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.343.1 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-N
2、Re objective perceptual video quality measurement for HDTV and multimedia IP-based video services in the presence of encrypted bitstream data Recommendation ITU-T J.343.1 Rec. ITU-T J.343.1 (11/2014) i Recommendation ITU-T J.343.1 Hybrid-NRe objective perceptual video quality measurement for HDTV an
3、d multimedia IP-based video services in the presence of encrypted bitstream data Summary Recommendation ITU-T J.343.1 provides hybrid no-reference encrypted (Hybrid-NRe) objective perceptual video quality measurement methods for HDTV and multimedia when encrypted bitstream data are available. The fo
4、llowing 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 transmitted over the Internet using Internet protocol; video quality monitoring at the receiver wh
5、en encrypted bitstream data are available; video quality monitoring at measurement nodes located between point of transmission and point of reception when encrypted bitstream data are available; quality measurement for monitoring of a transmission system that utilizes video compression and decompres
6、sion techniques, either a single pass or a concatenation of such techniques; lab testing of video transmission systems. This Recommendation includes an electronic attachment containing test vectors, including video sequences, bitstream files and predicted objective model scores. History Edition Reco
7、mmendation Approval Study Group Unique ID* 1.0 ITU-T J.343.1 2014-11-29 9 11.1002/1000/12316 _ * 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-
8、en. ii Rec. ITU-T J.343.1 (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 o
9、f ITU. ITU-T is responsible 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 topi
10、cs for study by the 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 prep
11、ared on a collaborative 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 ma
12、y contain certain mandatory 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 e
13、xpress requirements. 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 Pr
14、operty Right. ITU takes 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 i
15、ntellectual property, 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
16、 rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T J.343.1 (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
17、 3 3.2 Terms defined in this Recommendation . 3 4 Abbreviations and acronyms 3 5 Conventions 4 6 Performance metrics . 4 7 Description of the hybrid no-reference methodology . 4 8 Models 5 Annex A Hybrid-NRe model RST-V-model 6 A.1 Packet header data extraction . 6 A.2 Extraction of video frame feat
18、ure statistics 12 A.3 Hybrid core model 24 A.4 Additional information . 46 Annex B YHyNRe (Hybrid-NRe model) 51 B.1 Introduction 51 B.2 Hybrid-NRe VQM computation . 51 Bibliography. 58 Electronic attachment: Test vectors, including video sequences, bitstream files and predicted objective model score
19、s. Rec. ITU-T J.343.1 (11/2014) 1 Recommendation ITU-T J.343.1 Hybrid-NRe objective perceptual video quality measurement for HDTV and multimedia IP-based video services in the presence of encrypted bitstream data 1 Scope This Recommendation1 describes algorithmic models for measuring the visual qual
20、ity of IP-based video services. The models are hybrid no-reference encrypted (Hybrid-NRe) models, which operate by analysing packet header information and video image data captured at the video player. The models operate without parsing or decoding the packet payload. Thus, these models can be used
21、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 mean opinion score (MOS) scale, derived from five-point absolute category rating (ACR) as in ITU-T P.910. The models address low-resolution (VGA/WVGA) applica
22、tion 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 encapsulated in RTP/UDP/IP packets for the low resolution and encapsulated i
23、n 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 be used for applications such as to monitor the quality of deployed ne
24、tworks 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 limited precision. Therefore, directly comparing model results can be misl
25、eading. 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 transmitted over wired and wireless networks, such as WIFI and 3G mobile net
26、works. 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) conditions were included in the validation test: 1080i 60 Hz (29.97 fps);
27、 1080p (25 fps); 1080i 50 Hz (25 fps); 1080p (29.97 fps); SRC duration: HD: 10 s, 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 containing test vectors, including video sequences, bitstream files and predi
28、cted objective model scores. 2 Rec. ITU-T J.343.1 (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 and progressive Video frame rates 29.97 and 25 fps Video bitrates: 1
29、 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 ITU-T H.264/AVC (MPEG-4 Part 10) Tandem coding 1.1 Applications
30、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 those transmitted over the Internet using Internet protocol; vi
31、deo quality monitoring at the receiver when encrypted bitstream data and processed video sequence (PVS) are available; video quality monitoring at measurement nodes located between point of transmission and point of reception when encrypted bitstream data and PVS are available; quality measurement f
32、or 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 estimation models described in this Recommendation cannot be u
33、sed 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 rebuffering condition (i.e., video that has a steadily increasing de
34、lay 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 employed, the models in this Recommendation may not be used.
35、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 artifacts, which were not included in this evaluation, the objective
36、 model may produce erroneous results. Here, a subjective evaluation is required. Rec. ITU-T J.343.1 (11/2014) 3 2 References The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of
37、 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 the Recommendations and other references listed below. A list
38、 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 (2014), Advanced video coding for generic audiovisual servi
39、ces. 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.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
40、(2008), Subjective video quality assessment methods for multimedia applications. 3 Definitions 3.1 Terms defined elsewhere This Recommendation uses the following terms defined elsewhere: 3.1.1 hybrid no reference model ITU-T J.343: An objective video quality model that predicts subjective quality us
41、ing the decoded video frames, packet headers, and video payload. Such models can be deployed in-service but cannot analyse encrypted video. 3.1.2 hybrid no reference encrypted model ITU-T J.343: An objective video quality model that predicts subjective quality using the decoded video frames and pack
42、et headers. Such 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 HRC Hypothetical Reference Circuit Hybr
43、id-NR Hybrid No Reference Hybrid-NRe Hybrid No Reference encrypted LUT Look-Up Table MOS Mean Opinion Score MPEG Moving Picture Experts Group NR No (or Zero) Reference PES Packetized Elementary bitStream PVS Processed Video Sequence 4 Rec. ITU-T J.343.1 (11/2014) SRC Source Reference Channel or Circ
44、uit 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 in this Recommendation. Note that the RST-V-model is referr
45、ed to as “TVM-Hybrid Encrypted“ within b-VQEG Hybrid. 7 Description of the hybrid no-reference methodology This Recommendation specifies objective video quality measurement methods which use both processed video sequences and bitstream data. The bitstream data may be provided in the forms of element
46、ary bitstream (ES), packetized elementary bitstream (PES) or packet video (Figure 1). The Hybrid-NRe models use only PVS and bitstream data, as shown in Figure 1 and Figure 2. While the hybrid no reference (Hybrid-NR) models have access to all of this data, the Hybrid-NRe models do not have access t
47、o 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.343.1 (11/2014) 5 Figure 2 Block-diagram of the Hybrid-NRe model 8 Models Annexes A and B contain full disclosures of
48、 all models included in this Recommendation. These models are RST-V-model and YHyNRe. 6 Rec. ITU-T J.343.1 (11/2014) Annex A Hybrid-NRe model RST-V-model (This annex forms an integral part of this Recommendation.) Overview The RST-V-model is composed of the following three modules: 1) packet header
49、data extraction; 2) extraction of video frame feature statistics; alignment of edited PVS to PVS; 3) hybrid core model. Each of these modules is described in the following clauses, together with a clause describing auxiliary functions and containers at the end. The beginning of each clause contains a high level overview of the module. The model takes as input the filename of a .pcap file containing the bistream and a filename of an .avi file containing t
