Part of the reason bit torrent works really well is that the file is downloaded in random order. It lets everyone cooperate, while still being robust to bad peers, bad network connections, churn etc.

If you want live high quality streaming, a lot of reasons bit torrent works so well goes away.

Latency matters. In bit torrent if the peer goes away, no big deal, just try again in 5 minutes with another peer, you are downloading in random order, who cares if one piecs is delayed 5 minutes. In a live stream your app is broken if it cuts out for 5 minutes.

In bit torrent, everyone can divide the work - clients try to download the part of the file the least number of people have, quickly rare parts of the file spread everywhere. In streaming everyone needs the same piece at the same time.

Bit torrent punishes people who dont contribute by deprioritizing sending stuff to peers that freeride. It can do this on the individual level. In a p2p streaming setup, you probably have some peers getting the feed, and then sending it to other peers. The relationship isnt reciperocal so its harder to punish freeriders as you can't at the local level know if the peer you are sending data to is pushing data to the other nodes it is supposed to or not.

I'm sure some of these have work arounds, but they are hard problems that aren't really satisfactorily solved

For a while, I was CTO of a company called Livestation [0], which as the Wikipedia article states, was "originally based on peer-to-peer technology acquired from Microsoft Research".

This P2P stack was meant to allow for mass scaling of lowish latency video streaming, even in parts of the World with limited peer bandwidth to original content source servers. The VC-1 format got into a legal quagmire, as most video streaming protocols do, and it speaks volumes that by the time I turned up in ~2012-ish, the entire stack was RTMP, RTSP, HDS and HLS with zero evidence of that P2P tech stack in production.

My main role was to get the ingest stack out of a DC and into cloud, while also dealing with a myriad of poor design decisions that led to issues (yes, that 2013 outage in the first paragraph of the wiki article was on my watch).

At no point did anybody suggest to me that what we really needed to fix our attention back to was P2P streaming, beyond the fact the company built a version of Periscope (Twitter's first live streaming product), and launched it weeks/months before they did, and were pivoting towards a social media platform, at which point I decided to go do other things.

The technical and legal problems are real, and covered elsewhere here. People want reliable delivery. Even Spotify, YouTube and others who have licensed content and could save a pile by moving to DRM-ified P2P don't go near it, and that should tell you something about the challenges.

I'd love more widespread adoption of P2P tech, but not convinced we'll ever see it in AV any time soon, unfortunately.

[0] https://en.wikipedia.org/wiki/LiveStation

Splitcast Technology built this in 2012. The company folded (couldn't find revenue, and had founder struggles ) but as far as I remember the tech worked. It still needed a lot of seeding nodes, but a significant chunk of the bandwidth was provided by the "viewer peers".

Key part of that tech was that it synchronized the playback between all peers. That was nice for stock market announcements and sport events for example.

https://web.archive.org/web/20131208173255/http://splitcast....

https://www.youtube.com/watch?v=R5UYu9jeQbY

https://www.crunchbase.com/organization/splitcast-technology

There is peertube and webtorrent, but they does not seem to catch the mainstream users.

In my opinion, NAT and the extensive tracking that has led users to distrust sharing their IP addresses are the reasons why it hasn't caught on.

Imagine YouTube using P2P technology, it would save lot of money spent on caching servers.

The real reason is that bandwidth is dirt cheap, if you know what are you are doing at scale.

For 'hobbyists' there is a lot of complexity with setting up your own streaming infrastructure compared to just using YouTube or Twitch.

Then for media companies who want to own it, they can just buy their own infra and networking which is outrageously cheap. HE.net advertises 40gbit/sec of transit for $2200/month. I'm oversimplifying this somewhat, you do have issues with cheap transit and probably need backups especially for certain regions. But there isn't much of a middleground between hobbyists and big media cos.

For piracy (live sports streams), I've read about https://en.wikipedia.org/wiki/Ace_Stream being used for this exact purposes FWIW. This was a while back but I know it had a lot of traction at one point.

There was Joost in 2008, from Skype founders. Skype was originally P2P until Microsoft acquisition and killing this legally questionable feature - need to feed the big brother (: Joost raised ~$50M.

I remember it as it was one of rare apps built in XUL, the same framework as Mozilla apps (Firefox).

https://en.m.wikipedia.org/wiki/Joost

People have tried to build BitTorrent clients to do this. As far as I know they never took off. The primary problem is you oftentimes don't get people who want to share back or who have firewalls or other connections that don't allow them to share back. So you end up with a few people who end up seeding everything out. The second problem is in order to watch a streaming protocol things need to arrive in order. It is totally possible to do with BitTorrent and request the blocks in the order that you want but you may not always be able to get them in the order you want.

In general people aren't tolerant of lag and spinning circles and other such things when they're trying to watch streaming content. If you're fine with just watching it a little bit later might as well queue it up and left the whole thing down load so it's ready when you're ready.

The only entities that could use such a thing are major streaming platforms, and projects trying to stream copyrighted content without consent.

The former don't want to use it as it degrades their control over the content, and the later don't want to make a new system cause systems that are built on torrents are good enough.

There are streaming sites on the high-seas that use webtorrent. Interestingly (at least for me), this bypasses firewall based IPS/inspection that looks for bittorrent because it's all https. People use it to stream movies at work lol. Good for them I guess.

I am a contributor to Iroh ( https://github.com/n0-computer/iroh ), an open source library for direct QUIC connections between devices that can be behind a NAT.

Our library is general purpose and can be used whenever you need direct connections, but on top of Iroh we also provide iroh-blobs, which provides BLAKE3 verified streaming over our QUIC connections.

Blobs currently is a library that provides low level primitives and point to point streaming (see e.g. https://www.iroh.computer/sendme as an example/demo )

We are currently working on extending blobs to also allow easy concurrent downloading from multiple providers. We will also provide pluggable content discovery mechanisms as well as a lightweight content tracker implementation.

There is an experimental tracker here: https://github.com/n0-computer/iroh-experiments/tree/main/co...

Due to the properties of the BLAKE3 tree hash you can start sharing content even before you have completely downloaded it, so blobs is very well suited to the use case described above.

We already did a few explorations regarding media streaming over iroh connections, see for example https://www.youtube.com/watch?v=K3qqyu1mmGQ .

The big advantage of iroh over bittorrent is that content can be shared efficiently from even behind routers that don't allow manual or automatic port mapping, such as many carrier grade NAT setups.

Another advantage that BLAKE3 has over the bittorrent protocol is that content is verified incrementally. If somebody sends you wrong data you will notice after at most ~16 KiB. Bittorrent has something similar in the form of piece hashes, but those are more coarse grained. Also, BLAKE3 is extremely fast due to a very SIMD friendly design.

We are big fans of bittorrent and actually use parts of bittorrent, the mainline DHT, for our node discovery.

Here is a talk from last year explaining how iroh works in detail: https://www.youtube.com/watch?v=uj-7Y_7p4Dg , also briefly covering the blobs protocol.

AceStream is P2P, its primary use is to stream pirated live sports though. But looking it up, it seems to have been infected by "blockchain!" geniuses.

This tech has been developed several times but ultimately CDNs are now so cheap that P2P is pointless. You can't ignore development cost since it dominates all other costs in this case.

https://en.wikipedia.org/wiki/PeerTube ?

In many clients, you can set a "download in sequential order" option. With this option, it effectively IS a p2p streaming protocol. In fact, I often use it that way-- start watching as soon as the download started.

I think your other constraints (tree topology & connection prioritization) already describe how BitTorrent works.

I think there's one thing you'd need to change for /live/ streaming, where the file is actually being created /during/ broadcast-- I think the file verification hash systems require the seeder to have the entire file when initially seeding. I think magnet links and .torrent files are based on a hash of the entire file. Do maybe you need some kind of modification to DHT , .torrent , .magnet , to support verification by sequential chunks.

There's iroh.computer which can use a relay/ do direct nat punching.

They use bao hashing which is something that I discovered through them (IIRC) and its really nice.

Could create such a protocol though bittorrent/ipfs is fine

I once wanted to create a website which was just a static website.

and I used some ipfs gateway to push it with my browser and got a link of that static website, all anonymous.

Kind of great tbh.

It is a thing.

For livestreams there's AceStream built on BitTorrent, but I think it's closed-source. They do have some SDK but I never looked into it. It's mostly used by IPTV pirates. I've used it a few times and it's hit-or-miss but when it works well I have been able to watch livestreams in HD/FullHD without cuts. Latency is always very bad though.

Then for video-on-demand there are some web-based ones like PeerTube (FOSS) and I think BitChute? Sadly webtorrent is very limited.

Tribler has had video streaming over BitTorrent for a bit less than two decades. https://www.tribler.org/StreamingExperiment/

This used to exist in 2008 and it was perfect. It was called Joost and worked like this: - P2P streaming - You get a big menu of channel logos - You click on a channel and it would start the first episode of a randomly chosen series from that channel, or it would continue from where you left off - There might have been a "zap" function? I'm not sure - The GUI was so nice and large that if you connected a Wii Remote to your PC, you had the best TV experience from your couch, ever: Just press a button to bring up the menu, aim at the channel you want to switch to, done.

Such a shame that it failed, nothing after it ever came close.

It's been tried a few times. The bottleneck still exists in the last mile of the network. Users simply don't have good enough equipment to reliably handle this amount of streaming data.

BitTorrent is already a streamable P2P protocol. You just need a client that can prioritize downloading the file parts in order.

It is a thing.

Share 3 methods:

1. Hybrid architecture (CDN+P2P): - Use CDN to process backbone traffic, and edge nodes distribute through P2P to reduce the pressure on the central server (such as LivePeer trying to combine blockchain and P2P). - Platforms such as Youku have experimented with such solutions, but they need to weigh the cost and effect.

2. Protocol optimization: - Sliced transmission: Divide the streaming media into small pieces and improve efficiency through multi-path transmission. - Dynamic priority: Dynamically adjust the data allocation strategy according to node bandwidth and latency. - Buffering and preloading: Allow users to tolerate higher latency in exchange for more stable transmission (such as HLS/DASH protocol ideas).

3. Decentralized network exploration: - Projects such as IPFS and BitTorrent Live have tried real-time streaming, but are limited by technical maturity and ecological support. - Web3 projects (such as Theta Network) combine token incentives to encourage nodes to contribute bandwidth, which may promote development.

The thing is, if you pirate why would you stream when you can download and watch at your convenience?

And if you pay for the streaming, why would you donate your bandwidth to them? Would you get a discount?

There are companies doing something like that (StreamShark, Quanteec, Eyevinn; even Cloudflare with WHEP). On a company I worked on, they used Eyevinn for events with more than 100K users; and there were still performance issues.

Besides bandwidth problems (as you can't 100% rely on remote connections), any P2P solution would mean the same fragment will be shared many times between clients; something CDN networks have solved already (just serving content, instead of juggling with signalling)

I built a proof of concept doing exactly that a few years ago[0]. The codebase is unmaintained and the demo website has been down for a wee while too, but it's basically this idea. Only issue is that the overhead to establish WebRTC connection is heavy, so it's not exactly lightweight...

0: https://github.com/pldubouilh/live-torrent

As I understand it, P2P requires information sharing so when your distribution network grows this eventually turns into a performance bottleneck. You'll also need rather sophisticated mitigations against bad actors in the distribution network, like nodes that forward bad packets instead of distributing the good packets they receive and got requests for.

You might want to look into the tradeoffs Discord decided to go with, https://discord.com/blog/how-discord-handles-two-and-half-mi....

Here's some boilerplate for rolling your own, https://blog.swmansion.com/building-a-globally-distributed-w....

In theory you could gain resilience from a P2P architecture but you're going to have to sacrifice some degree of live-ness, i.e. have rendering clients hold relatively large buffers, to handle jitters, network problems, hostile nodes and so on.

A lot of comments mention it has been a thing in various forms through the internet’s brief history. The interesting question is why didn’t it take off—especially when the technology was there.

One possibility as you allude to is licensing. In a P2P streaming model “rights” holders want to collect royalties on content distribution. I’m not sure of a way you could make this feel legal short of abolishing copyright, but if you could build a way to fairly collect royalties, I wonder if you’d make inroads with enforcers. But overall that problem seems to have been solved with ads and subscription fees.

Another data point is that the behemoths decided to serve content digitally. Netflix and Spotify showed up. The reason the general population torrented music is because other than a CD changer, having a digital library was a requirement in order to listen to big playlists of songs on your… Zune. Or iPod. That problem doesn't exist anymore and so the demand dried up. There was also an audiophile scene but afaik with Apple Lossless the demand there has diminished too.

And finally, since people were solving the problem for real, we also entertained big deal solutions to reduce the strain on the network. If you stream P2P your packets take the slow lane. Netflix and other content providers build out hardware colocated with last mile ISPs so that content distribution can happen even more efficiently than in a P2P model.

In short: steaming turned into a real “industry”. Innovators and capitalists threw lots of time and money at the problem. Streaming platforms emerged, for better and for worse. And here we are today, on the cusp of repeating the past because short sighted business mongers have balkanized access with exclusive content libraries for the user numbers.

Great question — I’ve thought about this too. Technically, large-scale P2P streaming is possible, especially with today’s upload speeds and a tree-like distribution (log(N) structure). But there are big hurdles:

Churn & reliability: Peers come and go, making stable streaming tricky. Latency: BitTorrent-style protocols aren’t built for real-time delivery. Incentives: Without rewards, too many users just leech. WebRTC: It hits limits fast and often relies on centralized relays. Legal risks: Media companies don’t play nice with decentralized distribution.

Bram Cohen tried with BitTorrent Live, but it fizzled out. Would love to see someone revive this with modern tech — still feels like untapped potential.

You need good latency for streaming, torrents can get to a decent speed but the latency will always be bad.

Modern streaming protocols sometimes go to absurd lengths to avoid too many hops so you get the data as soon as possible... torrent has so many jumps and negotiations to get to the actual file. It's good for decentralization but decentralization and efficiency go against each other.

One problem with live and p2p is latency.

What does that mean?

The steps to live are pretty simple on the server side (assuming HLS):

1. Stream to your encoder, ideally at a bitrate higher than the transcoded bitrate.

2. Encode and transcode your video, ideally to 540/720/1080p 30fps. Each resolution will have its own bitrate, so maybe 2/3.5/5.5 respectively. Assume 2 second segments, and a manifest duration of 10 seconds. So you have 5 segments out there at any given time (though there are usually a few more hanging around).

3. Put the 3 newest segments to storage, and rewrite the four manifests with the new segment URLs. (do you need to rewrite the top-level manifest? I believe you do, but I can't remember).

4. Delete the older segment(s) (optional)

So when the client requests the manifest (the m3u8), it'll getch the three sub-manifests (forgot the term) and chose the appropriate resolution. It'll also start loading the segments up. Ideally it would look at the manifest and fetch the latest segment, so it starts nearer to "now."

Then the client will occasionally re-fetch the manifests to get the new segments (the manifest is marked as live; VoD manifests don't require reload). The fetch time probably must be < than the segment duration, which is in the manifest somewhere.

All that takes time. It takes time for the server to encode, time for the encoder to put the file(s), time for the client to fetch the manifests, and time for the client to fetch a video segment.

Looking at the above sequence, a client can be generally 0-10 seconds behind everyone else, depending on how the client behaves. And that's a few seconds behind "live," because receiving, encoding and putting files takes time.

So can you do p2p live? As long as you relax the constraints on what you mean by "live," yes. As you can imagine, the chain of latenty keeps growing longer the more peers a segment goes through. And that segment is only really good for 2 seconds (or up to 10 seconds, if the client is sloppy). If live means "up to 20 seconds since now" then yes, you can definitely do it. The tighter that time window gets the less likely you'll be able to do it. You might be able to do it with a lower bandwidth stream, but even TLS negotiation takes time. Does your client not use TLS? That will save you time.

It's hard to beat CDNs for streaming because the number of hops is low. Basically any p2p technology would have to mirror the way existing livestreams work; a local well-connected peer sucks down the livestream from farther away and rebroadcasts it to local peers. Anything else introduces latency or wastes WAN bandwidth. Peers are also rarely situated where they have moderate downstream and exceptional (local) upstream.

IPv6 multicast is probably the way forward for livestreams but I haven't really been keeping up on recent developments. In theory there could be dynamic registrations of multicast addresses that ISPs could opt-in to subscribe to and route for their customers.

Good question! I'm not too sure. But I often wonder why P2P hasn't become more robust as speeds and tech have improved. Like live service games.. it feels like there could be robust P2P implementation that could facilitate a lot of failed multiplayer.

I imagine that cutting out the live service ($$$) and SaaS have a large role to play.

> Also i think it wouldnt have to be live, people would definitely not mind some amount of lag.

I work on low latency and live broadcast. The appropriate latency of any video stream is the entire duration of it. Nobody else seems to share this opinion though.

I think the missing piece here is why we’d want P2P live streaming in the first place.

If the goal is to cut costs — like vendors trying to avoid AWS/CDN bills — that’s a very different problem than building for censorship resistance or resilience.

Without a clear “why,” the tradeoffs (latency, peer churn, unpredictable bandwidth) are hard to justify. Centralized infra is boring but reliable — and maybe that's good enough for 99% of use cases.

The interesting question is: what’s the niche where the pain is big enough to make P2P worth it?

Octoshape developed this tech, I believe it was sold to some american tv networks.

Peertube does P2P for both static videos and livestreams: https://docs.joinpeertube.org/

But the reality is for 99% of people Youtube and Twitch work just fine.

Plus most residential ISPs have really poor upload speed, and very restrictive data caps.

> I was thinking most people nowaday have at least 30mbps upload

Even “modern” cities like NYC are limited to a MAXIMUM of 30Mbps upstream due to ISP monopolies and red tape.

It’s getting better, but Spectrum is still literally the only ISP available for many city residents, and their offerings are so lopsided that their highest-end package is a whopping 980/30.

That’s right. If you use the majority of that 980Mbps your IP overhead will gladly take that 30Mbps, leaving you with just about Zero headroom for anything else.

I think there is acestream though I don't think it could do 1000s of users. It was my go to for watching live sports back in the day I dont watch sports so no longer kept up with it.

Ages ago, there was peercast[0]. Project stalled.

0. https://ja.wikipedia.org/wiki/PeerCast

(Outside of niche circles like HN) Nobody uses computers anymore. Nobody is going to seed from their phone.

Plus instead of a million people all wanting to watch Spider-Man 2, those million people have infinite options of short videos or whatever to watch. The desire to watch A Specific Video isn’t what it used to be.

Times have changed and P2P as a common way of sharing stuff is dead to the average person.

Lots of technical discussions - but the real answer is that bittorrent/P2P was displaced by Netflix for all but a small number of hard-core users. That, combined with legal threats, and that p2p required volume/scale to work well, meant that the critical mass died. It was a sad day that we, the users of the internet, en-mass exchanged bittorrent for streaming companies.

Have you checked out webtorrents? You can download movies from the P2P network sequentially and so watch them while they download.

BitTorrent Live did this, too:

https://www.bittorrent.com/blog/2016/05/17/bittorrent-live-m...

From a decade ago, I remember the Chinese-made PPLive software which distributes pirated TV streams through your peer-to-peer client software. https://en.wikipedia.org/wiki/PPTV

There are plenty. The problem is that it's pointless and far less effective. Centralized servers work great. The only viable reason for P2P we have found over the last 20 years seems to be illicit activity. Everyone else is just fine with regular servers.

The only way this will be possible is if there is widespread adoption of an Internet overlay network similar to Tailscale in its design. Fortunately or unfortunately depending on how you look at it Tailscale is limited to Layer 3 so Multicast doesn't work (it depends on IGMP to function correctly).

The degree of difficulty for building this is the premise of the 2001 movie Antitrust from back in the old days when Microsoft was evil. Notable as one of the first movies to use Linux desktops and reasonably correct shell script and code in all of their screen shots.

you can install Qbittorrent client, after loading torrent file/magnet link, right click on that torrent and click on Download in sequential order.

torrent PROTOCOL does not require to download random pieces, in random order.

ONLY bittorrent, inc. COMPANY which releases "Utorrent" and "Bittorent" NAMED APPLICATIONS/PROGRAMS does not want legal trouble from media/music companies. Because STREAMING is other legal category then downloading. There is no other reason for torrent PROTOCOL to not deliver file pieces in sequential order.

if you need instant nanosecond delayed stream, those does not exist anywhere, even radio, tv stations over the air are delayed so they all transmit synchronized. so 0 latency and synchronized can be mistaken for each other.

There are streaming platforms built on top of BitTorrent like Streamio with the torrents plugins

Isn't that what multicast is for?

You could utilize webtorrents, with a master seed, to in theory get really high scaling of content download, as one would scale peers at the same time of leetchers. Add a cordination server on top to sync timings and you should be there.

A related thing: wasn't PopcornTime using bittorent to stream movies? Did it have any notable difference from Bittorent or any notable issue/drawback? I never used it, but it sounded like a big thing at the time.

> I've been wondering if anyone knows why there is no P2P protocol for mass live stream content in decent quality?

We had torrent client/streaming video players maybe 20 years ago already.

> Does anyone have knowledge on why it isn't a thing still though?

It is a thing, it seems you didn't do your research.

There's articles all over the interweb if you went and looked, such as

https://www.makeuseof.com/best-torrent-streaming-apps/

This has been invented many times, but every time someone invents an actually effective method of person-to-person file transfer, it gets used for piracy and blocked and shunned.

For the same reason that BitTorrent doesn't work: providing a service costs money, and when there's no way to collect money then you get no service.

It's easier to control people with a centralised architecture.

Bittorrent already works fine for streaming:

https://github.com/johang/vlc-bittorrent/

You can stream over bittorrent... I do it all the time, you start your download, set it to download in order, and then just start watching it.

Build it. Use Go. Maybe nknorg/nnet for P2P. Signed HLS segments. Have Go also serve the web front-end with a WASM web worker. Public nodes can run on a very lightweight VPS/server with an autocert domain. Viewers browser join the swarm with WASM-- this way people can just type in a web address so it's very user friendly but the domain doesn't actually have to serve any data. I would just use a trusted pubkey to sign P2P updates so nodes can block naughty IP addresses. Should get you very friendly user experience, easy node deployment, pretty low latency, and bittorrent level of legal resilience.

What does PeerTube do?

I would not be surprised if the rise of CG-NAT put another nail in the proverbial coffin of P2P video streaming and related sharing.

A fun idea I had was to divide hd video over 4 and/or 16 and/or 64 lower resolution videos. For the 1/4 the pixels from video 1,2,3 and 4 would be arranged like so.

   1 2 1 2
   3 4 3 4
   1 2 1 2
   3 4 3 4

If you have [say] a 640 MB recording at 120 fps you would only need to successfully receive 2.5 MB at 30 fps to be able to watch the entire thing. With a slight delay in playback you could even hop from one sub set of channels to another.

It should work offline too. One could have the cutting edge crispy resolution on a large display or watch the same on a crappy old laptop. (and everything in between)

For fun I one time convert a 3.5 hour lecture to 75 MB and was stunned by how watchable it still was.

Is that not what PeerTube is?

Peertube does this AFAIk (or they plan to do this)

PeerTube is what you're looking for.

There are at least two projects like this for watching anime. I won't name them in this forum but they do exist if you look for them.

Isn't this what https://webtorrent.io/ is?

Latency.

Well.. it's sort of been done and then canned. Skype was peer to peer, which sort of blows my mind when it comes to slack, and how it was better tech than slack. Marketing eh.

Pears.com

Didn't popcorntime use BitTorrent as a streaming protocol by priorizing chunks to be played next?

Peertube?

it has, webRTC did this.

soulseek

I would see that easiest way to bring something like that would be some adaptation of m4u format, just instead of URLs to video it could have URL to torrent/magnet.

one issue I can imagine would be that each part would discover peers independently where assumption that most peers of previous parts should be expected to also have those files.

second idea would be to use ipfs in that way instead of torrent. that would probably have much easier time for reusing peer discovery between parts and also would solve issue when to stop seeding as this is already build in into protocol.

I guess that creating distributed twitch basing on ipfs would be feasible but not sure how many people would like to install ipfs node before that could use that. that's kind of chicken and egg problem, you need a lot of people before this system starts work really well, but to get interest it need to really perform well so people would migrate from twitch like services.

ofc you can use public gateways. afaik cloudflare have public ipfs endpoint that could serve as fallback