Vidi-RGB Manual July 1990

Hardware version 1

Copyright 1990 ROMBO Productions

ROMBO Productions

6 Fairbairn Road

Kirkton North

Livingston

Scotland

EH546TS

Tel:(0506)414631

Fax:(0506)414634

Vidi-RGB - Contents

Contents Introduction

• Using this manual ..... .... ........... ... ...... .. .. .. .... .............. .. .. : ............ ........ .. ........ 3 • How (and why) we did it.. ........................... .. .... ................. .. ............... ....... 3

Getting started • Requirements ... ..... ... ........ ....... ... .............. ....... ... ... .. .. .............. ... .... ...... ... .. .. .. 4 • Setting up ... ............ ...................... ................................. ........... .......... .. .. .. ..... 4 • Software support ......... ... ... ............ .... ... .. ..... ....... .. .... ....... .... ...... ............ ..... .. 5 • Connecting a video source ........ ...... .... ......... .... ..... ....... .... .......................... . 5 • Manual control ... ............ .... .. ........ ........... .............. ......... .... ........... ..... ... ..... .. 5

Tutorials • Getting it toge ther ........ ................................................... .. ........................ ... 5 • Contro ls ................... ...... ... ............... .... ......... ... ............ ...... .. ..... ......... ......... .. 6 • Brightness level ....................................... .... .......... .............. ........................ . 6 • Colour Saturation ..... ........... ..... .................. ......... ................ ......... ........ .. ...... 6 • Colour Balance ....... .......... ....... ... ........... ..... ... .................... ... .... ............ ....... . 6 • Manual control ................................................. ...... .... ........ ..... ........... .......... 6

Reference • Input ..... ..... ... .... ......... ... .... ........ ........................... ... ............... .. .. .... ............... . 7 • Output ....... .............. .... ..... ....... ... .. .. ......... .. ....... .. ... .............. .. .. ......... ..... ... ..... 7 • Manual colour se lect button .... ... .... ....... ............... ......... .. .......... .. ................ 7 • Automatic control ................................ ............................. ........ .. ................. 7 • Colour control ............. .. ..... .. ..... .. ......... .. .. .... .............. ..................... ..... ..... .. . 7 • Brightness Con trol ...... .... .. .... ............. ... ........ ........... .. ..... .......... ....... .. ....... ... 7 • 1/0 Feature connector ............................. ... ........... ................... ..... .. ............. 7

Appendices • A: Hints and tips ................. .. .... ...... ......................... ................................. .. . 8 • B: PAL signal Encoding/Decoding .................................. ... .......... .. ...... ..... 8 ) • C: VidiChrome control ports ................ .... ... .... ......... ......... ..... ................... . 9 • D: Troubleshooting .................. ................... .... .. ......... .................................. 9 • E: I/O Feature connector ...... ... .. ....... ... ..... .............. .......... .... .. ................... 10 • F: Technical support ..... ................... ................. ........ ... .................... .... ...... 11 • G: External power supply ........................ ................. ................ ...... .. ........ 11

2

Vidi-RGB - Introduction

Introduction Vidi-RGB is an electronic colour separator and sequencer. It can accept input from a variety of colour signal sources, the default being Composite colour. Separate Luminance/Chrominance (S-VHS) and discrete RGB and Sync . may be connected with specia l leads to the I/O Feature connector.

A combination of Vidi -RGB and a still colour source, will allow a monochrome digitiser (our own Vidi Frame Grabbers , Digi-View etc.). along with co lour processing software to produce full colour pictures with ease.

Using this manual To ensure you don't cause too much damage, I recommend you first read and understand the Getting started section to get you through installation of the hardware, connecting up a video signal and basic operation.

The Tutorials section guides you through a typical 'session', showing the various functions avai lable from the hardware. To find out more about a particular function, look it up in the Reference section.

How (and why) we did it. ..... Vidi-RGB was designed to fill a need, namely to replace conventional optical colour filter sets with a conven ient and AUTOMATIC means of co lour separation.

It was conceived (not immaculately) and designed by Colin Faulkner during the 1 st half of 1990. Many sugges tions - on ly the polite ones - from the ROMBO team and Vidi users were included in the final design. TIle original VidiChrome for Vidi-Amiga was revised by resident programmer Keith Wilson to incorporate automatic control for Vidi-RGB, so we know it works! .

All units are hand assembled and tested by our own dedicated production staff at ROMBO Productions in Livingston , Scotland. Please remember, being

merely human mistakes can happen ....

The manual text was written using Amor's Protext wordprocessor, all pictures were captured using Vidi-PC. The final manual layout was produced with Timeworks DeskTop Publisher and printed by laser printer.

3

Vidi-RGB - Getting Started

Getting started Requirements Your Vidi-RGB pack should contain:

• Vidi-RGB interface

• This manual • External 9-12 Volt DC Power Supply (UK only, See Appendix G)

To use Vidi-RGB you will need:

• Colour video source, camera or recorder with perfect freeze frame

• Vidi Frame Grabber, or other digitiser

• VidiChrome or other colour merging software

For best 'Live ' results from Vidi-RGB, we recommend:

• Bright f10urescent lighting

• Good quality Camera or Camcorder

• Copy stand or tripod

For good recorded image process ing you need:

• Video recorder with perfect freeze frame

• 1st generation video tapes

Setting up Vidi-RGB requires an external Power Supply to operate. this should be plugged into the mains supply and then into the DC input socket on Vidi-RGB.

Reset Vidi-RGB by pressing the col­our se lect button for approximately 5 seconds. set both the Brightness and Colour controls to mid travel and connect the video output lead from Vidi-RGB to the input of your digitiser.

4

Vidi-RGB - Tutorials

Software support If you have the foresight to be using one of our Vidi Frame Grabbers and VidiChrome software, this will incor- " porating AUTOMATIC co lour selec­tion, so connect the 9 pin joystick cable to the port detailed in the VidiChrome manual (see Appendix C), If not, leave this cable disconnected ,

Connecting a video source Lastly connect your colour signal to the video input socket (phono) on Vidi-RGB , Your digitiser should now be receiving a black and white signal.

Note thal 'Video-Out ' is different from 'RF-Out' and although you r cable may fit. you will be unable to grab any pictures!

Manual control Simply press the button briefly to step through to the required colour, shown by the LED, Off - Black and V/hite, Red, Green and Orange! I - blue LED 's are as rare as hens teeth.

Tutorials This section assumes you are using Yidi -RGB with our own hardware and software, I make no apologies for this. If you are not, read it anyway and extract the relevant details , at the very least it will show what you are missing! ,

Getting it together Firstly switch on your video equipment, computer and Yidi Frame Grabber then load and run the YidiChrome software. Grab a frame or 2 to check that your normal setup is operational. Connect Yidi-RGB between your video source and Vidi (see Getting started) and switch on the 'Splitter ' option in YidiChrome.

5

Vidi-RGB - Tutorials

Controls These allow you to setup Vidi-RGB for use with your other equipment. Brightness adjusts the B&W or Luminance level of the output signal. Saturation adjusts the colour or Chrominance content of the signal, and ranges from fully saturated to Black & White.

Brightness level For a first attempt, leave these at mid travel position and se lect ' Grab HAM or Grab RGB ' from the VidiChrome Grab menu. Initially the computer display will show a B&W image, the LED on Vidi-RGB should be off. On your Vidi, set the brightness to mid travel and contrast to fully open. If the grabbed image is too bright or 'burnt out ' adjust the brightness contro l on Vidi-RGB to compensate. It may be necessary to use both Vidi-RGB , Vidi's brightness control AND change the subject lighting to get the correct level. REMEMBER to leave the software brightness controls for colour co rrection. When the brightness is correct, use the contrast control (Vidi-PC' s software control) to set the black level. Try to set up the controls so that white areas in the picture digitise as white, black as black, with an even spread of shades in between. Press the key to capture the image. llle LED on Vidi-RGB should quickly sequence through the colours and VidiChrome will merge the separate components into a full co lour picture.

Colour Saturation This first attempt may not be perfect. colour saturation depends on a large range of variables , lighting, type of camera. white balance etc., so adjust Vidi-RGB 's colour control as required .

Colour Balance The Brightness option within VidiChrome allows you to change each level for the individual Red , Green and Blue components to compensate . For example a picture which is too ye llow is actuall y suffe ring from either a lack of blue or too much red and green. By changing the software brightness level for a colour and re -grabbing the picture. colour corrections can be easily made.

Manual control If you have to se lect co lours manually, press the button to step to the one required. REMEMBER fiddling with this may confuse VidiChrome, so use the 'Reset split ' option to re-synchroni se software and hardware before grabbing.

6

{

l

Vidi-RGB - Reference

Reference Input

The input to Vidi-RGB is standard I volt p-p composite colour signal, via the rear panel phono socket. This input is NOT terminated to 75 ohms, to enable the connection of other devices , monitor etc. to the same signal.

Output Vidi-RGB produces the decoded colour component, into which has been re-mixed all the sync. pulses stripped from the original. The signa l is fully buffered and leaves via the captive phono lead.

Manual colour select button This single control has a dual function, firstly if pressed for more than a couple of seconds, it resets the decoder to B&W. Second if pushed briefly, it sequences the B&W then RGB outputs in turn, when pressed.

Automatic control Vidi-RGB uses digital colour se lection, allowing the host computer to sequence through the Black & White, Red, Green and Blue decoded signals. This control is duplicated in the -push switch on lOp of the case, the tri-colour LED shows the se lection state.

Colour control This varies the co lour satu ration of the output from maximum, fully saturated to minimum, no colour. Note that if the input video signa l has little colour content, Vidi-RGB will not add false colour, but bring out as much of the origina l as possible .

Brightness control This adjusts the level of luminance (pure B& W) part of the composite signal fed to Vidi-RGB's decoder, and hence the overall brightness level of the video output.

I/O Feature connector This connector provides access to practica lly all signals fed to and produced by Yidi-RGB . See Appendix F for full details.

7

Vidi -RGB - Appendices

Appendices Appendix A: Hints and tips The human eye can discern many thousands of different colours, and here we are trying to produce FULL colour from the limited pallene range provided by your computer. This coupled with differences in camera sensitivity, lighting, co lour balance and monitor setup, all affect rhe final appearance - accurate colour pictures are not easy to produce.

When a professional video is produced great attention is paid to lighting to achieve realistic results. The final picture will depend upon the care you take to set it up. We find that flourescent or b right sunl ight give the most consistent resu lts.

Most colour cameras have provision for adjustment of colour or white balance, use it! - if you expect your whites to stay white, as the adds say.

Appendix B: Signal encoding/decoding RGB decoders are not new - in fact many millions exist, cleverly buried within any domestic colour TV set, the difficult part is extracting the important bits ...... All televisions are highly integrated, each section relies upon others for the signals it needs, remove one part and the whole set stops working. Vidi-RGB uses a Large Scale Integrated Circuit (LSI), which combines all the functions required into a single chip. This coupled with digital control and integrated switches makes for a compact and versatile unit.

The reason that encoding works is all to do with the way our eyes perceive different colours. In fact, eve ry visible colour can be mixed using varying proportions of red, green and blue light. These are the called primary colours because they can' t be created by colour mixing (artists please note that yellow and blue don't make green when dealing with light - this only happens with paint or ink).

You may recognise the diagram of three overlapping circles of coloured light producing yellow, cyan and magenta (the secondary colours) where they overlap, as well as pure whi te in the centre.

8

I ....

Vidi-RGB - Appendices

A colour video signal is produced by combining or encoding the Red Green and Blue signals in a special way. The eye is more sensitive to changes in intensity than to colour, then to the green, red, finally blue components.

Using these characteristics, the red green and blue signals are combined to produce the luminance or Y component using the formula Y =O.3R+O.S9G+O.II B. This Y signal has no colour content and would give an accurate monochrome picture, it is transmitted with as large a bandwidth as possible.

Pure colour signals are derived by subtracting the Y signal from the R.G and B signals , producing R-Y. G-Y and B-Y. Because the Y signal is used, it can be shown that only the R- Y and G-Y colour difference signals need to be transmitted - simultaneous equations and all that.

111ese colour signals are transmitted on altemate picture lines within a compressed frequency band and mixed in with the transmitted Y signal.

Decoding is simply(?) the reverse of this process .

Appendix C: VidiChrome control ports At present VidiChrome uses :­

Vidi-Amiga/Vidi-ST second joystick port

Vidi-PC Plus its own 9 way ' D Type ' control port

Appendix D: Troubleshooting No video signal

If your digitiser gives this message, first ly re-check all connections. If possible use your computer monitor to check that you are feeding a signal to Vidi-RGB, similarly look at its output to see if its there. Always reset Vidi-RGB fully before use.

Bad colour or 'st reaky' pictures

Vidi-RGB can lose its ' lock ' on difficult colour signals , VCR 's on fast forward etc. If this happens simply disconnect the video input to Vidi-RGB for a few seconds, re-connect and proceed as normal.

Washed out or no colour

Adjust colour and brightness contro ls, check original to see if it has any!.

9

Vidi-RGB - Appendices

Appendix E: 1/0 Feature connector This was added in response to the suggestion ' If you've got it, flaunt it' .

Below is a block diagram of Vidi-RGB. All the useful input and output signa ls are available tJlrough this connector, the pin-out is as detailed. To utilise tllese extra features you will need a special lead to connect to Vidi-RGB. ROMBO wi ll produce these leads as and when they are requested according to demand, contact teclmical support (by letter preferably) for details .

The list below shows the pin-out for the 1/0 feature connector.

NOTE, no responsibi lity can be accepted for any damage to your video equipment or Vidi-RGB caused by incorrect connection to the feature connector.

• I .... .. .. ... ..... ......... .. .. 's' Luminance input • 2 ........ ...... ........ .. .... . 's' Chrominance input • 3 ..... .......... ... ........... Gnd for'S ' inputs • 4 .. .... .. ..... ... ....... .. .... Decoded RED output • S .. .... ... ...... .. .... ........ Decoded GREEN output • 6 ......... ........ ........ .. .. Decoded BLUE output • 7 .. ... ....... ..... ............ Gnd for RGB outputs

. • 8 ............. ................ SYNC* output (TTL level comp.) • 9 ... ... .. ........ ..... ... .. ... Duplicate of Video lip phono socket • 1O .......... ................. Duplicate of Video Olp phono lead • 11 ........................ .. . BURST* Burst output • 12 ........................... SC Subcarrier clock sig.( 200mv olp high imp.) • 13 .......................... . Duplicate of of EXT DC P5U lip • 14 ...................... ..... GND • IS ........................... '5 ' input select, hold low to enable '5' inputs . NOTE

no connection must be made to Video l ip if these are used. • 16 .......... ...... ....... .... Extemal RED lip • 17 .. ......................... Extemal GREEN lip • 18 ................ ..... ...... Extemal BLUE lip • 19 ........................... GND • 20 ........................... Extemal SYNC* lip • 21 ...... .... ................. Extemal lip select, hold low to enable • 22 ....... .. .. .. .............. GND • 23 ...... .. ............ .... .. . SYNC, compliment of pin 8 • 24 ........................... GND • 2S .... .. .......... .. ...... .. . Regulated +5v Olp (MAX SOmA)

10

Vidi-RGB - Appendices

Appendix F: Technical support Tchnical support is, as always FREE from Rombo - contact us if have any problems, suggestions or special requirements. However, if you are having problems with Vidi-RGB , please make sure that you have read the relevant parts of this manual before getting in touch!

Contact us by phone if possible between 9am and Spm (lunch 12.30-1.3Opm) and it would be helpful if you call whilst actually in front of the machine with the appropriate software loaded. If you are writing, clearly mark the envelope Vidi-RGB Technical Support and try to send examples on disk or a print-out to illustrate the problem.

Appendix G: External DC Power Supply Vidi-RGB requires an external DC input of approx . 9v @ lOOmA. In practice this can be obtained from a small ' battery eliminator' type unit. These are readily available, and anything which gives out between 8 and 12v at l OOmA is adequate.

11

~ .

~~--------------------