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[Reply #15 on:]

Is access beyond the what's available in the driver interfaces required to get timing signals onto gpio pins?

It is getting at the timing signals that is the problem.

However that is not what you need to be able to do this project. You need to get the signals from the GPIO pins and use it to control the timing of the video output, that is something that is not available in the high level drivers.

[Reply #16 on:]

You need to get the signals from the GPIO pins and use it to control the timing of the video output, that is something that is not available in the high level drivers.

That's interesting. Do you have a source for that information?

[Reply #17 on:]

Do you have a source for that information?

Have you seen the high level driver?

[Reply #18 on:]

Do you have a source for that information?

Have you seen the high level driver?

No. I've only read some descriptions of what people have found they can do with it so far. There appear to be at leat three interfaces, a 3D, a 2D, and a general lower level interface.

But you seem to have more certain knowledge as to exactly what the drivers can and can't do.

Do you have any sources of your information regarding that? I assume you're not just assuming. 

[Reply #19 on:]

There appear to be at leat three interfaces, a 3D, a 2D, and a general lower level interface.

These are all output modes.

I assume you're not just assuming

I know what the broadcom chip was designed to do. I used to work designing set top boxes. I can't point you to any information in the public domain other than the high level drivers. However, I know that this is the sort of thing that is outside the remit of the normal use for this chip so it is an almost impossible thing to do. While not 100% sure I am 99% sure.

[Reply #20 on:]

While not 100% sure I am 99% sure.

I see. In other words, you are assuming.

BTW, I'm not sure what kind of video programming interface would be "output only". How do you expect to be able to program a card if you can't read even basic state information?

I've done a little bit of this kind of stuff myself, over the years. Obviously not as expert as you though, LOL.

So I guess we shall just have to wait to see if the truth of the matter lies in your 1% of uncertainty.  
 

[Reply #21 on:]

...so not necessarily the right piece of hardware at all
I have actually just ordered a raspberrypi too, to make a media centre, but I won't cancel my arduino order just yet, I'd love to learn more about it.

One reply interested me, talking about not processing the HD at all. Would this be possible, it's something that crossed my mind when I was originally thinking of this project- would this at all be possible with what I'm doing?
The problem with what I'm trying to achieve is that I need it to be real small- the arduino/raspberrypi are ideal.

So I guess I'll just see how things develop on both fronts to make this work.

Any other suggestions of where to start?

[Reply #22 on:]

After much hunting the only domestic chip I can find that might do the job is a SII9573 as blurb says it supports HDMI in/out with OSD but I can find no other information on the chip (apart from $34.16 price) so don't if it's really suitable or what other support chips it may need.

[Reply #23 on:]

One reply interested me, talking about not processing the HD at all. Would this be possible, it's something that crossed my mind when I was originally thinking of this project- would this at all be possible with what I'm doing?

No not really the analog kit I gave the link to appears to work by finding the h/v sync signals embeded in the analog video signal and then just adding its data at the right time to the video stream. On the analog systems there is no compression.

The HD signals are I believe compressed think MP4. So you would need to decompress, hold the frame in memory, add your data, and then recompress.

Mark

[Reply #24 on:]

The HD signals are I believe compressed think MP4

No, not at all.
Think baseband.

[Reply #25 on:]

I'm fairly new to this whole arduino thing, so I'm not really sure which one to go with.

I have ordered the starter pack to introduce myself to it and teach myself how to use it ...

You will have a lot more fun if for your first few projects you work through some of the (many) tutorials and ideas online. Just get up to speed on what it can do, and get your skills up. Then new ideas will naturally come to you. Good luck.

[Reply #26 on:]

No, not at all.
Think baseband.

Mmmmmm are we talking about the same thing? I found this spec for HD video it shows mpeg2 as the compression method.http://www.hdv-info.org/HDVSpecifications.pdf

Mark

EDIT - Found two competing systems HDV and AVCHD the spec for which is here http://www.avchd-info.org/format/index.html

M

[Reply #27 on:]

You're confusing how the image is stored and transmitted with how it is delivered to the (pretty dumb) display device. DVI and its largely compatible cousin HDMI do not carry compressed video.

[Reply #28 on:]

Any other suggestions of where to start?

I think there is a chip that will impose text onto video, I think one of my amplifiers has that for when you enter setup mode. I'm guessing it synchronizes with the incoming video and then just forces it to white (for the duration of a pixel) when text needs to be displayed.

However that is hardly an Arduino, unless the Arduino tells the chip what to display (which could well be a use for it).

[Reply #29 on:]

I agree that if the requirement requires overlay onto an HD signal, then an Arduino isn't going to cut it.  I designed the Video Experimenter shield for Arduino, but this only works for a composite video signal.  It uses an LM1881 sync separator chip to detect the timing of the video signal, then in Arduino code you can overlay low-res monochrome pixels onto the video.  It works well for many applications, but is decidedly low-tech!
http://nootropicdesign.com/ve