1、SMPTE STANDARD SMPTE 279M-2001 Revision of ANSVSMPTE 279M-1996 a for Digital Video Recording - 1/2-in Type D-5 Standard-Definition Component Video and Type HD-D5 10-kHz tone at reference level b) A signal of constant frequency (Le., one-half the Nyquist frequency) shall be recorded only on the track
2、s of field O, segment O for the purpose of mechanical align- ment. The recording level should conform to that in 6.6.3. 4 Videotape 4.1 Base The base material shall be polyester or equivalent. 4.2 Width The tape width shall be 12.650 mm I 0.008 mm. The tape, covered with glass, shall be measured wit
3、hout tension at a minimum of five different positions along the tape using a calibrated comparator having an accuracy of 0.001 mrn (1 pm). The tape width is defined as the average of the five readings. Page 3 of 88 pages SMPTE 279M-2001 Table 1 - Record location and dimensions (525/60 system) Dimens
4、ions Nominal Tolerance A B C D E F G H I KO K1 L M P1 P2 x1 x2 x3 x4 x5 X6 Y Time and control code track lower edge Time and control code track upper edge Control track lower edge Control track upper edge Program area lower edge Program area width Cue audio track lower edge Cue audio track upper edg
5、e Helical track pitch Video sector O length Video sector 1 length Helical track total length Audio sector length Control track reference pulse to program reference point (see figure 4) CueAime and control code signal, start of code word, to program reference point (see figure 4) Location of start of
6、 video sector VO Location of start of audio sector Al ) Location of start of audio sector A2) Location of start of audio sector A3) Location of start of audio sector A4) Location of start of video sector V1) Program reference point O 0.450 0.900 1.300 1.629 10.020 11.950 12.550 0.0200 55.458 55.391
7、11 6.397 0.936 180.549 183.400 O 55.752 57.049 58.345 59.642 60.938 1.640 Basic f 0.050 f 0.050 f 0.050 Derived Derived f 0.050 f 0.050 Ref Derived Derived Derived Derived f 0.050 i 0.100 f 0.050 f 0.050 f 0.050 f 0.050 i 0.050 i 0.050 Basic - e Track angle 4.9384 Basic cc0 Azimuth angle (track O) -
8、20.038 f 0.1 50 CL1 Azimuth anale (track 1) 19.962 f 0.1 50 NOTES 1 Measurements shall be made under the conditions specified in 3.1. The measurements shall be corrected to account for actual tape speed (see figures B.l and 8.2). 2 All dimensions are in millimeters. ) Audio channel numbers vary. Pag
9、e 4 of 88 pages SMPTE 2791111-2001 Table 2 - Record location and dimensions (625150 system) Dimensions Nominal Tolerance A B C D E F G H I KO K1 L M P1 P2 x1 x2 x3 x4 x5 X6 Y Time and control code track lower edge Time and control code track upper edge Control track lower edge Control track upper ed
10、ge Program area lower edge Program area width . Cue audio track lower edge Cue audio track upper edge Helical track pitch Video sector O length Video sector 1 length Helical track total length Audio sector length Control track reference pulse to program reference point (see figure 4) Cue/time and co
11、ntrol code signal, start of code word, to program reference point (see figure 4) Location of start of video sector VO Location of start of audio sector Al) Location of start of audio sector A2) Location of start of audio sector A3) Location of start of audio sector A4l) Location of start of video se
12、ctor V1 ) Proaram reference Doint O 0.450 0.900 1.300 1.716 9.940 11.950 12.550 0.01 80 55.066 54.993 11 5.558 0.936 179.606 182.995 O 55.344 56.631 57.91 8 59.205 60.492 1.728 Basic f 0.050 f0.050 f 0.050 De rived Derived f 0.050 f 0.050 Ref Derived Derived Derived Derived f 0.050 f 0.1 O0 f 0.050
13、f 0.050 f0.050 f 0.050 f 0.050 f 0.050 Basic 0 Track angle 4.9345 O Basic ao Azimuth angle (track O) -20.035“ f 0.1 50 a1 Azimuth angle (track 1) 19.965“ f 0.1 50 NOTES 1 Measurements shall be made under the conditions specified in 3.1. The measurements shall be corrected to account for actual tape
14、speed (see figures B.l and 8.2). 2 All dimensions are in millimeters. ) Audio channel numbers vary. Page 5 of 88 pages SMPTE 279M-2001 4.3 Width fluctuation Tape width fluctuation shall not exceed 5 pm peak to peak. Measurement of tape width fluctuation shall be taken over a tape length of 900 mm. T
15、he value of tape width fluctuation shall be evaluated by measuring the tape width at 1 O points, each separated by a distance of 100 mm. 4.4 Tape thickness Two types of tape thickness shall be permitted by this standard. The first tape thickness shall be 10.2 pm to 11.0 pm (referred to as 11 pm); th
16、e second tape thick- nessshallbe13.0pmto 14.0pm (referredtoas 14pm). 4.5 Transmissivity Transmissivity shall be less than 5%, measured over the range of wavelengths 800 nm to 900 nm. 4.6 Offset yield strength The offset yield strength shall be greater than 9 N for Il-pm tape and 10 N for 14-pm tape.
17、 The force required to produce 0.2% elongation of a 1000-mm test sample with a pull rate of 10-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 l
18、ine and the stress-strain curve. 4.7 Magnetic coating The magnetic layer of the tape shall consist of a coating of metal particles or equivalent. 4.8 Coating coercivity The coating coercivity shall be a class 1800 (144000 Alm) with an applied field of 400000 Alm (5000 Oe) as measured by a 50-Hz or 6
19、0-Hz B-H meter or vibrating sample magnetometer (VSM). 4.9 Particle orientation The metal particles shall be longitudinally oriented. 5 Helical recording 5.1 Tape speed The tape speed shall be 167.228 mm/s. The tolerance shall be k 0.2%. 5.2 Record location and dimensions 5.2.1 The format requires f
20、ull-width erasure for continuous recording and flying erasure for in- sert editing. 5.2.2 Record location and dimensions for con- tinuous recording shall be as specified in figures 3 and 4 and tables 1 (525/60 system) and 2 (625/50 system). In recording, sector locations on each helical track shall
21、be contained within the tolerance specified in figure 3 and tables 1 (525/60 system) and 2 (625150 system). 5.2.3 The reference edge of the tape for record location dimensions specified in this standard shall be the lower edge as shown in figure 3. The magnetic coating, with the direction of tape tr
22、avel as shown in figure 3, is on the side facing the observer (measuring techniques are shown in annex B). . 5.2.4 As indicated in figure 3, this standard antici- pates a zero guard band between recorded tracks, and the record head width should be equivalent to the track pitch of 20 krn (525160 syst
23、em) or 18 pm (625/50 system). The scanner head configuration should be chosen such that the recorded track widths are contained within the limits of 18 pm to 22 pm (525160 system) or 16 pm to 20 pm (625150 system). 5.2.5 In insert editing, this standard provides a guard band of 2 mm (nominal) betwee
24、n the pre- viously recorded track and the inserted track at editing points only. A typical track pattern for insert editing is shown in figure C.l of annex C. 5.3 Helical track record tolerance zones The lower edges of any eight consecutive tracks starting at the first track in each video frame shal
25、l be contained within the pattern of the eight tolerance zones established in figure 5. Each zone isdefined by two parallel lines which are inclined with respect to the tape reference edge at an angle of 4.9384 basic (525160 system) or 4.9345“ basic (625/50 system). SMPTE 279M-2001 Direction of tape
26、 travel f- I Reference edge al CI NOTES 1 Al, A2, A3, and A4 are audio sectors. 2 VO and V1 are video sectors. 3 The tape is viewed from the magnetic coating side. 4 Dimensions X1 to X6 are determined by the program reference point as defined in figure 4. Figure 3 - Location and dimensions of record
27、ed tracks Page 7 of 88 page6 - SMPTE 279M-2001 TFAVEL f- TIME AND CONTROL CODE TRACK PROGRAM REFERENCE 5 L II REFERENCE EDGE TIME AND CONTROL CODE TRACK DETAIL B f CERVO ;:F RECORDINGCURRENT WAVEFORM RECORDINGCURRENT WAVEFORM DETAL A PROGRAM REFERENCE POINT DETAIL C Figure 4 - Location of cue and ti
28、me and control code track record Page 8 of 88 pages c SMPTE 2791111-2001 NOTES TAPE REFERENCE EDGE / TRACK LOWER EDGES 1 Tolerance zone centerlines. 2 0.0200 (525/60 system); 0.01 80 (625/50 system). 3 4.9384“ (525/60 system); 4.9345“ (625/50 system). 4 All dimensions are in millimeters. Figure 5 -
29、Location and dimensions of tolerance zones of helical track record The centeriines of all zones shall be spaced apart 0.0200 mm basic (525/60 system) or 0.018 mm basic shall be 0.006 mm basic. The width of zone 4 shall be 0.004 mm basic. These zones are established to contain track angle errors, tra
30、ck straightness errors, 5.4 Relative positions of recorded information h (625/50 system). The width of zones 1 to 3 and 5 to 8 5.4.1 Relative positions of longitudinal tracks Audio, video, control track, time and control code, and cue track with information intended to be time and vertical head offs
31、et tolerance (measuring tech- nique is shown in annex B). coincident shall be positioned as shown in figures 3 and 4. Page 9 of 88 pages SMPTE 279M-2001 5.4.2 Program area reference point The program area reference point is determined by the intersection of a line parallel to the referenceedge of th
32、e tape at a distance Y from the reference edge and the centerline of the first track in each video field (segment O, track O). (See figures 3 and 4.) The end of the preamble and start of the video sector are located at the program area reference point, and the tolerance is dimension X1. The location
33、s are shown in figures 3 and 4; dimensions X1 and Y are in tables 1 and 2. The relationship between sectors and contents of each sector are specified in clause 6. 5.5 Gap azimuth 5.5.1 Cue track, control track and time code track The azimuth angle of the cue, control track, and time and control code
34、 head gaps used to produce longitu- dinal track records shall be perpendicular to the track record. 5.5.2 Helical track The azimuth of the head gaps used for the helical track shall be inclined at angles 010 and al, as specified in tables 1 and 2, with respect to a line perpendicular to the helical
35、track. The azimuth of the first trackof every field (segment O, track O) shall be oriented in the counterclockwise direction with respect to a line per- pendicular to the helical track direction when viewed from the side of the tape containing the magnetic record. 5.6 Transport and scanner The effec
36、tive drum diameter, tape tension, helix angle, and tape speed taken together determine the track angle. Different methods of design andor variations in drum diameter and tape tension can produce equivalent recordings for interchange purposes. One possible configuration of the transport uses a scanne
37、r with an effective diameter of 76.000 mm. Scanner rotation is in the same direction as tape motion during normal playback mode. Data are recorded by two groups of four heads mounted 180 apart. Figures 6 (525160 system) and 7 (625150 system) show one possible mechanical configuration of the scanner,
38、 and table 3 shows the corresponding mechanical parameters. Figures 8 (525160 system) a and 9 (625/50 system) show the relationship between the longitudinal heads and the scanner. Other mechanical configurations are allowable pro- vided the same footprint of recorded information is produced on tape.
39、 Erase heads are described in 5.2.1 and figures 6 and 7. 6 Program track data 6.1 Introduction Each television field is recorded on 12 tracks (525160 system) or 16 tracks (625150 system). The helical tracks contain digital data from the video channel and four audio channels. Each track contains a vi
40、deo sector followed by four audio sectors corre- sponding to four audio channels and followed by a second video sector, recorded in that order. An edit gap between sectors accommodates timing errors during editing. Figure 10 shows the arrangement of video and audio sectors on the tape. 6.2 Labeling
41、convention The least significant bit is written on the left and first recorded to tape. The lowest numbered byte is shown at the IefVtop and is the first encountered in the input data stream. Byte values are expressed in hexadecimal notation unless otherwise noted. An h subscript indicates a hexadec
42、imal value. 6.3 Sector details Each sector (audio or video) is divided into the following elements: - Preamble containing clock run-up sequence, sync pattern, identification pattern, and fill pattern; 8 - Sync blocks containing sync pattern and identifi- cation pattern, followed by a fixed-length da
43、ta block with error control; r - Postamble containing sync pattern and identifica- .-, ;i. tion pattern. Page 10 o 88 pages SMPTE 279M-2001 I H4H10: FLYING ERASE HEAD TIPS (INSERT EDITING ONLY) 41.7850 76.0Mmm(NOMINAL) DRUM DIAMETER UPPER DRUM k I b I LOWER DRUM I- Figure 6 - A possible scanner conf
44、iguration (525160 system) Pagellof88pages SMPTE 279M-2001 Page 12 of 88 pages 76.000mn(NMINAL) DRUM DIMnmR Figure 7 - A possible scanner configuration (625O system) UPPER DRUM k I CENTER OF HQ HI0 %-.- OH I I 1 SMPTE 279M-2001 c- ol TAPE TRAVEL CONTROL HEAD . WRAP EFFECnM ) WRAP / MGLE“ TOP VIEW PRO
45、GRAM 59.3 REFERENCE HELICAL TRACK END OF FONT ,-7 CENTER :I 1 LNE L- I 3.9w) I 1.640 - - - v I 180.549 I 1- NOTE - Unwrapped; viewed magnetic coating side. Figure 8 - A possible longitudinal head location and tape wrap (525/60 system) Page 13 of 88 pages SMPTE 279M-2001 ANGLE ANGLE POLE nP ROTATION
46、I -.- CONTROL HEAD 59.3 - TOP VIEW END OF HEUCAL PROGRAM REFERENCE POINT I TRACK I I 179.606 NOTE - Unwrapped; viewed magnetic coating side. Figure 9 - A possible longitudinal head location and tape wrap (625/50 system) Page 14 of 88 pages I SMPTE 279M-2001 Scanner rotation speed (rps) Table 3 - Par
47、ameters for a possible scanner design 90/1 .o01 1 O0 Number of tracks per rotation 8 Drum diameter (mm) 76.000 H1, H3 overwrap head exit (degrees) I 6 13.570 An a u I ar re I at i o ns h i D H1 -H4: Center span tension (N) - (degrees) 0.31 H2 - H4: H3 - H4: HS - Ha: Helix anale Idearees) 9.047 4.523
48、 13.570 4.9000 Effective wrap angle (degrees) Scanner ci rc u mf e re nt ia I sp e e d (m/s) H1, H3 overwrap head entrance (degrees) NOTES 1 T = track preamble (58 bytes). 2 E = in-track preamble. 3 P = postamble (4 bytes). 4 Sync block 97 bytes (525/60 system); 88 bytes (625/50 system). 5 Edit gap:
49、 162 bytes nominal (525160 system); 144 bytes nominal (625150 system). Figure 10 - Sector arrangement on helical track 176.9 175.5 21.5 23.9 14.1 15.5 Page 15 of 88 pages Hi - Hi. H7 - H8: H4 - H8: Vertical displacement H1 - H4: H2 - H4: H3 - H4: H5 - H8: H6 - H8: H7 - H8: (mm) Maximum tip projection (pm) Record head track width (pm) 9.047 4.523 180.000 0.054 0.0486 0.036 0.0324 0.01 8 0.0162 0.0486 0.054 0.036 0.0234 0.01 8 0.0162 42. O 20 18 SMPTE 2791111-2001 6.3.1 Sync block The sync block format is common to both audio and video secto
