Maker Pro
Maker Pro

analog to digital video

J

John

Jan 1, 1970
0
Posted a few minutes ago, but the subject, and the questions, were not
a precise as I should have made them, so if you picked that message up
in the two minutes it was posted, I am sorry to have misled.... :)

Meanwhile:

This is a rather generic question, as the standards, and final
requirements, are not really well defined for me to deal with at the
moment.

A company I sometimes work for, sells character generators. They are
analog output, and of course, in the broadcast world, that is not
very appealing any more.

I am researching alternatives to some very expensive "black box"
solutions that they have been offered, to convert the CG
analog output, to digital video. . These boxes they have used, are
overkill, and include audio channels, which do not apply to the CG
application in its broadcast application.

Many head ends are using these kinds of 'black boxes' as a solution to
the fact that they do analog commercial insertion, while the
broadcasters are quickly moving to digital delivery. A stopgap
method, but a
popular one nonetheless, at this point in the changeover.

I know there are many standards for DV. Just a generic question

What I am searching for, is information and ideas as to how to create
our own 'black box' that only converts video, more of a custom
solution. The management is convinced this is doable, and so I have
been tasked with finding out how to proceed.

Its not my field of expertise, being an analog video engineer, but I
think if I can find the basic requirements of the circuits, and
hopefully the IC building blocks, I could handle it, or at least help
provide them with a direction, even if I am able to do the job.

Again, rather a generic inquiry, as opposed to all the dirty details.
Can anyone point me to a source for such components, or discussions on
this issue?

Just hoping to get a road map, to find out how to proceed.

Thanks very much for any suggestions or references.

John
 
M

martin griffith

Jan 1, 1970
0
Posted a few minutes ago, but the subject, and the questions, were not
a precise as I should have made them, so if you picked that message up
in the two minutes it was posted, I am sorry to have misled.... :)

Meanwhile:

This is a rather generic question, as the standards, and final
requirements, are not really well defined for me to deal with at the
moment.

A company I sometimes work for, sells character generators. They are
analog output, and of course, in the broadcast world, that is not
very appealing any more.

I am researching alternatives to some very expensive "black box"
solutions that they have been offered, to convert the CG
analog output, to digital video. . These boxes they have used, are
overkill, and include audio channels, which do not apply to the CG
application in its broadcast application.

Many head ends are using these kinds of 'black boxes' as a solution to
the fact that they do analog commercial insertion, while the
broadcasters are quickly moving to digital delivery. A stopgap
method, but a
popular one nonetheless, at this point in the changeover.

I know there are many standards for DV. Just a generic question

What I am searching for, is information and ideas as to how to create
our own 'black box' that only converts video, more of a custom
solution. The management is convinced this is doable, and so I have
been tasked with finding out how to proceed.

Its not my field of expertise, being an analog video engineer, but I
think if I can find the basic requirements of the circuits, and
hopefully the IC building blocks, I could handle it, or at least help
provide them with a direction, even if I am able to do the job.

Again, rather a generic inquiry, as opposed to all the dirty details.
Can anyone point me to a source for such components, or discussions on
this issue?

Just hoping to get a road map, to find out how to proceed.

Thanks very much for any suggestions or references.

John
Have a look at the TDA8754 from NXP (was philips).
It is only 8 bit, and I think lots of video is 10bit now, then you
will need someone to program a micro to control it, followed a smpte
encoder, possibly, gennum or national do them


martin
 
J

joseph2k

Jan 1, 1970
0
John said:
Posted a few minutes ago, but the subject, and the questions, were not
a precise as I should have made them, so if you picked that message up
in the two minutes it was posted, I am sorry to have misled.... :)

Meanwhile:

This is a rather generic question, as the standards, and final
requirements, are not really well defined for me to deal with at the
moment.

A company I sometimes work for, sells character generators. They are
analog output, and of course, in the broadcast world, that is not
very appealing any more.

I am researching alternatives to some very expensive "black box"
solutions that they have been offered, to convert the CG
analog output, to digital video. . These boxes they have used, are
overkill, and include audio channels, which do not apply to the CG
application in its broadcast application.

Many head ends are using these kinds of 'black boxes' as a solution to
the fact that they do analog commercial insertion, while the
broadcasters are quickly moving to digital delivery. A stopgap
method, but a
popular one nonetheless, at this point in the changeover.

I know there are many standards for DV. Just a generic question

What I am searching for, is information and ideas as to how to create
our own 'black box' that only converts video, more of a custom
solution. The management is convinced this is doable, and so I have
been tasked with finding out how to proceed.

Its not my field of expertise, being an analog video engineer, but I
think if I can find the basic requirements of the circuits, and
hopefully the IC building blocks, I could handle it, or at least help
provide them with a direction, even if I am able to do the job.

Again, rather a generic inquiry, as opposed to all the dirty details.
Can anyone point me to a source for such components, or discussions on
this issue?

Just hoping to get a road map, to find out how to proceed.

Thanks very much for any suggestions or references.

John
Well lets see, first how is the sync handled in the digital interface?
Second, since the resolution is higher you will want to use more pixels
(rows and columns) for your characters. Third, cut away the analog video
portion and substitute a digital mux (if video bleed through is desired use
adders). Then match the interfaces and the crying is over.
 
J

John

Jan 1, 1970
0
John wrote:
Well lets see, first how is the sync handled in the digital interface?

I do not know....
Then match the interfaces and the crying is over.

I'm sorry, I didn't realize anything I said was crying. I am just
wanting to know if anyone can point me to where to go to find the
information, and hardware I might use, to see how this can be done...

Thanks,

John
 
M

martin griffith

Jan 1, 1970
0
I do not know....


I'm sorry, I didn't realize anything I said was crying. I am just
wanting to know if anyone can point me to where to go to find the
information, and hardware I might use, to see how this can be done...

Thanks,

John
You need to open up the box, find out what ics drive the analogue
output, and if they are not custom, look at the apporpriate data
sheets, and figure out how to serialise the signal


martin
 
J

joseph2k

Jan 1, 1970
0
John said:
I do not know....


I'm sorry, I didn't realize anything I said was crying. I am just
wanting to know if anyone can point me to where to go to find the
information, and hardware I might use, to see how this can be done...

Thanks,

John
Your management was doing the crying. Use your loaf.
 

eedesignpro

Oct 29, 2007
1
Joined
Oct 29, 2007
Messages
1
Hi John

You should have most of the circuits and signals in your generator to do what you want to do. You only need to size the analog video signal, convert it with an ADC there are many that you could use. To do the conversion you need a clock signal, todays clock rate of choice is 13.5Mhz. But almost any clock that is 3 times the expected bandwidth of the video signal would work. 10.7Mhz,14.3Mhz,17.7Mhz it should be the same clock as you use to generate the video signal in the beginning.
 
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