Peertube: Magnet link never starts download

[strypey]

What happened?

I tried to download a video from a PT instance using a magent link, but the download never started. It never found any peers, nor downloaded any metadata.

What do you expect to happen instead?

I expected the metadata to be downloaded from the PT instance, and a BitTorrent download to begin, just as it does it I download the .torrent file.

Steps to reproduce:

1. Click 'Download' to bring up the 'Download video' modal, choose 'Torrent (magnet llnk)', and click the orange 'Download' button.

2. Look at BitTorrent client so see that although it has responded to the magnet link and tried to start a download, no peers are being found, and no metadata being downloaded, even after half an hour.

Additional information

• PeerTube version or URL: https://vidcommons.org/videos/watch/8464f77b-31f4-4d02-a473-afa288f64506
• Browser name/version: ABrowser 64.0 (32-bit)
• BitTorrent client name/version: Transmission: 2.84
• OS name/version: Trisquel 8 (32-bit)

I have tried this numerous times over the last couple of months, on a variety of PT sites, always with the same outcome.

[buoyantair]

@strypey Hi, I tried the above steps over https://instant.io/ . It seems to work for me and the torrent client was able to download metadata & start the download. Can you verify if it works this way or not?

[Serkan-devel]

I think you seem to confuse webtorrent with regular bittorrnent. It needs a webtorrent client to download from those magnet links.

[strypey]

Yes @buoyantair , the magnet link from Vidcommons.org worked on instant.io.

@Serkan-devel

It needs a webtorrent client to download from those magnet links.

Are you sure? Nothing in the UI indicates that, nor anything in the discussion at #639 about introducing the magnet links to the UI. The .torrent file available from the same modal works as normal on Transmission, it's just the magnet link that doesn't.

[Chocobozzz]

Transmission does not support xs parameter in magnet uris: https://github.com/transmission/transmission/issues/317

[ghost]

I've tried to download a video using the magent link with:

• Deluge 1.3.13 and it doesn't work.
• qbittorrent 3.3.7 and it's stuck at "retrieving metadata..."
• ktorrent 4.14.26 doesn't work
• Tixati 2.58 stuck at "Fetching meta-info..."

[ealgase]

Works for me in aria2c.

[Serkan-devel]

Again, magnet links from webtorrents don't work on regular bittorrent clients.

You can list tests with more bittorrent clients with the same result.

Unless it has been routed through a hybrid client which supports both webtorrent and bittorrent

[rigelk]

@Serkan-devel it has nothing to do with webtorrent, but everything to do with how clients parse the magnet links fed to them.

[ealgase]

@Serkan-devel aria2c does not support WebTorrent (https://github.com/aria2/aria2/issues/595) but the download works. It just doesn't download or seed WebTorrent peers.

[Jorropo]

Also, transmission doesn't support ws{s} tracker, so even if xs option is added in transmission, nothing will change

[Chocobozzz]

@Jorropo No, if transmission gets the torrent file (with the xs parameter) it will be able to download the video via webseed and other TCP/UDP peers because the peertube tracker supports HTTP

[Serkan-devel]

@ealgase maybe you were able to download through that specific magnet link because someone probably had a hybrid-client which can communicate with bittorrent and webtorrent

https://webtorrent.io/desktop/

And can't find any dependency which hints traditional bittorrent support.

[Serkan-devel]

Also to note:

Can I seed videos with my classic BitTorrent client (Transmission, rTorrent...)?

Yes you can, but you won't be able to send data to users that watch the video in their web browser. The reason is they connects to peers through WebRTC whereas your BitTorrent client uses classic TCP/UDP. To check if your BitTorrent client supports WebTorrent you can see this issue: https://github.com/webtorrent/webtorrent/issues/369

src: https://github.com/Chocobozzz/PeerTube/blob/master/FAQ.md#can-i-seed-videos-with-my-classic-bittorrent-client-transmission-rtorrent

[ealgase]

@Serkan-devel no one was seeding with bittorrent or webtorrent, it was downloaded directly from the server (as a webseed).

[Jorropo]

@Chocobozzz, you are right, I didn't thinked about that but, using transmission to download over http is overkill.
If transmission support xs but don't support ws tracker that will fix this problem but not in the best way.

[Chocobozzz]

Since most of bittorrent clients are not able to parse our magnet URI, maybe we should remove it from the download modal (and just keep DDL/torrent file).

[strypey]

From a user POV that it would be better to have no magnet link, than to
have a magnet link that often doesn't work as expected. So removing it
may be the best short term solution, but I hope you would continue
experimenting with it in a dev branch, and communicating with the BT
client devs about how to get it to work reliably.

Ideally, if and when you can do that, the best place to put magnet links
would be directly under the video embed on the video page. What I
suggest is to add a button to the settings menus that allow admins to
toggle downloads off for their instance, and allow users to toggle
downloads off for their channel. You'd need to set this up so that it
also either a) prevented their videos being mirrored on other instance,
or b) prevented downloads from the video page of mirrored copies.

Doing it that way means that video hosts worried about unauthorized
copying can prevent it by completely disallowing downloads. Those who
want to allow downloads can do so and all the download buttons can be
right there on the video page, rather than hidden away in a pop-up.

[ealgase]

What I suggest is to add a button to the settings menus that allow admins to toggle downloads off for their instance, and allow users to toggle downloads off for their channel.

I really suggest against this. Unless Peertube employs obfuscation, it will be easy to rip the streams, and just annoy legitimate users who want to watch the videos in a player other than the web client.

[strypey]

@ealgase as a legitimate user, it annoys me that the download options for PT videos are obscured and inconvenient to use. This is OT for this issue but since it keeps coming up, I have opened an issue for it (#1797).

[ealgase]

Yeah, download buttons should be easier to access. However, I don't think having an admin option to remove them would be a good choice.

[Chocobozzz]

Closed by https://github.com/Chocobozzz/PeerTube/commit/7c51916a61d53526c594a2115f1c0e6051a895d9