IEC 62289 pdf download.Video recording – Helical-scan digital video cassette recording format using 12,65 mm magnetic tape and incorporating MPEG-2 compression
This standard specifies the formatting for the recording of data blocks containing MPEG-2 compressed video, multiple channels of AES3 audio and associated data which form helical records on 12,65 mm tape in cassettes. This standard also defines the helical track record parameters, the content and format of the longitudinal records and the cassette physical specifications. The compressed video uses the MPEG-2 compression which is defined by ISO/IEC 13818-2 with constraints as defined by Annex F. The compressed video channel supports frame frequencies of 30/1,001 Hz (hereafter referred to as 525/60 system) and 25 Hz (hereafter referred to as 625/50 system).
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 12,650 mm ± 0,01 mm. Tape width fluctuation shall not exceed 6 µm peak to peak. The value of tape width fluctuation shall be evaluated by measuring 10 points, each 20 mm apart, over a tape length of 200 mm.5.1.3 Tape thickness The tape thickness shall be from 12,3 µm to 14,5 µm. 5.1.4 Offset yield strength The offset yield strength shall be greater than 15 N. 5.1.5 Magnetic coating The magnetic tape shall have a coating of longitudinally oriented metal particles or equivalent. The coating coercivity shall be in the range of 118 000 A/m to 136 000 A/m, with an applied field of 800 000 A/m as measured by a 50 or a 60 Hz BH meter or a vibrating sample magnetometer (VSM).5.2.3 Datum planes Datum plane Z shall be determined by three datum areas A, B and C, as shown in Figures 3 and 16a. Datum plane X shall be orthogonal to datum plane Z and shall include the centres of datum holes (a) and (b) as shown in figures 2 and 15. Datum plane Y shall be orthogonal to both datum plane X and datum plane Z and shall include the centre of datum hole (a) as shown in Figures 2 and 15. 5.2.4 Tape winding The magnetic coating side of the magnetic tape shall face outside on both the supply reel and the take-up reel as shown in Figures 4 and 17. 5.2.5 Label area and window area The hatched areas shown in Figures 1 and 14 are for the label and window. Labels attached to the cassette shall not protrude above the outside cassette surface plane. 5.2.6 Guiding groove For correct insertion into the VTR, four guiding grooves for S-cassettes as shown in Figures 1 and 2, and three guiding grooves for L-cassettes as shown in Figure 15 shall be provided.5.2.7 Safety tab and safety plug for recording inhibition For S-cassettes, a safety plug at the supply reel side and a hole of minimum depth 10 mm from datum plane Z at the take-up reel side shall be provided as shown in Figure 2. For L-cassettes, a safety plug shall be provided at the take-up reel side as shown in Figure 15. The safety plug shall not be deformed by 0,3 mm or more when a force of 2,0 N (204 gf) is applied to the centre of it, using a 2,5 mm diameter rod. See Figures 12 and 25. 5.2.8 Identification holes Six identification holes (holes 1 to 6) shall be located as specified in Figures 2 and 15. For this format, holes 1, 2, 3 and 6 shall be closed. Holes 4 and 5 shall be open. 5.2.9 Reels The reels shall be automatically unlocked when the cassette is inserted into the video tape recorder and/or player unit and automatically locked when the cassette is ejected from it. The locations of the reels, when in the unlocked position, are shown in Figures 4 and 17. Dimensions of the reels are shown in Figures 6 and 19. Heights of the reels are shown in Figures 7 and 20. The reel shall be completely released when the cassette lid is opened 23,5 mm minimum from datum plane Z. 184.108.40.206 Reel spring force The reels assembled in the cassette shall be pressed by the reel spring with a specified force under the conditions specified in Figures 11 and 24. The spring force shall be 1,5 N ± 0,5 N (153 gf ± 51 gf) for S-cassettes and 3,5 N ± 0,5 N (357 gf ± 51 gf) for L-cassettes when pressing on a reel 2,4 mm above datum plane Z as shown in Figures 11 and 24.