PDA

View Full Version : "Video Generator" documentation ?



Bean
10-27-2006, 08:56 PM
Is there any documentation on the "Video Generator" that exists in each cog ?
I didn't see anything in the manual.
I want to make a video overlay module, so it won't be "normal" video output.

Bean.


▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Cheap used 4-digit LED display with driver IC·www.hc4led.com (http://www.hc4led.com)

Low power SD Data Logger www.sddatalogger.com (http://www.sddatalogger.com)
SX-Video Display Modules www.sxvm.com (http://www.sxvm.com)

"People who are willing to trade their freedom for·security deserve neither and will lose both." Benjamin Franklin
·

potatohead
10-27-2006, 09:16 PM
I'm wanting the same, as I want to generate some video that will be added to another video signal. I'm guessing my questions are the same as Bean's, I just don't know it yet.

In my case, I want to suppress sync and other framing signals and just output pixels at the right time to overlay with the master video signal.

Mike Green
10-27-2006, 09:25 PM
The sync and other framing signals are generated by the video driver code itself. The "Video Generator" is mostly for help in generating the color information on a pixel by pixel basis. You would have to rewrite the TV.spin driver to use an external sync separator to mark the start of a scan line, then delay a fixed amount of time (easy to do with WAITCNT), then start outputting pixels using the video generator. Obviously, you'd also have to count scan lines from the vertical sync pulse. Take a close look at TV.spin and how it generates the sync information.

Bean
10-27-2006, 11:06 PM
Thanks Mike,
So is the "Video Generator" just a shift register or what ?
And is there any documentation on it (beside the tv.spin object) ?
Inquiring minds want to know.

Bean.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Cheap used 4-digit LED display with driver IC·www.hc4led.com (http://www.hc4led.com)

Low power SD Data Logger www.sddatalogger.com (http://www.sddatalogger.com)
SX-Video Display Modules www.sxvm.com (http://www.sxvm.com)

"People who are willing to trade their freedom for·security deserve neither and will lose both." Benjamin Franklin
·

cbmeeks
10-28-2006, 12:07 AM
So Bean, have you gotten a Propeller TOO? http://forums.parallax.com/images/smilies/smile.gif

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Coders' Hangout
A place for programmers to hangout!
http://www.codershangout.com

METROID?
Metroid Classic (http://metroidclassic.com)

Bean
10-28-2006, 12:12 AM
I've had one for quite some time, but I haven't had much time to "play" with it.

I'm working on my high-res (256x192 pixel) overlay using the SX48. I got everything working except the serial comms.

I just can't get it reliable, and when I started thinking "Hmmm maybe I'll add another SX just to handle the comms", I knew it was time to use the propeller.

I also won't need an external SRAM (only need 12K for pixel data), and the comms will be no-sweat. It is a bit more expensive, but I think the expense will be worth it.

Bean.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Cheap used 4-digit LED display with driver IC·www.hc4led.com (http://www.hc4led.com)

Low power SD Data Logger www.sddatalogger.com (http://www.sddatalogger.com)
SX-Video Display Modules www.sxvm.com (http://www.sxvm.com)

"People who are willing to trade their freedom for·security deserve neither and will lose both." Benjamin Franklin
·

cbmeeks
10-28-2006, 12:22 AM
Well, I am in the same boat. I was thinking of using two SX's for a blitter and GPU and thought it was time to use the Prop as well. I felt a little depressed leaving the SX because it is such a great µC. I felt the same way when I left the PIC world for the SX. But I remind myself of my original goal. To design an 8-bit 6502 based computer. I just don't have time to spend 6 months on a GPU.

While I probably won't use the built-in graphic functions in the Prop on version 2, I probably will on version 1.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Coders' Hangout
A place for programmers to hangout!
http://www.codershangout.com

METROID?
Metroid Classic (http://metroidclassic.com)

Paul Baker
10-28-2006, 01:01 AM
The video documentation will be released after the counter documentation, it's is pretty low on the list of priorities at this moment, so that means not until next year sometime.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Paul Baker (mailto:pbaker@parallax.com)
Propeller Applications Engineer
[/url][url=http://www.parallax.com] (http://www.parallax.com)
Parallax, Inc. (http://www.parallax.com)

Mike Green
10-28-2006, 01:01 AM
Bean,
The "Video Generator" is essentially a shift register with quite a bit of logic around it for mostly configuration ability. It can generate VGA, TV baseband, or TV broadcast signals on any group of 8 pins (4 pins for TV) with configurable timing. The shift register is loaded by the WAITVID instruction which provides a group of 16 or 32 pixels using 1 of 4 or 1 of 2 colors respectively and the actual color information is also provided by the WAITVID instruction separately as 4 or 2 bytes.

Look at the WAITVID call and the VCFG and VSCL register descriptions in the SPIN section of the Propeller Manual.
Mike

Phil Pilgrim (PhiPi)
10-28-2006, 01:22 AM
Bean,

Several years ago I built an overlay generator for a customer who needed GPS info on top of his underwater camera video. I used an SX48 and ran into the same comm issues you did. It just wasn't possible to manage the video timing and an incoming asynchronous data stream at the same time. I ended up adding an SX20 to the board just to field the comms and supply them to the SX48 when it asked for them during the blanking intervals. If I were to do it again, I'd probably use an 8-pin AVR for the comms: an SX is overkill for that. The SX48 was great for the overlay generation, though.

-Phil

AndreL
10-30-2006, 04:17 PM
FYI - "Game Programming for the Propeller Powered HYDRA" not only discusses the HYDRA, but is the most in depth documentation on propeller graphics programming available. The book will be available shortly, and VERY detailed explanations of everything are in it.

Andre

cbmeeks
10-30-2006, 07:37 PM
Andre, do you completely re-write the graphics core for the Hydra? What kind of resolution are you getting? Color depth? Can you give details on the sprites?

Thanks!

PS, by my quick calculations, it looks like you posted that at around 1:00 am on a Monday (Pacific). Get some sleep dude! hahaha

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Coders' Hangout
A place for programmers to hangout!
http://www.codershangout.com

METROID?
Metroid Classic (http://metroidclassic.com)