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.343.3 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-R
2、Re objective perceptual video quality measurement for HDTV and multimedia IP-based video services in the presence of a reduced reference signal and encrypted bitstream data Recommendation ITU-T J.343.3 Rec. ITU-T J.343.3 (11/2014) i Recommendation ITU-T J.343.3 Hybrid-RRe objective perceptual video
3、quality measurement for HDTV and multimedia IP-based video services in the presence of a reduced reference signal and encrypted bitstream data Summary Recommendation ITU-T J.343.3 provides hybrid reduced-reference encrypted (Hybrid-RRe) objective perceptual video quality measurement methods for HDTV
4、 and multimedia when a reduced reference signal and encrypted bitstream data are available. The following are 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
5、transmitted over the Internet using Internet protocol; video quality monitoring at the receiver when a reduced reference signal and encrypted bitstream data are available; video quality monitoring at measurement nodes located between point of transmission and point of reception when a reduced refere
6、nce signal and 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
7、includes an electronic attachment containing test vectors, including video sequences, bitstream files and predicted objective model scores. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T J.343.3 2014-11-29 9 11.1002/1000/12318 _ * To access the Recommendation, type the URL
8、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.343.3 (11/2014) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the
9、 field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standa
10、rdizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is cov
11、ered 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 collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indi
12、cate both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achiev
13、ed 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. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL P
14、ROPERTY 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 takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asse
15、rted 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, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that
16、 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 part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec.
17、ITU-T J.343.3 (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 in this Recommendation . 3 4 Abbreviations and acronyms 3 5 Conventions 4 6 Performance metrics . 4 7 Description of th
18、e hybrid reduced-reference methodology 4 8 Models 5 Annex A YHyRRe (Hybrid-RRe model) . 6 A.1 Introduction 6 A.2 Hybrid-RRe VQM computation . 6 Bibliography. 10 Electronic attachment: Test vectors, including video sequences, bitstream files and predicted objective model scores.Rec. ITU-T J.343.3 (11
19、/2014) 1 Recommendation ITU-T J.343.3 Hybrid-RRe objective perceptual video quality measurement for HDTV and multimedia IP-based video services in the presence of a reduced reference signal and encrypted bitstream data 1 Scope This Recommendation1 describes algorithmic models for measuring the visua
20、l quality of IP-based video services. The models are hybrid reduced-reference encrypted (Hybrid-RRe) models, which use features extracted from the unimpaired reference video signal, packet header information, and video image data captured at the video player. The models operate without parsing or de
21、coding the packet payload. Thus, these models can be used with encrypted bitstream data as well as non-encrypted bitstream data. 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 rating (ACR) as
22、 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 payload encapsu
23、lated 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. The models may b
24、e 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 Recommendation have limit
25、ed 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 included media transmi
26、tted 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 channel (SRC) cond
27、itions 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 attachment containin
28、g test vectors, including video sequences, bitstream files and predicted objective model scores. 2 Rec. ITU-T J.343.3 (11/2014) The following hypothetical reference circuit (HRC) conditions were included in the validation test for each resolution: Test factors Video resolution: 1920 1080 interlaced
29、and progressive Video frame rates 29.97 and 25 fps 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 technolog
30、ies 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 inclu
31、ding those transmitted over the Internet using Internet protocol; video quality monitoring at the receiver when side-channels and encrypted bitstream data are available; video quality monitoring at measurement nodes located between point of transmission and point of reception when side-channels and
32、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. 1.2 Limitations The video quality e
33、stimation model 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 for measuring video quality in a rebuffer
34、ing 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). If forward error correction techniques are e
35、mployed, 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 PVS. It should be noted that in case of new coding and transmission technologies producing artifact
36、s, which were not included in this evaluation, the objective model may produce erroneous results. Here, a subjective evaluation is required. Rec. ITU-T J.343.3 (11/2014) 3 2 References The following ITU-T Recommendations and other references contain provisions which, through reference in this text,
37、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 to investigate the possibility of applying the most recent edition of t
38、he 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, the status of a Recommendation. ITU-T H.264 Recommendation ITU-T H.264
39、 (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 J.342 (2011), Objective multimedia video quality measurement of HDTV f
40、or 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-T P.910 (2008), Subjective video quality assessment methods for multim
41、edia applications. 3 Definitions 3.1 Terms defined elsewhere This Recommendation uses the following terms defined elsewhere: 3.1.1 hybrid reduced reference model ITU-T J.343: An objective video quality model that predicts subjective quality using the decoded video frames, packet headers, video paylo
42、ad and features extracted from the reference video. Such models can be deployed in-service but cannot analyse encrypted video. 3.1.2 hybrid reduced reference encrypted model ITU-T J.343: An objective video quality model that predicts subjective quality using the decoded video frames, packet headers,
43、 and features extracted from the reference video. These models can be deployed in-service and are suitable for use with encrypted video. 3.2 Terms defined in this Recommendation None. 4 Abbreviations and acronyms This Recommendation uses the following abbreviations and acronyms: CODEC Coder-Decoder
44、DMOS Difference Mean Opinion Score HRC Hypothetical Reference Circuit Hybrid-RR Hybrid Reduced Reference Hybrid-RRe Hybrid Reduced Reference encrypted LUT Look-Up Table 4 Rec. ITU-T J.343.3 (11/2014) MPEG Moving Picture Experts Group PES Packetized Elementary bitStream PVS Processed Video Sequence R
45、R Reduced Reference SRC Source Reference Channel (or Circuit) 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-T J.343. See b-VQEG Hybrid for a complete analysis of the models included i
46、n 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 bitstream data may be provided in the forms of elementary bitstream (ES), packeti
47、zed elementary bitstream (PES) or packet video (Figure 1). In addition, Hybrid-RRe models also use features extracted from source video sequences. Figure 2 shows a Hybrid-RRe model. In addition to the bitstream data, the Hybrid-RRe model uses the features extracted from the SRC. Where the Hybrid-RR
48、models have access to all of this data, the Hybrid-RRe models do not have access to the video payload. Therefore, these models can be used with encrypted bitstreams. Figure 1 Block-diagram depicts the core concept of hybrid perceptual/bitstream models Rec. ITU-T J.343.3 (11/2014) 5 DMOSp: predicted
49、DMOS by the model Figure 2 Block-diagram depicts the Hybrid-RRe model 8 Models Annex A contains full disclosures of the model included in this Recommendation. The model is YHyRRe. 6 Rec. ITU-T J.343.3 (11/2014) Annex A YHyRRe (Hybrid-RRe model) (This annex forms an integral part of this Recommendation.) A.1 Introduction The YHyRRe model first computes a video quality metrics (VQM) value using the total number of packets and number of packet loss using a predefined l
