Download PEVQ Data Sheet PDF

PEVQ™ AnalyzerPerceptual Video Quality-of-Experience Measurement

OPTICOM Product Line:

VideoQualityTesting

VoiceQualityTesting

AudioQualityTesting

DataQualityTesting

The new PEVQ Analyzer evaluates the quality ofmultimedia (QCIF, CIF, VGA), SD and HD video for-mats based on perceptual video quality-of-experience measurement, reliably and objectively.The system allows for synchronous SD and HDplay-out and recording over a range of interfaces(HD-SDI, DVI) and comes with a high-perfor-mance, front accessible array of hard disk drives.

Perceptual Evaluation of Video Quality (PEVQ) isan accurate, reliable and fast video quality meas-urement technology, developed by OPTICOM. Itprovides mean opinion score (MOS) analysis ofthe video quality degradation occurring through anetwork, e.g. in mobile and IP-based networks.PEVQ can be ideally applied to test video telepho-ny, video conferencing, video streaming, and IPTVapplications.

PEVQ is a full-reference, end-to-end measurementbased on signal analysis: The degraded video sig-nal output from a network is analyzed by compar-ison to the undistorted original reference videosignal on a perceptual basis. Based on theapproach to model the human visual system,PEVQ can detect anomalies in the video signal andquantify them by a multitude of key performanceindicators (KPIs). With PEVQ one can analyze thevideo quality based on a human visual model, thusrepresenting the true image quality as perceivedby subjects, for example paying subscribers. Itsvalue proposition is obvious: equipment manufac-turers, network operators and service providers

can analyze QoE issues and optimize next genera-tion networks and thus avoid customer’s dissatis-faction, which otherwise might lead to complainsor churn.

OPTICOM, the leading provider of signal basedperceptual measurement technology for voice,audio and video, offers its new easy to use PEVQtesting technology in combination with its provenaudio quality analysis techniques PESQ(Perceptual Evaluation of Speech Quality) andPEAQ (Perceptual Evaluation of Audio Quality).The combination with these state-of-the-art testalgorithms allows for audio-visual quality analysisand thus provides useful means for lip-sync arte-fact measurement.

Users can choose among the PEXQ software suitefor Windows™ and the PEVQ Analyzer. PEVQ isalso available as an OEM solution and has beenadopted by a range of leading industry partners(see www.pevq.org for further information onthird parties’ product availability).

PEVQ is based on the earlier PVQM technologydeveloped by KPN Research and new develop-ments of OPTICOM. The PEVQ analyzer is pro-duced in cooperation with DVC Germany(www.digitalvideo.de).

PEVQ has been verified by the Video QualityExperts Group in 2008 and has become part ofnew ITU-T Recommendation J.247in late 2008.

Key Features:• Accurate, reliable and fast

objective analysis of per-ceived video quality

• Full reference based end-to-end quality analysis

• Outputs MOS scorethat correlates wellwith subjective MOS

• Additional KPIs fordetailed analysis

• Measurement of multime-dia (QCIF, CIF, VGA), SDand HD video quality

• Applications: IPTV, stream-ing video, 3G, videotelephony

• Performance verified bythe Video Quality ExpertsGroup (www.vqeg.org)2008

• Part of New InternationalStandard ITU-T J.247(2008)

PEXQ™, 3SQM™, PEAQ™, PEVQ™, PEDQ™ and the OPTICOM logo are registered trademarks of OPTICOM GmbH; PESQ™ is a registered trademark of OPTICOMGmbH and Psytechnics Ltd.; the ‘Single-sided Speech Quality Measure’ and ‘The Perceptual Quality Experts’ are trademarks of OPTICOM GmbH.This information may be subject to change. All other brand and product names are trademarks and/or registered trademarksof their respective owners. All rights reserved. Copyright © 2010 OPTICOM GmbH - www.opticom.de

Voice Quality TestingPSQM ITU-T P.861PESQ ITU-T P.8623SQM ITU-T P.563ECHOAudio Quality TestingPEAQ ITU-T BS.1387Video Quality TestingPEVQ ITU-T J.247Network Quality TestingVQmon

NEW:

VQEG approved and

new ITU Standard

The PEXQ split screen feature of the viewerwindow allows for a 1:1 comparison of thedegraded (test) video with the original ref-erence by horizontal and/or vertical split ofthe overlay. This display feature is ideallysuited for codec developers and causeanalysis, as sliding through the image mayvisualize even slight deviations from theoriginal (left half of the image). In this HDIPTV example, bit errors were inserted dur-ing the IP transport (visible in the right halfof the image).

PEXQ™, PEAQ™, PEVQ™, PEDQ™, 3SQM™ and the OPTICOM logo are registered trademarks of OPTICOM GmbH; PESQ™ is a registered trademark of OPTICOM GmbH andPsytechnics Ltd.; the ‘Single-sided Speech Quality Measure’ and ‘The Perceptual Quality Experts’ are trademarks of OPTICOM GmbH. This information may be subject tochange. All other brand and product names are trademarks and/or registered trademarks of their respective owners.All rights reserved. Copyright © 2010 OPTICOM GmbH – www.opticom.de

2 PEVQ™ Analyzer

Comfortable Graphical User Interface

Split View Overlay

2

1

3

The PEVQ Analyzer desktop combines PEXQ (1), OPTICOM’s unified graphical user interfaceproviding a Quad-KPI set for voice, audio, video and data analysis, and QuickClip (2) (pow-ered by Drastic Technologies) for comfortable play-out and record. The PEXQ view window(3) allows for visual frame-by-frame overlay comparison of original, degraded (test) signaland PEVQ internal error patterns.

3PEVQ™ Analyzer

Principle

Human Visual Model View

The internal PEVQ views expose an insightto the human visual model at work. Fromleft to right:

1) Frame of the original referencesequence

2) Corresponding frame of the degraded(test) signal

3) Degraded signal after temporal andspatial alignment

4) Difference error pattern according toPEVQ’s human visual model, this per-ceptible error forms the basis for theMOS calculation.

In the example shown, it can be noted thatthe degraded signal contained a lowerframe rate than the original, which leadsto temporal and spatial alignment arte-facts that may contribute to the error pat-tern for the particular frame analyzed.(This example was pictured intentionallyfor illustration purposes).

The algorithm can be divided up into fourseparate blocks. The first block – pre-pro-cessing stage – is responsible for the spa-tial and temporal alignment of the referenceand the impaired signal. This processensures that only corresponding frames arecompared to each other.

The second block calculates the perceptualdifference of the aligned signals. Perceptualmeans that only those differences are takeninto account which are actually perceivedby a human viewer. Furthermore the activityof the motion in the reference signal pro-vides another indicator representing thetemporal information. This indicator isimportant as it takes into account that inframe series with low activity the percep-tion of details is much higher than in frameseries with quick motion.

The third block in the figure classifies thepreviously calculated indicators and detectscertain types of distortions.

Finally, in the fourth block all the appropri-ate indicators according to the detected dis-tortions are aggregated, forming the finalresult - the mean opinion score (MOS). TheMOS value describes the video quality on a

range from 1 for very bad quality, to 5 forexcellent quality. Besides the final qualityscore additional indicators are provided atthe output of the algorithm for further causeanalysis.

This approach to video quality estimationincludes the effects of both packet levelimpairments (loss, jitter) and signal relatedimpairments such as blockiness, jerkiness,

blur and distortions caused by codingprocesses.

Future releases will be further optimized incomputational performance and predictionaccuracy for high definition video.

OPTICOM’s PEVQ is one of the two top-ranked models in the 2008 Video QualityExperts Group (VQEG) multimedia evalua-tion and approved for standardization.

Temporal indicators

Temporaland spatialalignment Distortion

classifi-cation

Reference Signal

Impaired Signal Y

Cr

Cb

Perceptualdifference(Y, Cr, Cb)

PEVQ Score

Indicatorsfor causeanalysis}

time

timeDistortionindicator

integration

PEVQ is a full reference, intrusive measurement algorithm for video quality. Itsbasic structure is shown in the figure below.

PEVQ™ Analyzer


4

The PEVQ Analyzer employs theQuickClipXO clip-recorder toolset (powered

by Drastic Technologies) for comfortablesystem configuration, play-out and recordcontrol. A variety of common SD (625/50

or 525/60) and HD (720p, 1080i, 1080p)format settings are supported.

Clip Recorder/Player

Detailed graphical output for PEVQ: The‘Summary’ window (top) includes information on

the analyzed reference and test video files likeframe rate, duration and pixel resolution. On the

right the overall PEVQ MOS is depicted in acoloured bar graph that turns from red (bad quali-

ty) to green (good quality). The lower windowallows for more detailed cause analysis based on

a number of state-of-the-art KPIs, includingPSNR. The radar chart to the right presents a

multidimensional error indicator, including tem-poral, luminance and chrominance information

along with indicators for blur, jerkiness andblockiness.

Comprehensive Numericaland Graphical KPI Set

5PEVQ™ Analyzer

PEVQ MOSThe PEVQ MOS value lies within a rangefrom 1 (bad) to 5 (excellent). The PEVQMOS is based on a multitude of percep-tually motivated parameters.

Distortion indicatorsFor a more detailed analysis the percep-tual level of distortion in the luminance,chrominance and temporal domain areprovided.

DelayThe min, max and mean delay of eachframe of the test signal related to thereference signal, as well as delay vs.time.

BrightnessThe brightness of the reference anddegraded signal.

ContrastThe contrast of the distorted and the ref-erence sequence.

PSNRTo allow for a coarse analysis of distor-tions in different domains the PSNR isprovided for the Y, Cb and Cr componentsseparately.

Jerkinessdescribes the smoothness of a videoplayback which is often impaired bydown-sampling, coding processes andperturbed transmissions.

Bluris a distortion characterized by reducedsharpness of contour edges and spatialdetail.

Blockinessis often the result of a low bit rate cod-ing that uses a block matching algorithmfor the motion estimation and a coarsequantization for the image blocks.

Frame Skips and Freezesare temporal artefacts occurring in videotransmissions caused by e.g. overloadednetworks.

Effective Frame RateDown-sampling of a video signal on aframe by frame basis often results in lossof information which often leads to thedegradation of the video signal. Theeffective frame rate is an indicator quan-tifying the severeness of such a process.

Temporal Activity and SpatialComplexityTemporal activity and spatial complexityindicators quantify the amount of activi-ty/movement and spatial detail in thevideo content. These indicators arederived from ITU-T recommendationP.910.

Output

New in PEXQ: The composite result viewfor audio-visual quality analysis reportingthe video MOS (PEVQ) (upper frame) andthe audio MOS (PESQ) (middle frame).The combination of perceptual video andaudio quality measures allows fordetailed lip-sync analysis based on time-variant delay analysis (lower frame).


6 PEVQ™ Analyzer

In the course of International Standardi-zation of video quality metrics, in 2007 and2008 the Video Quality Experts Group(www.vqeg.org) conducted a huge testseries of 41 validation tests run acrosstwelve different labs in Europe, USA andAsia. OPTICOM’s PEVQ showed superiorperformance and is going to be proposedfor standardization. Most importantly,PEVQ could also significantly outperformPSNR, a commonly used industry metricsfor objective video quality estimation.

The accuracy of PEVQ has been trained ona huge number of human visual test data-bases. The photo shows OPTICOM’s subjec-tive test setup which is in line with ITU-TRec. P.910 and further adaptations devel-oped by VQEG for the multimedia testseries.

Subjective Validation

Superior Accuracy

7PEVQ™ 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

PEVQ

MO

S

Shuttle

Calendar

Football

MOS = 3.3MOS = 3.3

MOS = 2,5MOS = 2,5

MOS = 1.6MOS = 1.6

The image quality of advanced videocodecs, like H.264, does very much dependon the content material and in particular atlower bitrates significant performancedeviations can be observed for variousprogramme material. In the diagram oneand same H.264 encoding was applied tothree test sequences of differing, individ-ual complexity. As a result, the measuredMOS scores vary between 3,3 and 1,6, asignificant content depending differencewhich outlines why NGNs carrying IPTVand multimedia services need to be ana-lyzed by true perceptual signal analysislike PEVQ. An example that clearly showswhy packet-loss analysis based E-modelestimates simply can’t tackle this level ofperformance issue.

Headend/Aggregator Core Network Metro Network

Home

ContentProvider/Studio

Home

Mobile PDA

Cell

PEVQAnalyzer

IPAccess Network

Stream

Stream

Stream

Decode/Transcode/Reformat

Decode/Transcode/Reformat

Decode/Transcode/Reformat Encrypt/

Server

Encrypt/Server

Encrypt/Server

STB/TV

PCVoIP

STB/TV

PCVoIP

Reference 1

Reference 2

Test 1Test 2

Test 3

Regional Service Provider

VOD File

VOD File

VOD File

LegacyCable Network

IP (IPTV)Core Network

IMSEcosystem

SD/HDTV

SD/HDTV

Mobile TV

DishFarm

Application to IPTV and IMS Architectures

Product Differentiator

PEVQ is a full reference video quality measure that compares the original signal from thesatellite downlink (reference1) or a stored reference from the studio (reference2) with thetest signal, degraded by transmission artefacts. Test Signals can be acquired e.g. aftertranscoding 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 tonetwork segments represents a very useful toolset for serviceassurance and SLA compliance testing.

Specifications

Functionality• Perceptual Evaluation of Video Quality-

PEVQ, with mapping to MOS scale(1 bad, … 5 excellent quality)

• Analysis of multimedia, SD and HD videoformats

Input• Raw YUV, AVI Files with RGB24, YUV444,

YUV422 or YUV420 data, any frame rate from2,5 up to 60 fps

• Video test sequences of 6 to 20 secondsduration

In Cooperation with

DVC –Digitalvideo ComputingGmbHLandsberger Strasse 23-2582110 Germering, GermanyPhone: + 49 89 89 44 46 400Fax: + 49 89 89 44 46 [email protected]

PEVQ - Perceptual Evaluation of Video Quality

PEXQ™, 3SQM™, PEAQ™, PEVQ™, PEDQ™ and the OPTICOM logo are registered trademarks of OPTICOM GmbH; PESQ™ is a registered trademark of OPTICOMGmbH and Psytechnics Ltd.; the ‘Single-sided Speech Quality Measure’ and ‘The Perceptual Quality Experts’ are trademarks of OPTICOM GmbH.This information may be subject to change. All other brand and product names are trademarks and/or registered trademarksof their respective owners. All rights reserved. Copyright © 2010 OPTICOM GmbH - www.opticom.de

Sales Contacts:OPTICOM GmbHNägelsbachstraße 3891052 Erlangen, GERMANYPhone: +49-91 31/5 3020 -0Fax: +49-91 31/5 3020 [email protected]

North America:

Telchemy Inc.Phone +1-678 387 3000

JDSU - Acterna U.S.Phone +1-978 250 1185

Europe, Latin America,Middle East & Africa,Asia Pacific, CIS Countries:

JDSU - ActernaGermany GmbHPhone: +49-7121 86 2222

Through our distributor net-work, we are represented inmore than 80 countries. To findyour local sales office, pleasecontact [email protected]

OPTICOM GmbHNägelsbachstraße 3891052 Erlangen, GERMANYPhone: +49-91 31/5 30 20 -0Fax: +49-91 31/5 30 20 [email protected]

PVQ-101-000-D• PEVQ Analyzer, Desktop Version

(DVC Boxxster)• Single channel SD/HD SDI Interface for cap-

turing video (uncompressed reference videoplay-out OR test record)

• Available with internal SATA-2-Storage 480GB, 720 GB or 1200 GB (others on request)

PVQ-102-000-R• PEVQ Analyzer, Rack-mountable Version

(DVC Cliprecorder AVX2)• Dual channel SD/HD SDI Interface for cap-

turing video (uncompressed reference videoplay-out AND test record)

PVQ-00X-XXX-S• PEVQ Analyzer, Software-only Version

(for upgrade of existing DVCBoxxster/Cliprecorder systems)

Optional available on request:• Rack-mountable 1U breakout box incl.

SD/HD SDI I/O and analog/digital audio• SD/HD SDI to DVI converter• System flight-case (wheeled)

NOTE:The PEVQ Analyzer comes with pre-configuredsystem installation, system documentation,hard disk array as specified, break-out cablesfor analog video and analog/digital audio(Stereo), USB keyboard and mouse. The systemdoes NOT include a monitor as shown on thefirst page.

Ordering Information

About OPTICOMOPTICOM GmbH is the leading vendor forvoice, audio and video quality measurementtechnology and OEM products for mobileand IP based network testing. With PSQM,PESQ, PEAQ, PEVQ and P.563, the pioneersin perceptual quality testing have been pro-viding by now five international world-classstandards for voice and audio quality meas-urement since the foundation of OPTICOMas a spin-off from Fraunhofer’s MP3 develop-ment team in 1995.

After the great success with PESQ - theInternational Standard for voice quality test-ing, the experts from Germany now alsosource PEVQ, the new ITU-T standard tomeasure a perceptual video quality KPI forstreaming, conferencing and messagingapplications.

PEXQ, the next level of Perceptual QualityMeasurement, is the ideal ‘all-in-one’ testsuite for developers, manufacturers andoperators, while the ‘X’ just symbolizes theongoing evolution of perceptual QoE metrics:Based on PESQ, PEAQ, PEVQ and PEDQ thesoftware provides the most comprehensivestandards-based MOS-KPI set to score voice,audio/visual and data quality as experiencedby subscribers. OPTICOM’s proven OEMtechnology can be found in most state-of-the-art products of leading T&M vendors,see also www.opticom.de/company/cus-tomers-licensing.html.

OPTICOM GmbH is a privately held companylocated in Erlangen, Germany.

Documents

Download PEVQ Data Sheet PDF