I have a computer which is outputting its display graphics on a VGA cable. I could change output modes if I had to. I want to take that signal, and provide it as webcam input to another computer. Specifically, I will be using it as input to a program I wrote in OpenCV.
Is this possible? Feasible? If so, how? I'm in uncharted territory here.
Of course it is possible.
But not with an Arduino.
Kethis:
I have a computer which is outputting its display graphics on a VGA cable. I could change output modes if I had to. I want to take that signal, and provide it as webcam input to another computer. Specifically, I will be using it as input to a program I wrote in OpenCV.Is this possible? Feasible? If so, how? I'm in uncharted territory here.
Yup they are called scan converters were common back in the late 80's 90's. First hit on google is 20 bucks via amazon. Mind you they never worked that well that I remember.
Why not?
The RGB information is sent serially along 3 pins, at 5v. You should be able to capture that with the Arduino, right? Don't you "just" need to write a driver to present the Arduino as a webcam? Again, I am new to this, but I want to make sure I actually understand the issues at hand.
If not using an Arduino, how?
Could you link me to that converter? A brief bit of Googling doesn't seem to show one that converts VGA output to webcam input.
You should be able to capture that with the Arduino, right?
Wrong. Where are you going to put it?
Use a scan converter.
Kethis:
Why not?The RGB information is sent serially along 3 pins, at 5v. You should be able to capture that with the Arduino, right? Don't you "just" need to write a driver to present the Arduino as a webcam? Again, I am new to this, but I want to make sure I actually understand the issues at hand.
If not using an Arduino, how?
Could you link me to that converter? A brief bit of Googling doesn't seem to show one that converts VGA output to webcam input.
Because it's nowhere near fast enough. It's sent analog on 5 pins, even assuming you can skip the h and v sync your still talking about doing 3640480*30 analog samples a sec aka 27 million samples on a16mhz chip that can do about 1 thing per clock cycle. Add to that any arduino besides the leo is serial attached you can not get enough data though a pc serial port to get a video signal though it.
Sorry I read composite input you would also need a composite input again a few bucks on amazon/ebay. There are some devices like the lantroix spider that can convert vga to IP but they cost more (and look better than) but do not show up as a camera input unlike the scan converter and usb composite input (see if you ca get s-video it looks a bit better) combo. Opengear made a PCI card to do this I believe it was an open design it was made to have a custom vnc server use it http://okvm.sourceforge.net/.
AWOL:
Wrong. Where are you going to put it?Use a scan converter.
An SD card.
I'm sure its unintentional but your terse responses truthfully came off as condescending. I have plenty of places to go to have people authoritatively tell me what I can't do. Here, I am looking for help in how to achieve a goal. If an approach won't work, I need to understand why, and how to overcome.
Assume I had not understand what you meant by "Wrong. Where would you put it?". Would that reply have helped me better understand the limiting factor? Just telling someone asking for help that they are "Wrong" is not constructive.
Are there any scan converters that perform how I need them to in the mentioned $20 range? I found a used one at ~$160. I can handle a low frame rate, but my budget is tight.
http://www.amazon.com/Videosecu-Converter-Computer-Composite-Switcher/dp/B000X3FAJU 20 buck scan converter, could be cheaper that just my first match on google
http://www.amazon.com/BestDealUSA-Video-Adapter-Audio-Grabber/dp/B005KO3L6G/ref=sr_1_15?s=electronics&ie=UTF8&qid=1348080703&sr=1-15&keywords=usb+composite 10 buck usb composite (and s-vdeo) dongle (mind you it's probably not linux compatible) again first thing I found not necessarily the best.
Like I said you do not have nearly enough cpu umph to capture vga on a duino or even shift it around uncompressed.
silasmoeckel:
http://www.amazon.com/Videosecu-Converter-Computer-Composite-Switcher/dp/B000X3FAJU 20 buck scan converter, could be cheaper that just my first match on google
http://www.amazon.com/BestDealUSA-Video-Adapter-Audio-Grabber/dp/B005KO3L6G/ref=sr_1_15?s=electronics&ie=UTF8&qid=1348080703&sr=1-15&keywords=usb+composite 10 buck usb composite (and s-vdeo) dongle (mind you it's probably not linux compatible) again first thing I found not necessarily the best.Like I said you do not have nearly enough cpu umph to capture vga on a duino or even shift it around uncompressed.
Thanks, I appreciate it. I saw that but didn't realize it would do what I needed. That should be enough for me to do the rest of the research myself.
It doesn't /have/ to be Linux compatible, but it'd be nice.
I was originally assuming that I'd be able to at least catch it, and then simply learn to deal with a low frame rate.
The other issue, which didn't seem to be addressed here, is what was meant
by "webcam input". Seems to me that webcams typically come in 2 varieties,
those that transmit wi-fi signals and those that plug into USB ports on PCS and
come with Windows or Linux drivers. Neither one is gonna work with Arduino.
So what is probably needed is more the VGA -> scan converter -> video capture
pod [as shown on some of the previous links]. However, those video capture pods
are mostly USB devices and come with drivers to run on PCs.
So, Arduino isn't gonna figure in this in any manner. It's all PCs.
Is this possible? Feasible?
You should be able to capture that with the Arduino, right?
I'm sure its unintentional but your terse responses truthfully came off as condescending.
After two questions, then a strange rhetorical assertion, I was aiming for "authoratative", but I guess I fell short.
The arithmetic is simple, and the SD card suggestion only compounds the difficulty (camcorders don't write raw video to SD, and the Arduino isn't up to compression at video rates either)
I was only trying to save you wasting time/money.
It is also a good idea to do some real research first... before asking for help, Just so you can "Properly" frame the questions, like the abilities of an Arduino, It's ability to write to an SD card is a limit but so is the sd card for real time video work. there is also the thought that it is the same technology as the EEPROM in the Arduino and thus write time limited which is likely to be an issue.
Doc
harumpy pumpy bump!
what if the capture resolution was brought down... say, 10hz, and the capture size was retimed, instead of trying for 640480, you drop the capture time by a factor of 10 and capture 6448, this end would be 36448*10, 92160... would these be feasible figures for the arduino to play with?
kelvinmead:
harumpy pumpy bump!what if the capture resolution was brought down... say, 10hz, and the capture size was retimed, instead of trying for 640480, you drop the capture time by a factor of 10 and capture 6448, this end would be 36448*10, 92160... would these be feasible figures for the arduino to play with?
Possibly, but I'd not want to watch a moving picture of that quality for long. The TV out library gives me a screen size of 128*96 (and that's very 'blocky') at 50 frames/second in black and white. I can't imagine 'pixels' 4 times as large and moving at 10 frames/second being of viewable quality. It would be like trying to make a sphere out of Duplo bricks.