1、SMPTE STANDARD for Television 1/2-in Type 525/60 SMPTE 264M-1998 Revision of ANCVCMPTE 264M-1993 Table of contents 1 2 3 4 5 6 7 9 10 11 a Scope Normative references Environment and test conditions Video tape Helical recording Program track data Video interface Audio interface Video processing Audio
2、 processing Longitudinal track Annex A Tape tension Annex B Cross-tape track measurement technique Annex C Mathematically processed measured tapedata Annex D Track pattern during insert editing Annex E Bibliography 1 Scope This standard specifies the content, format, and recording method of the data
3、 blocks containing video, audio, and associated data which form the helical records on 12.65-mm (0.5-in) tape in cassettes as specified in ANSI/SMPTE 263M. In addition, this standard specifies the content, for- mat, and recording method of the longitudinal record containing tracking information for
4、the scan- ning head associated with the helical records, and also the longitudinal cue audio and time code tracks. One video channel and four independent audio channels are recorded in the digital format. Each of these chan- nels is designed to be capable of independent editing. Page 1 of 42 pages T
5、he video channel records and reproduces a compos- ite television signal in the 525-line system with a frame frequency of 29.97 Hz. Figures 1 and 2 show a block diagram of the proc- esses involved in the recorder. 2 Normative references The following standards contain provisions which, through refere
6、nce in this text, constitute provisions of this standard. Ail standards are subject to revision and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent edition of the standards indicated below. ANSI/SMPTE 244M-1995, Television - Syst
7、em M/NTSC Composite Video Signals - Bit-Parallel Digital Interface SMPTE RP 155-1 997, Audio Levels for Digital Audio Records on Digital Television Tape Recorders IEC 60461 (1986-09), Time and Control Code for Video Tape Recorders ITU-R BS. 647-2 (1994), A Digital Audio Interface for Broadcasting St
8、udios ITU-R BT.470-4 (1 994), Television Systems Copyright Q 1998 by THE SOCIETY OF MOTION PICTURE ANDTELEVISION ENGINEERS 595 W. Hartsdale Ave., White Plains, NY 10607 (914) 761-1100 Approved December 8, 1998 STD-SMPTE 2b4M-ENGL 1998 a 8357401 0003131 BT9 SMPTE 264M-1998 - DIGITAL/ VIDEO CHANNEL +-
9、 INTERFACE CONCEAL SWITCH ANALOG t ERROR MUX +- Figure 1 - Record block diagram OUTER INTRA- ECC +- FIELD DECODER DESHUFFLE AUDIO 4 BLOCK DESHUFFLE OUTER (ANALOG) DIGITAL/ AUDIO INTRA- ANALOG +- ERROR t FIELD 4 INTERFACE CONCEAL IXWUFFLE i (DIGITAL) CONTROL TRACK TRACK P.B. I -_- - HEADS AND PLAYBAC
10、K (ANALOG) P.B.AMP TIME CODE _-_-_- -a - CUE/REF Figure 2 - Playback block diagram Page 2 of 42 pages STD-SMPTE 2bLifl-ENGL 1798 8357401 0003132 735 SMPTE 264M-1998 3 Environment and test conditions 3.1 Environment Tests and measurements made on the system to check the requirements of this standard
11、shall be car- ried out under the following conditions: - Temperature (20 I 1)OC - Relative humidity - Barometric pressure - Tape conditioning - Center tape tension (50 - Audio: 1 kHz-tone at -20 dB below full level; - Cue: 1 -kHz tone at reference level; 1 O-kHz tone at reference level. (b) Asigna1
12、of constant recorded frequency (.e., one- half the Nyquist frequency) only with tracks of field O, segment O for the purpose of mechanical alignment. 4 Videotape 4.1 Base The base material shall be polyester or equivalent. 4.2 Width The tape width shall be 12.650 mm $r 0.008 mm. The tape, covered wi
13、th glass, is measured without tension at a minimum of five different positions along the tape using a calibrated comparator having an accuracy of 1/1000 mm = 1 pm. The tape width is defined as the average of the five readings. 4.3 Width fluctuation Tape width fluctuation shall not exceed 5 pm peak-t
14、o- peak. Measurement of tape width fluctuation shall be over a tape length of 900 mm at the beginning of tape winding. The value of tape width fluctuation shall be evaluated by measuring the tape width at 10 points each separated by a distance of 100 mm. 4.4 Reference edge straightness The reference
15、 edge straightness maximum deviation is 6 pm peak to peak. Edge straightness fluctuation is measured at the edge of a moving tape guided by three guides having contact to the same edge and having a distance of 85 mm from the first to second guide and 85 mm from the second to third guide. Edge measur
16、ements are averaged over 1 O-mm lengths and are made 5 mm from the midpoint be- tween the first and second guide, toward the first guide. 4.5 Tape thickness The thickness of the tape (including all coatings) shall be 10.2 pm to 11.0 pm and 13.0 pm to 14.0 pm, respectively 4.6 Transmissivity Transmis
17、sivity shall be less than 5%, measured over the range of wavelengths 800 nm to 900 nm. 4.7 Offset yield strength The offset yield strength shall be greater than 9 N for 11 pm tape and 10 N for 14 pm tape. The force to produce 0.2% tangential elongation of a 1000-mm test sample with a pull rate of 1
18、O mm per minute shall be used to confirm the offset yield strength. The line beginning at 0.2% elongation parallel to the initial tangential slope is drawn and then read at the point of intersection of the line and the stress-strain curve. Page 3 of 42 pages - - STDSMPTE 2b4M-ENGL L77 835740L 000333
19、3 b7L H SMPTE 2641111-1998 Table 1 - Record location and dimensions Mi I I i meters - Dimensions Nominal A B C D E F G H I K L Mi M Pl P2 W xi x2 x3 x4 x5 Y e ao a1 Time code track lower edge Time code track upper edge Control track lower edge Control track upper edge Program area lower edge Program
20、 area width Cue audio track lower edge Cue audio track upper edge Helical track pitch Video sector length Helical track total length Audio sector 1 length ) Audio sector 2-4 length 2, Control reference pulse to program reference point (see figure 22) Cuehime code signal (bit No. O) to program refere
21、nce point Tape width Location of start of video sector Location of start of audio sector A4 3, Location of start of audio sector A2 3, Location of start of audio sector A3 3, Location of start of audio sector AI 3, Program area reference Track angle 4.91 92“ basic Azimuth angle (track O) -20.01 9“ *
22、 0.1 50“ Azimuth anale (track 1) 19.9810 f 0.1500 O 0.450 0.900 1.300 1.567 10.090 11.950 12.550 0.0200 107.095 1 17.667 2.266 2.185 176.000 177.430 12.650 O 110.155 107.533 2.623 5.245 2.030 Tolerance Basic * 0.050 f 0.050 * 0.050 Derived Derived * 0.050 f 0.050 Ref Derived Derived Derived Derived
23、10.050 f 0.100 f 0.008 10.050 f 0.050 I 0.050 f 0.050 f 0.050 Basic -. ) Audio sectors located at the start of helical tracks. *) All other audio sectors. 3, Audio channel numbers vary (see 10.9). NOTE - Measurements shall be made under the conditions specified in 3.1. The measurements shall be corr
24、ected to account for actual tape speed (see figures B.l and B.2). 4.8 Magnetic coating 4.10 Particle orientation The magnetic tape used shall have a coating of metal particles or equivalent. The metal particles shall be longitudinally oriented. 4.9 Coating coercivity 5 Helical recording The coating
25、coercivity shall be a class 1600 (1 27300 Ah), with an applied field of 5000 Oe as measured by a 50- or 60-Hz B-H meter or vibrating sample magnetometer (VSM). 5.1 Tape speed The tape speed shall be 83.880 mm/s; the tolerance shall be f 0.2%. Page 4 of 42 pages 5.2 Record location and dimensions 5.2
26、.1 The format requires a full-width erase head for continuous recording and a flying erase head for insert editing. 5.2.2 Record location and dimensions for continu- ous recording shall be as specified in figures 3 and 4 and table 1. In recording, sector locations on each helical track shall be cont
27、ained within the tolerance specified in table 1 and figure 3. 5.2.3 The reference edge of the tape for dimen- sions specified in this standard shall be the lower edge as shown in figure 3. The magnetic coating, with the direction of tape travel as shown in figure 3, is on the side facing the observe
28、r. (Measuring techniques are shown in annexes B and C.) DIRECTION OF TAPE TRAVEL - REFERENCE EDQE SO is a segment number (typical). The track number is identified by the azimuth angle. 3 Tape viewed from magnetic coating side. 4 Dimensions Xl-X5 are determined by the program reference point as defin
29、ed in figure 4. Figure 3 - Location and dimensions of recorded tracks Page 5 of 42 pages STD-SUPTE ZbLiM-ENGL 3998 8357403 0003L35 L(4L( L. D I CMPTE 264M-1998 PROGRAM REFERENCE lo CONTROL TRACK RECORD SERVO REFERENCE PULSE j- ! RECORD I NG-CURRENT WAVEFORM I IN+-S S-N 1 I MAGNETIZATION ON THE TAPE
30、w PREAMB V I DEO SECTOR 4 - CONTROL TRACK 1- Y:BASIC L :ADE REFERENCE EDGE TRACK DETAIL A DETA I L B 2.CUE/TIME CODE RECORD P2 -. CUE TRACK I L/ HEAD MOTION I TAPE i TRAVEL 1 d7 d * B =TIME CODE TRACK Figure 4 - Location of cue, time code and control track record Page 6 of 42 pages STD- SMPTE 2bLiM-
31、ENGL 3998 D 8357401 000333b 380 SMPTE 2641-1 998 5.2.4 As indicated in figure 3, this standard anticipates a zero guard band between recorded tracks, and the record head width should be equivalent to the track pitch of 20 pm. The scanner head configuration should be chosen such that the recorded tra
32、ck widths are contained within the limits of 18 pm to 22 pm. 5.2.5 In insert editing, this standard provides a guard band of 2 pm (nominal) between the previously recorded track and the in- serted track at editing points only. (A typical track pattern for insert editing is shown in figure D.l.) 5.3
33、Helical track record tolerance zones 5.3.1 The lower edges of any four consecutive tracks starting at the first track in each video frame shall be contained within the pattern of the four tolerance zones established in figure 5. Each zone is defined by two parallel lines which are inclined at an ang
34、le of 4.9192 basic, with respect to the tape reference edge. 5.3.2 The centerlines of all zones shall be spaced apart 0.0200 mm basic. The width of zones 1, 3, and 4 shall be 0.006 mm basic. The width of zone 2 shall be 0.004 mm basic. These zones are established to contain track angle errors, track
35、 straightness errors, and ver- tical head offset tolerance. (Measuring tech- niques are shown in annexes B and C.) 5.4 Relative positions of recorded tracks 5.4.1 Relative positions of longitudinal tracks Audio, video, ancillary data, control track, time code, and cue track with information intended
36、 to be time coincident shall be positioned as shown in figures 3 and 4. 5.4.2 HelicaUcontrol track relationship The spatial relationship among the cue track record, time code record, control track record, and helical tracks is specified in figures 3 and 4. tape at a distance Y from the reference edg
37、e and the centerline of the first track in each video field (segment O, track O). The end of the preamble and the start of the video sector shall be recorded at the program area reference point; the tolerance is dimension Xi. The locations are shown in figures 3 and 4; dimensions Xi and Y are specif
38、ied in table 1. The relationship between sectors and contents of each sector is specified in clause 6. 5.5 Gap azimuth 5.5.1 Cue track, control track, time code track The azimuth angle of the cue, control track, and time code head gaps used to produce longitudinal track records shall be perpendicula
39、r to the track record. 5.5.2 Helical track The azimuth of the head gaps usedfor the helical track recording shall be inclined at angles ao and ai as specified in table 1 to the perpendicular to the helical track record. The azimuth of the first track of every field (segment O, track O) shall be orie
40、nted in a counterclockwise direction with respect to the line perpendicular to the track direction when viewed from the side of the tape containing the magnetic record. 5.6 Transport and scanner The effective drum diameter, tape tension, helix angle, and tape speed taken together determine the track
41、 angle. Different methods of design and/or variations in drum diameter and tape tension can produce equivalent recordings for interchange purposes. One possible configuration of the transport uses a scanner with an effective diameter of 76.000 mm. Scanner rotation supports tape motion during normal
42、playback mode. Data is recorded by 2 head pairs mounted at 180“ angles from each other. Figure 6 shows one possible mechanical configuration of the scanner and table 2 shows the corresponding mechanical parameters. Figure 7 shows the relation- ship between the longitudinal heads and the scanner. 5.4
43、.3 Program area reference point The program area reference point is determined by the intersection of a line parallel to the reference edge of the Other mechanical configurations are allowable pro- vided the same footprint of recorded information is Produced on tape. Erase heads are described in 5.2
44、.1 and figure 6. Page 7 of 42 pages STD-SMPTE 2b4M-ENGL 1998 m 8357403 O003337 237 I o. o 185 OF ATYt , TOLERANCE ZONES CENTER LINES I i O. 0485 1 UPPER DRUM CENTER OF j 1 +-.-.-I-_._ HLHL ni ! 1 CENTER DRUM 117 i i i - i %LOWER DRUM 4. 91 92- / / TRACK LOWER EDGES Figure 5 - Location and dimensions
45、 of tolerance zones of helical track record TAPE TRAVE P ROTATION H5-H6 : FLY I NG ERASE HEAD HI-H4:RECORDING HEAD TIPS (INSERT EDITING ONLY) 76. O00 rnm (NOMINAL) DRUM D IAMETER Figure 6 - A possible scanner configuration Page 8 of 42 pages STD-SMPTE ZbYM-ENGL 1998 M 8357901 0003338 153 I SMPTE 264
46、1-1998 POLE TIP ROTAT I ON TAPE TRAVEL CONTROL TOP VIEW PROGRAM REFERENCE 59. 3 END OF -I I 1% 176. O0 NOTE - Unwrapped, viewed magnetic coating side. Figure 7 - A possible longitudinal head location and tape wrap Page 9 of 42 pages STD-SMPTE 2bLIM-ENGL 3778 83574011 0003337 07T I SMPTE 264M-1998 Ta
47、ble 2 - Parameters for a possible scanner design Parameters Values Scanner rotation speed (rpc) 90/1.001 Number of tracks per rotation 4 Drum diameter (mm) 76.000 Center span tension (N) 0.31 Helix angle (degrees) 4.9000 Effective wrap angle (degrees) 178.1 Scanner circumferential speed (ms) 21.5 Hl
48、,H3 overwrap head entrance (degrees) HI ,H3 overwrap head exit (degrees) Angular relationship H1 - H2 6.789 (degrees) H3 - H4 6.789 12.9 6 H1 - H3 180.00 Vertical displacement H1 - H2 0.0185 (mm) H3 - H4 0.01 85 Maximum tip projection (pm) 35 Record head track width (pm) 20 6 Program track data 6.1
49、Introduction Each TV field is recorded on six tracks. The helical tracks contain digital data from the video channel and four audio channels. The audio data is contained in four recorded sectors per track, two at the beginning of the track and two at the end of the track. The video data is recorded in a sector in the middle part of each track. An edit gap between sectors accommodates timing errors during editing. Figure 8 shows the arrangement of video and audio sectors on t
