1、Rec. ITU-R BR.715-1 1 RECOMMENDATION ITU-R BR.7 15- 1 * International exchange of analogue electronic news gathering recordings* (Question ITU-R 239/11) (1990-2001) The ITU Radiocommunication Assembly, considering that electronic news gathering (ENG) is widely used in broadcasting in several parts o
2、f the 4 world; b) that videotape recording is a fundamental element in ENG operation; c) that it would be beneficial to broadcasters in their ENG recording operation if common ENG interface standards, recording formats and operating practices were adopted in the world; while a variety of standards w
3、ould be wasteful and impede the international exchange of ENG recordings and, possibly the compatibility of equipment, recommends 1 that in order to facilitate the interconnection of ENG equipment of different models, uniform interfaces should preferably be used in ENG equipment; it is noted that, i
4、n the case of analogue component ENG equipment, an EBU Recommendation exists for the camera-to-VTR interface (see Annex 1) and an EBU standard exists for the parallel analogue component video interface (see Annex 2); 2 that in order to facilitate the international exchange of ENG recordings, uniform
5、 ENG recording formats should preferably be used; it is noted that the EBU has recommended to its members that, for electronic news gathering equipment using analogue component signals, they should use the recording format described in IEC Publication 961, i.e., format L (so-called BETACAM system).T
6、he EBU Recommendation has the reference R32-1984; 3 shown in Annex 3 should be followed; that, in order to facilitate the use of exchanged ENG recordings, the operating guidelines 4 that, in order to preserve picture quality in international exchange of ENG recordings, when using analogue component
7、ENG VTR machines of format L, if the signal remains in the analogue component domain, recordings of up to the third generation may be used, and certainly not more than the fourth. * This Recommendation should be brought to the attention of the EC, Broadcasting Unions and the SMPTE. international pro
8、gramme exchange is defined as the transmission of television or sound programme material (or components thereof) among professional parties in different countries. It should be based on internationally agreed and widely employed technical standards or operating practices, except by prior bilateral a
9、greement among the parties involved. * . 17 2 Rec. ITU-R BR.715-1 NOTE 1 -Normally, ENG tape recordings can undergo several further generations of copying by full-broadcast quality VTR machines, without significant deterioration in picture quality. ANNEX 1 EBU Technical Recommendation R34 Interface
10、for the interconnection of ENG cameras and portable VTRs using non-composite signals This interface is designed to enable the ENG signals produced in a non-composite form to be sent through a parallel link between a camera and a portable VTR which are separated by about 5 to 1 O m, instead of being
11、combined in a “camcorder“. The specification includes the electrical characteristics that the interface must satis in order to transmit the programme signals produced by the camera (audio and video components) and those fed back to the viewfinder (video playback), as well as the operational controls
12、 and the monitoring indications. The specification includes only those characteristics considered to be essential to facilitate the interconnection of equipment produced by different manufacturers. In order to prevent damage due to incorrect connections, it is necessary to make sure that the equipme
13、nt concerned complies with these specifications, and furthermore that the additional connections provided by the manufacturers in the case of particular systems are not incompatible with these specifications. - One system has been recommended by the EBU for the production of non-composite ENG signal
14、s (Recommendation R32). The detailed specification of the interface for this system is given in an annex to Recommendation R32, and the correspondences between the contacts in that case and the signals taken into account by the EBU are indicated. 1 Electrical characteristics of the interface 1.1 Pro
15、gramme signais In practice, component video signals are generally designated by the letters Y, R-Y, and B-Y, but in the following the notation adopted by the ITU-R has been used: E;, E = 0.299 ER + 0.587 E and Ei are the primary signals after gamma pre-correction. In the present application, the amp
16、litude range of the primary signals is 0.700 V. The luminance signal should include synchronizing pulses and line and field blanking in accordance with Report ITU-R BT.624 (Tables I, I. 1 and 1.2). 18 Rec. ITU-R BR.715-I 3 The amplitude of this signal should comply with the following specifications:
17、 Peak-to-peak amplitude (including sync.): Nominal value of the d.c. component: 1 V O V at blanking level or a.c. coupled output Input and output impedance: z, =zi =75n Colour-diflerence signals (camera + VTR) The colour-difference signals are obtained from the E; signal and the primary signals spec
18、ified above. When the amplitude range of the primary signals is 0.700 V, the colour-difference signals comply .with the ITU-R BT.629: following equations, which are the same as those given in the Report E,) EkB = 0.564 (Eh -E;) should include line and field blanking in accordance with Report ITU-R B
19、T.624 2). Neither of them should include sync. pulses. Both these signals (Tables I, 1.1 and I The amplitude of the E, EkR and E;, should be simultaneous in real time and convey time-coincident information. Their characteristics are illustrated in Fig. 1. The specification does not include any band-
20、limitation for the luminance or colour-difference signals; if necessary, in order to ensure that the equipment operates correctly, such limitation should be applied at the input stages of the equipment. The insertion of signals during the field-blanking period is reserved by the EBU. The use of line
21、s 12/325 in the E - - Ln practice, these signals are generally represented by the symbols Y, R-Y and B-Y, but in the following the notation adopted by ITU-R has been used: E;, E blue colour-difference signal (without sync.). * For copying, but no other purpose, a different interface may be used if n
22、ecessary (such an interface must not be used for other applications, as it will depend on the format). 22 Rec. ITU-R BR.715-1 7 2 Waveform of the signal The luminance signal E; should include sync. pulses and line and field blanking in accordance with Report ITU-R BT.624 (Tables I, I. 1 and 1.2). Th
23、e two colour-difference signals EhR and E,) should be simultaneous in real time and carry time- coincident picture information. The insertion of signals in the field-blanking period is reserved by the EBU. The use of lines 12/325 of the ER /E = 0.299 Ea + 0.587 Ei; +O. I 14 Ei where Eh, EG and Eh ar
24、e the primary signals after gamma pre-cokection. In this application, the amplitude range of the primary signals is 0.700 V. The amplitude of the E), signal should comply with the following specifications: Peak-to-peak amplitude (including sync.): Nominal value of the d.c. component: Input and outpu
25、t impedances of the interface: 1 V O V at blanking level or a.c. coupled output 2, =75R zi =75R These characteristics of the signals are shown in Fig. I. 3.2 Colour-difference signals The colour-difference signals are obtained from the Ei signal and the primary signals specified above. When the ampl
26、itude range of these signals is 0.700 V, the colour-difference signals comply with the following equations, which are the same as those given in Report ITU-R BT.629: ECR 0.713 (Ei -E;) E;, = 0.564 (Eh -E;) 23 8 Rec. ITU-R BR.715-1 The amplitude of the signals EbR and EhB should comply with the follo
27、wing specification: Peak-to-peak amplitude: 0.700 V for 100/0/100/0 colour bars 0.525 V for 100/0/75/0 colour bars O V at blanking level or a.c. coupled output Nominal value of the d.c. component: Input and output impedances of the interface: z, =75n zi =75R Neither of these signals includes sync. p
28、ulses, but both include clamping periods. The Characteristics of the signals are shown in Fig. 1. The specification does not require any limitation of the pass-band; if necessary, such limitation should be applied in the input stages of the equipment. 4 Mechanical characteristics The interface takes
29、 the form of type BNC connectors, with the female part mounted on VTRs and other equipment. ANNEX 3 Operating guidelines for the international exchange of ENG recordings 1 Allocation of audio tracks All the prevailing types of ENG recorders have two (or more) audio tracks. When only one programme so
30、und signal is recorded with the programme material, this should be on the most protected audio track (e.g. a track away from the edge of the tape rather than a track on the edge of the tape). 2 Information on the recording label Suitable information should be provided, preferably on a label affixed
31、to the tape cassette or tape reel as appropriate, to identi the content of exchanged ENG recordings. However, in the case of ENG recordings it does not seem essential to provide all the programme information described in , 24 Rec. ITU-R BR.715-1 9 Recommendation -R BR.469, 0 9.1. It appears that onl
32、y the following information is really necessary: - - - location of each event; - date of each event; - - - recording format; - television standard; - content of audio tracks. name of organization which originated the recording; programme number or cassette number; subject of each event and shot list
33、; playing time of each event; The same information should also be provided on a label affixed to the tape or cassette container. 3 Identification of different shots on a recorded ENG video cassette When several shots of the same event are included in an ENG recording their location on the tape can be identified by means of the tape counter, provided that care is taken to reset the tape counter to zero at the start of the tape. Alternatively, the location of the shots on the tape can be identified bymeans of the time and control code or “clip pictures”, if used. 25
