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by DanBlake 4491 days ago
The 30 seconds is not because twitch sucks. They do encoding/decoding/sampling

And honestly, if you were streaming a 1080p video over p2p, I see no physical way that it would be below a 30s delay if there was 1k+ people watching it.

You are limited by peers outbound bandwidth and for most in the US that is going to be sub 5MB/s. With that in mind, you can really only have a maximum of 5 or less streams per user. That means to get to the 1000th viewer, its going to be a daisy chain of 50+ users in front of you before you get the data.

P2P does not and can not work for distributed video until home connections catch up. (Unless you are OK with insane delays)
3 comments
teraflop 4491 days ago
If each peer can retransmit to 5 other users, then a simple tree-structured fanout gets you to more than 1000 users with only 5 hops of delay.

Obviously in practice you wouldn't get a perfectly balanced tree, but I don't see where your "50+ users" is coming from.

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e12e 4491 days ago
So, lets assume every viewer can broadcast to three others, so the first one reaches 3 that reaches 9 etc. You'd be "behind" 7 others for "up to" 2187 viewers. This is assuming no "super hubs" in between. Or am I missing something? Even if every peer on average is only able to reach two "new" peers, that's still just 10 hops for 1024 users...?
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wmf 4491 days ago
Can you explain why delay matters? AFAIK TV usually has over 1 minute of delay for live events.
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jan_g 4490 days ago
TV has usually about 5-6s delay for live events, add a second or two for HD content. 1 minute delay might be in case of legal issues (where broadcasters are bound by law to add a delay) or some very convoluted video signal distribution.

Delay matters most in case of live betting and live score. There is whole industry around this, I am sure you've heard about bwin.com or bet365.com.

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warcode 4490 days ago
Delay matters when a twitch.tv streamer is interacting with their viewers through the stream chat.

Delay matters when multiple people are trying to watch the same stream "together", but end up seeing wildly different points of time in that stream.

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