1、 I n t e r n a t i o n a l T e l e c o m m u n i c a t i o n U n i o n ITU-T J.343.6 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (11/2014) SERIES J: CABLE NETWORKS AND TRANSMISSION OF TELEVISION, SOUND PROGRAMME AND OTHER MULTIMEDIA SIGNALS Measurement of the quality of service - Part 3 Hybrid-F
2、R objective perceptual video quality measurement for HDTV and multimedia IP-based video services in the presence of a full reference signal and non-encrypted bitstream data Recommendation ITU-T J.343.6 Rec. ITU-T J.343.6 (11/2014) i Recommendation ITU-T J.343.6 Hybrid-FR objective perceptual video q
3、uality measurement for HDTV and multimedia IP-based video services in the presence of a full reference signal and non-encrypted bitstream data Summary Recommendation ITU-T J.343.6 provides hybrid full reference (Hybrid-FR) objective perceptual video quality measurement methods for HDTV and multimedi
4、a when a full reference signal and non-encrypted bitstream data are available. The following list shows example applications that can use this Recommendation: potentially real-time, in-service quality monitoring at the headend; video television streams over cable/IPTV networks including those transm
5、itted over the Internet using Internet protocol; video quality monitoring at the receiver when a full reference signal and non-encrypted bitstream data are available; video quality monitoring at measurement nodes located between point of transmission and point of reception when a full reference sign
6、al and non-encrypted bitstream data are available; quality measurement for monitoring of a transmission system that utilizes video compression and decompression techniques, either a single pass or a concatenation of such techniques; lab testing of video transmission systems. This Recommendation incl
7、udes test vectors, including video sequences, bitstream files and predicted objective model scores. This Recommendation includes an electronic attachment containing test vectors, including video sequences, bitstream files and predicted objective model scores. History Edition Recommendation Approval
8、Study Group Unique ID* 1.0 ITU-T J.343.6 2014-11-29 9 11.1002/1000/12321 _ * To access the Recommendation, type the URL http:/handle.itu.int/ in the address field of your web browser, followed by the Recommendations unique ID. For example, http:/handle.itu.int/11.1002/1000/11830-en. ii Rec. ITU-T J.
9、343.6 (11/2014) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is resp
10、onsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the
11、ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborat
12、ive basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain ma
13、ndatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory language such as “must“ and the negative equivalents are used to express requirements.
14、 The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTSITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU ta
15、kes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had received notice of intellectual property
16、, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2015 All rights reserved. No
17、 part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T J.343.6 (11/2014) iii Table of Contents Page 1 Scope . 1 1.1 Applications 2 1.2 Limitations 2 2 References . 3 3 Definitions 3 3.1 Terms defined elsewhere 3 3.2 Terms defined
18、 in this Recommendation . 3 4 Abbreviations and acronyms 3 5 Conventions 4 6 Performance metrics . 4 7 Description of the hybrid reduced-reference methodology 4 8 Models 5 Annex A Description of video quality measure PEVQ-S . 6 A.1 Introduction 6 A.2 Description of the PEVQ-S algorithm 6 Annex B YHy
19、FR . 38 B.1 Introduction 38 B.2 Hybrid-FR VQM computation . 38 Bibliography. 43 Electronic attachment: Test vectors, including video sequences, bitstream files and predicted objective model scores. Rec. ITU-T J.343.6 (11/2014) 1 Recommendation ITU-T J.343.6 Hybrid-FR objective perceptual video quali
20、ty measurement for HDTV and multimedia IP-based video services in the presence of a full reference signal and non-encrypted bitstream data 1 Scope This Recommendation1 describes algorithmic models for measuring the visual quality of IP-based video services. The models are hybrid full reference (Hybr
21、id-FR) models, which use the unimpaired reference video signal, non-encrypted bitstream data and video image data captured at the video player. As output the models provide an estimate of visual quality on the 1,5 difference mean opinion score (DMOS) scale, derived from five-point absolute category
22、rating (ACR) as in ITU-T P.910. The models address low-resolution (VGA/WVGA) application areas, including services such as mobile TV, as well as high-resolution (HD) application areas, including services such as IPTV. This Recommendation is to be used with videos encoded using ITU-T H.264 and media
23、payload encapsulated in RTP/UDP/IP packets for the low resolution and encapsulated in MPEG-TS/RTP/UDP/IP for the high resolution. The models in this Recommendation measure the visual effect of spatial and temporal degradations as a result of video coding, erroneous transmission or video rescaling. T
24、he models may be used for applications such as to monitor the quality of deployed networks to ensure their operational readiness or to benchmark service quality. The models in this Recommendation can also be used for lab testing of video transmission systems. The models identified in this Recommenda
25、tion have limited precision. Therefore, directly comparing model results can be misleading. The accuracy of models has to be understood and taken into account (e.g., using ITU-T J.149). The validation test material consisted of video encoded using different implementations of ITU-T H.264. It include
26、d media transmitted over wired and wireless networks, such as WIFI and 3G mobile networks. The transmission impairments included error conditions such as dropped packets, packet delay, both from simulations and from transmission over commercially operated networks. The following source reference cha
27、nnel (SRC) conditions were included in the validation test: 1080i 60 Hz (29.97 fps); 1080p (25 fps); 1080i 50 Hz (25 fps); 1080p (29.97 fps); SRC duration: HD: 10s, VGA/WVGA: 10 s or 15 s (rebuffering); VGA at 25 and 30 fps; WVGA at 25 and 30 fps. _ 1 This Recommendation includes an electronic attac
28、hment containing test vectors, including video sequences, bitstream files and predicted objective model scores. 2 Rec. ITU-T J.343.6 (11/2014) The following HRC conditions were included in the validation test for each resolution: Test factors Video resolution: 1920 1080 interlaced and progressive Vi
29、deo frame rates 29.97 and 25 frames per second Video bitrates: 1 to 30 Mbit/s (HD), 100 kbit/s to 3 Mbit/s (VGA/WVGA) Temporal frame freezing (pausing with skipping) of up to 50% of video duration Transmission errors with packet loss Rebuffering (VGQ/WVGA only): up to 50% of SRC Coding technologies
30、ITU-T H.264/AVC (MPEG-4 Part 10) Tandem coding 1.1 Applications The applications for the estimation model described in this Recommendation include, but are not limited to: potentially real-time, in-service quality monitoring at the headend; video television streams over cable/IPTV networks including
31、 those transmitted over the Internet using Internet protocol; video quality monitoring at the receiver when a copy of the unimpaired reference video and non-encrypted bitstream data are available; video quality monitoring at measurement nodes located between point of transmission and point of recept
32、ion when a copy of the unimpaired reference video and non-encrypted bitstream data are available; quality measurement for monitoring of transmission systems that utilize video compression and decompression techniques, including concatenations of such techniques; lab testing of video transmission sys
33、tems. 1.2 Limitations The video quality estimation models described in this Recommendation cannot be used to fully replace subjective testing. When frame freezing was present, the test conditions had frame freezing durations up to 50% of SRC duration. The models in this Recommendation were validated
34、 for measuring video quality in a re-buffering condition (i.e., video that has a steadily increasing delay or freezing without skipping) only for VGA/WVGA. The models were not tested on other frame rates than those used in TV systems (i.e., 29.97 fps and 25 fps, in interlaced or progressive mode). I
35、f forward error correction techniques are employed, the models in this Recommendation may not be used. It is important that no additional transmission errors occur between the collection point of the bitstream data and the capture point of the processed video sequence (PVS). It should be noted that
36、in case of new coding and transmission technologies producing artifacts, which were not included in this evaluation, the objective model may produce erroneous results. Here, a subjective evaluation is required. Rec. ITU-T J.343.6 (11/2014) 3 2 References The following ITU-T Recommendations and other
37、 references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject to revision; users of this Recommendation are therefore encouraged t
38、o investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document,
39、the status of a Recommendation. ITU-T H.264 Recommendation ITU-T H.264 (2014), Advanced video coding for generic audiovisual services. ITU-T J.149 Recommendation ITU-T J.149 (2004), Method for specifying accuracy and cross-calibration of Video Quality Metrics (VQM). ITU-T J.342 Recommendation ITU-T
40、J.342 (2011), Objective multimedia video quality measurement of HDTV for digital cable television in the presence of a reduced reference signal. ITU-T J.343 Recommendation ITU-T J.343 (2014), Hybrid perceptual bitstream models for objective video quality measurements. ITU-T P.910 Recommendation ITU-
41、T P.910 (2008), Subjective video quality assessment methods for multimedia applications. ITU-R BT.601 Recommendation ITU-R BT.601 (2011), Studio encoding parameters of digital television for standard 4:3 and wide screen 16:9 aspect ratios. 3 Definitions 3.1 Terms defined elsewhere This Recommendatio
42、n uses the following term defined elsewhere: 3.1.1 hybrid full reference model ITU-T J.343: An objective video quality model that predicts subjective quality using the reference video, the decoded video frames, packet headers, and the video payload. Such models cannot analyse encrypted video. 3.2 Te
43、rms defined in this Recommendation None. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: CODEC Coder-Decoder DMOS Difference Mean Opinion Score DTS Decoding Time Stamp FR Full Reference HRC Hypothetical Reference Circuit HVS Human Visual System Hybrid-
44、FR Hybrid Full Reference LUT Look-Up Table 4 Rec. ITU-T J.343.6 (11/2014) MOS Mean Opinion Score MPEG Moving Picture Experts Group MSE Mean Square Error PES Packetized Elementary bitStream PEVQ-S Perceptual Evaluation of Video Quality for Streaming PID Packet Identifier Field PTS Presentation Time S
45、tamp PVS Processed Video Sequence ROI Region Of Interest SEQ Sequence index SRC Source Reference Channel (or Circuit) TS Transport Stream VQEG Video Quality Experts Group VQM Video Quality Metrics 5 Conventions None. 6 Performance metrics A summary of this and other hybrid models may be found in ITU
46、-T J.343. See b-VQEG Hybrid for the complete analysis of the models included in this Recommendation. 7 Description of the hybrid reduced-reference methodology This Recommendation specifies objective video quality measurement methods that use both processed video sequences and bitstream data. The bit
47、stream data may be provided in the forms of elementary bitstream (ES), packetized elementary bitstream (PES) or packet video (Figure 1). In addition, the Hybrid-FR models also use reference video sequences. Figure 2 shows a Hybrid-FR model. The Hybrid-FR model need the source video sequence (SRC). R
48、ec. ITU-T J.343.6 (11/2014) 5 Figure 1 Block-diagram depicts the core concept of hybrid perceptual bitstream models DMOSp: predicted DMOS by the model Figure 2 Block-diagram depicts the Hybrid-FR model 8 Models Annexes A and B contain full disclosures of all models included in this Recommendation. T
49、hose models are perceptual evaluation of video quality for streaming (PEVQ-S) and YHyFR. 6 Rec. ITU-T J.343.6 (11/2014) Annex A Description of video quality measure PEVQ-S (This annex forms an integral part of this Recommendation.) A.1 Introduction PEVQ-S is a very robust model that is designed to predict the effects of transmission impairments on the video quality as perceived by a human subject. Its main targets are mobile applications and multimedia applica
