1、 STD-SMPTE 2LiSM-ENGL 377b 8357401 0002573 TUT = SMPTE STANDARD for Television Analog Recording - 1/2-in Type M-2 - Records ANSVSMPTE 249M-T996 Revision of ANSVSMPTE 249M-1991 Page 1 of 7 pages 1 Scope This standard specifies the dimensions and locations of the video, audio, time code, and tracking-
2、control records, as recorded by 1/2-in type M-2 helical-scan video tape recorders operating with video signals having a typical scanning structure of 525 lines, 59.94 fields/s, 2:l interlace, and utilizing the video cassettes specified in ANSVSMPTE 250M. This standard also specifies the records for
3、two different audio record- ing modes - common audio mode and pulse code modulation (PCM) audio mode. 2 General specifications 2.1 All dimensions are in the metric system. 2.5 The reference edge of the tape for dimen- sions specified in this standard shall be the lower edge as shown in figures 1 to
4、4. The magnetic coating, with the direction of tape travel as shown in figures 1 to 4, is on the side facing the observer. 3 Tapespeed The tape speed shall be 67.693 mm/s, basic. 4 Record locations and dimensions 4.1 The locations and dimensions of the video and audio mode records shall be as specif
5、ied in figures 1 and 2 and table 1. 2.2 A basic dimension is a fundamental dimen- cion to which no tolerance is applicable. 2.3 Tests and measurements made on the tape record to check the requirements of this standard shall be made under the following conditions unless otherwise specified: 4-2 The l
6、ocations and dimensions Of the video and PCM audio mode records shall be as speci- fied in figures 3 and 4 and table 2. The PCM records are recorded by the luminance and chrominance heads and only a single longitudi- na1 audio record shall be available. 4.3 Dimensions O, P, Q, R, W, W, and PE are sh
7、own for reference purposes only. The actual value of these dimensions is determined by the tape speed, the transport parameters, and their tolerances. , - Temperature: 20C f 1C - Relative humidity: (50f 2)% - Barometric pressure: - Tape Tension: 86 kPa to 106 kPa 0.31 N f 0.05 N 2.4 cording and test
8、ing shall be as follows: Conditioning of the tape stock before re- - Environment: specified in 2.3 - Tape tension: of 0.4 N f 0.1 N - Condition time: 24 hours elasticity. Established to the conditions Wound on a reel at a tension The tape speed of 67.693 mm/s basic shall result in angle 8 as shown.
9、The nominal values given are based on tensioned tape; therefore, direct measure- ments without tension must take into account tape CAUTION NOTICE: This Standard may be revised or withdrawn at any lime. The procedures of the Standard Developer require that action be taken to reaffirm, revise, or with
10、draw this standard no later than five years from the date of publication. Purchasers of standards may recaiva current information on all standards by calling or writing the Standard Developer. Printed in USA. L American National Standard CopyrigM O 1996 by THE SOCIW OF MOTION PICTURE ANDTEEVISION EN
11、GINEERS 595 W. Hartsdale Ave., White Plains, NY 10607 (914) 761-1100 Approved November 29,1996 STD-SMPTE 249M-ENGL L77b 9 8357403 0002592 94b 9 ANSVSMPTE 249M-1996 Figure 1 - Record locations and dimensions (common audio mode) Y Track C Track - Control- t Y Time code Reference edge vape lower edge)
12、Figure 2 - Video record locations (common audio mode) Page 2 of 7 pages STDmSflPTE ZLiSM-ENGL 377b m 8357403 0002573 882 m ANSVSMPTE 249M-1996 Table 1 - Record locations and dimensions (common audio mode) Dimensions Micrometers Minimum Nominal Maximum A B C D E F G H J K L M N O P Q R W X Y e Time c
13、ode track lower edge Time code track upper edge Color track width Y-C track pitch Control track lower edge Control track upper edge Video track lower edge Video track upper edge Audio 1 track lower edge Audio 1 track upper edge Audio 2 track lower edge Audio 2 track upper edge Y track width Lead sig
14、nal overlap Y-C track offset Video track pitch Video track length Video area effective width Audio, time code, and control track record offset Lower limit of W O O O 400 450 500 34 36 38 40.7 42.2 43.7 850 900 950 1250 1300 1350 1469 1503 1537 10601 10634 10668 10830 10850 10870 11400 11450 1 1500 1
15、1900 11950 12000 12500 12550 12650 42 44 46 3H ref 4505 (= 10H) ref 84.5 ref 118254.3 (262.5H) ref 8847.1 ref 202000 1621 1626 1631 Track angle 4.2906 (basic) JOTE - “Ref” indicates those measurements which are fixed by other parameters and are given for reference purposes only. 5 Video record curva
16、ture The edge of any video record contained within an area defined by dimension W or the edge of any video and PCM audio record contained within an area defined by dimension W shall be contained within two parallel straight lines 0.006 mm apart (see annex A). 6 Relative positions of signal records V
17、ideo luminance, color difference, tracking-control, longitudinal audio, and time code signals, with infor- mation intended to be time coincident, shall be posi- tioned as shown in figures 1 to 4. PCM audio shall be positioned as shown in figures 3 and 4. 7 Gapazimuth 7.1 The azimuth of the audio, tr
18、acking-control, and time code head gaps used to produce longi- tudinal track records shall be perpendicular to the direction of relative head-to-tape motion (see figures 1 and 3). 7.2 The azimuth of the video head gaps for the luminance signal shall be -15.0 and for the color-difference signals shal
19、l be +15.0 to the perpendicular of the direction of head motion (see figures 2 and 4). Page 3 of 7 pages - - - STD-SMPTE 247M-ENGL 379b 8357403 0002594 737 ANSVCMPTE 2491111-1996 X Vape lower edge) Figure 3 - Record locations and dimensions (PCM audio mode) Tape upper edge / / Audio Reference edge (
20、lape lower edge) Figure 4 - Video record locations (PCM audio mode) Page 4 of 7 pages STD-SUPTE ZqSM-ENGL L77b 8357403 0002575 b55 ANSVSMPTE 249M-1996 Table 2 - Record locations and dimensions (PCM audio mode) Dimensions Micrometers. Minimum Nominal Maximum i O O OI I A Time code track lower edge 6
21、C Color track width D Y-C track pitch E Control track lower edge F Control track upper edge G Video track lower edge Time code track upper edge 400 450 500 34 36 38 40.7 42.2 43.7 850 900 950 1250 1300 1350 1469 1503 1537 I H Video track upper edge 10601 10634 10668 I L Audio track lower edge M Audi
22、o track upper edge 11 900 11950 12000 12500 12550 12650 N Y track width 42 44 46 O Lead signal overlap 3H ref P Y-C track offset 4505 (= 10H) ref Q Video track pitch R Video track length W Video area effective width W Video and PCM audio (CH6) area effective width X Audio, time code, and control tra
23、ck record offset Y Lower limit of W 9 Track angle 84.5 ref 11 8254.3 (262.5H) ref 8847.1 ref 9973.5 ref 202000 1631 I 1621 1626 4.2906“ (basic) PA PB Effective PCM audio track lower edge (luminance head) 10676 10709 10743 Effective PCM audio track lower edge (c h rom nance head) 10724 10758 10791 PC
24、 . (chrominance head) PCM audio track upper edge 11 660 11693 11727 1 PD Preamble 360 450 541 PE PCM audio data area 11820 ref PF Postamble 360 450 541 NOTE - “Ref“ indicates those measurements which are fixed by other parameters and are given for reference purposes only. Page 5 of 7 pages STD-SMPTE
25、 247M-ENGL 377b m 8357403 000257b 571 = ANSVSMPTE 249M-1996 Annex A (normative) Cross tape track measurement technique (preferred) MEASUREMENT TECHNIQUE MEASUREMENT PATH VTAPE i -REFERENCE EDGE PERPENDICULAR TO MEASUREMENT PATH WITHIN O“ 10 Y (I) MUST USE SAME HEAD FOR EACH MEASUREMENT (.e. EVERY 2n
26、d TRACK) CTM =CONTROL TRACK PULSES (UNTENSIONED TAPE) CORRECTION FACTORS ACTUAL TAPE SPEED, TENSION o F=TENSION (0.31 N) E=YOUNGS MODULUS (WOO Nlmm? A=CROSS SECTIONAL AREA (THICKNESS x WIDTH) L=CORRECTED DISTANCE CFREa=CONTROL TRACK FREQUENCY (59.94HZ) * PITCHESICFRW i- VTApEAmUAL=CTM * CFRE;I/( - F
27、I( * A) * PITCHES) MODEL 1 V,B=VELOCITY OF HEAD wrt BAND VT*pEAmAL=ACTUAL VELOCITY Of TAPE VHm=VELOCIT of HEAD wl TAPE D=EFFECTIVE SCANNER DIAMETER N=SCANNER SPEED (7) REV THETA=TRACK ANGLE BETA=SCANNER HELIX ANGLE Page 6 of 7 pages STDeSMPTE 2LISfl-ENGL L77b 8357i.101 0002577 Li28 ANSVSMPTE 2491111
28、1996 T,=TIME BETWEEN HEAD PASSES 1 - -N*HPPR HPPR=HEAD PASSES per REVOLUTION FROM D PI * 0 * N * SI N (BETA) TAN CTHETA)=Pl * D* N *COS (BETA)-VTApEACTUAL FROM THEREFORE: TRACK LOCATION ERROR=Y (l)-Y (I)THEORICAL Annex B (informative) Bibliography ANSVSMPTE 250M-1996, Television Analog Recording -
29、112417 Type M-2 - Tapes and Cassettes ANSI/SMPTE 252M-1996, Television Analog Recording - 112417 Type M-2 - Puise Code Modulation Audio ANSIISMPTE 251M-1996, Television Analog Recording - 1/2-in Type M-2 - Electrical Parameters of Video, Audio, Time and Control Code and Tracking Control SMPTE RP 158-1991 (R1995), Basic System and Transport Geometry Parameters for 1/2-in Type M-2 Format Page 7 of 7 pages
