Averlogic AL250 and scan doubling

Does anyone have experience with the Averlogic AL250 Video Scan Doubler IC?

Datasheet is here

http://www.ortodoxism.ro/datasheets/Averlogic/mXvqxzx.pdf

and Application notes

http://www.ieechina.com/Upload/Tech/200405191539390937.pdf

As far as interfacing to this IC, do think it's out of reach for a 
beginner?  They don't provide a schematic for their evaluation board, 
but the parts list doesn't look too crazy.

It has I2C control, which should be easily accessed from any 
microcontroller.

I've got a simple application for the IC, and it would be setup in a 
fixed configuration mode.  There's no need for multiple connectors, 
multiple display modes, etc.  One NTSC input(~15khz), one VGA 
output(~31khz).

In general, is scan doubling/de-interlacing a hard thing(TM) ?  This IC 
does some fancy things, but would simply sampling one side, buffering, 
and then outputting the other side generally work?

Thanks

Keith

"Keith M" <keithvz@yanktheobvious.verizon.net> wrote in message
news:9X%Gj.4590$N_5.2704@trnddc05...
> Does anyone have experience with the Averlogic AL250 Video Scan Doubler
IC?

Not directly but doing various resolution video deinterlacing to various
resolution
LCD panels.

> Datasheet is here
>
> http://www.ortodoxism.ro/datasheets/Averlogic/mXvqxzx.pdf
>
> and Application notes
>
> http://www.ieechina.com/Upload/Tech/200405191539390937.pdf
>
> As far as interfacing to this IC, do think it's out of reach for a
> beginner?  They don't provide a schematic for their evaluation board,
> but the parts list doesn't look too crazy.

Depends on definition of beginner as various things with video are beyond
most beginners.

> It has I2C control, which should be easily accessed from any
> microcontroller.
>
> I've got a simple application for the IC, and it would be setup in a
> fixed configuration mode.  There's no need for multiple connectors,
> multiple display modes, etc.  One NTSC input(~15khz), one VGA
> output(~31khz).

For a fixed input to LCD you will have to use NTSC YUV mode and note
that the effective 24 bit colour input is cropped to 16bit colour by the
chip.
Anything non-square pixel or using 601 formats requires a CRT that hopefully
can sync to that rate. Anything using an LCD would need register setups to
CROP the image.

> In general, is scan doubling/de-interlacing a hard thing(TM) ?  This IC
> does some fancy things, but would simply sampling one side, buffering,
> and then outputting the other side generally work?

Line doubling is one way to go. This device sort of claims interpolated
doubling
which is usually better method for handling different resolutions. But it
only
partially does this.

As this chip has to use an external video decoder/digitiser, the I would
look at other alternatives. Logic Devices make various chips for digital
processing which can be
setup quite easily to do various interpolation schemes, even changing
horizontal
resolution for full image display.

A good resource for this type of thing is the book

    Video Demystified (I have first and fourth editions)
    By Keith Jack (ex Brooktree engineer)

    ISBN 0-7506-7622-4

> Thanks
>
> Keith
--
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<http://www.pcserviceselectronics.co.uk/>    PC Services
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Paul Carpenter wrote:

> For a fixed input to LCD you will have to use NTSC YUV mode and note
> that the effective 24 bit colour input is cropped to 16bit colour by the
> chip.
> Anything non-square pixel or using 601 formats requires a CRT that hopefully
> can sync to that rate. Anything using an LCD would need register setups to
> CROP the image.

In my case I'm coming analog RGB NTSC to standard analog VGA HD15.  I 
think that the AL250 requires digital inputs, so I think I'd need to 
front the AL250 with an AL875.

 > Logic Devices make various chips for digital
> processing which can be
> setup quite easily to do various interpolation schemes, even changing
> horizontal
> resolution for full image display.

Thanks for the pointer, I'll check there.

> A good resource for this type of thing is the book
> 
>     Video Demystified (I have first and fourth editions)
>     By Keith Jack (ex Brooktree engineer)
> 
>     ISBN 0-7506-7622-4

Excellent. Thanks for the reference.  I've actually looked at that book 
before.

Thanks

Keith

"Keith M" <keithvz@yanktheobvious.verizon.net> wrote in message
news:j69Hj.12$p97.9@trnddc03...
> Paul Carpenter wrote:
>
> > For a fixed input to LCD you will have to use NTSC YUV mode and note
> > that the effective 24 bit colour input is cropped to 16bit colour by the
> > chip.
> > Anything non-square pixel or using 601 formats requires a CRT that
hopefully
> > can sync to that rate. Anything using an LCD would need register setups
to
> > CROP the image.
>
> In my case I'm coming analog RGB NTSC to standard analog VGA HD15.  I
> think that the AL250 requires digital inputs, so I think I'd need to
> front the AL250 with an AL875.

If you have RGB NTSC consider almost ANY triple Video ADC or for that matter
even 3 off TDA8702 NXP 8bit 40Mhz video ADC (available everywhere farnell
Digikey...)
These are very cheap.

Comapnion chip is TDA8703 8 bit DAC, but I generally use Fujitsu MB40760
10bit
60MHz DAC.

If you just want to line double without interpolation, it can be acheived
digitally
very simply by PLD and a selection of FIFOs or memory.

At NTSC video rates, most memorys/FIFO's can be obtained with much faster
rate than pixel rate.

>  > Logic Devices make various chips for digital
> > processing which can be
> > setup quite easily to do various interpolation schemes, even changing
> > horizontal
> > resolution for full image display.
>
> Thanks for the pointer, I'll check there.
>
> > A good resource for this type of thing is the book
> >
> >     Video Demystified (I have first and fourth editions)
> >     By Keith Jack (ex Brooktree engineer)
> >
> >     ISBN 0-7506-7622-4
>
> Excellent. Thanks for the reference.  I've actually looked at that book
> before.
>
> Thanks
>
> Keith

If this is for experimentation building one from PLD and memories/FIFOs, is
very instructional to understanding timing and what you then require when
looking
at specs for much more integrated solutions.

To drive NTSC RGB to VGA (640x480) display I would choose either LCD with
18 bit digital interface and/or full 24 bit analog o/p for better
performance.
With PLD solution and FIFOs becomes a module you can tweak or add methods.

Look at Logic devices structures I used to use LF3330 a lot.

--
Paul Carpenter          | paul@pcserviceselectronics.co.uk
<http://www.pcserviceselectronics.co.uk/>    PC Services
<http://www.pcserviceselectronics.co.uk/fonts/> Timing Diagram Font
<http://www.gnuh8.org.uk/>  GNU H8 - compiler & Renesas H8/H8S/H8 Tiny
<http://www.badweb.org.uk/> For those web sites you hate