12 Hours Urgent! - Video RCA to VGA Schematic Needed - Page 1
Forum section: electronics / beginners

author: Mechatrommer
author_rank: Super Contributor
timestamp: October 21, 2011, 10:43:34 am
content: i have a task tommorow (12 hours and counting) that i have to shoot/record an event and show live on LCD projector. my video cam only has that yellow rca out for TV, but the projector in the hall has VGA input. is there any simple and quick wiring on how to output my video cam (rca) to the projector (vga)? hope to get answer within 4 hours so i'll have 4 hours soldering and another 4 hours sleeping. please help.

author: deephaven
author_rank: Frequent Contributor
timestamp: October 21, 2011, 11:05:40 am
content: You can't do it by simple wiring, it is a completely different standard and you would need a video to VGA converter box. Are you sure the projector doesn't have any other inputs besides VGA?

author: amspire
author_rank: Super Contributor
timestamp: October 21, 2011, 11:13:34 am
content: You need to get a TV tuner card for a Windows PC with a composite video input. Probably worth something like $30-$40, but retail may be double.The as long as the PC has VGA output, you can take the composite (RCA) in and output it to the VGA screen.In a pinch, you can do the same thing with the USB video capture dongles worth about $20, but really, USB is not quite fast enough. You may find yourself stuffing around trying to get the right compression working.Richard

author: Psi
author_rank: Super Contributor
timestamp: October 21, 2011, 11:18:36 am
content: Almost all projectors have an RCA video input.There may be an issue though if the projector is mounted high up on the roof out of reach and they have only cabled the VGA connector down to the floor.

author: Joshua
author_rank: Regular Contributor
timestamp: October 21, 2011, 12:44:59 pm
content: What kind of storage does your camera use? If its flash memory than just copy it to a computer (borrow a laptop?) and use that. If it used DVD storage, use Handbrake software to 'rip' the DVD to computer.If it uses DVDs, you will probably have to format it in the camera before using the software.Let me know if you need more details.Joshua

author: Mechatrommer
author_rank: Super Contributor
timestamp: October 21, 2011, 03:34:53 pm
content: ok. times up. deephaven seems to conclude it in clearest manner, there's no direct way. i guess 2 wires rca -> 15 pins vga is impossible without extra components (chip?). i googled i saw vga->rca is possible, but i guess not the other way around. the projector is high above as Psi predicted, few tens feet overhead, the wire goes inside the ceiling and popped out another tens feet away to the back of hall, vga only. @Joshua: thats not an option, this is a "live" show, storage is even not mandatory. i guess i'll go as amspire's suggested, that is my backup plan, ie rca->usb convertor->netbook->vga. i have the device. but it kinda inefficient, its like going round the longer road to go to your neighboor house just next to you. thanks everybody for suggestions, i'll go setting up my netbook and video convertor tonight to bring tomorrow.

author: deephaven
author_rank: Frequent Contributor
timestamp: October 21, 2011, 03:56:08 pm
content: This is the sort of thing you need:http://www.amazon.co.uk/ClimaxDigital-Video-S-Video-Converter-Compatible/dp/B001AUFVYE/ref=pd_cp_ce_2

author: Mechatrommer
author_rank: Super Contributor
timestamp: October 21, 2011, 04:19:57 pm
content: yes, if i can have the schematic.

author: Unknown
author_rank: Unknown
timestamp: October 21, 2011, 05:03:47 pm
content: My guess is that it uses something likethis. How's the schematic going to help you?

author: Mechatrommer
author_rank: Super Contributor
timestamp: October 21, 2011, 08:12:01 pm
content: looking at your linked picture, well its not going to help. btw, my netbook is set, not up to the desired performance fps, maybe due to multiple conversion and software rendering, but thats the best i can cramp this few hours. gtg sleep, 2 hours left

author: NiHaoMike
author_rank: Super Contributor
timestamp: October 23, 2011, 04:11:13 am
content: Quote from: amspire on October 21, 2011, 11:13:34 amUSB 2.0 is more than fast enough for digitized composite video.If it's a newer camera, it likely would have IEEE1394 and/or USB. Then it's just a matter of using xawtv, mplayer, or similar to play back the stream.

author: amspire
author_rank: Super Contributor
timestamp: October 23, 2011, 04:26:02 am
content: Quote from: NiHaoMike on October 23, 2011, 04:11:13 amI was talking about using the standard cheap USB video capture dongle to capture the composite video. Converting from Composite Video was the original requirement.USB2.0 cannot maintain the video framerate uncompressed, so you have to use the built in MPEG2 compression in the dongle. It works, but is low quality.Yes, if the signal is being compressed in the camera, then USB2.0 would be adequate without any dongle.Richard

author: NiHaoMike
author_rank: Super Contributor
timestamp: October 23, 2011, 05:07:51 am
content: Composite video only has a 6MHz bandwidth. That's only 96Mbps after 8 bit digitization, while USB 2.0 does up to 480Mbps. (Account for blanking and the actual data rate is even less.)

author: amspire
author_rank: Super Contributor
timestamp: October 23, 2011, 05:41:19 am
content: You are right, but USB is not great at maintaining the full rate - particularly coming from a $20 dongle. It might manage 15 frames a second.Firewire was always much better at streaming, but the new USB3 will be fine.

author: Mechatrommer
author_rank: Super Contributor
timestamp: October 23, 2011, 08:19:50 am
content: my video cam has firewire (ieee1394) and can transfer the video realtime to my PC, but the netbook doesnt have the port, so the usb. and yes that was cheapo dongle i was using. and all video capture devices i have (all categorized as cheapo though) are sucks at transferring vidz through USB, i got the feeling i will blame on the usb connection, or more like the software capturing it. the way i see it, 720 x 480 x (3bytes/pixel) x 30fps = ~30MB/sec uncompressed. taking mpg let say 1/10 compression size = 3MB/s, still a big figure from practical point of view. greater compression achiveable but that should take a real hardware converter i guess, and that not taking into account the efficiency for the driver/OS/API/software when the data is actually arrived inside the CPU. btw, the event is over, maybe one time i will look into the RCA->VGA device suggested by deephaven above, or more robust USB video capture device.edit: and i'm a strong believer that 480Mbps (60MB/s) is purely theoritical, from my day to day experience using USB connection transferring large data.