsequent frames

u Describes the "motion” within a sequence

u Determined by grouping pixels by eight and averaging their amplitudes in

subsequent frames

TA small TA high (maximum)

t t

Subjective Weighting (part II)


Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

The whole Quality Analysis ProcessMasking of perception of quality degradations by high spatial (SA) & temporal (TA) activity values

MPEG2 TSorITU-R 601

DVQL-W

Processpart #1

Processpart #2

“Weighting”

Adaptation to subj.

perception0 2 4 6 8 10 12 14 16 18 20 22 24 26

0

2

4

6

8

10

12

14

16

Av

era

ge

Dif

fere

nc

e

Frame number

AD(i=0)

AD(i=1)

AD(i=2)

AD(i=3)

AD(i=4)

AD(i=5)

AD(i=6)

AD(i=7)

AD(i=8)

AD(i=9)

AD(i=10)AD(i=11)

AD(i=12)

AD(i=13)

AD(i=14)

AD(i=15)

SSCQE scaling

TASA

DVQL-U (Y)DVQL-U (Cb)DVQL-U (Cr)


Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

SSCQE acc. ITU-R B.T.500-7Test persons watching sequence (Single Stimulus)

Continuous Quality Evaluation with slider movements while watching

Value sampling and averaging over viewers


Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Comparison with Subjective Values (I)

time [sec]

Digital VideoQuality Level- weighted

0 50 100 150 200 250 300 350 400 450-10

0

10

20

30

40

50

60

70

80

90

100 Subjective Valuation

DVQL-W by DVQ

Video Test SequenceSSCQE Scaling


Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Comparison with Subjective Values (II) Correlation of 82.79% with Version 2.0 of the algorithm

y = -0,4484x + 95,014R2 = 0,6854r = 82,79%

60

65

70

75

80

85

90

95

100

0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00

Subjective Scoring

DV

QL-

WAll

Tree

Barcelona

Harp

MovingGraphic

CanoaValsesia

F1car

Fries

HoriScrolling

Rugby

MobileCalendar

BalloonPops

NewYork2

525_MobileCalendar

Betes_pas_betes

Le_point

AutumnLeaves

Football

Sailboat

Susie

Tempete

Linear (All)

Linear (All)


Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Quality analysis without reference

Real time operation

Integrated MPEG2 decoder (incl. 422 profile)

Referenced measurements possible

Detection of basic distortions

u Picture freeze and loss

u Sound loss (right / left separately)

Key Features of DVQ & DVQM

Transport StreamDUT


Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Characteristics of the Basic Unit

Result Output4 LC display [bars/histogram/long time]

4 OS display inside decoded video

4 Integrated long-term statistics

4 Detailed event & error report

4 Relay outputs

Signal Inputs4 Transport stream inputs:

- DVB-ASI & -SPI/LVDS- SMPTE310M optional [DV-B310]

4 SDI serial plus AES/EBU[ITU-R B.T.601 or SMPTE259E]

4 CA descrambling optional[DVQ-B10/11/12/15/16]

Control Interfaces4 Network

[TCP/IP & SNMP]

4 Serial [RS232]

4 12 Alarm closures

4 Printer [Parallel]


Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Block Diagram / In- & Outputs

AES/EBU (dig. audio)

SDI / ITU-R 601

TS DVB-SPI (parallel)

TS DVB-ASI (serial) x2

TS DVB-ASIscrambled (opt.)

OptionDescramblingDVQ-B11,12,..

Audio L analog

Audio R analog

RS232

Ethernet 10BaseT

Relay outputs x12

Composite

AES/EBU

SDI / ITU-R 601

Printer parallel

LC/OS-Display

MPEG2Decoder

QualityAnalysis

PAL/NTSC& AudioEncoderTS SMPTE310M (opt.)


Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Referenced MeasurementQuality analysis for two signalsu MPEG2-TS vs. SDI

u SDI vs. MPEG2-TS

Comparing evaluation of artefactsu No comparison of pictures !

u Difference of single quality values,

subjectively weighted

u Evaluation of quality differences

Separate detection of distortionsu Picture freeze & loss

u Sound loss (right / left)

Propagation delay u max. ± 5 s

u automatic detection from typical signal

characteristics

TA / SA -Calculation

Inputs„INP“ „REF“

DVQL-WWeighting

Quality values (absolute) orQuality differences (relative)

AD(i) -Calculation

TA / SACalculation

AD(i) -Calculation

Mode“REF”

Mode“INP”

Detection ofDistortions

Detection ofDistortions


Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Multiplex Scan ModeSequential check of all programs

contained in one transport streamu No Scanning of multiple TS !

Variable duration per program

Program selectionu Automatic all

u Manual choice

Limits for TA / SA / DVQL-Wu Adjustable per program

Indication of distortionsu Immediately or

u After 1...5 detections in subsequent scan cycles

Status display of resultsu All programs in one clear view


Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

MonitoringDetailsu Freeze frames

u Picture outages

u Sound outagesu Video quality profile

Benefitsu 24 hour real time

u Without operator

u Quality assuranceu Network optimization

u Fault identification

Transport StreamDUT

time

Digital VideoQuality Level

-7 -6 -5 -4 -3 -2 -1 0

Threshold

Picture Freeze

DVQ


Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Quality Explorer Software DVQ-B1Functionsu Video ES analysis

u Offline or on-line

Benefitsu Detailed coding analysisu Network valuation

u Equipment valuation

Transport StreamDUT

QualityExplorer™

DVQ

QuantificationFactors/Tables

Video ESOrganization

Macro blockData

MotionVectors

QualityStatistics


Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Options for CA DescramblingMain characteristics

u One descrambling board per DVQ

u Separate DVB-ASI interface 45 Mbit/s

u Smart card reader included

u Smart card not supplied

u Product designation DVQ-B10/11/12/15/16

CA systems supported

u Conax - Nagravision - Viaccess (one board)

u Irdeto

u Mediaguard

u NDS-Videoguard (BSkyB)

u BetaCrypt

u Philips Cryptoworks


Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Multi Channel Quality Analyzer DVQMOfficial introduction NAB 2001

Broadcast Engineering Pick-Hit Award 2001

8 RU 19” wide - 12 slots

Modules available

u Quality board (DVQ like)

u CA descrambling options

Remote operation

u TCP/IP & SNMP protocols

Actual customer reference

u SES-Astra, Luxembourg

Europe’s largest satellite operator


Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Main Features of DVQM

Up to 12 totally independent processing cards

Same characteristics as DVQ

u Real time quality analysis

u No reference signal

u Freeze frame, video & audio outage detection

u Internal error report

u TS input, SDI 601 input

u MPEG2 decoder included, composite outputs

u Scan mode available

u TCP/IP & SNMP connectivity

Monitoring software “NetView”


Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

DTV NetView - Statistics


Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

DTV NetView - Error Report


Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Application 1 - Network Monitoring

NetworkAdapter

SourceTS

SDH - PDH (- ATM)Network

NetworkAdapter

NetworkAdapter

Destination

NetworkAdapter

TS

TS

DVG TS

• Functional test

• Network design

• Network optimizationDVQ

DVQ


Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Transmission bandwidth / data rate optimization

• For

– Encoder

– Statistical Multiplexer

• Data rate minimization

• Quality assurance

Ü Minimum data rate forconstant quality level

Ü Long-term measurement withreal live program materialinstead of short test sequences

Application 2 - Process Control

DVQL

time

TS

MUX

MPEG-2Encoder

DVQ

TS

TS

TS

DVQL-W

control

control


Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Application 3 - Detailed Fault Analysis

Functionl Picture quality decreases

l DVRG receives trigger

l DVRG records the faulty signal before and after the trigger

l Further offline in depth analysis

Benefitsl Fault tracing

l Fault verification

l Network optimization

Trigger

Transport StreamDUT

DVRG

DVRM

DVQ

Stream QualityExplorer Explorer


Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Application 4 - Satellite Monitoring

QPSK

SatelliteReceiver(s)

• Automated monitoring

• Quality assurance

Uplink

TS’s

Multiple Quality Monitoring by DVQMplus optional Protocol Monitoring with

multiple DVRM’s

IRDIRDIRDIRD7


Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Application 5 - Playout CenterQuality control on

• Inputs

• Encoding

• Outputs

MUX

VideoServer

MPEG-2Encoder

Output

MPEG-2Encoder

TS

InputDVQM


Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Site: Berlin, Germany

Play out centre Winterfeldstraße

Identical parallel structure

u Constant MUX

u Statistical MUX

3 or 4 live programs

Configurations

u 3 x 3.5 Mbit/s (Video 3.2 Mbit/s)



Average data rate with stat. MUX identical to constant data rate

Encoder and multiplexer fromsame supplier

Performed by T-Nova Berkom, Deutsche Telekom

Sample Measurements

DVQ

TS (stat.)

ACD

ACD

ACD

ACD

MUXV

CD

VCD

VCD

VCD

A3

V3

A2

V2

A1

V1

A4

V4

DVQ

TS (const.)

Constant Multiplex

ACD

ACD

ACD

ACD

MUXV

CD

VCD

VCD

VCD

A1

V1

A4

V4

A3

V3

A2

V2

Statistical Multiplex

With courtesy ofT- Nova Berkom


Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Comparison of Statistical vs. Constant MUXProgram: ORB, 7.12.99, 19:00 - 19:06 h

Stat.. and const. MUX, 4x3,5 Mbit/s

0

10

20

30

40

50

60

70

80

90

10018

:59:

5919

:00:

1019

:00:

2019

:00:

3119

:00:

4219

:00:

5219

:01:

0319

:01:

1419

:01:

2419

:01:

3519

:01:

4619

:01:

5619

:02:

0719

:02:

1819

:02:

2919

:02:

3919

:02:

5019

:03:

0119

:03:

1219

:03:

2219

:03:

3319

:03:

4419

:03:

5419

:04:

0519

:04:

1519

:04:

2619

:04:

3719

:04:

4719

:04:

5819

:05:

0919

:05:

1919

:05:

3019

:05:

4119

:05:

51

Time

Qu

alit

y va

lue

DV

QL

-W

0

2

4

6

8

10

12

14

16

18

20

Dat

a ra

te [

Mb

it/s

]

VidQu stat VidQu const Data rate stat Data rate const



Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Average Picture QualityEach with constant and statistical MUX

0

10

20

30

40

50

60

70

80

3x3.5 Mbit/s 4x3.5 Mbit/s 3x4.7 Mbit/s

Configuration

Qu

alit

y va

lue

DV

QL

-W

ARD (const.)

ARD (stat.)Eurosport (const.)

Eurosport (stat.)

MTV (const.)

MTV (stat.)

ORB (const.)ORB (stat.)



Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Hitting a low Quality LimitFrequency of hitting the quality limit “DVQL-W=20”

with constant and statistical MUX

0

1

2

3

4

5

6

7

8

9

3x3.5 Mbit/s 4x3.5 Mbit/s 3x4.7 Mbit/s

Configuration

Sec

on

ds

per

ho

ur ARD (const.)

ARD (stat.)Eurosport (const.)Eurosport (stat.)MTV (const.)MTV (stat.)ORB (const.)ORB (stat.)



Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Quality Distribution with 4 x 3.5 Mbit/s

Quality value DVQL-WValues: Ø ó nconst. 56.4 10.37 24448stat. 61.2 8.39 24440

const.stat.

0

200

400

600

800

1000

1200

1400

0 20 40 60 80 100

Nu

mb

er



Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Quality Distribution with 3 x 4.7 Mbit/s

Quality value DVQL-W Values: Ø ó nconst. 62,8 9,55 24454stat. 64,8 9,38 24430

const.stat.

0

200

400

600

800

1000

1200

1400

0 20 40 60 80 100

Nu

mb

ers



Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Ø 4,1 5,0ó 0,52 0,59n 24439 24429

3 3.5 4 4.5 5 5.5 6 6.5 7

Distribution of Data Rates in Stat. MUX4 x 3.5 Mbit/s

2 2.5 3 3.5 4 4.5 5 5.5 6

3 x 4.7 Mbit/s



Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Conclusions for DVQ & DVQMVideo quality measurements

Due to subjective perception

Objective & reproducible

Real time process

No reference signal required

Typical video material

MPEG2 decoder included

Optional CA descrambling

EMMY award 2000


Overview &Abstracts





ApplicationExamples

SampleMeasurements

Conclusions

Contact Info

Coordinates % +1 - 410 - 910 - 7836 (EDT time zone)

Fx +1 - 410 - 910 - 7801

) Alexander.Woerner @ rsa.rohde-schwarz.com

Web http://www.rohde-schwarz.com

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A Realtime No Reference Video Quality Analysis...2001/10/03 · A Realtime No Reference Video...

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