Video Over Ip

[marc]

Hi all,

 

I have an application a few times a year where I need to send composite video over about 500m of PSF 1/3, it was not my installation and I can not mod it e.g. put a booster in half way, now amazingly I can get a pretty good image out the other end.

 

What I would like to do is fire the video streams (2) into a pc and run the data down a fibre link then back out at the other end and into a projector, via a video switcher, now in my mind I think this can work as fibre can hold a lot of data and its not going down a phone wire so the band width can be kept at a good rate.

 

Has any one done this kind of thing, if so what application have you used? I am looking at using pukka matrox capture cards, and running 1000 base T out of the pc to a fibre link, then running the distance and back out again, ideally I could do with running 2 streams of audio as well, a send and return, but for starters I would like to just get video working.

 

The camera I'm using is a canon XL1s, so has a pretty good picture.

 

Any thoughts much appreciated!

 

Thanks,

 

Mk

[bruce]

What I would like to do is fire the video streams (2) into a pc and run the data down a fibre link then back out at the other end and into a projector, via a video switcher, now in my mind I think this can work as fibre can hold a lot of data and its not going down a phone wire so the band width can be kept at a good rate.

 

Has any one done this kind of thing, if so what application have you used? I am looking at using pukka matrox capture cards, and running 1000 base T out of the pc to a fibre link, then running the distance and back out again, ideally I could do with running 2 streams of audio as well, a send and return, but for starters I would like to just get video working.

 

what's the application, what's the budget?

 

There are several completely different approaches you can take:

 

1. As you suggest, use some sort of capture cards, then video-over IP. Latency may be high, but may not matter - depends on the application. Don't worry about the fibre at this stage - see if you can get it to work over a Cat5 IP conection. The nice thing about IP (here comes the good old 7-layer model..) is that the higher level applications don't care what's underneath - it could be running over fibre, or copper, or wireless or...

 

Assuming you've got decent multimode fibre, driving 500m won't be a problem at Gb speeds. The cheapie way to

do it would be to use a pair of UTP-fibre media converters - a Gb converter will costy a couple of hundred pounds, although a 50 quid 100Mb/s one would probably do the job.

 

2. The other alternative is to use a dedicated video<>IP box. About the size of a paperback book, video+audio in one

end, data connection (usually UTP) at the other. Some are bidirectional. Saves all of the PC encoding gubbins.

 

3. Stay in the analogue domain. You can get converter boxes that have a composite video plus balanced audio connection - they fm modulate the signal, and then send it out over fibre. A corresponding decoder box at the other

end decodes it. Works fine, with the usual composite video quality, and virtually no latency. No IP involved, just a

dedicated fibre link

 

The hardware for (2) and (3) is commodity stuff - it's commonly used in the CCTV/surveillance industry.

 

 

I've got several sets of (3) in regular use (for lecture overspills etc) and am about to take delivery of some (2) units for some remote CCTV surveillance.

 

Bruce.

[MikeR]

Have frequently done pretty much exactly what youre talking about . Camera at one end outputting composite signal which is sent via fibre with a separate audio feed also sent via the same fibre to various output monitors and video walls etc. Control of the camera, pan tilt zoom etc achieved by sending control signal back along the fibre to the camera. Audio feed also sent back to the camera end (2 way audio). Control is over IP, video is composite although the camera I use also serves video over IP as well.

Application - visual & audio communication with F1 team garage during race etc .

Dont bother introducing margin for error with streaming video, just send the feed itself.

[mac.calder]

You may want to look into VLC which is designed for media streaming from Video Lan dot Org

[dosxuk]

I have an application a few times a year where I need to send composite video over about 500m of PSF 1/3, it was not my installation and I can not mod it e.g. put a booster in half way, now amazingly I can get a pretty good image out the other end.

 

Provided the cable is in a decent state, and you stick a decent signal down it, I see no reason why you'd have any trouble with running composite video down a 500m cable. The only trouble I've had is when you use a PC or other consumer grade device which have very low power video outs, which would require a video amp before sending.

 

In my experience working with several TV companies running analogue PAL over cables greater than 1KM long, there shouldn't be a problem. If you're getting a decent picture out the other end, why bother trying to change it?

 

We've also just tried using video/IP, using VLC and an osprey capture card, and we found the minimum delay on it to be several seconds, which is not suitable for our application. We're now sending video over CAT5 (baluns) and this works much more reliably (no windows to worry about!).

[bruce]

Provided the cable is in a decent state, and you stick a decent signal down it, I see no reason why you'd have any trouble with running composite video down a 500m cable. The only trouble I've had is when you use a PC or other consumer grade device which have very low power video outs, which would require a video amp before sending.

 

In my experience working with several TV companies running analogue PAL over cables greater than 1KM long, there shouldn't be a problem. If you're getting a decent picture out the other end, why bother trying to change it?

 

We have also run video over around a km of co-ax - works ok. Best idea is to have a decent amp at the sending end, and a scope at the rx end, and increase the input gain until the output is at an acceptable level, to compensate for the cable losses.

 

However, I think the OP was wanting to move to an alternative system as they want to transmit several video and audio streams.

 

VLC is also an option, if you have a decent capture card. I'm currently streaming about 8-10 signals, at about VHS-level quality, over a single link, and using about 15-20 Mb/s total...

[marc]

Thanks for the PM Chat Bruce,

 

So to add, I like the idea of a more hardware based system, the less it has to do with windows the better.

 

So any hot tips on web pages to find such hardware at an amazing price? I could Google for hours, but hopefully some one will have a product code of a box that works really well and save me the trial and error part of buying new kit!

 

The reason I'm after fibre is that the overall diameter is less than 4 coax and 3 audio lines! The smaller the better for the application I have for it, but it is gigging not install so the boxes will get racked, and the fibre well looked after, but if it works for a year then needs a new fibre line so be it.

 

I am used to the fibre that is used on say digico D5t's and the like, and I know all the problems with it, but it’s worth the careful application for the job I have for it.

 

Thanks for replies so far

 

Mark

[James S]

I'd suggest that the video direct to fibre converter would be the best option - less to go wrong/ delay in pc etc.

 

Try:

Race Commuinications

Website

01344 621531

 

They recently installed a 38 channel fibre video network over a large estate but I'm sure they would be able to help with what you have described.

 

HTH

[bruce]

The analogue video-over-fibre units I have used were from American Fibertek. Seem to work well. Can't remember who the UK distributers are. I have seen several on Ebay.

 

There was also a company in Fife who produced a similar, but cheaper, unit. Can't remember the details though....

 

For video-over-IP hardware, I'm about to take delivery of some units from Indigovision. Based in Edinburgh, but they don't sell direct - you need to go via a reseller. We had a demo, and it looked good.

 

These products, and other similar ones, are really aimed at the CCTV/surveillance market. So have a look at CCTV suppliers for other similar options.

 

 

Re the fibre installation - if this was for a regular event in the same location, I'd look at getting some fibre - say a 12 core multimode - permanently installed with a patch panel at each end. Any reputable data installation company should be able to do this.