[vlc-devel] [Videolan-devel] Bittorrent VoD

Marijn Swenne marijn.swenne at gmail.com
Tue Dec 22 20:24:27 CET 2009

Dear Remi,

What you're saying is that most BT clients do not support VoD because
they act on the "rarest piece first" policy. And this is correct.
However, there has been a fair bit of research, changing the piece
picker policy to make it compatible with VoD whilst keeping your swarm

If you're really interested, Google for pdfs:
LiveBT Providing Video-on-demand Streaming Service over BitTorrent
BitTube CaseStudyofaWeb-basedPeer-AssistedVideo-on-DemandSystem
BASS BitTorrentAssistedStreamingSystemforVideo-on-Demand
Is High-Quality VoD Feasible using P2P Swarming
BiToS  Enhancing BitTorrent for Supporting
Improving VoD Server Efficiency with BitTorrent

I'm going to continue this research and fine-tune this piece picket
policy and use VLC as a proof of concept. Is this implementation going
to be feasible in a real world application? I'm not sure yet, that's
part of the research, but I definitely think there's a good chance
that it is (otherwise I wouldn't be doing the research ;))

But a separate question is: Assuming that a BT VoD client would be
feasible, would the VLC project be interested in incorporating this in
their release? (having native support for BT files), or is this
outside of the scope of the project?

Kind Regards,

2009/12/22 Rémi Denis-Courmont <rem at videolan.org>:
>        Hello,
> Le mardi 22 décembre 2009, Marijn Swenne a écrit :
>> I'm looking into making a Bittorrent VoD integration for VLC. So in
>> other words, being able to open a BT metafile in VLC as you would a
>> HTTP file and start viewing it before the whole file is downloaded.
>> Obviously you'de need a BT client that supports VoD. I was looking
>> into using http://www.rasterbar.com/products/libtorrent/ which has a
>> BSD-license and modifying it to become a VoD client.
> In my understanding, the BitTorrent protocol is fundamentally
> incompatible with video on demand. VoD requires data to be fetched
> linearly. BitTorrent fetches file chunks starting from the scarcest to
> the most commonly available. This enables users to trade chunks, thus
> maximizing the bandwidth usage. But then, you need to fetch the
> complete video file before you can play it with a media player. Then,
> VLC will be just worse than a dedicated BitTorrent client.
> --
> Rémi Denis-Courmont
> http://www.remlab.net/

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