IEC 60843-4:2000 pdf download

IEC 60843-4:2000 pdf download.Helical-scan video tape cassette systemusing 8 mm magnetic tape (8 mm video)-Part 4: Video subcode (vsc).
The data sign of the search mark shall be all 1 for disable. Table I shows the recording condition of the search mark.
4.5 SynchronizatIon code
Figure 6 shows the synchronization code.
The synchronization code indicates the start position of each CRC block.
4.6 End mark
The end mark shows the end of the data area.
The end mark Consists of 12 successive synchronization codes.
5 Data contents
5.1 Block
Table 2 shows the contents of the block.
A block consists of the synchronization COde, live words and the CRC code.
Blocks from Block 0 to Block 3 shall be used with 5 block VSC only.
Block 4 is common to 5 block VSC and 1 block VSC.
5.2 Word
Table 3 shows the contents of the word.
Word 0 shows the mode which indicates a category of data code.
Words from Word I to Word 4 consist of the data code for the mode.
5.3 CRC code and error detection
The error detection system shall be based on the CRC method.
The CRC block consists of five words and the CRC code.
The CRC code contains 8 bits and its generator polynomial shall be as follows:
6 Recording method of mode data (Block 4)
6.1 TIme code
6.1.1 Basic recording rules
The time code shall be recorded on all the tracks if it is not necessary to record other data.
If other data are recorded, by replacing some of the time code data, the time code shall be recorded at least by the pattern specified in 6.1.2.
6.1.2 Recording patterns
Tables 5 and 6 show the recording conditions of the time code.
6.2 RecordIng date’Recording time
6.2.1 Basic recording rules
The recording date/recording time shall be recorded on the specific track simultaneously with the time code.
The recording date and the recording time shall be recorded simultaneously.
6.2.2 RecordIng patterns
Tables 7 and 8 show the recording conditions of the recording date/recording time.
6.3 Video control code
The contents shall be indicated in accordance with clause A.4.
6.3.1 Recording rules
The video control code shall be recorded on the same track as the other data, Both video control code and time code shall be recorded.
For pie-recorded tape. the video control code shall be recorded on the track on which the next chapter code is permitted to be recorded.
6.3.2 RecordIng length
Table 9 shows the recording length of the video control code.
6.4 Pre-recorded tape modes
6.4.1 Contents of mode
Pro-recorded tape can deal with four modes: the present chapter. the next chapter, the pie-
recorded tape ID and the total time/total chapter numbers in addition to the time code.
The ‘time code’ shows the time elapsed in the active programme.
The present chapter shows the chapter number at the tape position and the time elapsed in the chapter.
The “next chapter” shows the next chapter number and the remaining time of the present chapter.The “pre-recorded tape lD” indicates the pre-recorded tape.
The “total time/total chapter number” shows the total chapter number and the time elapsed inthe active programme.
6.4.2Basic recording rules
All the data should be recorded according to the rules shown in tables 10 and 11.The present chapter and the next chapter shall be recorded in pairs.
The pre-recorded tape lD and the total data shall be recorded in pairs.
The time code and the chapter number of the present chapter are mandatory.The time code shall be based on a non-drop frame sequence.
The length of each chapter shall be more than 2 min.
6.4.3 Recording patterns
Tables 10 and 11 show the recording patterns of pre-recorded tape.
In the active programme, if the remain time of the present chapter is more than 59 min 59 s29 frames (24 frames), words from Word 2 to Word 4 of the next chapter shall be “0o0o o0o1″(from bit 0 to bit 7).
In the lead-out part,words from word 1 to Word 4 shall be “0oo0 o00o”(from bit 0 to bit 7).
In the last chapter of the active programme, Word 1 shall be *1000 oo0o”(from bit o to bit 7).
lf the next chapter is disabled,words from Word 1 to Word 4 shall be “0oo0 oooo”(from bit oto bit 7).