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The Technology Behind the Magic Yellow Line

CurtMonash writes "Fandome offers a fascinating video explaining how the first-down line on football broadcasts actually works. Evidently, theres a lot of processing both to calculate the exact location being photographed on the field — including optical sensors and two steps of encoding — and to draw a line in exactly the right place onscreen. For those who don't want to watch the whole video, highlights are here."

18 of 261 comments (clear)

  1. Weathermen have been doing this for ??? by MerlynEmrys67 · · Score: 4, Insightful

    Yeah - it is one guy and as long as he doesn't put on an annoyingly green tie - it all just works. It is actually amazing how much technology is behind simple video effects done seamlessly. I thought it was funny when Forest Gump won the oscar for special effects - everyone was like... that isn't a special effects movie... I was like - that is the point

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    I have mod points and I am not afraid to use them
    1. Re:Weathermen have been doing this for ??? by Rich0 · · Score: 4, Insightful

      Don't forget the live component. There is a big difference between a movie where you have 6-18 months to add in FX, and a TV broadcast which is at best delayed a few seconds. In a movie you can conceivably tweak your algorithms to catch the unexpected or clean up a few frames by hand if needed. With live the whole thing needs to work in realtime automatically.

    2. Re:Weathermen have been doing this for ??? by peacefinder · · Score: 4, Insightful

      Yeah, I remember very clearly when I first saw the "magic yellow line" some years ago. I watched for a couple minutes before I realized what the line meant. I turned to my friend and asked "You know what that yellow line means?"

      He said "Yeah, that's where they have to go for a first down."

      I said, "That too. But what the line really means is that you can't believe live video any more."

      --
      With reasonable men I will reason; with humane men I will plead; but to tyrants I will give no quarter. -- William Lloyd
  2. Re:Watch the video by direktorxxx · · Score: 5, Insightful

    Plus, you get to see the ugly UI that appears to have been built as an afterthought - just like the UI of all the other industrial television software I've operated.

    It's true, 90% of software that I've used in a television studio has a poorly designed, or worse, broken, user interface. Gets the job done but in the most convoluted way. The only well made interfaces are the ones by major companies who have been around for a while, ie Newtek, Adobe, Pinnacle, Chyron.

  3. Re:Watch the video by Spy+Hunter · · Score: 5, Insightful

    Well, when you have a user base in the dozens, and operating the UI is the user's entire job, it doesn't have to be intuitive or even easy. It's cheaper to teach a few dozen guys how to use a bad UI than it is to design and program a really good UI.

    Honestly, the UI in the video didn't seem too bad though (from a 10-second impression). Sure it was ugly but it seemed to have useful features for the operator; did you notice when the guy dragged the line of scrimmage past the first down marker it automatically reset the first down marker to +10 yards?

    --
    main(c,r){for(r=32;r;) printf(++c>31?c=!r--,"\n":c<r?" ":~c&r?" `":" #");}
  4. Re:nerdiness by Yvanhoe · · Score: 4, Insightful

    Can't we just call it genuine curiosity ?

    --
    The Wise adapts himself to the world. The Fool adapts the world to himself. Therefore, all progress depends on the Fool.
  5. Re:Watch the video by RegularFry · · Score: 3, Insightful

    Unfortunately you'll have the word "unfamiliarity" thrown right back at you. It's a bigger hurdle than you might think.

    --
    Reality is the ultimate Rorschach.
  6. Re:Flamebait +1 by cdrudge · · Score: 3, Insightful

    Football doesn't require you to know where the magic yellow line is at to understand what's happening. The refs seem to be able to do it as well as the 22 players on the field or more on the sidelines. It's there on screen is the first down markers aren't always visible. If the shot is zoomed in on the play, a ref's standing in front of the marker, etc you can't visually see where the first down point is at.

  7. It's Called "Marketing" by RobotRunAmok · · Score: 1, Insightful

    If your sport requires special on-screen aids to understand what's happening it's probably overdue for a rethink.

    That's like saying if your software requires a flashy box and a slick interface, it's probably due for a re-coding.

    These TV tricks are pure marketing, designed to extend the appeal of the game to the very casual observer. Football has been extraordinarily successful at every level for decades, and clearly does not need "on screen aids" to be understood.

    This is not the first example of such "dumbing down" of pro TV sportscasts. You may remember Fox Sports' "streaking puck" experiment a few seasons back during their NHL broadcasts. That proved a dismal failure (although it was a technical wonder at the time); the first down line-generation has proven a much more successful gimmick.

    No, you know your sport is due for a re-think when its fans riot in the streets and generate massive amounts of property damage. Violence and Premature Death are civilization's long-established barometers of failure.

    1. Re:It's Called "Marketing" by bws111 · · Score: 2, Insightful

      While I do agree it is marketing, I don't know that I would put it in the 'dumbing down' category. I think it is there to get the TV viewers more involved. Watching the game is more exciting when you can immediately see if a play was successful or not (like you could if you were at the game). Without the line, either the cameras must use a wide shot so you can see the sideline markers, or you must wait for an indication from the ref (or announcers) as to whether the play was successful or not.

  8. Re:Watch the video by tedgyz · · Score: 2, Insightful

    I have developed this maxim:
    Software quality is indirectly proportional to it's cost and/or user-base.

    I worked at a company that charged millions of $$ for it's software, including up to $1M to fly someone out to install it. It was the biggest steaming pile I ever witnessed.

    --
    "No matter where you go, there you are." -- Buckaroo Banzai
  9. Re:The reason for SI units by hal2814 · · Score: 5, Insightful

    "First of all, when someone writes "football" on slashdot. Is he referring to what is commonly known as "football" all over the world, i.e. "soccer" or what is commonly referred to all over the world as "american football"?"

    Sometimes a single word has more than one meaning, especially among different cultures. When that is the case, you have to use something called context to derive which meaning the word has. So "football" could mean a few different things when written on Slashdot depending on who wrote it. Lucky for us, we're given a LOT of context here. Given that we're talking about first down lines and there's ample video showing the sport in question, the context should be pretty obvious. But since you're confused, what they're referring to would likely translate to "American football" in your vernacular.

  10. Re:The reason for SI units by xaxa · · Score: 5, Insightful

    The traditional system of measurement that exists here rarely causes significant difficulties in every day life.

    200g of steak mince per person. 17 people. I'll have 3400g please.
    6oz of steak mince per person. 17 people. 102oz... but I can't ask for that. How many pounds?

    Large bottle of vodka: 1 litre. 1000mL. Double measure: 50mL. Bottle has 20 double measures.
    Normal bottle: 0.75L. 15 double measures.
    I think you buy vodka in a "fifth", a fifth of a gallon, and I think a double measure would be 2 fluid ounces. Erm...

    My wall: 4.37m by 2.39m. Area: 4.37m*2.39m = 10.4m^2. The can of paint covers 10m^2, damn.
    Your wall: 14 feet 4 inches by 7 feet 10 inches. Area... 172in * 94in = 16168 square inches ~= 112 square feet. The paint covers 10 square yards, is there enough? (No)

    I don't really see how the benefits would outweigh the costs of forcing people to switch over. Many things are already labeled with both sets of units anyways.

    Due to pressure from the EU ;-).

    I have a set of SI wrenches and a set of "standard" wrenches.

    That's twice as many wrenches as you'd need if everything came with one system of fixings.

  11. Re:The reason for SI units by Pope · · Score: 2, Insightful

    What possible difference could it make whether or not you can personally directly measure the base units?

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    It doesn't mean much now, it's built for the future.
  12. Re:Flamebait +1 by Neoprofin · · Score: 4, Insightful

    May I remind you that the U.S. is the only country to win to win 2 Olympic golds in Rubgy, and it happens to also be the only two years they competed, primarily with a team of (american) football players and track athletes?

    If the IOC hadn't dropped Rugby from the summer games it'd be interesting to see how developed Rugby in America would be. The reason for the padding, like it or not, is that American football developed into a game with much larger, stronger, faster, players rather than a slogged out game of endurance. It's not a question of superiority or toughness, there are few American football players who I think would be able to play an entire Rugby match in the style they play now, on the other hand I don't see a lot of Rugby players who I think would particularly effective on the NFL field trying to push around guys who would regularly 100lbs heavier and who are built and trained to be very good at pushing for 40 seconds at a time then taking a break.

  13. Re:The reason for SI units by cayenne8 · · Score: 1, Insightful
    "200g of steak mince per person. 17 people. I'll have 3400g please.

    6oz of steak mince per person. 17 people. 102oz... but I can't ask for that. How many pounds?"

    First, what the fuck is "steak mince"? I'm guessing some form of meat? Beef? I know what a steak is, but, no idea what mince is...

    And really, if you've lived with non-metric units all your life, it is easy. I have no problem knowing what size and 8 oz tenderloin or 16oz strip steak is or how big it is. I'd be completely lost trying to, off the top of my head...buy or cook with metric units. When I college in a lab, sure, no problem in doing chemistry experiments in metric, but, that isn't real every day life stuff.

    I know how to dress when it is 72F outside. I'd have no clue what to dress for at something like 32C (random temp)...

    If you grew up using metric...sure it is easy, just as easy as the non-metric units are for me since I grew up with them.

    And sure..you can ask for 102oz. Not sure who you'd ask...most of the groceries bought in the US are self serve, you rarely see a butcher live in person. If it were me, I'd round it up to 8oz per person (6 oz is kind of a skimpy portion?) and buy 8.5 lbs of whatever type of meat steak mince is....

    --
    Light travels faster than sound. This is why some people appear bright until you hear them speak.........
  14. Re:The reason for SI units by Anonymous Coward · · Score: 1, Insightful
    You are aware that humans generally use base 10 numbers, not base 12 right?

    This makes multiplying or dividing by 10 much easier than multiplying to dividing by 12.

    Quick, whats 120120934820394820843840983 multiplied by 10?

    What about 120120934820394820843840983 multiplied by 12?

  15. Re:Flamebait +1 by Pollardito · · Score: 2, Insightful

    The reason for the padding, like it or not, is that American football developed into a game with much larger, stronger, faster, players rather than a slogged out game of endurance.

    the helmets are there to prevent head injuries, and the padding is there to protect people's bodies from the helmets