# Composite video???



## RonHebbard (May 6, 2019)

Does composite video still exist or has it gone the way of Edison cylinder recorders and open reel audio decks*?*
Life used to be so simple in the era of analogue composite video: An infra-red sensitive camera, clear colored images under normal stage lighting shifting automatically to decent black and white images under infra-red; camera output into a powered video splitter, runs of simple co-ax to every monitor in your complex. It was all so easy.
Have "_improvements_" robbed us of the reliable simplicity*??*
Did I miss composite video's funeral*???*
Toodleoo!
*@MNicolai @FMEng @Ancient Engineer @TimMc @Amiers* At anyone*????* 
Toodleoo!
Ron Hebbard


----------



## Ancient Engineer (May 6, 2019)

I just installed a Videotek 1X6 compensating DA into a local theater that had an astonishing array of Y-cables (dear <insert name of your favorite diety here> don't get me started on the awfulness of Y-cables!) to solve stage and dressing room monitor problems...

It is sad that the simplicity of a BNC connector that any ol' drunken sailor could put on has been replaced with HDMI that, quite frankly, is way easier to just buy made.

Composite would go over a 1000' run and still make a passable picture.

Nowadays if the booth is more than 300' from the stage... you have to resort to compromising the signal by converting it to something else, or inserting boxes into the signal path.

Generally reducing the reliability just to make lengths... HDMI over NIC is not an improvement really with now two boxes (needing power) and two connections becoming six connections (with at least -2dB loss at each connection interface)

The real difference is that analog composite would show you _something_, even if the cable, camera, and monitor were all crap. 

In an emergency I ran composite over 14/2 lamp cord to get through a show, it made a good enough image...

HDMI is not robust in that regard, it needs a _lot_ of good packets before anything like an image makes the trip.

It is one of many reasons why I use HD-SDI if at all possible for high definition data.


----------



## RonHebbard (May 6, 2019)

Ancient Engineer said:


> I just installed a Videotek 1X6 compensating DA into a local theater that had an astonishing array of Y-cables (dear <insert name of your favorite diety here> don't get me started on the awfulness of Y-cables!) to solve stage and dressing room monitor problems...
> 
> It is sad that the simplicity of a BNC connector that any ol' drunken sailor could put on has been replaced with HDMI that, quite frankly, is way easier to just buy made.
> 
> ...


* @Ancient Engineer* To answer my query: Are you telling me I've missed the funeral AND the obit*?*
Toodleoo! 
Ron Hebbard


----------



## Ancient Engineer (May 6, 2019)

Well... I think the ashes have already been spread...

Us elders will wax poetically about the "good ol' days" while the whipper-snappers will scoff at us and our 525 lines of resolution as petroglyphs.


----------



## jtweigandt (May 6, 2019)

I use digital for my backstage monitors, but I use a miniature color camera with composite output and run it to an rf modulator to feed the coax to our
2 offstage monitors (old 12 inch color tv's) used so offstage chorus can sing in time with the director. Analog video is the ONLY thing that will do here. Even very expensive digital has too much
encoding and decoding lag ... I got ryh thm..... I .........who c...ould.. ...ask fo ...r anything more.


----------



## FMEng (May 6, 2019)

Composite may be dead, but coax with BNC lives on for video. It's used for SDI, serial digital interface. Mostly used with pro gear, although I found a security camera with it. It's good for distances to 300 meters. Beyond that, it's fiber optic cable.


----------



## RonHebbard (May 7, 2019)

FMEng said:


> Composite may be dead, but coax with BNC lives on for video. It's used for SDI, serial digital interface. Mostly used with pro gear, although I found a security camera with it. It's good for distances to 300 meters. Beyond that, it's fiber optic cable.


 *@FMEng* Coax with what type of connectors, larger PL connectors or smaller F connectors*?* My mind's drawing a blank on Amphenol's designation for their larger pro' connectors, PL259 possibly*??* I was pleased and delighted to see *@jtweigandt* 's post regarding composite video and particularly enjoyed how he illustrated his problems with the newer gear. 
Toodleoo! 
Ron Hebbard


----------



## Ancient Engineer (May 7, 2019)

Yup, we use HD-SDI all over the place with good-ol BNCs. It is a great system for high-speed data.

PL259 style connectors don't handle the higher frequencies as well as BNCs.

300MHz is the bleeding edge a PL2549 and 100MHz is really the practical limit. BNCs can be used up to 4GHz! Interestingly the lowly "F" or RF connector is good up to about 2Ghz!

Considering the PL259 was designed with NTSC video in mind (which has a 6MHz bandwidth) its eventual transition to RF uses is reasonable for VHF types of applications.

I have seen them on 2 meter ham equipment, but this is really above the practical limit for the connector. (I convert my Yaesu 2M ham gear to BNCs...)


There is a delay-less (well... nearly) HD digital transmission system.

I had used it for broadcast applications and we use it at the park for remote real-time cameras: https://www.teradek.com/collections/bolt-family

It is some serious magical wonderment...


----------



## jtweigandt (May 7, 2019)

I am guessing even with wonderful encoding/transfer on the send side, my cheap HD Tv monitors would still be problematic on the decode side. Interesting to turn on 2 tv’s these days to an over the air HD station. They many times (most?) will not be synchronized. As it is even with a really nice encoder.. we get a 1.5 second delay from Reality to monitor output. But then I am encoding to a cable video channel so I don’t need any special hardware on the far end. Have a nice encoder from Pro Video (PVI). Supposed to be getting Something like 40 ms encoding... but even that is 4/100 of a second. My delay I’m sure is on the cheap tv side.


----------



## Ancient Engineer (May 7, 2019)

We did a test in NYC back oh, in 2011, with 10 commercially available televisions set up in the same room.

All tuned to the same local station with a basic antenna on each.

3 of the TVs were the same make and model.

When turned on at the same time, none were in sync.

Even within the same brand/model.

The greatest difference was just over 5 seconds (!).

Sometimes... digital is just awful.


----------



## RonHebbard (May 7, 2019)

Ancient Engineer said:


> Yup, we use HD-SDI all over the place with good-ol BNCs. It is a great system for high-speed data.
> 
> PL259 style connectors don't handle the higher frequencies as well as BNCs.
> 
> ...


 *@Ancient Engineer* Back in my broadcast days our Motorola 2-ways used PL259's for antenna connectors, we had a line powered base station in our control room with its antenna routed to the roof of our 15 story building. When our studios were relocated to a taller building, we moved our base station to an elevator penthouse where we could use a much shorter run of coax to feed its antenna. We had several portable units, one lived in the main news department car while another went in a boat during the summer for our marine patrol and also went in a copter for traffic reports; during the winter it ended up in another news vehicle. Al of our Motorola's used PL259's for their antenna connectors; even our news guys couldn't mis connect them, we sealed the one outside on the roof with some kind of waterproof sealant that never dried out. 
Toodleoo!
Ron Hebbard


----------



## Ancient Engineer (May 7, 2019)

Sure, but I'd wager they were in the 30-60MHz VHF frequency range,_ back in the day_ when you could use those frequencies... perfectly suited.

We use N-type connectors for our 400-475MHz UHF stuff here. The goop on the connectors at the bottom of the radiators needs annual care, here by the lake...

Icky


----------



## ruinexplorer (May 7, 2019)

RonHebbard said:


> Does composite video still exist or has it gone the way of Edison cylinder recorders and open reel audio decks*?*
> Life used to be so simple in the era of analogue composite video: An infra-red sensitive camera, clear colored images under normal stage lighting shifting automatically to decent black and white images under infra-red; camera output into a powered video splitter, runs of simple co-ax to every monitor in your complex. It was all so easy.
> Have "_improvements_" robbed us of the reliable simplicity*??*
> Did I miss composite video's funeral???
> ...



I don't think that you missed the funeral, composite is hanging out in hospice. It's there and good as it ever was. The problem is, composite isn't up to snuff with the quality of image being processed. 

As for digital not being good enough for theatrical use (latency), you just need to get the right equipment. Cheap gear has always given sub-par results. Same goes with newer technology. Video technology today is considerably different than 2011. Even five years ago, I might have agreed that conductor monitors had to still be analog. That may be still the case for some budgets. Going against changing technology won't help anyone. Do you still tell audio technicians that they should use tube amps?


----------



## jtweigandt (May 7, 2019)

OK call me when you have a digital conductor setup that can match mine in price performance ratio. 30 buck camera 25 buck rf modulator 2 free color tv’s. No detectable latency. For the conductor, I don’t need great resolution, I need as close to zero lag as possible. For the stage monitors, I have a 300 buck camera an 800 buck digital encoder and a series of 8 $100 digital TV’s which are much more satisfying to see the stage. You can’t get me zero apparent latency on the conductor for less than $5,000 bucks I’m betting. So in this case, in our community theater, old, cheap, and effective is the rule of the day for the pitcam. The 2 most recent concerts I was at.. Jeff Dunham, and James Taylor had live video, I’m sure they were not using cheap stuff either. You could watch, and not be annoyed, latency was still in the 250 millisecond range, but the feed was not good enough for use by a musician following a conductor. 250 ms is a 16th note at only a 60 tempo. That aint that fast musically speaking.


----------



## jtweigandt (May 7, 2019)

This is audio, but you all owe it to yourself to listen to this series “Ways of hearing” about the transition from analog to digital audio recording over the last few decades. Really well done and thought provoking. 99% invisible is one of my favorite podcasts. I listened to this part of the series to get me through painting the kitchen. https://99percentinvisible.org/episode/ways-of-hearing/


----------



## EdSavoie (May 8, 2019)

Composite video over coax with BNC connectors? Why, clearly the future is using that coax to pass your video data over 10BASE5 or 10BASE2!


----------



## ruinexplorer (May 8, 2019)

jtweigandt said:


> OK call me when you have a digital conductor setup that can match mine in price performance ratio. 30 buck camera 25 buck rf modulator 2 free color tv’s. No detectable latency.



Snark duly noted. As I stated, it depends on budget. Community theater often has to support itself in thrift shops. That will be your source for TV monitors. It might start to be difficult even there as some thrift stores are refusing the old TV sets since most people don't want them, they take up a lot of space, and legally you can't just throw them away (even though many people still do).

> For the conductor, I don’t need great resolution, I need as close to zero lag as possible. For the stage monitors, I have a 300 buck camera an 800 buck digital encoder and a series of 8 $100 digital TV’s which are much more satisfying to see the stage. You can’t get me zero apparent latency on the conductor for less than $5,000 bucks I’m betting. So in this case, in our community theater, old, cheap, and effective is the rule of the day for the pitcam. The 2 most recent concerts I was at.. Jeff Dunham, and James Taylor had live video, I’m sure they were not using cheap stuff either. You could watch, and not be annoyed, latency was still in the 250 millisecond range, but the feed was not good enough for use by a musician following a conductor. 250 ms is a 16th note at only a 60 tempo. That aint that fast musically speaking.


Once you understand how digital equipment processes a signal, you can get no noticeable latency if you do it right. Yes, even in a $5000 budget, depending on your space.


----------



## jtweigandt (May 8, 2019)

I actually have a stack of 4 "reserve" monitors up in the light loft. I understand digital endoding, and decoding. It's really as simple as my sisters tell me.
"Natural Beauty just takes time and money." I've turned away more analog set "donations" over the last 5 years than I can shake a stick at. Hopefully by the time
I exhaust my reserves, then natural beauty will have fallen drastically in price, as it did for my backstage digital monitors. But for now, no way I can justify the outlay
to myself, or my board of directors. What I really want is an old philco predicta set though... now those are the coolest analog monitors on the planet.


----------



## Ancient Engineer (May 9, 2019)

ruinexplorer said:


> Do you still tell audio technicians that they should use tube amps?



Apples and oranges... Tube amps and solid state amps process the same analog signal in similar ways. 
NPN transistors are essentially a triode made out of rocks... and there is no PNP transistor tube equivalent... OK, so similar...


To make your comparison more relevant IMHO you need to address the signal and all its 'isms...

Like:
"Do you still tell audio engineers to record direct to 2" analog audio tape?"
or 
"Do you still tell video engineers to send the subcarrier separate from the video?"


...


But more to your point: I am _not_ an advocate for going against changing technology.

I _never ever_ want to have to use a quadruplex recorder for a critical recording application. (I could if I had to though...ugh)


I _am_ an advocate for not leaping from a crawl. Mayhaps we we could walk a little first...


Maybe we (the collective "we") could make logical choices based on the compromises inherit in all decision making.

That would be nice.


----------



## jtweigandt (May 9, 2019)

I guess what I am sayingt right now is that in the analog video world, we had incremental improvements until we reached the technical ceiling so to speak. But each part of the path forward didn’t come with as much sticker shock. To move from a 100 buck analog no latency director cam to digital is not a few bucks more, but rather an order of magnitude. Fine if you want to be an “Early adopter” or if you really want/need the increased video resolution. For me the matrix of price, latency, and quality.. is still a “pick any two” situation. Especially if it’s a function that does not impact what the audience sees or hears.


----------



## Jay Ashworth (May 11, 2019)

With HDMI, and a decent camera and a monitor chosen for the purpose, I strongly suspect that it's possible to get delay of no more than 3 frames, maybe 4. That's .1 second or so, which is at the limit of perception of most untrained observers.

https://www.pubnub.com/blog/how-fast-is-realtime-human-perception-and-technology/

The only way you'll see something less than 3-4 frames (30ms per frame or so) is if you have 2 monitors *of different delays* next to one another, and you watch for cuts; it won't be perceptible in dissolves either.


----------



## ruinexplorer (May 11, 2019)

jtweigandt said:


> I guess what I am sayingt right now is that in the analog video world, we had incremental improvements until we reached the technical ceiling so to speak. But each part of the path forward didn’t come with as much sticker shock. To move from a 100 buck analog no latency director cam to digital is not a few bucks more, but rather an order of magnitude. Fine if you want to be an “Early adopter” or if you really want/need the increased video resolution. For me the matrix of price, latency, and quality.. is still a “pick any two” situation. Especially if it’s a function that does not impact what the audience sees or hears.



We have been making incremental improvements in digital as well. Problem is, most people weren't aware of the early bits. It was too expensive and analog was still an option. With the analog sunset in consumer gear, many people who wanted to not move forward are starting to have their hand forced. The cost of digital gear has plummeted as a result. However, with that, there is a much greater gap in quality.

My best advice for anyone who is moving to digital is to get the display with the fewest type of inputs, preferably one type of input. Ideally, if you can go with SDI all the way (camera, distribution, monitor), then you will have the best results. Every piece of gear that has the possibility of processing the signal will add latency. SDI, created for the broadcast industry, may add some additional cost to your purchase as it was never intended for consumer equipment. Another option is HDBase-T, which is designed for consumer gear. It has dramatically increased in availability and dropped in price over the past few years. Again, if you have the camera, distribution, and monitor that are all using that protocol, then it has essentially no latency. 

As I said before, composite is not dead. It may become increasingly more difficult to support, but it isn't dead. It is still the right method of distribution for some situations.


----------



## EdSavoie (May 11, 2019)

The only thing I've used my composite cables for in the last five years was coaxial digital audio


----------



## ruinexplorer (May 11, 2019)

Last week, I used RGBHV for a confidence monitor. The signal to the projector was DVI over fiber. It should always be a combination of what's best and what is necessary.


----------



## TimMc (May 13, 2019)

ruinexplorer said:


> Last week, I used RGBHV for a confidence monitor. The signal to the projector was DVI over fiber. It should always be a combination of what's best and what is necessary.



"What's best, what's necessary, what's available, what's your budget?"


----------



## eadler (May 15, 2019)

Composite video is not 'dead' but you're only going to find it on small security/lipstick cameras and maybe some low-end consumer 'toy' cameras and you'll still want either a professional monitor or a CRT (ideally a professional CRT) to display as real-time as possible. It's definitely harder to find what you need for a real-time composite feed than it used to.

SDI (and HDSDI and 3GSDI and ...) is true realtime and the signaling format is backwards compatible*. If you get a professional (3G/HD)SDI camera and feed it into a professional (3G/HD)SDI display then the only delay you should have is the capture and display time delay - there shouldn't be any buffers in the way and the image is 'scanned' down the cable just as it was for a CRT with a flyback. Note that a CCD capture device does not scan sequentially so there may be some added minor delay here so you would probably want a CMOS imager and most LCDs display what is essentially whole-image at once so you may have some minor delay here but those delays even if you have them should add up to at most 2 frames (1/15 of a second) - the better you configure your system, the lower that delay. If you want to talk standards and details (SAV/EAV/color encoding/etc.), let me know. 
Oh, and I don't feel like I'm old enough to be an "old timer" but I can wax philosophically about NTSC, NTSC-II, NTSC-III, System B/G/I/K/..., PAL, SECAM, et al. all day long. 


* seriously, us TV folks keep making sure everything works in lock-step with the previous generation so in theory you could take a 12GSDI dual link 4K signal and generate a NTSC black and white [not NTSC-II or NTSC-III color] signal in realtime and the most delay would be less than a front porch, likely less than a color subcarrier wave or two - if someone has made the hardware to do this is a different question.


----------



## Ancient Engineer (May 15, 2019)

Remember when Chyron, Vidifont, and other CG (thats Character Generators, you yutes) systems relative quality was measured in waveform rise-times.

27ns and so on. I think the 4100s got down to like 15ns.

Yup, I was sittin' on the front porch admiring the burst of subcarrier shrubs...


----------



## RonHebbard (May 15, 2019)

eadler said:


> Composite video is not 'dead' but you're only going to find it on small security/lipstick cameras and maybe some low-end consumer 'toy' cameras and you'll still want either a professional monitor or a CRT (ideally a professional CRT) to display as real-time as possible. It's definitely harder to find what you need for a real-time composite feed than it used to.
> 
> SDI (and HDSDI and 3GSDI and ...) is true realtime and the signaling format is backwards compatible*. If you get a professional (3G/HD)SDI camera and feed it into a professional (3G/HD)SDI display then the only delay you should have is the capture and display time delay - there shouldn't be any buffers in the way and the image is 'scanned' down the cable just as it was for a CRT with a flyback. Note that a CCD capture device does not scan sequentially so there may be some added minor delay here so you would probably want a CMOS imager and most LCDs display what is essentially whole-image at once so you may have some minor delay here but those delays even if you have them should add up to at most 2 frames (1/15 of a second) - the better you configure your system, the lower that delay. If you want to talk standards and details (SAV/EAV/color encoding/etc.), let me know.
> Oh, and I don't feel like I'm old enough to be an "old timer" but I can wax philosophically about NTSC, NTSC-II, NTSC-III, System B/G/I/K/..., PAL, SECAM, et al. all day long.
> ...


* @eadler * Would you mind '_philosophically waxing'_ a few frames from a couple of RCA's 2" Helical cartridge shuffling decks; these were practically from the steam age and somewhat 'Rube Goldberg' like when a pair were steaming their way through a top of the hour commercial break with a station ID and a couple of PSA's tossed in for extra credits. 
Toodleoo! 
Ron Hebbard


----------



## EdSavoie (May 15, 2019)

(If i may slightly de-rail the initial subject of this thread while we're on the topic of video latency)

What's up with NDI? The barebones theoretical latency is tiny, yet whenever I've tried using it over a 10Gb/s connection between two machines, it always seems to be in the 100s of milliseconds...


----------



## ruinexplorer (May 15, 2019)

EdSavoie said:


> (If i may slightly de-rail the initial subject of this thread while we're on the topic of video latency)
> 
> What's up with NDI? The barebones theoretical latency is tiny, yet whenever I've tried using it over a 10Gb/s connection between two machines, it always seems to be in the 100s of milliseconds...


I wish that I could speak to that, but I haven't had a chance to play with any NDI signal paths as of yet. Have you checked with NewTek?


----------



## macsound (Jan 28, 2020)

Just started messing around with NDI. Tried to do something simple at the church. 
Created an NDI network stream of live video for people on campus to view by installing the NDI VLC plugin.
So far, couldn't get it to work.
Has anyone used NDI successfully? They make it seem so easy


----------

