WebTorrent support

[paullouisageneau]

This PR suggests an implementation of the WebTorrent protocol inside libtorrent. With this add-on, libtorrent can be used to run hybrid peers seamlessly.

WebTorrent peers use the same application protocol as classic peers but with WebRTC Data Channels as underlying transport instead of uTP or TCP, allowing to run peers in web browsers. Due to the necessary connection signaling, WebTorrent peers require a specific WebSocket tracker to connect.

Since documentation seems to be lacking, I implemented the WebTorrent signaling protocol the best I could guess by looking at existing code. You can find useful information and the reference Javascript implementation here: https://github.com/webtorrent/webtorrent

The implementation requires two external dependencies added as submodules:

• libdatachannel, my lightweight WebRTC Data Channels implementation, which relies on my ad-hoc UDP Interactive Connectivity Establishment (ICE) library libjuice
• boost.JSON, a header-only JSON library for the tracker protocol

This PR does not add new external dependencies to libtorrent (it only requires OpenSSL or GnuTLS depending on the compilation option).

To test, you need a torrent file with at least one WebSocket tracker, for instance wss://tracker.openwebtorrent.com.
You can find such a torrent file here: https://ageneau.org/upload/sintel.torrent
You can also run a web browser peer on this page: https://webtorrent.io/

[paullouisageneau]

@Clodo76 That's very nice of you, however for now I'm the only one maintaining the integration. Any contribution to help to test and fix issues (for instance #5831) is welcome!

[gubatron]

is webtorrent support built as a default feature, or does it need to be specified with some build flags?

Can't find anything in Build Features or any examples on how to enable webtorrent.

[paullouisageneau]

@gubatron Webtorrent support is present only on master branch for now, not on RC_2_0 branch, and it requires the build feature webtorrent to be enabled

libtorrent/CMakeLists.txt

Line 708 in 61ab0eb

target_optional_compile_definitions(torrent-rasterbar PUBLIC FEATURE NAME webtorrent DEFAULT OFF

[petterreinholdtsen]

Is there a time frame for a new release with webtorrent support?

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-- Happy hacking Petter Reinholdtsen

[petterreinholdtsen]

[Andrew]

Any updates on the timeframe for this PR? Would be great to see this out! :)

Yeah. I hope it will bring webtorrent support to the VLC bittorrent plugin, <URL: https://github.com/johang/vlc-bittorrent >. :)

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-- Happy hacking Petter Reinholdtsen

[leoherzog]

Any news on when we'll get this build flag enabled by default in a release?

[plotasse]

hello friends ! it seems peertube is having trouble finding bandwidth and storage in these hard times.

webtorrent support in mainstream clients may be a great step towards decentralized video hosting, which is arguably very needed when traditionnal models such as youtube are beginning to show their limits.

seeing the code is already there, please make an official release with this support if you can!

i am willing to help if any more development is needed.

anyway, thanks for making this awesome software and making the world a better place. cheers!~

[leoherzog]

Unfortunately, PeerTube 6 (out now) has dropped WebTorrent support.

We needed to settle a technical debt : v6 removes support for WebTorrent to focus on HLS (with WebRTC P2P). Both are technical bricks used to get peer-to-peer streaming in web browsers, but HLS is more fitted to what we are doing (and plan to do) with PeerTube

https://framablog.org/2023/11/28/peertube-v6-is-out-and-powered-by-your-ideas/

[plotasse]

oof

[petterreinholdtsen]

[Leo]

Unfortunately, PeerTube 6 (out now) has dropped WebTorrent support. > We needed to settle a technical debt : v6 removes support for > WebTorrent to focus on HLS (with WebRTC P2P). Both are technical > bricks used to get peer-to-peer streaming in web browsers, but HLS is > more fitted to what we are doing (and plan to do) with PeerTube https://framablog.org/2023/11/28/peertube-v6-is-out-and-powered-by-your-ideas/

It will take a while before PeerTube 6 is deployed everywhere, and PeerTube is not the only use of Webtorrent, so it would still be useful with WebTorrent support in libtorrent. But I am not quite sure I understand the difference between Webtorrent and WebRTC P2P. If I understand Peertube using Webtorrent correctly, it provide more available bandwidth per user and improved availability the more users are looking at the same video. HLS with WebRTC P2P seem to provide less available bandwidth per user and reduced availability the more users are looking at the same video, but the description I found so far was a bit unclear so I am not sure.

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-- Happy hacking Petter Reinholdtsen

[leoherzog]

I would still love to see WebTorrent support included in the default builds of libtorrent, of course. The functionality has already been developed. It would be nice to get that enabled.

[petterreinholdtsen]

I agree. I eagerly await a VLC bittorrent plugin with WebTorrent support in Debian, and this depend on a release of libtorrent with WebTorrent support.

[itschasa]

Any update on making this a default feature on release? This seems like a brilliant way to support streaming directly in the browser!

[petterreinholdtsen]

[chasa]

Any update on making this a default feature on release? This seems like a brilliant way to support streaming directly in the browser!

I agree. Given the time passed and the progress made, I suspect a forked project might be needed to make it happen. If such fork existed, I would du my best to get it into Debian and link the vlc-plugin-bittorrent package in Debian to such library with webtorrent support included by default. :)

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-- Happy hacking Petter Reinholdtsen

[itschasa]

That would be good, but having WebTorrent support out of the box in millions of clients across the globe on already existing torrents would be better, as it would make most torrents accessible from the browser just with an update.

[petterreinholdtsen]

[chasa]

That would be good, but having WebTorrent support out of the box in millions of clients across the globe on already existing torrents would be better, as it would make most torrents accessible from the browser just with an update.

Sure. Any idea how to get that option on the table? This request is from 2019-11-25, and as far as I can tell, is not near getting any resolution where the support is enabled by default in a official libtorrent release.

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-- Happy hacking Petter Reinholdtsen

[itschasa]

I'm not sure how to get it attention, that's why I asked if there were any updates on making it available in release. Maybe opening an issue might create some attention to it?

[tuxayo]

If feedback can help, I've been using LibreTorrent on Android since months and it seeded to more than hundred webtorrent peers.
https://gitlab.com/proninyaroslav/libretorrent (build from libtorrent master with webtorrent compile option enabled)

It was by adding the webtorrent.io demo torrent: https://webtorrent.io/torrents/sintel.torrent
And letting it seed.

DHT causes issue on my ISP terrible router so I disabled it. So I'm only relying on webtorrent tracker. And when I catch it seeding, it's indeed seeding to webtorrent peers.