Embedded OSD (Not STV5370A)

Hi, I have a need for an OSD generator IC/module with PAL output but I 
only seem to find references to the STV5370A which is obsolete. Anyone 
out there using a current product? I need to be able to interface to a 
dedicated micro (probably PIC16F87x) simply and with little overhead, 
display in colour over a CCTV image and record the output (no odd 
timings)
-- 
Clint Sharp

On Sunday, in article
     <BFjH1sBvs2HBFwn+@clintsmc.demon.co.uk>
     clint@clintsmc.demon.co.uk "Clint Sharp" wrote:
>Hi, I have a need for an OSD generator IC/module with PAL output but I
>only seem to find references to the STV5370A which is obsolete. Anyone 
>out there using a current product? I need to be able to interface to a 
>dedicated micro (probably PIC16F87x) simply and with little overhead, 
>display in colour over a CCTV image and record the output (no odd 
>timings)

Sounds like a time/date generator for CCTV recording... Lots already
exist, last one I bought was about 40 pounds in UK (www.cpc.co.uk have
several available). Unless I needed it for part of a design I personally
would not reinvent the wheel, unless it is a project to learn about.

Most OSD modules/chips work in RGB domain as they are _mainly_ used in
monitors that are in RGB domain. Philips have a bunch often with I2C
interface.

Work out what you actually need, i.e.

  1/   does it have to be colour or monochrome?
  2/   does it need black borders or grey borders around the text?
  3/   does it need graphic symbols?

If you are using monochrome and simple character sets, with a border or
video mixed border, you can do simple switching of video and OSD o/p, mixing
can be done by reducing chroma and luminance before mixing on a simple
alpha mixer[1] which exist as analog mixer/multiplier chips from many
manufacturers. Ensure your alpha signal does not have sharp edges as this
can cause image artifacts, especially if your clock to generate the OSD
has jitter on it.

Lots of people have made OSDs and time date generators that are driven by
a PIC and limited external circuitry to overlay onto a composite video
stream by the above methods. There are propbably articles about doing the
same thing on Circuit Cellar magazine site, I have seen various articles
about this in many places.

You could use a piece of dual ported RAM that holds enough bits for a
small section of the screen to overlay the data. Some timing circuit to
read out the OSD data at the right time, and change the RAM contents from
the micro at a time when the RAM is not being read. So if the RAM is read
out over a 2ms portion of the field, you have 18ms available to update the
RAM.

Most colour OSD work is done for simplicity in the RGB domain, as this
requires simpler locking of line and subcarrier frequencies, hence
derivation of pixel clocks for the OSD. A reconstituted composite output
PAL/NTSC has both parts driven by the same subcarrier. Even studio equipment
works by separating the video into at least Y/C or YUV to remove the artifacts
and what phase each video stream is to each other to mix signals.

[1] alpha mixer

        output = ( X * alpha ) + ( Y * ( 1 -alpha ) )

        Where
          alpha = 0 to 1

          X and Y  are matched inputs on amplitude range

          output is matched amplitude range to inputs

-- 
Paul Carpenter		| paul@pcserv.demon.co.uk
<http://www.pcserv.demon.co.uk/>        Main Site
<http://www.gnuh8.org.uk/>              GNU H8 & mailing list info.
<http://www.badweb.org.uk/>             For those web sites you hate.

In message <20040815.2159.302184snz@pcserv.demon.co.uk>, Paul Carpenter 
<paul$@pcserv.demon.co.uk> writes
>Sounds like a time/date generator for CCTV recording... Lots already
>exist, last one I bought was about 40 pounds in UK (www.cpc.co.uk have
>several available).
Close, but I need to be able to overlay serial data, it's for recording 
checkout transactions with the camera output. Might be worth hacking one 
of the CPC units though.
> Unless I needed it for part of a design I personally
>would not reinvent the wheel, unless it is a project to learn about.
Well, I'd prefer not to have to reinvent the wheel, but I really don't 
want to have to pay almost 1000ukp per site (four sites, five checkouts 
each )
>
>Most OSD modules/chips work in RGB domain as they are _mainly_ used in
>monitors that are in RGB domain. Philips have a bunch often with I2C
>interface.
>
>Work out what you actually need, i.e.
>
>  1/   does it have to be colour or monochrome?
Colour would be nice as I could then select for maximum contrast against 
a range of different backgrounds.
>  2/   does it need black borders or grey borders around the text?
Would be nice to have a black outline for readability but other than 
that I don't need it.
>  3/   does it need graphic symbols?
Hmmm, pound sign would be nice but not essential.
>
>If you are using monochrome and simple character sets,
Snipped lots of useful information,  thanks for your reply.

-- 
Clint Sharp

On Monday, in article
     <bTKhgiB01QIBFwcx@clintsmc.demon.co.uk>
     clint@clintsmc.demon.co.uk "Clint Sharp" wrote:

>In message <20040815.2159.302184snz@pcserv.demon.co.uk>, Paul Carpenter 
><paul$@pcserv.demon.co.uk> writes
>>Sounds like a time/date generator for CCTV recording... Lots already
>>exist, last one I bought was about 40 pounds in UK (www.cpc.co.uk have
>>several available).
>Close, but I need to be able to overlay serial data, it's for recording 
>checkout transactions with the camera output. Might be worth hacking one 
>of the CPC units though.
>> Unless I needed it for part of a design I personally
>>would not reinvent the wheel, unless it is a project to learn about.
>Well, I'd prefer not to have to reinvent the wheel, but I really don't 
>want to have to pay almost 1000ukp per site (four sites, five checkouts 
>each )

Once you consider all the parts (including power, connectors, case), unless
you have something that easily allows this to be added to that already
processes the video; you may well find getting below 50ukp per unit is
difficult.

>>Most OSD modules/chips work in RGB domain as they are _mainly_ used in
>>monitors that are in RGB domain. Philips have a bunch often with I2C
>>interface.
>>
>>Work out what you actually need, i.e.
>>
>>  1/   does it have to be colour or monochrome?
>Colour would be nice as I could then select for maximum contrast against 
>a range of different backgrounds.
>>  2/   does it need black borders or grey borders around the text?
>Would be nice to have a black outline for readability but other than 
>that I don't need it.

Making the background a box at grey that is mixed with the background
is one trick film/video subtitling is done to achieve the same effect.

>>  3/   does it need graphic symbols?
>Hmmm, pound sign would be nice but not essential.

I was thinking more like graphics such as icons or larger things like logos.

>>If you are using monochrome and simple character sets,
>Snipped lots of useful information,  thanks for your reply.

No problem, been messing with video and image processing for too many years.

-- 
Paul Carpenter		| paul@pcserv.demon.co.uk
<http://www.pcserv.demon.co.uk/>        Main Site
<http://www.gnuh8.org.uk/>              GNU H8 & mailing list info.
<http://www.badweb.org.uk/>             For those web sites you hate.

In message <20040817.0849.302207snz@pcserv.demon.co.uk>, Paul Carpenter 
<paul$@pcserv.demon.co.uk> writes
>>Well, I'd prefer not to have to reinvent the wheel, but I really don't
>>want to have to pay almost 1000ukp per site (four sites, five checkouts
>>each )
>
>Once you consider all the parts (including power, connectors, case), unless
>you have something that easily allows this to be added to that already
>processes the video; you may well find getting below 50ukp per unit is
>difficult.
I'm sure I would, but the units I have seen that fulfil my needs are a 
penny under 200 each and I need twenty of them! A target price of &#4294967295;100 
per unit would, therefore, be reasonable.
>
>Making the background a box at grey that is mixed with the background
>is one trick film/video subtitling is done to achieve the same effect.
>
>>>  3/   does it need graphic symbols?
>>Hmmm, pound sign would be nice but not essential.
>
>I was thinking more like graphics such as icons or larger things like logos.
Ah, not needed then. It's really only the UK Pound sign that is anyway 
out of the ordinary.
>
>>>If you are using monochrome and simple character sets,
>>Snipped lots of useful information,  thanks for your reply.
>
>No problem, been messing with video and image processing for too many years.
>

-- 
Clint Sharp

Coulden't help but notice your application.

http://www.multiview.net/vsi-pro.html  UK
http://www.americanvideoequipment.com/catalog/vsi-pro.htm US
We interface to more cash registers than anybody else.

Cheers,

Chris Moya
cmoya@aveusa.com



"Clint Sharp" <clint@clintsmc.demon.co.uk> wrote in message
news:BFjH1sBvs2HBFwn+@clintsmc.demon.co.uk...
> Hi, I have a need for an OSD generator IC/module with PAL output but I
> only seem to find references to the STV5370A which is obsolete. Anyone
> out there using a current product? I need to be able to interface to a
> dedicated micro (probably PIC16F87x) simply and with little overhead,
> display in colour over a CCTV image and record the output (no odd
> timings)
> -- 
> Clint Sharp
>

On Sun, 15 Aug 2004 14:54:55 +0100, Clint Sharp wrote:

> Hi, I have a need for an OSD generator IC/module with PAL output but I 
> only seem to find references to the STV5370A which is obsolete. Anyone 
> out there using a current product? I need to be able to interface to a 
> dedicated micro (probably PIC16F87x) simply and with little overhead, 
> display in colour over a CCTV image and record the output (no odd 
> timings)

I was just looking at these the other day.  There are a bunch of
people who make parts with R/G/B and syncs out, fewer who make parts
with composite video out.  For the r/g/b parts you can try
ST, Philips, Renesas, Fujitsu, Sanyo, Zilog and probably Samsung and
Toshiba.

Fujitsu has two parts with composite out MB90050 and MB90092 listed on
their site here:
http://edevice.fujitsu.com/fj/DATASHEET/ef-lvmb18_50_86_1_1.html but I was
told one was obsolete, and I don't recall which it was right now.

I haven't used any of these in a product yet, so I can't comment on
how well they perform.  I also saw a few very low-res attempts using
a PIC or similar along with a LM1881 (or the updated elantec version of
same) to allow the micro to time out the data outputs and simply force
white/black pixels at the appropriate time.