1、 Recommendation ITU-R BT.1865(03/2010)Metadata to monitor errors of SDTV and HDTV signals in the broadcasting chainBT SeriesBroadcasting service(television)ii Rec. ITU-R BT.1865 Foreword The role of the Radiocommunication Sector is to ensure the rational, equitable, efficient and economical use of t
2、he radio-frequency spectrum by all radiocommunication services, including satellite services, and carry out studies without limit of frequency range on the basis of which Recommendations are adopted. The regulatory and policy functions of the Radiocommunication Sector are performed by World and Regi
3、onal Radiocommunication Conferences and Radiocommunication Assemblies supported by Study Groups. Policy on Intellectual Property Right (IPR) ITU-R policy on IPR is described in the Common Patent Policy for ITU-T/ITU-R/ISO/IEC referenced in Annex 1 of Resolution ITU-R 1. Forms to be used for the subm
4、ission of patent statements and licensing declarations by patent holders are available from http:/www.itu.int/ITU-R/go/patents/en where the Guidelines for Implementation of the Common Patent Policy for ITU-T/ITU-R/ISO/IEC and the ITU-R patent information database can also be found. Series of ITU-R R
5、ecommendations (Also available online at http:/www.itu.int/publ/R-REC/en) Series Title BO Satellite delivery BR Recording for production, archival and play-out; film for television BS Broadcasting service (sound) BT Broadcasting service (television) F Fixed service M Mobile, radiodetermination, amat
6、eur and related satellite services P Radiowave propagation RA Radio astronomy RS Remote sensing systems S Fixed-satellite service SA Space applications and meteorology SF Frequency sharing and coordination between fixed-satellite and fixed service systems SM Spectrum management SNG Satellite news ga
7、thering TF Time signals and frequency standards emissions V Vocabulary and related subjects Note: This ITU-R Recommendation was approved in English under the procedure detailed in Resolution ITU-R 1. Electronic Publication Geneva, 2010 ITU 2010 All rights reserved. No part of this publication may be
8、 reproduced, by any means whatsoever, without written permission of ITU. Rec. ITU-R BT.1865 1 RECOMMENDATION ITU-R BT.1865 Metadata to monitor errors of SDTV and HDTV signals in the broadcasting chain (Questions ITU-R 44/6, ITU-R 48/6, ITU-R 109/6 and ITU-R 130/6) (2010) Scope This Recommendation de
9、fines metadata to monitor errors of audio, video and data signals at arbitrary monitoring points in an SDTV/HDTV broadcasting chain1. The metadata is packetized into ancillary data packets. This mechanism may also be applied to other types of metadata for picture quality measurement. The ITU Radioco
10、mmunication Assembly, considering a) that digital broadcasting has been introduced in many countries, and monitoring of the digital broadcasting chain by broadcasters and network operators has become increasingly important; b) that in broadcast operational monitoring, an objective method of automati
11、cally detecting malfunctioning equipment and quality degradation in audiovisual content is needed; c) that the monitoring method should be reliable, efficient, and cost-effective; d) that the cause of degradation such as signal loss, blackouts, freezing, and muting may be transmission paths, equipme
12、nt, human error, or intentional audiovisual effects, and operators have to accurately assess the cause of the alarms and rectify the problems; e) that if appropriate metadata were to be added to the audiovisual content at an early stage of the broadcasting chain, it would make the monitoring system
13、at later stages of the chain more reliable and help operators to analyse the cause of malfunctions or degraded quality, recognizing a) that ITU-R has established Recommendation ITU-R BT.1364 Format of ancillary data signals carried in digital component studio interfaces, which defines the data struc
14、ture for packetized data that may be carried as part of the payload in serial digital interfaces as defined in Recommendations ITU-R BT.656 and ITU-R BT.1120, recommends 1 that for the use of metadata to monitor errors of audio and video signals in television broadcasting chains, the specifications
15、in Annex 1 should be used. NOTE 1 Appendix 1, attached to this Recommendation, provides additional explanations of metadata for operational monitoring. 1Monitoring on a broadcasting chain from news gathering, programme production and postproduction through master control is the primary subject of th
16、is Recommendation. 2 Rec. ITU-R BT.1865 Annex 1 Reference (informative) Recommendation ITU-R BT.1790 Requirements for monitoring of broadcasting chains during operation. ITU-T Recommendation J.243 Requirements for operational monitoring in television programme transmission chains. ITU-T Recommendati
17、on P.911 (1998) Subjective audiovisual quality assessment methods for multimedia applications. ITU-T Recommendation J.240 (2004) Framework for remote monitoring of transmitted picture signal-to-noise ratio using spread-spectrum and orthogonal transform. ITU-T Recommendation J.249 (2009) Perceptual v
18、isual quality measurement techniques for digital cable television in the presence of a reduced reference. Reference (normative) Recommendation ITU-R BT.1364-1 Format of ancillary data signals carried in digital component studio interfaces. ITU-T Recommendation J.187 Transport mechanism for component
19、-coded digital high-definition television signals using MPEG-2 video coding including all service elements for contribution and primary distribution. ISO 3166-1:2006 Codes for the representation of names of countries and their subdivisions Part 1: Country codes. 1 Overview A schematic diagram of an
20、operational monitoring process using metadata in a broadcasting chain is shown in Fig. 1 where operational monitoring is assumed to be conducted at arbitrary monitoring points in a broadcasting chain. Details on the monitoring process are given at the bottom of Fig. 1. This can be summarized as: 1 T
21、he metadata inserted at the upstream monitoring points are extracted. 2 Audio and video signals are analysed at monitoring points to generate metadata. 3 By comparing the current and upstream metadata, the audio and video signals are monitored to determine if any problems have occurred. 4 The metada
22、ta generated at the current monitoring point are added to the metadata history. Only metadata that are used for operational monitoring are updated within the process, and audio, video and any other auxiliary signals are left unchanged. Rec. ITU-R BT.1865 3 FIGURE 1 Configuration of monitoring points
23、 in broadcasting chain and monitoring process for metadata BT.1865-01A/V/MetademultiplexingCalculation ofvideo featuresHistory of metadata(metadata at previous points)Calculation ofaudio featuresEncoding tometadataUpdatedmetadataVideoMetadataExtraction and updateof metadataMonitoringExtraction and u
24、pdateof metadataMonitoring MonitoringUtilized for monitoringExtraction and updateof metadataEncoding tometadataBroadcastingchain1st monitoringpoint2nd monitoringpointN-th pointmonitoringFor video transmission(mainstream)Update of metadata(A/V signals themselvesare unchanged)Audio/videosignalFor meta
25、datagenerationAudio2 Metadata for operational monitoring 2.1 Configuration The basic configuration for the metadata for operational monitoring is outlined in Fig. 2. The configuration allows the use of different types of metadata, but the same type of metadata is to be used for the series of metadat
26、a in a broadcasting chain. Metadata such as those defined in ITU-T Recommendation J.249 for perceptual picture quality measurement and ITU-T Recommendation J.240 for remote monitoring of transmitted picture signal-to-noise ratio may also be used. FIGURE 2 Configuration for metadata BT.1865-02Metadat
27、aat currentmonitoring point Metadataat upper-endmonitoring point Metadataat previousmonitoring point Metadataat upstreammonitoring point ParametersHeaderParametersHeader ParametersHistory of MetadataHeader ParametersHeaderType4 Rec. ITU-R BT.1865 The metadata at the monitoring point on the upper end
28、 always appear first, followed by the metadata at the current monitoring point. Other metadata at the previous monitoring points follow in order of those most recently monitored in the broadcasting chain. The number of history items of metadata depends on the capacity of the data area; however, the
29、first two sets of metadata, i.e. the metadata at the monitoring point on the upper end and the current monitoring point, should be retained. When the history items are no longer valid for comparison with the metadata at the down stream monitoring points, the metadata are to be reset. The syntactical
30、 definitions of the metadata are listed in Table 1. The definitions of the header, video parameters, audio parameters, and data parameters of the metadata are given in the following sections. TABLE 1 Definition of metadata for monitoring Syntax No. of bytes Mnemonic metadata_type 1 bslbf for(i=0; iN
31、; i+) monitoring_metadata( ) Syntax monitoring_metadata header( ) video_parameters( ) audio_parameters( ) data_parameters( ) metadata _type indicates the type of metadata used. The metadata may not have to contain all three parameters. Value Assignment Type Video parameter Audio parameter Data param
32、eter 0x00 Reserved Not applicable 0x01 to 0xFE To be specified To be specified 0xFF Reserved Not applicable 2.2 Header The header information precedes the video, audio, and data parameters to identify the data number, types of video, audio, and data signals, the location of the monitoring point and
33、the organization that generated the metadata. The header may contain data_number, video signal_type, audio_sygnal_type, data_signal_type, country_code, organization_code, and user_code. An example of the header is provided in Appendix 1 (to Annex 1). Rec. ITU-R BT.1865 5 data_number indicates the da
34、ta number within the history of metadata. The first metadata inserted at the upper-end monitoring point has a data number of 0, the current metadata has a data number of 1, and the previous metadata has a data number of 2. Due to the restricted size of the user data word (UDW) of an ancillary data p
35、acket, the number of metadata sets as the history is limited. Figure 3 shows the flow chart with respect to managing the metadata history and the data number. When the history is reset, the metadata are to be inserted starting from the data number of 0. FIGURE 3 Management of metadata history and da
36、ta number BT.1865-03data_number = 0 data_number = 1data_number = 0data_number = 0 data_number = 1 data_number = 2data_number = 0 data_number = 1 data_number = 2 data_number = 3 data_n umber = 4data_number = 0 data_number = 1 data_number = 2 data_number = 3data_number = 0 data_number = 1 data_number
37、= 2 data_number = 3 data_number = 4 data_number = 5Upper-endUpper-end Current PreviousCurrentvideo_signal_type indicates the type of video signal (e.g. uncompressed, compressed). audio_signal_type indicates the type of audio signal (e.g. uncompressed, compressed). In some cases, audio signals may no
38、t be embedded with video signals. country_code indicates the country where the monitoring point is, specified by the two-letter country code as per ISO 3166-1. organization_code indicates the organization that operates the monitoring point designated by four ASCII characters. user_code indicates the
39、 monitoring point in an organization designated by four ASCII characters. 2.3 Video parameters The video parameters need to be able to detect video errors between two monitoring points. An example of the video data parameters is provided in Appendix 1. 2.4 Audio parameters The audio parameters need
40、to be able to detect audio errors between two monitoring points. An example of the audio parameters is provided in Appendix 1. 6 Rec. ITU-R BT.1865 2.5 Data parameters The data parameters need to be able to detect data errors between two monitoring points. 3 Transport of metadata The metadata for op
41、erational monitoring is conveyed by being packetized into the ancillary data packets which are multiplexed with the video and audio signals. 3.1 Format for ancillary data packets for metadata The format for the ancillary data packets of the metadata conforms to Type 2 ancillary data packets as defin
42、ed in Recommendation ITU-R BT.1364, and one word consists of 10 bits in this format. The format for the data packets is given in Fig. 4. DID and SDID need to be assigned. FIGURE 4 Format for ancillary data packets of metadata BT.1865-04ADF DID SDID DC UDW CS3111Max.25 1ADF: Ancillary data flag (0 00
43、0 , 0 3FF , 0 3FF )DID: Data identification word.SDID: Second data identification word.DC: Data count word.UDW: User data word. Maximum of 255 data words.CS: Check sum word.Note: Numbers indicate number of words.(10) (10) (10)3.2 User data word format User data words (UDW) comprise the metadata defi
44、ned in 2. The format for the UDW is listed in Fig. 5. The metadata are to be byte aligned, where the first bit of a byte occupies b7 and the last bit occupies b0. FIGURE 5 Bit assignment for data words BT.1865-05Bit number DescriptionB9(MSB) Not b8B8 Even parity for b0 through b7B7Metadata as per Se
45、ction 2.B6B5B4B3B2B1B0(LSB)LSB: least significant bit.MSB: most significant bit.Rec. ITU-R BT.1865 7 3.3 Transport of ancillary data packets The metadata generated for the video, audio, data signals in a given video frame are to be transported by an ancillary data packet attached to the following fr
46、ame. Synchronization between the video frame and the metadata needs to be ensured. Ancillary data packets containing the metadata are transported by one of the following methods: 1 The ancillary data packets are multiplexed into the ancillary data space of the serial digital interface, preferably in
47、 the vertical ancillary space. It is necessary to identify the available data area for this purpose by taking into consideration the current usage by broadcasters of the ancillary data space. 2 The ancillary data packets are multiplexed into the MPEG-2 Transport Stream. This method is specified in I
48、TU-T Recommendation J.187. 3 The ancillary data packets are transported through a path different from that for video and audio signals. This method requires a means for synchronization between the ancillary data packets and video and audio signals. Appendix 1 (to Annex 1) Example of metadata for ope
49、rational monitoring This appendix describes the Type-1 metadata for operational monitoring as defined in ARIB TR-B29. Reference ARIB Technical Report TR-B29 Metadata to monitor errors of video and audio signals on a broadcasting chain. Terminology AES stream: digital audio stream as defined in Recommendation ITU-R BS.647. One AES stream contains two audio channels. bslbf: bit string, left bit first, where “left” is the order in which bit strings are written in this Recommendation. uimsb: unsigned integer, most significa
