Video communications is growing in use. Its adoption by larger and larger audiences will require IT managers and service providers to validate their networks for video communication. This presentation will explain the various problems affecting video quality and the ways in which video quality analysis can assist fleshing out these problems from networks.
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Improving Video Quality in Your Network
1. Improving Video Quality in Your Network RADVISION Video Quality solution Eli Cohen Director, Product management
2. Video In Our World - User Cases Enterprises deploying a new video service Videoconferencing, Video Chat, Video Portal R&D departments building a video application Video terminal, surveillance, Set Top Box, traffic cameras,… Service providers deploying new video services Video Mail, Video-share (V-share), Videoconferencing, … Videophones Room Systems SetTopBoxes IP Phones
3. Quality of the Video Experience Network ConditionsReal-Time, Streaming, Messaging, Standards, Quality Parameters
4. Video Quality Issue How do network conditions affect Video Quality? Is your network ready to provide video services? What is the source of the video problem? Local distortion due to packet loss within a high-quality frame (H.264) Local distortion due to packet loss
5. How Video Differs From Voice A more complex user experience than with audio Video compression includes depth and contains more information More complex network and codec parameters HD Video can use up to 16 Mega
6. Video Quality Score Challenges Can Video Quality be measured? If so, how do we measured it?
9. Video MOS MeanOpinion Score (MOS): The arithmetic mean of all individual observations, ranging from 1 (Bad) to 5 (Excellent). MOS Quality Impairment: 5 Excellent: 4 Good: 3 Fair: 2 Poor: 1 Bad Good Fair Poor Bad
11. Video Quality, Full-Reference “Full-Reference”Based Full-reference allows you to perform a Video Quality analysis and compare the original video sequence to a degraded one: Unique synchronization algorithm original and degraded streams Measurement based on frame analysis Partial or Part-picture analysis
12. Video Quality Metrics “Full-Reference”Based Blockiness Blurriness Noise Video Metrics such as Blockiness Bluriness PSNR (Noise) Delay Partial Image Analysis : Analyze only the relevant part of the image
13. Video Quality Online and Real-time Measurement “No Reference”Online ITU G.1070 performs global video quality estimation based on network and codec parameters that are unprecedented in scope to guarantee that the tool maintains the highest correlation with video quality test results measured by individual perception. Video Quality Online standards ITU-T G.1070 (Objective Video Quality) ITU-R BT.500-9. RADVISION’s extensive Human Vision survey (Subjective Video Quality) to support more codecs
14. RADVISION Advanced Video Quality Techniques “No Reference”Online Additional technique to perform global video quality estimation based not only on network parameters, but also on: Effect of packet-loss as long as no I-frame is received Quality score based on dynamism level of the video Bit-rate and frame-rate fluctuation considered as indication of quality Quality score based on codec quantization level Reason for video Quality degradation and optimization methods
15. Video Quality, Image-Based “No Reference”Image - based Video content measurement complex technology in the multimedia world. Video Content algorithm combines network impairment data and video content to diagnose cause for quality issues. Integrated approach enables to isolate operability issues Video Content analysis such as Blockiness, blurriness, image loss, … Video MOS is the aggregate of video metrics
16. RADVISION Video Quality Standard Involvement “No Reference”Image - based Video packet loss concealment detection based on image content Innovative research presented in 16th European Signal Processing Conference (EUSIPCO2008) Different algorithm for I-frame and P-frame Over 90% detection precision
18. RADVISION Video Quality Solution Video Quality SDK toolkit provides the video Quality measurement in real-time based on objective and subjective correlated to human perception. eVident Voice and Video Quality monitoring solution to improve the video conferencing in the network and to ensure a high quality end user experience. ProLab: Automated tests for voice and video Quality measurement using IMS, SIP, 3g-324M and H.323 protocols and multiple Video Quality measurements technology. ProLab Video Quality monitoring is combined both image processing, network impairment data and incorporates standard methodology and diagnose the cause of the quality issue.
19. ProLab - A Rich Testing Solution for IMS, SIP, H.323, 3G-324M AND VOICE/VIDEO OVER IP ProLab SIP IMS 3G-324M H.323 Automation Test Result Analysis Server Emulation Terminal Emulation Media Analysis & Quality
20. eVident Testing Solution eVident ensures: Network readiness for Voice and Video over IP Improved/Ensured end-user experience Correct network configuration Topology emulation, including interaction with various types of infrastructures Fault protection and preventing problems via proactive testing Application & protocol testing using SIP and H.323
22. Thank You Elie Cohen elic@radvision.com +97237679631 +97257679606
Notes de l'éditeur
We use 3 methods for measuring video quality.The first method is used mainly by developers and QA teams to improve video applications and video quality. This reference-based method involves an in-depth comparison between the original source stream and a degraded stream. The second method measures online and real-time video quality. This method is based on objective and subjective parameters and focuses on online video quality. The third method is image-based, measuring the image quality on video metrics, without reference and network parameters.
Using the full reference method we need to synchronize the original video stream to the degraded one before carrying out a comparison between the two. Based on a frame by frame comparison this method requires a CPU to synchronize and perform the measurement. Not recommended for thousands of streams this method is implemented by R&D, QA and SP-Labs in order to debug the video quality inside applications or new video services.
This reference method provides different video metrics when analyzing the video steam such as a blockiness, jerkiness or a blurred effect. The block effect can be the result of a high compression rate. All these instances can be the result of packet loss or erroneous packets. In a nutshell, this reference method is best utilized when the system has both a reference and degraded stream.
Online Video Quality is not measured using a reference method but according to an objective mean bit rate, frame rate, packet loss rate, codec type resolution and I-frame rate. Function execution is extremely quick and in order to support additional codec’s a subjective survey must be implemented. The video quality online standard is based on objective and subjective video quality using network and codec parameters.
Certain applications lack the ability to save the degraded stream or send a reference stream, for example an endpoint that sends media from a camera. In this situation we suggest using the image-based quality score. This CPU consumption algorithm measures the image without reference, basing the evaluation on the image blockiness and blurred effects as well as image loss.
Our innovative research with Technion University, one of the leading in image processing, was published and presented to the 16th European Signal Processing Conference (EUSIPCO2008).The algorithm indicates whether the image is affected by packet loss. It includes the solution for I-frame and P-frame and can detect with up to 90 % precision.
ProLab testing Suite has been designed for the R&D and SP-Labs and simulates IMS, SIP, H.323 and 3G-324M. The simulation incorporates the terminal and server, for example a SIP or IMS server and a Gatekeeper. ProLab provides the ability to analyze real-time voice and video and the quality by using two methodologies, reference based and none reference based.
I would like to introduce you to eVident, a testing suite for the enterprise market. eVident is a software testing solution that provides active monitoring using H.323 and SIP for pre and post deployments. This testing solution ensures network readiness for voice and video while improving the end-user experience with high quality, real time voice and video communications.
To obtain further information about how Video Quality measurement works, find an article on embedded computing design that will provide you with much more detail. Thank you for reviewing this webinar, if you have additional questions or require clarification relating to specific issues, please contact Eli Cohen and he will be more than happy to assist.