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  #1  
Old 05-04-2012, 03:38 PM
spunkymuzicnote spunkymuzicnote is offline
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How long does it take for "live" TV to transmit to your home television?

It seems to me that it's got to take at least a few seconds for the image to get edited, sent up into the sky, and arrive back down at your home. So how long does it take? And is it a long enough amount of time that tv shows have to take that into account? For example, if the show time starts at 7:00, do they have to actually begin at 6:58? Also, do they ever delay the show intentionally to prevent incidents like M.I.A. flipping everyone the finger at last Superbowl?
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  #2  
Old 05-04-2012, 03:46 PM
Great Antibob Great Antibob is offline
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Yes, there's a broadcast delay. I don't think they account for it when starting a broadcast, though. How many events actually start exactly on time, anyway?

Most broadcast networks do include a broadcast delay, though, to account for edits they may have to make (profanity, nudity, etc). The exact length of the delay can vary with the event. The broadcast delay issue got a lot more play about 10 years ago when Janet Jackson had her "wardrobe malfunction".

Also, the same event being covered by radio or TV may have different delays. I hate the ESPN coverage of my alma mater's baseball team during the NCAA playoffs, so I tend to mute the TV and tune into the school's radio broadcast. The only problem is that it's usually a few seconds ahead of the TV, so you'll hear about a great play or hit before it shows up on screen.

Likewise, I noticed there's sometimes a difference between the HD and analog feeds from the cable company. I've noticed the analog feed of several live sporting events has been a few seconds ahead of the HD broadcast. Possibly due to differences in processing the data.
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  #3  
Old 05-04-2012, 03:46 PM
Mdcastle Mdcastle is offline
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When I was in TV school someone donated an hour of satellite time for us to play with, we had a "live monitor" and one sent to and back, I recall the delay was a couple of seconds.

And yes, shows are delayed occassionally by a couple of seconds to enable someone to hit the mute button. Live sports and such aren't which results in the occasional F-bomb or wardrobe malfuncition to get through.
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  #4  
Old 05-04-2012, 03:51 PM
Procrustus Procrustus is offline
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Before we lived together, my now-wife had cable tv and I had satellite. We would sometimes both be watching a ball game, and she would know the play about five seconds before I would. So, apparently it takes longer for the signal to go to space and back than it does to go over the cable wires.
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  #5  
Old 05-04-2012, 03:53 PM
FatBaldGuy FatBaldGuy is online now
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First of all, on a live show there is no editing involved, other than switching between cameras and inserting graphics, etc., but that is all done in "real time", so there is no delay there.

The rest of the delay is caused by one or more satellite up-link/down-link transmissions, and will vary depending on who is doing the origination, and who your TV provider is.

For example, let's say you're watching a football game on ESPN. At the stadium is a truck where the program is originated, and the signal is up-linked to a satellite and down-linked at ESPN Headquarters. There they add commercials and analyst comments, etc. to the feed and it is again up-linked to a satellite and down-linked again at your cable or dish provider's facility.

From there, if you have cable, the signal is sent on wires to your house, which is relatively quick. If you have a dish provider, the signal has to make one more round trip into space so you can pick it up on your receiver.

Even at the speed of light, it takes a couple of seconds to make a round trip from the ground to the satellite and back again.

As for your last question, ever since the Janet Jackson wardrobe malfunction, most of the networks introduce a several second delay into some live broadcasts so they can hit the "kill switch" in an emergency.

ETA: Got to type faster.

Last edited by FatBaldGuy; 05-04-2012 at 03:55 PM..
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  #6  
Old 05-04-2012, 03:54 PM
Omar Little Omar Little is offline
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Quote:
Originally Posted by Procrustus View Post
Before we lived together, my now-wife had cable tv and I had satellite. We would sometimes both be watching a ball game, and she would know the play about five seconds before I would. So, apparently it takes longer for the signal to go to space and back than it does to go over the cable wires.
You think your local cable company has a wire running all the way from your house to the Cowboy's stadium in Dallas? I little clue. The cable company uses satellites too.
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  #7  
Old 05-04-2012, 03:57 PM
Jackknifed Juggernaut Jackknifed Juggernaut is online now
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Originally Posted by Great Antibob View Post
...The only problem is that it's usually a few seconds ahead of the TV, so you'll hear about a great play or hit before it shows up on screen....
Interesting. I noticed that the TV broadcast for ESPN's Mike & Mike (on Fios) shows up on screen faster than the radio broadcast by about 1 second.
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  #8  
Old 05-04-2012, 04:00 PM
Jackknifed Juggernaut Jackknifed Juggernaut is online now
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I'm actually surprised that the delay isn't longer for sporting events. I would think that delaying by an extra 30 seconds would allow for real-time editing, resulting in a much better program. For example, sometimes you'll see a baseball player making a great play, but with a poor angle. Only later through replays can you see the better angle version. Given a longer delay, the network would be able to show the best angle the very first time every time.
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  #9  
Old 05-04-2012, 04:03 PM
johnpost johnpost is offline
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Originally Posted by Great Antibob View Post
Also, the same event being covered by radio or TV may have different delays. I hate the ESPN coverage of my alma mater's baseball team during the NCAA playoffs, so I tend to mute the TV and tune into the school's radio broadcast. The only problem is that it's usually a few seconds ahead of the TV, so you'll hear about a great play or hit before it shows up on screen.
that's a good thing, you know to pay close attention. like when someone fouls you get to watch close and cuss longer.
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  #10  
Old 05-04-2012, 04:13 PM
FatBaldGuy FatBaldGuy is online now
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Quote:
Originally Posted by Jackknifed Juggernaut View Post
Interesting. I noticed that the TV broadcast for ESPN's Mike & Mike (on Fios) shows up on screen faster than the radio broadcast by about 1 second.
It depends on the source and transmission of the radio signal, just like TV. If the radio signal is bounced off of satellite, it will have delays.

If you are watching your home town team play on satellite TV and listening to the broadcast on your home town radio station, the radio signal will be virtually instantaneous, while the TV signal is making 2-4 round trips into space.
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  #11  
Old 05-04-2012, 04:20 PM
TriPolar TriPolar is offline
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Originally Posted by Jackknifed Juggernaut View Post
I'm actually surprised that the delay isn't longer for sporting events. I would think that delaying by an extra 30 seconds would allow for real-time editing, resulting in a much better program. For example, sometimes you'll see a baseball player making a great play, but with a poor angle. Only later through replays can you see the better angle version. Given a longer delay, the network would be able to show the best angle the very first time every time.
I'm not seeing the big advantage there. It usually takes several replays to show everything happening in a particular play, so you might get one of the better shots first a little more often, but that's about it. Instant replay emerged as part of the technology making the short delay and quick edits possible, so it's just been the format traditionally used. You also have far more than 30 seconds to come up with the best replays and show them in super slo-mo with added graphics by inserting them in the uninteresting time that most sports have plenty of.
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  #12  
Old 05-04-2012, 04:24 PM
si_blakely si_blakely is offline
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There are additional delays introduced by compression/decompression on digital signals. The problem is that these delays are implementation dependent, and can add several seconds depending on algorithm/buffering.
In the UK, there were complaints that the digital radio broadcasts of BBC Radio sound pips were several seconds late - which they always will be.

Si
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  #13  
Old 05-04-2012, 04:55 PM
friedo friedo is online now
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Originally Posted by Omar Little View Post
You think your local cable company has a wire running all the way from your house to the Cowboy's stadium in Dallas? I little clue. The cable company uses satellites too.
That's exactly how they did it until the late 1970s. AT&T had a whole business leasing transmission lines to TV networks.
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  #14  
Old 05-04-2012, 05:04 PM
Gary "Wombat" Robson Gary "Wombat" Robson is offline
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Sometimes there are multiple satellite delays compounding each other. In a college sporting event, for example, they may set up a remote truck on-site. They'll have an on-site control room where they switch between cameras and commentary, and then "squirt the bird" to send the signal back to headquarters. From there, it may have different routes to get to your house, which may involve another trip to the satellite and back to get to your local station and then to the cable TV office.

My wife works as a realtime closed captioner, and when I set up her studio I included both an analog steerable dish (one of the big nine-footers), and fixed digital dishes (both DirecTV and Dish Network). Whenever the same signal was available on the big dish and one of the small dishes, we'd always pick the big dish to avoid the 2-second (or so) encoding delay of the small digital dishes.

I've done a number of experiments timing when the caption signal leaves our studio and when we actually see the text on the signal from the satellite. It can vary from a couple of seconds up to four or five in news. It goes a bit longer in sports, probably because they induce the delay for potential censoring (generally that isn't used in studio news).
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  #15  
Old 05-04-2012, 08:49 PM
Fiendish Astronaut Fiendish Astronaut is offline
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I worked in television transmission for several years sitting in front of a big bank of monitors. One of the monitors is always dedicated to the return feed, so it would show the broadcast picture picked up in the same way that viewers in their homes would get it. Next to it you'd have various other pictures including one showing the broadcast as it leaves the transmission suite. If my return feed went black but my output is still up I would know the problem doesn't lie at my end (although I'd still need to try to find out what's happening).

The delay between the two was about a second and a tiny bit. If we were relaying a live feed coming into us then it would take about a tenth of a second for that signal to rattle around the transmission suite and leave us. Add x for whatever time it takes for that signal to get to us from its source. If its from the other side of the world perhaps as much as two seconds but probably never longer than than and more typically about half a second.

However that's the long cheap way. If you watch a live interview on a satellite link up you'll notice there's not much of a delay between the questions and the answers. The delays are so much shorter than they used to be. If you watch a satellite link up interview from the 80s the delay was much longer, so long in fact you'd frequently get awkward silences and confused interruptions. I think the improvement is due to faster processing and more direct link ups (although I'm not an expert in these things).

Last edited by Fiendish Astronaut; 05-04-2012 at 08:53 PM..
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  #16  
Old 05-04-2012, 09:17 PM
Fiendish Astronaut Fiendish Astronaut is offline
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Oh to answer another part of your question: no, the 10 O'Clock News is not transmitted at 9.59 and 59 seconds, it gets transmitted at 10. TV companies cannot account for the time it takes audiences to receive the signal especially because there are so many variations in broadcast methods and peoples distance from transmitters and so on.

At the BBC I never saw a short delay in a live event designed for someone to put in a censoring beep, though sometimes programmes would be broadcast "as live": recorded by the production team then sent down the line for playout. And that might happen if e channel thought there was a chance of an f-bomb or something offensive and depending on the audience and time. I'm not sure about the US but in the UK a live event is a Iive event. Either it's recorded a good chunk of time in advance and therefore not live or it's patched straight through to viewers without any chance of censorship.

Last edited by Fiendish Astronaut; 05-04-2012 at 09:21 PM..
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  #17  
Old 05-05-2012, 12:46 AM
AK84 AK84 is offline
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I once was chatting to a friend on a mobile while I was at a cricket match which he was watching on TV. I was in one of the corporate boxes so we could chat without being bothered by the noise. Suddenly, one batsman gets out and I tell him, only to be informed that "what do you mean, the bowler has not even begun his run yet". It took several seconds for the "Live" telecast to catch up and that is not even counting the time it took for the mobile phone transmission. Surprisingly, the box had a TV and we could watch the match if we wanted and I saw no noticeable difference between the live action and the transmission, even though my friend and I were watching the same channel; Sky Sports. I can only presume that the feed at the ground was deliberately a different one.
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  #18  
Old 05-05-2012, 01:04 AM
Fiendish Astronaut Fiendish Astronaut is offline
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Originally Posted by AK84 View Post
The box had a TV and we could watch the match if we wanted and I saw no noticeable difference between the live action and the transmission, even though my friend and I were watching the same channel; Sky Sports. I can only presume that the feed at the ground was deliberately a different one.
You may not remember but did your picture have the white SkySports DOG in the top right corner? That would have been put on in the Sky transmission suite. I doubt it, you were almost certainly watching a ringmain feed from the nearby OB trucks with only the match graphics telling you it was Sky coverage. Your friend would have been watching a signal beamed from the cricket ground, to Sky, to an upload site, to a satellite and then down to his dish, with a possible extra step in between. Seven seconds is a long time though. Maybe four or five seconds is more realistic.
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  #19  
Old 05-05-2012, 01:15 AM
AK84 AK84 is offline
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Originally Posted by Fiendish Astronaut View Post
You may not remember but did your picture have the white SkySports DOG in the top right corner? That would have been put on in the Sky transmission suite. I doubt it, you were almost certainly watching a ringmain feed from the nearby OB trucks with only the match graphics telling you it was Sky coverage. Your friend would have been watching a signal beamed from the cricket ground, to Sky, to an upload site, to a satellite and then down to his dish, with a possible extra step in between. Seven seconds is a long time though. Maybe four or five seconds is more realistic.
It was in 2006 at Lords. From what I could tell, it was just a normal TV and sky box, nothing special and we could switch to other channels in the package and we did so (it was the day Tony Blair announced when he was leaving).

BTW, explnations sought on what you mean by "ringmain feed" with sky graphics.
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  #20  
Old 05-05-2012, 01:41 AM
Fiendish Astronaut Fiendish Astronaut is offline
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That is odd. I'm unfamiliar with how Sky works so I can't explain the difference between yours and your friend's delay. You should have seen at least a couple of seconds of delay. A ringmain is just what you call a locally available set of channels. Think of it as a local network - it might contain lots of public channels but some might also have been pictures that are only available in the ground such as a permanent electronic scorecard or something. If it had adverts then that's definitely not local.

Last edited by Fiendish Astronaut; 05-05-2012 at 01:44 AM..
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