IEC 62122 pdf download.Methods of measurement for consumer-use digital VTRs – Electronic and mechanical performances
1 Scope and object
This standard specifies the basic methods of measurement for evaluating the electronic and mechanical performances of consumer-use digital VTRs. The formats of open reel VTRs, Beta, VHS, and 8 mm VTRs have been standardized. Methods of measurement for these analogue VTRs have been standardized in IEC 61 041 -1 , IEC 61 041 -2, IEC 61 041 -3, IEC 61 041 -4, IEC 61 041 -5, and IEC 61 1 46-3. Digital VTR 6,35 mm DV format and 1 2,65 mm D-VHS format have now been brought on the market. The methods of measurement for these consumer-use digital VTRs should be specified and standardized. With these measurement techniques, some items for the evaluation of performances specific to digital VTRs have also been included. There are two objectives for the proposed methods of measurement. One is to check the interchangeability and characteristics of the equipment under test which are indispensable to manufacturers, and the other is to evaluate the quality of image and sound, which concerns the customer. The latter is a priority for consumer satisfaction. Since a consumer can use only general-purpose instruments, any test which needs dismantling of apparatus and requires special instruments is in principle not specified. As error rate is important for digital equipment, an example of a method for measuring error rate is given in annex A.
3 Terms and definitions
For the purposes of this International Standard, the following terms and definitions apply. 3.1 consumer-use digital VTR consumer-use video tape recorder using digital recording technology, 6,35 mm to 1 2,65 mm width videotape and bandwidth compression technology for the image signal. Two tape formats are standardized, as defined in the following two definitions. Although different formats may be introduced in the future, fundamental measuring methods can be adapted to all formats 3.1.1 DV format 6,35 mm helical-scan VTR standardized in IEC 61 834 3.1.2 D-VHS format 1 2,65 mm helical-scan VTR which will be standardized in the near future. Until then, refer to the outline of the D-VHS format in documents [1 ] 1 and  3.2 ferrofluid development direct observation of the magnetization on the videotape by the adherence of iron powder to its surface by dipping the tape into a fluid containing powder of fine iron in order to observe the recorded pattern using a microscope 3.3 byte unit which separates the information series 1 into m bits. m usually consists of 8 bits, but not always 3.4 error rate ratio of the number of erroneous elements to the total number of elements reproduced and/or transmitted during a given time interval NOTE 1 The elements may be, for example, digits, code words or blocks. NOTE 2 “Error ratio” is defined in similar terms as in IEV 704-1 8-03. 3.5 byte error rate error rate for a signal constructed from byte units (number of erroneous byte units)/(total number of elements of byte units) 3.6 MPEG-2 transport stream MPEG-2 TS data transmission format standardized by ISO/IEC MPEG (Moving Picture image coding Experts Group) 3.7 three dimensional (3D) signal processing TV video signal process taken from three viewpoints: the horizontal and vertical directions and the time domain. Generally, it contains the operation processing between the fields or between frames using a field memory or a frame memory 3.8 audio operational output voltage standard output voltage specified by the manufacturer for the audio analogue signal interface between equipment when the output terminal is terminated by a specified load impedance 3.9 audio operational input voltage input voltage specified by the manufacturer to generate the audio operational output voltage at the output terminal 3.10 audio maximum output voltage maximum audio output voltage that a VTR under test can generate. In this standard, it is the voltage for an output signal of 3 % harmonic distortion, or it can be the voltage just before clipping when the output signal is digitally clipped.