IEC 62375-2004 pdf – Video systems (625/50 progressive) – Video and accompanied data using the vertical blanking interval – Analogue interface.
1 Scope This International Standard specifies the method of transfer of aspect ratio information code, copy control information code and other codes in the vertical blanking interval of the luminance signal. This International Standard is applicable to the transfer of video related information with the video signal through the baseband analogue signal of 625-line/50-frame progressive scan video system between digital and analogue video equipments. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ITU-R BT.1358: Studio parameters of 625 and 525 line progressive scan television systems 3 Terms, definitions, symbols and abbreviated terms 3.1 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1.1 letterbox picture display format to display a picture with an aspect ratio greater than the screen, in such a way that empty (black) lines are added to conform to the screen 3.1.2 full format picture display format with full screen size conforming to its scanning format 3.1.3 CGMS-A copy generation management system on analogue video interface, for use in digital video recorders and digital video equipments 3.2 Symbols and abbreviated terms 0 h falling sync edge a aspect ratio F S clock frequency LSB Least Significant Bit MSB Most Significant Bit NRZ Non-Return-to-Zero T d data bit period T s sampling period
4 Defined signal The signal defined in this standard is defined for use with systems complying with ITU-R BT.1358. 5 Construction of identification signal 5.1 Position The identification signal bits shall be transmitted as a data burst in the first part of line 43. The position of the beginning of the bits shall be 5,5 µs ± 0,125 µs from 0 h of the horizontal sync, as indicated in Figure 1. This figure is intended to illustrate the position of the signalling bits in line 43. In each frame, line 43 shall be occupied with this identification signal.
5.5 Preamble The preamble contains a run-in and a start code. The preamble shall be in accordance with Table 1. 5.6 Data bits There shall be 14 bits in total. 1 out of these 14 bits shall be allocated to the error detection code. There shall be 13 data-bits available for transmission of information.
6 Information content of data bits The 13 data bits shall be grouped in 4 groups in accordance with Table 1. Group 1 shall contain 4 bits in which the first 3 bits carry data and the last bit shall denote the odd parity bit over the first three data bits. Group 2 shall contain 4 data bits, Group 3 shall contain 3 data bits and Group 4 shall contain 3 data bits. The data bits shall be labelled b 0 up to and including b 2 combined with b 4 up to and including b 13 . b 3 shall be the odd parity bit as shown in Table 1 and 2. The index also indicates the order of transmission: b 0 shall be the first transmitted bit.