Recommendation itu-r bt. 1358 studio parameters of 625 and 525 line progressive scan television systems




Yüklə 120.83 Kb.
tarix16.04.2016
ölçüsü120.83 Kb.

Rec. ITU-R BT.1358

RECOMMENDATION ITU-R BT.1358

STUDIO PARAMETERS OF 625 AND 525 LINE PROGRESSIVE
SCAN TELEVISION SYSTEMS

(Question ITU-R 1-3/11)


(1998)
Rec. ITU-R BT.1358

The ITU Radiocommunication Assembly,



considering

a) that there is interest in using progressive scan systems as input to enhanced analogue services and for digital television broadcasting;

b) that the progressive signal offers improved vertical and temporal resolution over the conventional interlaced signal;

c) that parameter values for the progressive systems should have maximum commonality with the existing conventional television and high-definition television systems;

d) that progressive systems can be scaled up from conventional interlaced 625 and 525 line systems;

e) that progressive systems can be scaled down from high-definition television systems which will embody internationally agreed unified colorimetric parameters;

f) that the above two approaches could lead to systems with different parameters, for example colorimetry and synchronizing waveforms;

g) that a scaled up 525 line system is already used as source for EDTV II,



recommends

1 that the following parameters derived from conventional interlaced television systems be used for 625 and 525 line progressive scan television systems.

NOTE – 625 and 525 line progressive scan television systems are still under study, in particular, those derived from high-definition television (HDTV) systems. These systems should be considered for inclusion in the Recommendation when they are developed.


ANNEX 1

Signal parameter values for 625/50/1:1 and 525/59.94/1:1 progressive scanning
systems derived from conventional 625 and 525 line standards

1 Opto-electronic conversion








Characteristics

Item

Parameter

625/50/1:1

525/59.94/1:1

1.1

Chromaticity coordinates, CIE 1931(1)

x

y

x

y




Primaries Red

0.640

0.330

0.630

0.340




Green

0.290

0.600

0.310

0.595




Blue

0.150

0.060

0.155

0.070

1.2

Assumed chromaticity for equal
primary signals - Reference white

D65




x

y




EREGEB

0.3127

0.3290

1.3

Opto-electronic transfer characteristics before non-linear precorrection

Assumed linear

1.4

Overall opto-electronic transfer characteristic at source

E  (1.099 L0.45 – 0.099) for 1.00  L  0.018
E  4.500 L for 0.018  L  0
where:
L: luminance of the image 0  L  1 for conventional colorimetry
E: corresponding electrical signal.

(1) Chromaticity coordinates specified are those currently used by 625-line and 525-line conventional systems.

NOTE – See Recommendation ITU-R BT.1361, (Worldwide unified colorimetry and related characteristics of future television and imaging systems).


2 Picture and scanning characteristics







Characteristics

Item

Parameter

625/50/1:1

525/59.94/1:1

2.1

Order of scanning

Left to right, top to bottom

2.2

Scanning format

Progressive 1:1

2.3

Picture rate (Hz)

50

60/1.001

2.4

Total number of lines

625

525

2.5

Active lines per picture

576 (lines 45 - 620)

483 (line 43 - 525)

2.6

Aspect ratio(1)

16:9 (4:3)

2.7

Line frequency (Hz)

31 250  0.0001%

31 500/1.001  3 ppm

(1) The aspect ratio for HDTV and EDTV applications will normally be 16:9. It is possible that progressive scanning systems will be used within standard TV (SDTV) applications with an aspect ratio of 4:3. Parameters for such systems are contained within standard parenthesis, i.e. (4:3).


3 Analogue representation


The terms refer to gamma pre-corrected analogue signals.

Levels are specified in millivolts measured across a matched 75  termination.






Characteristics

Item

Parameter

625/50/1:1

525/59.94/1:1

3.1

Primary signals nominal level,
Standard colorimetry,



Reference black: 0%, 0 mV
Reference peak level: 100%, 700 mV

3.2

Derivation of luminance component signal



3.3

Derivation of colour-difference component signals



3.4

Component signals nominal level,
Standard and extended colorimetry,

Luminance



Colour difference

Reference black: 0%, 0 mV


Reference White: 100%, 700 mV
No signal: 0%, 0 mV
Maximum colour difference: 50%, 350 mV

3.5

Nominal signal bandwidth

12 MHz


6 MHz

3.6

Form of synchronizing signal on primary and component signals(2)

Bi-level bipolar (Fig. 1)

3.7

Horizontal sync timing reference

OH (Fig. 1)

3.8

Sync level (mV)

–300  7.5 mV

3.9

Inter-component timing accuracy

10 ns

3.10

Horizontal sync and blanking interval signal timing

Fig. 1 and Table 1

3.11

Vertical sync and blanking interval signal timing

Fig. 2 and Tables 2 and 3

(1) The luminance and colour difference encoding equations used here are those currently recommended for conventional systems.

(2) Addition of synchronizing signal on R, B, PB and PR signals is optional.

FIGURE 1


Horizontal synchronizing pulse

TABLE 1


Details of horizontal synchronizing signals

Symbol

Characteristics

625/50/1:1

525/59.94/1:1

H

Nominal line period (s)

32

1001/31.5 (31.778)

a

Horizontal blanking interval (s)

6.0  1.5

5.35  0.15

   – 0.1


b

Interval between time datum (OH) and back edge of horizontal blanking pulse (s)

5.25

4.6  0.1

  – 0.05


c

Front porch (s)

0.75  0.15

0.75  0.05

d

Synchronizing pulse (s)

2.35  0.1

2.35  0.05

e

Build-up time (10 to 90%) of the edges of the horizontal blanking pulse (s)

0.15  0.05

0.07  0.01

f

Build-up time (10 to 90%) of the edges of the horizontal synchronizing pulses (s)

0.1  0.05

0.07  0.01

FIGURE 2


Vertical synchronizing pulses

TABLE 2


Details of vertical synchronizing signals

Symbol

Characteristics

625/50/1:1

525/59.94/1:1

V

Nominal frame period (ms)

20

1001/60 (16.683)

D

Vertical blanking interval

49H + a(1)

42H + a(1)



Build-up time (10 to 90%) of the edges of vertical blanking pulse (s)

0.15  0.05

0.07  0.01

A

Interval between front edge of vertical blanking interval and front edge of first vertical synchronizing pulse

5H(1)

6H(1)

C

Interval between back edge of last vertical synchronizing pulse and back edge of vertical blanking interval

39H(1)

30H(1)

B

Duration of sequence of vertical synchronizing pulses

5H(1)

6H(1)

p

Duration of vertical synchronizing pulse (s)

29.65  0.1

29.428  0.05

r

Interval between vertical synchronizing pulse (s)

2.35  0.1

2.35  0.05

s

Build-up time (10 to 90%) of the vertical synchronizing pulses (s)

0.1  0.05

0.07  0.01

(1) For H and a, see Table 1.

TABLE 3


Vertical blanking interval line numbers




Line number












625/50/1:1

621

1

6

44

525/59.94/1:1

1

7

13

42


4 Digital representation


The terms R, G, B, Y, CB, CR, refer to quantized and digitally encoded signals. These signals are obtained from gamma pre-corrected signals.

The digital representation in the following table follows Recommendation ITU-R BT.601 Part A which defines the 4:2:2 13.5 MHz standard for 4:3 and for wide-screen 16:9 aspect ratio systems. For 16:9 aspect ratio only, Recommendation ITU-R BT.601 Part B defining a higher horizontal resolution is equally valid and the appropriate values should be substituted from Recommendation ITU-R BT.601 as required.






Characteristics

Item

Parameter

625/50/1:1

525/59.94/1:1

4.1

Coded signal

R, G, B, or Y, CB, CR

4.2

Sampling lattice R, G, B, Y

Orthogonal, line and picture repetitive

4.3

Sampling lattice CB, CR,

Orthogonal, line and picture repetitive, co-sited with odd (1st, 3rd, 5th, etc.) Y active samples in each line

4.4

Sampling frequency R, G, B, Y
Sampling frequency CB, CR,

27 MHz  3 ppm
Half luminance sampling frequency
13.5 MHz  3 ppm

4.5

Number of samples per full line
R, G, B, Y
CB, CR

864
432


858
429



4.6

Number of samples per active line
R, G, B, Y
CB, CR

720
360



4.7

Coding format(1)

Linear, 8 or 10 bits/sample for each primary and component signal

4.8

Quantization:(2)
Primary signals R, G, B:



220 or 877 quantization levels with black level at 16 or 64 and peak white level at 235 or 940, respectively






Characteristics

Item

Parameter

625/50/1:1

525/59.94/1:1

4.9

Quantization:(2)

Component signal Y:

Component signals CB, CR:



220 or 877 quantization levels with black level at 16 or 64 and peak white level at 235 or 940, respectively


225 or 897 quantization levels symmetrically disposed about zero signal at 128 or 512 respectively



4.10

Derivation of Y, CB, CR from quantized primary signals R, G, B:(3)



4.11

Timing relationship between analogue sync reference (OH) and video data

132 samples @ 27 MHz

(Fig. 3)


122 samples @ 27 MHz

(Fig. 3)


4.12

Quantization level assignment:

Video data:


Timing references:

1.00 through 254.75
0.00 to 0.75 and 255.00 to 255.75

4.13

Filter characteristics(4)

R, G, B, Y
CB, CR

Fig. 4
Fig. 5

(1) To avoid confusion between 8-bit and 10-bit representations, the eight most-significant bits are considered to be an integer part while the two additional bits, if present, are considered to be fractional parts. For example, the bit pattern 10010001 would be expressed as 145d or 91h, whereas the pattern 1001000101 would be expressed as 145.25d or 91.4h. The fractional parts are shown here if valid, otherwise they are assumed to have the binary value 00. Levels are quoted for 8 and 10 bit quantization.

(2)n” denotes the number of the bit length of the quantized signal. The operator INT returns the value of 0 for fractional parts in the range of 0 to 0.49999.... and 1 for fractional parts in the range of 0.5 to 0.99999...., i.e., it rounds up fraction above 0.5.

(3) Coefficients of length other than 8 or 10 may be used.

(4) The filter templates are shown in Fig. 4 and Fig. 5 as a guideline.








Verilənlər bazası müəlliflik hüququ ilə müdafiə olunur ©azrefs.org 2016
rəhbərliyinə müraciət

    Ana səhifə