IEC 62141-2005 pdf – Helical-scan digital video cassette recording format using 12,65 mm magnetic tape and incorporating MPEG-4 compression – Type D-16 format.
2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 61 21 3:1 993, Analogue audio recording on video tape – Polarity of magnetization IEC 61 237-1 :1 994, Broadcast video tape recorders – Methods of measurement – Part 1: Mechanical measurements ISO/IEC 1 4496-2:2004, Information technology – Coding of audio-visual objects – Part 2 : Visual ITU-R Recommendation BT.709:2002, Parameter values for the HDTV standards for production and international programme exchange SMPTE 1 2M:1 999, Television – Audio and Film – Time and Control Code SMPTE 274M:2003, Television – 1920 × 1080 Scanning and Analog and Parallel Digital Interfaces for Multiple Picture Rates SMPTE 276M:1 995, Transmission of AES-EBU Digital Audio Signals Over Coaxial Cable SMPTE 292M:1 998, Bit-Serial Digital Interface for High-Definition Television Systems SMPTE 296 M:2001 , Television – 1280 × 720 Progressive Image Sample Structure – Analog and Digital Representation and Analog Interface SMPTE 299M:1 997, Television – 24-Bit Digital Audio Format for HDTV Bit-Serial Interface SMPTE 372M:2002, Television – Dual Link 292M Interface for 1920 x 1080 Picture Raster SMPTE RP 1 88:1 999, Transmission of Time Code and Control Code in the Ancillary Data Space of a Digital Television Data Stream
4.1 Calibration tape Calibration tapes meeting the tolerances specified below should be made available by manu- facturers of digital television tape recorders and players in accordance with this standard. 4.2 Record locations and dimensions Geometrical location and dimensions of the recordings on the tape and their relative positions with regard to timing relations of the recorded signals shall be as specified in Figure 27 and Table 2. Tolerances shown in Table 2 should, however, be reduced by 50 % for calibration tapes. 5 Tape and cassette physical specifications 5.1 Magnetic tape specifications 5.1.1 Base The base material shall be polyester or equivalent. 5.1.2 Tape width and width fluctuation The tape width shall be 1 2,650 mm ± 0,005 mm. Tape width fluctuations shall not exceed 6 µm peak to peak. The value of tape width fluctuation shall be evaluated by measuring 1 0 points, each 20 mm apart, over a tape length of 200 mm. 5.1.3 Tape thickness The tape thickness shall have a minimum value of 1 0,1 µm and a maximum value of 1 1 ,3 µm. 5.1.4 Offset yield strength The offset yield strength shall be greater than 1 3 N. 5.1.5 Magnetic coating The magnetic tape used shall have a coating of metal particles or equivalent, longitudinally oriented. The coating coercivity shall be in the range of 1 90 000 A/m to 240 000 A/m, with an applied field of 800 000 A/m (1 0 000 oersted) as measured by a 50 Hz or 60 Hz BH meter or vibrating sample magnetometer (VSM). 5.2 Cassette specifications 5.2.1 Cassette dimensions Two sizes of cassettes shall be identified as follows.
7 Longitudinal track signal and magnetic parameters 7.1 Longitudinal track record parameters 7.1.1 Method of recording The control track and time-code track signals shall be recorded using the hysteretic (non-bias) recording method. 7.1.2 Flux level The recording level shall be at saturation of the magnetic domains which is defined as that point above which a 0,5 dB increase in output level results from 1 dB increase of input level as indicated on an r.m.s. level meter. 7.2 Control track record parameters 7.2.1 Control track pulse period The control track pulse, at the point of recording, shall be a series of pulses as shown in Figure 29. The period of the pulses for each record unit rate shall be as defined in Table 3.
7.2.2 Control track pulse definition The rising edge of all control track pulses should be timed to coincide with the input reference signal. The frame start point is defined as the midway point of the leading sync edge position which identifies the start of line 1 of the video signal represented by the input reference signal. The control track pulses shall have nominal periods of 35 T, 50 T or 65 T between the rising and falling edges where T is equal to 0,1 668 ms (for 29,97 Hz record unit rates), 0,200 ms (for 25 Hz record unit rates), 0,20833 ms (for 24 Hz record unit rates) or 0,20854 ms (for 23,98 Hz record unit rates) as shown in Figure 29. The sequence of the control track pulse width shall be locked to the segment information included in the corresponding video data. 7.2.3 Flux polarity The polarity of the tracking-control recording flux shall be as defined by Clause 5 of IEC 61 21 3 and Figure 29.