EN 61237-3:1995
(Main)Methods of measurement for broadcast video tape recorders - Part 3: Electrical measurements for analogue component video signals
Methods of measurement for broadcast video tape recorders - Part 3: Electrical measurements for analogue component video signals
Describes the methods of measurement, test signals and procedures which may apply to characteristics of video recording/playback machines mainly intended for professional use.
Meßverfahren für Videobandgeräte für den Rundfunk - Teil 3: Elektrische Messungen für Videosignale mit analogen Komponenten
Méthodes de mesure pour les magnétoscopes de radiodiffusion - Partie 3: Mesures électriques pour les signaux vidéo analogiques à composantes
Décrit les méthodes de mesure, les signaux et les procédures d'essai qui peuvent s'appliquer aux caractéristiques des appareils d'enregistrements de lecture vidéo, ces appareils étant principalement destinés à une utilisation professionnelle.
Methods of measurement for broadcast video tape recorders -- Part 3: Electrical measurements for analogue component video signals (IEC 61237-3:1995)
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-april-1999
Methods of measurement for broadcast video tape recorders -- Part 3: Electrical
measurements for analogue component video signals (IEC 61237-3:1995)
Methods of measurement for broadcast video tape recorders -- Part 3: Electrical
measurements for analogue component video signals
Meßverfahren für Videobandgeräte für den Rundfunk -- Teil 3: Elektrische Messungen
für Videosignale mit analogen Komponenten
Méthodes de mesure pour les magnétoscopes de radiodiffusion -- Partie 3: Mesures
électriques pour les signaux vidéo analogiques à composantes
Ta slovenski standard je istoveten z: EN 61237-3:1995
ICS:
33.160.40 Video sistemi Video systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
NORME CE1
IEC
INTERNATIONALE
1237-3
INTERNATIONAL
Première édition
STANDARD
First edition
1995-02
Méthodes de mesure pour les magnétoscopes
de radiodiffusion
Partie 3:
Mesures électriques pour les signaux vidéo
analogiques à composantes
Methods of measurement for broadcast
video tape recorders
Part 3:
Electrical measurements for analogue
component video signals
de reproduction réservés — Copyright — all rights reserved
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-3 -
1237-3 © IEC:1995
CONTENTS
Page
FOREWORD 5
Clause
1 Scope and object
2 Normative references 9
3 General
4 Test conditions
13 5 Measuring methods and test signals
5.1 Manual and automatic methods of measurement
5.2 Measurement of differences between adjacent tracks (fields/segments)
13 5.3 Procedure of measurement
5.4 Test signals
6 Measurement of characteristics 19
Luminance bar amplitude error
6.1
21 6.2 Synchronizing pulse amplitude error
6.3 Bar tilt
6.4 Pulse/bar ratio error
25 6.5 Pulse shape distortion
27 6.6 Amplitude/video-frequency characteristic
27 6.7 Chrominance-luminance gain inequality
6.8 Chrominance-luminance delay inequality
Line-time non-linearity 6.9
33 6.10 High-frequency non-linearity
33 6.11 High-frequency intermodulation
6.12 Crosstalk between channels
37 6.13 Luminance random noise
6.14 Chrominance random noise 39
6.15 Group delay
6.16 FM characteristic frequencies
6.17 Jitter
6.18 Velocity errors
6.19 Moiré
6.20 Noise reduction
6.21 Coder alignment 49
6.22 Power-supply interference
Figures
Annex A - Bibliography
1237-3 © IEC:1995 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
METHODS OF MEASUREMENT FOR BROADCAST
VIDEO TAPE RECORDERS -
Part 3: Electrical measurements for analogue
component video signals
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization
comprising all national electrotechnical committees (IEC National Committees). The object of the IEC is to
promote international cooperation on all questions concerning standardization in the electrical and
electronic fields. To this end and in addition to other activities, the IEC publishes International Standards.
Their preparation is entrusted to technical committees; any IEC National Committee interested in
the subject dealt with may participate in this preparatory work. International, governmental and
non -governmental organizations liaising with the IEC also participate in this preparation. The IEC
collaborates closely with the International Organization for Standardization (ISO) in accordance with
conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of the IEC on technical matters, prepared by technical committees on
which all the National Committees having a special interest therein are represented, express, as nearly as
possible, an international consensus of opinion on the subjects dealt with.
3) They have the form of recommendations for international use published in the form of standards, technical
reports or guides and they are accepted by the National Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
International Standard IEC 1237-3 has been prepared by sub-committee 60B: Video
recording, of IEC technical committee 60: Recording.
The former IEC 698: Measuring methods for television tape machines, will not be
withdrawn because it contains the two transverse track video recorders (IEC 347), which
will not be included in the new draft. IEC 698 is valid for mechanical measurements on
transverse track video recorders only.
The text of this standard is based on the following documents:
Report on voting
DIS
60B(CO)160
60B(CO)172
60B(CO)160A
rt
Full information on the voting for the approval of this standard can be found in the repo
on voting indicated in the above table.
rts, under the general title Methods of measurement
IEC 1237 consists of the following pa
for broadcast video tape recorders:
Part 1: Mechanical measurements
Part 2: Electrical measurements of analogue composite video signals
- 7 -
1237-3 © I EC:1995
Part 3: Electrical measurements of analogue component video signals
Part 4: Measurements of audio performance
Part 5: Electrical measurements of digital composite video signals and digital audio
sigals
Part 6: Electrical measurements of digital component video signals and digital audio
signals
Annex A is for information only.
1237-3 © IEC:1995 –9–
METHODS OF MEASUREMENT FOR BROADCAST
VIDEO TAPE RECORDERS -
Part 3: Electrical measurements for analogue
component video signals
1 Scope and object
This part of IEC 1237 describes the test signals and measurement methods for equipment
mainly dedicated to record/playback of analogue component TV signals on magnetic tape
on reels or in cassettes. It may also be applied for measuring methods for general use in
television production and transmission. The allowable tolerances for the rated values for
ormance are not given in this standard, but may be derived from appropriate
acceptable pe rf
system specifications, manufacturers' specifications, etc.
The necessary reference and calibration tapes are either mentioned in the specific
IEC Publication of the equipment under test or included in IEC 1105 (reference tapes) and
IEC technical report 1295 (calibration tapes) [1]*.
rformance comparisons and, as far as
The methods are applicable to acceptance tests, pe
possible, to routine checks.
The principal object of this document is to describe the methods of measurement, test
signals and procedures which may apply to characteristics of video recording/playback
machines mainly intended for professional use. The measuring methods described hereafter
do not directly concern home equipment and it would appear that some will be difficult to
apply to them.
2 Normative references
The following normative documents contain provisions which, through reference in this
text, constitute provisions of this part of IEC 1237. At the time of publication, the editions
indicated were valid. All standards are subject to revision, and parties to agreements
based on this part of IEC 1237 are encouraged to investigate the possibility of applying
the most recent editions of the standards indicated below. Members of IEC and ISO
maintain registers of currently valid International Standards.
Measuring methods for television tape machines
IEC 698: 1981,
Helical-scan video tape cassette system using 12,65 mm (0,5 in) magnetic
IEC 961: 1989,
tape on type L
* Figures in square brackets refer to annex A, Bibliography.
1237-3 ©IEC:1995 - 11 -
I EC 1105: 1991, Reference tapes for video tape recorder systems
ITU-R Recommendation 471-1: 1990, Nomenclature and description of colour bar signals
(Vol. XI-1)
ITU-R Recommendation 567-3: 1990, Transmission performance of television circuits
designed for use in international connections (Vol. XII)
ITU-R Recommendation 601-2: 1990, Encoding parameters of digital television for studios
(Vol. XI-1)
ITU-R Recommendation 656: 1986, Interfaces for digital component video signals in 525-line
and 625-line television systems (Vol. XI-1)
3 General
To ensure that the results obtained at a specific time at a specific place are comparable to
other measurements, it is advisable to specify the test signals, measuring devices and
types of tapes used together with results obtained.
Since measurements of television tape machines on the basis of a single test-line per field
may not be fully representative of the full-field performance (see 5.1 and 5.2), they may
give results which differ from those obtained or calculated with full-field test signals.
Therefore is necessary to additionally specify the measuring method:
it
- single line measurement (line number);
- block measurement (start-line, step-by-step line(s), number of steps);
- full-field measurement.
Additionally, it should be stated if the selection of lines coincides with a single
record/playback head only.
4 Test conditions
If not otherwise stated all measurements shall be carried out at the following atmospheric
conditions:
Temperature (20 ± 1) °C
Relative humidity (50 ± 2) %
Air pressure 106 kPa
86 kPa to
Conditioning before testing 24 h
1237-3 ©IEC:1995 - 13 -
5 Measuring methods and test signals
5.1 Manual and automatic methods of measurement
If automatic measuring apparatus is designed to give reliable results under the special
conditions of television tape playback as e.g. drop-out, jitter, noise, time-base errors,
suppression of vertical blanking interval or insufficient head-to-tape contact, a significant
improvement in measurement speed, accuracy and comparability of results can be
achieved.
Therefore preference was given to measurement methods which can be carried out by
automatic measuring equipment or which are suitable for automatic measuring techniques.
Except where a distinction is made in particular clauses between manual and automatic
methods of measurement, the measurement procedures given in this standard are valid
for both methods. However, although in the case of automatic measurements the
procedure is carried out automatically by the test signal analyzer, the various steps are
described as if they were performed manually.
Measurement of differences between adjacent tracks (fields/segments)
5.2
All currently standardized recording formats make use of segmented recording techniques.
The length of the segments (tracks) varies between approximately 16 lines and one field
where the latter is often termed "non-segmented recording" which only indicates that there
is no cut within the field.
Since two or more heads are used for record and playback of the video information to and
from the tracks, it is desirable to restrict the measurement to segments or tracks related to
a specific head. This requires a special signal arrangement which provides identical
information to the heads or segments in turn.
A suitable arrangement for most formats is to repeat a packet of up to 16 different signals
of a duration of one line within a field and to make the signals identical in both fields [2].
5.3 Procedure of measurement
The measurements shall be carried out by measuring the playback signal after recording
rformance,
on the same machine (best-case configuration). Before testing the overall pe
the playback channel shall be measured by means of a calibration tape (see clause 1).
rformance of a video recording system
In certain particular cases, if the multigeneration pe
is measured, the measurements shall be carried out by measuring the playback signal
after recording on a different machine (worst-case configuration).
If the television tape machine under test is equipped with external controls, e.g. tracking
control, gain control, etc., these controls shall be set to their preset- or mid-position for all
measurements.
1237-3 © IEC:1995 - 15 -
5.4 Test signals
5.4.1
Introduction
A representative range of test signals is shown in figures 1 to 10. For ease of reference,
they are indicated by roman numerals. Other test signals not shown in the figures are
collected in 5.4.2.
All signals are defined as a luminance and two colour-difference signals. In practice, these
signals are generally represented by the symbols Y, B-Y, R-Y, but in the following a short
CR) has been used:
form of the notation adopted by the ITU-R (E' Y, E'C8 and E'
Y,CB and CR
These components are defined in terms of the primary signals R, G and B by:
= 0,564 (B-Y), CR = 0,713 (R-Y)
Y = 0,587 • G + 0,299 • R + 0,114 • B, CB
It should be noted that some of the test signals will produce "illegal" values of R, G, B or
composite if dematrixed and/or coded.
Amplitudes and bandwidth of test signals
5.4.2
The amplitude of the signals is given in per cent of full-picture amplitude of the luminance
and/or chrominance signals. The nominal full amplitude shall be identical but may differ
between systems. The preferred levels given in table 1 are those defined by the common
EBU/SMPTE Standard (EBU N10, SMPTE 253) ([3] and [4]). They are in use in all 625-line
countries. In 525-line countries several other luminance and sync levels as well as colour
difference offset levels can be found. In those cases the signals delivered to and received
from the system under test should comply with the individual machine setting.
Table 1 - Nominal signal amplitudes for 625-line and 525-line standards
525-line standards
625-line standards
mV %
mV %
714 100 or IRE
Luminance (Y) 700 100
±350 ±50 ±350 ±50 or IRE
Colour difference (C B, C R)
–300 42,8
Sync –300 42,8
...
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