Why the picture sits twelve seconds behind the event

A live stream is not live, and it is not a fault. The picture passes through five stages that each add time, and the largest single addition is a buffer that exists to keep the picture from breaking. The reader watches a recording that is running a dozen seconds late.

Desk spec

stages: 5
picture lag: 12.0 s
largest stage: 7.5 s
price lag: 0.2 s

the pictureA live picture is a licensed broadcast shown beside a market, not a window onto the event. It has an owner, a territory and a cost, and only 96 of 300 events in the month carry one.

the two clocksThe event happens at 0.0 s, the price refreshes at 0.2 s and the picture arrives at 12.0 s, so the number beside the picture is 11.8 seconds newer than the picture it sits beside.

the one sourceThree things describe an event - the picture, the data feed and the official result - and only the official result settles a bet. The picture looked decisive in 96 of 100 disputes and settled none of them.

Direct answer

A live stream is delayed by five stages - capture, encoding, packaging, delivery and a player buffer - that on the samples add up to 12.0 seconds between the event and the screen. The buffer alone is 7.5 of those seconds and is deliberate: a shorter buffer would start or stutter more often. The price beside the picture refreshes in 0.2 seconds, so the picture is 11.8 seconds behind the number.

The five stages

Each stage exists for a reason, and each one spends time. Capture and encoding turn the pictures into a stream. Packaging cuts it into short segments a player can fetch. Delivery moves those segments across a network. The buffer holds a few of them back so that a momentary drop in the network does not become a visible break. Only the last stage is a deliberate choice to be late.

Sample C - the five stages from event to screen
Stage	Adds	Running total	Why it exists
capture	0.0 s	0.0 s	the camera is at the event
encode	0.4 s	0.4 s	turn pictures and sound into a stream
package	0.6 s	1.0 s	cut the stream into fetchable segments
deliver	3.5 s	4.5 s	move the segments across the network
buffer	7.5 s	12.0 s	hold segments back so a blip is not a break
the chain	12.0 s	12.0 s	the buffer is 62.5% of the delay

sample C - where the twelve seconds go capture 0.0 + encode 0.4 + package 0.6 + deliver 3.5 + buffer 7.5 = 12.0 s the buffer alone is 7.5 / 12.0 = 62.5% of the delay the network is 3.5 / 12.0 = 29.2% the two production stages together are 1.0 / 12.0 = 8.3% so the delay is mostly a choice, not a limitation: 11.0 of the 12.0 seconds are delivery and deliberate buffering.

The picture against the price

The delay matters because of what sits next to it. A market beside a delayed picture is not a market about the picture, and the gap between the two clocks is the number a reader should carry.

sample C and J - three clocks, not one the event happens = 0.0 s the price refreshes = 0.2 s -> the market is 0.2 s behind the event the picture appears = 12.0 s -> the picture is 12.0 s behind the event the reader reacts = 1.4 s after the picture, so 13.4 s behind the event picture behind the price = 12.0 - 0.2 = 11.8 s reader behind the price = 13.4 - 0.2 = 13.2 s so the reader is never reacting to what the price is reacting to, and the price can move 60 times (12.0 / 0.2) before the picture catches up.

Check what you are actually watching before you act on it

Is the picture a second or two behind the commentary, or several seconds behind the field?
Does the price move before the picture does, which tells you the two are not synchronised?
Did the delay grow during the event, which points at buffering rather than at a fixed lag?
Is the stream a lower tier than the one advertised, which adds delay rather than removing it?
Can you name the time between the event and your screen, or are you guessing at live?

Why the picture sits twelve seconds behind the event

The five stages

The picture against the price

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