1、 Rec. ITU-R BR.1442 1 RECOMMENDATION ITU-R BR.1442 USERS REQUIREMENTS FOR DIGITAL HDTV TAPE CASSETTE RECORDERS (Question ITU-R 108/11) (2000) Rec. ITU-R BR.1442 The ITU Radiocommunication Assembly, considering a) that HDTV is defined as one of the picture formats in DTV standards; b) that compressio
2、n technology is widely used and provides adequate picture quality in SDTV and HDTV applications not only for secondary distribution to the home but also for broadcasting studio equipment; c) that devices for HDTV signal compression have been developed by several integrated circuit manufacturers and
3、are available economically in the market; d) that compression technology makes it possible to produce digital HDTV tape cassette recorders not only for studio production applications but also for field acquisition applications; e) that there are several different frame frequencies used in HDTV appli
4、cations in the various regions in the world, recommends 1 that a unified tape format for HDTV recording should be recommended to facilitate international exchange of programmes; 2 that the digital HDTV tape cassette recorder should be designed to be switchable to various frame frequencies depending
5、on the requirements of services in each region of the world; 3 that the compression scheme for HDTV recording in the studio should be based on the ability: to interoperate with other applications in the production and transmission chain while minimizing loss in quality (this may imply that similar c
6、oding technologies should be applied across the production/transmission path); to provide production editability performance with minimal loss in quality (this may imply intra-frame or inter-frame coding over a small number of frames). NOTE 1 Further information is provided in Annex 1 that provides
7、a text of the Association of Radio Industries and Business (ARIB) (Japan) and applies to 60 Hz field rate. 2 Rec. ITU-R BR.1442 ANNEX 1 Users requirements for the digital HDTV tape cassette recorder by the high-definition digital video cassette recorder (HD-DVCR) Working Group, ARIB (Japan) Preface
8、Several types of HD-DVCR are currently available in different formats for high-definition production and broadcast applications. The 3/4 inch-type HD-DVCR records baseband (non-compressed) HD signals and the 1/2 inch-type one records compressed HD signals. Recently, to fulfil the increasing market d
9、emands in field acquisition in the high-definition quality, a new 1/2 inch format of the HD-DVCR has been introduced in camcorder form and also stand-alone recorder form. In the process of discussing users requirements for the HD-DVCR in ARIB of Japan, a unified tape format for the HD-DVCR has been
10、strongly requested by the majority of members. Considering the current multiple tape formats and the availability of several products, this Annex summarizes users requirements in terms of specifications, required functions, and tape interchange. The user requirements shown here in this Annex can be
11、applied to the HD-DVCR in broadcast and production applications. To specify user requirements for the HD-DVCR, ARIB Standards BTA S-001B, S-004B, S-005B and S-006B are normative. Contents Section 1 The application area of the users requirements Section 2 Requirements for picture quality Section 3 Op
12、erations under 1125/60.00, 1125/59.94 Section 4 Input/output (I/O) specifications of the HD-DVCR Section 5 Reference signals Section 6 Recording time and battery operations Section 7 HD-DVCR tapes and tape interchange Section 8 Background 1 The application areas of the users requirements The user re
13、quirements defined in this Recommendation are applicable to the HD-DVCR for use in broadcast and production applications. The digital representation of the HDTV signal and the interface specifications are defined in the normative ARIB Standards BTA S-001B, S-004B, S-005B and S-006B. 2 Requirements f
14、or picture quality Acceptable picture quality of the HD-DVCR is one of the main user requirements. The compression scheme commonly used in the DVCR is designed to remove redundancy in the digitized pictures in temporal and/or spatial domains. The redundancy originated in high correlation both betwee
15、n successive pictures and as spatial correlation within pictures. The loss of quality by dubbing occurs mainly by picture shifts at each stage of the dubbing. Rec. ITU-R BR.1442 3 2.1 The picture quality requirements for the compression-based DVCR (under regular recording/ playback operations) For s
16、tudio programme productions through a dubbing process, the picture quality of television programmes shall be evaluated by a predetermined method. The measurement method and the picture sources used for the evaluation are listed as below. A method of the evaluation: The double stimulus continuous qua
17、lity scale (DSCQS) subjective evaluation method specified in Recommen-dation ITU-R BT.710 shall be used. Pictures used in the evaluation: Pictures generated by simple multiple dubbing, between the HD-DVCRs (about nine times, no clear definitions or indications have been set yet). Pictures generated
18、by multiple dubbing with picture shifts between each dubbing, both in the spatial and temporal domains (about four times, no clear definitions or indications have been set yet). For studio applications, the results of the evaluation must indicate that the quality difference between the original pict
19、ure and the picture under test shall be within the predetermined value. Pictures for evaluation shall be selected from various picture sources, such as pictures supplied by the Broadcasting Technology Association (BTA) as standard pictures for evaluation. 2.2 The picture quality requirements for the
20、 compression-based DVCR (for off-the-track playback operations) Following is a set of picture quality requirements for off-the-track playback operations. Under variable speed playback operations, such as still and slow-motion, no picture quality degradation shall be subjectively observed. Under high
21、-speed shuttle playback, picture contents shall be recognizable to facilitate operational compatibility with current video tape recorders (VTRs). Even under overload condition of the error correction scheme, degradation of the picture quality has to be kept minimum. 3 Operations under 1125/60.00 and
22、 1125/59.94 The current practice in HDTV studio in Japan requires two different field rates for daily operations depending on the application services. The HD-DVCR is required to be operable under the different frame rates, such as 60.00 and 59.94 Hz. The following are the users requirements for the
23、 HD-DVCR operations in terms of adaptability to different reference sync systems. 3.1 Switchability between 1125/60.00 and 1125/59.94 The HD-DVCR shall function under one of the two system modes. The system mode can be selected by the following ways: a) mode selection via a control panel; b) mode se
24、lection via a remote control panel; c) both a) and b). 4 Rec. ITU-R BR.1442 3.2 System modes of the HD-DVCR under recording and playback 3.2.1 Recording The following are the recommended ways of setting system modes of the HD-DVCR in recording: The system mode shall be set by the mode selection on a
25、 DVCR control panel. The Mode ID signal (see Note 1) on HD serial digital interface (SDI) shall set the modes of the HD-DVCR. For a portable type HD-DVCR, if CAMERA-IN is active, the mode shall be set by the control command defined in BTA S-1005B. Preservation of the system mode status on the tape i
26、s recommended. NOTE 1 Mode ID signal is a tentative naming. It is to identify the system mode, that is 1125/60.00 or 1125/59.94. If the Mode ID signal can be recovered off the tape, it shall be maintained and used accordingly. 3.2.2 Playback The following are ways of selecting system modes of the HD
27、-DVCR in playback. A portable type of the HD-DVCR shall be exempt from this condition: a) Automated selection of the system mode depending on the external sync applied (1125/60.00, 1125/59.94 only). b) System modes shall be set by the mode selection mechanism on the DVCR control panel. c) Automated
28、selection of system mode depending on the information recovered off the tape. If external sync is not available in 3.2.2, a), the system mode shall be selected depending on 3.2.2, b). The portable HD-DVCR shall facilitate a feature that can use its input signal as external reference. 3.3 Mode indica
29、tion in recording and playback The mode indication of 1125/60.00 and 1125/59.94 shall be as follows: Recording: System mode should be indicated properly on the control panel of HD-DVCR. The system mode status shall be output for display on a monitor and at a remote terminal. Playback: The system mod
30、e should be indicated on the control panel and should also be sent out for display on a monitor and at a remote terminal. A warning light should indicate when the HD-DVCR is functioning in a system mode which differs from the one on the tape. 3.4 External control interface for system mode selections
31、 A new highly adaptable control interface should be defined to be implemented or integrated into the current system. 4 Input/output (I/O) specifications of the HD-DVCR For each type of stand-alone and portable/camcorder HD-DVCR, the following I/O capabilities are recommended as part of the users req
32、uirements. Rec. ITU-R BR.1442 5 4.1 I/O requirements of stand-alone HD-DVCR Input Connector Connector Output REF IN(1125) BNC BNC REF OUT(1125) REF IN(525) NC BNC REF OUT(525) BNC WFM OUT HD-SDI IN BNC BNC HD-SDI OUT “ “ “ “ (W/CHAR) Digital AUDIO IN 1/2 BNC BNC Digital AUDIO OUT 1/2 Digital AUDIO I
33、N 3/4 BNC BNC Digital AUDIO OUT 3/4 Analogue AUDIO IN 1 XLR XLR Analogue AUDIO OUT 1 Analogue AUDIO IN 2 “ “ Analogue AUDIO OUT 2 Analogue AUDIO IN 3 “ “ Analogue AUDIO OUT 3 Analogue AUDIO IN 4 “ “ Analogue AUDIO OUT 4 CUE IN XLR XLR CUE OUT TIME CODE IN BNC BNC TIME CODE OUT REMOTE IN D-9P D-9P RE
34、MOTE OUT RS 232C D-25P VIDEO CONTROL D-15P PARALLEL CONT D-50P BNC 525-SDI OUT “ “ (W/CHAR)BNC NTSC OUT “ “ (W/CHAR)XLR L-CH MONITOR OUT “ R-CH “ 6 Rec. ITU-R BR.1442 4.2 I/O requirements of portable-type HD-DVCR 5 Reference signals The following are the users requirements for a system reference reg
35、arding various modes of the HD-DVCR: a) For confidence playback in recording and E-to-E, video and audio timing need to be adjusted depending on the system reference sync of the HD-DVCR, such as an external reference, an input video or a selected reference in auto mode. If a large size of memory is
36、necessary to output the video in external sync timing, this requirement is not mandatory (EXT*, refer to Tables in 5.1 and 5.2). Input Connector Connector Output LINE IN(1)LINE OUT Analogue video(2)(Y) BNC BNC Analogue video(2), (3)(Y) (Pb) “ “ (Pb) (Pr) “ “ (Pr) Analogue audio(4)(1CH) XLR XLR Analo
37、gue audio(4)(1CH) “ (2CH) “ “ “ (2CH) CAMERA IN 26P(5)26P(5)CAMERA RETURN Analogue video (Y, Pb, Pr) Analogue audio (1,2 CH) Control TIME CODE IN BNC BNC TIME CODE OUT REMOTE IN D-9P Stereo Mini Jack HEAD PHONE(6)DC IN XLR BNC NTSC OUT(7)(1)Video input signal, analogue or SDI (option), will be used
38、as an external reference signal in playback mode. (2)An SDI video input shall be available as an option. The selection of analogue input and SDI input should be mutually exclusive. (3)Warnings and various set-up parameters shall be super-imposed in output for monitoring. (4) Digital audio of 4 chann
39、els shall be available as an option. The selection of analogue input and digital input should be mutually exclusive. A BNC connector can be used instead of a XLR. (5)The connector specifications are defined in BTA S-1005B. The digital connection with a camera unit needs further study. (6)Each record
40、ed audio channel can be assigned to either L or R channel output independently. (7)An NTSC output as an output of down converter shall be available as option.Rec. ITU-R BR.1442 7 b) Under any system reference selections, recording of internal signal generator should be done correctly. c) E-to-E outp
41、ut of an internal signal generator should be synchronized with the external reference sync. Preferably, the E-to-E output timing should coincide with the output reference sync (INP*, refer to Tables in 5.1 and 5.3). d) In recording, synchronization to the external reference sync is not required. e)
42、The following tables show the relationships between the system reference sync and reference sync to be used internally for each output in various system modes, such as recording, playback, and E-to-E, etc. 5.1 With both external reference and input video signal at input of the VCR 5.2 With external
43、reference but without input video signal 5.3 Without external reference but with input video signal REC reference OUT reference REC Processing PLAYBACK Processing E-to-E Confidence SG output INP INP INP INP INP* INP EXT INP EXT EXT* EXT AUTO INP EXT INP EXT REC reference OUT reference REC Processing
44、 PLAYBACK Processing E-to-E Confidence SG output INP INT INT INT INT INP EXT INT EXT EXT* EXT AUTO INT EXT INT EXT REC reference OUT reference REC Processing PLAYBACK Processing E-to-E Confidence SG output INP INP INP INP INP* INP EXT INP INT INT INT AUTO INP INT INP INT 8 Rec. ITU-R BR.1442 5.4 Wit
45、hout either external reference and input video signal Definition of words and abbreviations: Confidence: Simultaneous playback during recording mode E-to-E: Output through recording and playback circuitry EXT: External reference sync INP: Input video signal INT: Internal sync signal REC reference: S
46、ystem reference sync in recording mode OUT reference: Reference sync to output the video signal SG output Sync generator output. 6 Recording time and battery operations 6.1 Recording time Greater than 60 min of recording time is recommended for a portable type of the HD-DVCR. For a stand-alone type
47、of the HD-DVCR, cassette capacity of more than 120 min, is recommended. 6.2 Portable HD-DVCR operations with a battery A battery should supply sufficient power for a full cassette length of recording. It is recommended that specifications for a battery connector be standardized. 6.3 Weight and physi
48、cal dimensions Mechanical specifications are preferably comparable to those of conventional TV equipment. 7 HD-DVCR tapes and tape interchange A stable supply of HD-DVCR tapes is important to secure HDTV production operations. To do so, considerations should be given to the following. 7.1 Tape suppl
49、y VCR manufacturers are requested to open necessary information for tape manufacturing soon after their VCR shipping in the market. At least two independent tape manufactures are considered to be essential for secured tape supply. Tape manufacturers are requested to maintain their tape production facility for secured tape supply. Disclosure of relevant information for stable production of tapes is considered to be important. Any changes in tape specifications should be supplied to tape users and VCR manufacturers
