# Time Lag?



## Bronxiniowa (Apr 14, 2013)

Odd occurrence the other night while watching the Rangers beat the Canadiens: Was talking with a friend of mine while watching the game and it was apparent that my NBCSN feed, on DirecTV, was about two or three seconds ahead of his, on DISH. My friend also said that his feed was about five or so seconds behind that of his sister's, who was watching via Verizon FIOS. What would this result from?


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## Stewart Vernon (Jan 7, 2005)

Could be any number of things.

For satellite/cable channels, Dish or DirecTV either have to pick up the transmission from the source via satellite OR have a fiber direct feed from the channel. From there it might get processed before uplink to their (Dish/DirecTV) satellite and then beamed back down to earth wherever you are.

Each hop takes a little bit of time... and any processing that happens could take more.

When I say "processing"... it depends on what the feed they get consists of... IF they get a raw/uncompressed OR at least less-compressed feed from the source, Dish/DirecTV has to decode that and then recompress using their desired levels.

Cable has a similar thing, except they aren't beaming back into space for transmission to your home.

So.. IF all other things are equal, I would expect a cable channel to be slightly ahead of a satellite channel if you had them both in your home for a side-by-side comparison.


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## KyL416 (Nov 11, 2005)

It's various things, the satellite delay, transcoding the feed to MPEG2 since NBCSN's master HD feed is MPEG4, along with the buffer delay if there's a DVR involved.


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## SayWhat? (Jun 7, 2009)

26,000 miles up and 26,000 miles back down, maybe more than once takes time.

It's why satellite internet has problems with certain things.


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## slice1900 (Feb 14, 2013)

There is often a lag between HD and SD channels on a single provider, unless they delay the SD feed to make up for the additional processing HD requires.

Nothing you watch is truly live, if you live close enough to a football stadium that you can hear the cheering, or are tailgating outside while the game is going on, you can tell when something good or bad happens while the players are huddling on screen


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## Bronxiniowa (Apr 14, 2013)

Is less lag time better or worse?


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## Stewart Vernon (Jan 7, 2005)

Bronxiniowa said:


> Is less lag time better or worse?


Neither.

There is no worse or better here, just different.

To be technical, we are always seeing and hearing the past anyway. Even if you're right there at the action live, the light and sound takes a small amount of time to reach you and be processed by your brain... so there is always some small amount of lag in everything!

OTA TV or radio adds a little bit more lag, then cable/satellite retransmission adds a little bit more... and on we go.


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## harsh (Jun 15, 2003)

Bronxiniowa said:


> Is less lag time better or worse?


As long as it comes uninterrupted and you're not taking last second bets, it doesn't really matter.


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## SayWhat? (Jun 7, 2009)

Stewart Vernon said:


> Neither.
> 
> There is no worse or better here, just different.


True for video and audio.

Not true for data. More lag or latency is bad which is why satellite for internet has problems with some VoIP and gaming.


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## Bronxiniowa (Apr 14, 2013)

harsh said:


> As long as it comes uninterrupted and you're not taking last second bets, it doesn't really matter.


Hah! When I'm in the den watching a game that's telecast by an OTA network, I always use my AM-21 to get the OTA signal because it's sharper and clearer than satellite. If the game is also on in the kitchen, which gets D* signals only, I know I'm 5-6 seconds ahead. Maybe I should try doing that! :hurah:


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## Laxguy (Dec 2, 2010)

So, for those of us who watch sports almost exclusively via recording, the lags are all academic!

But, question on earlier post:



KyL416 said:


> It's various things, the satellite delay, transcoding the feed to MPEG2 since NBCSN's master HD feed is MPEG4, along with the buffer delay if there's a DVR involved.


I thought DIRECTV was sending us MPEG4 already, so if NBC were sending in MPEG2, there'd be transcoding, and there could be transcoding even if all were MPEG4-different compression, no?

Also, do not some feeds get sent OTA to the sat uplinks?


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## slice1900 (Feb 14, 2013)

Laxguy said:


> So, for those of us who watch sports almost exclusively via recording, the lags are all academic!
> 
> But, question on earlier post:
> 
> ...


There's always transcoding, because Directv will dynamically adjust quality levels as needed (downward, of course, since you can't add quality) using statistical multiplexing, since they carry multiple channels in a single transponder. Dish, cable companies and sometimes even OTA channels (when they have subchannels) all must do this. They will do MPEG2 to MPEG4 transcoding, MPEG4 to MPEG4 transcoding for bit rate reduction, and probably even MPEG4 to MPEG2 transcoding (if they have SD channels that are delivered to them in MPEG4)

Directv picks up some locals via OTA and some via fiber links.


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## jimmie57 (Jun 26, 2010)

My mother is in Georgia and has Comcast Cable TV. Sometimes when we are talking she will be watching the Atlanta Braves and it is on the DTV channel also at the same time.
I remember a few times she would say "Oh he hit another home run". What I was looking at was that the hit and even the pitch that led to the home run had not been thrown yet.
I started counting to see how long it took for something I heard on her TV to show up on mine. It was a count of 6 most times.

It makes sense that if a wire feed is sent to DTV and to homes for viewing that DTV has to do something with it to get it to the sat and then send it back down that there would be a delay. 

My son plays a couple of online video games on his computer. I asked him if anyone on the games uses satellite for internet. he said "Heck No, you would get killed and not even know it until it was too late. We all use cable to play the games."


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## Laxguy (Dec 2, 2010)

Indeed. When I had OTA, cable and DIRECTV on the same TV, six seconds was the most common count on sat. delays.


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