Watch the whole video from while downloading. Progressive download

[ilnar]

I've read FAQ and all announcements and didn't find the request of this feature neither.

Would it be possible to implement the feature to utorrent which will allow to watch video (in external player) while downloading it?

Something like it was in FoxTorrent.

http://www.lostremote.com/2007/04/27/firefox-torrent-plugin-lets-you-watch-while-you-download/

For example, videos are around 700-800 kbits and bandwidth is around of 1.5-2 Mbit/s.

So it's possible to start to watch whole video from begining whithout previous 100% download.

Potentially this feature is extremely required and can make utorrent be even more massive (however is already enough massive).

Thank you.

[DreadWingKnight]

It's called sequential downloading and no it won't be implemented.

[ilnar]

Could you explain a little bit why it wouldn't be implemented?

Is it due to complexity of video format, torrent system or simply out of any plans?

[DreadWingKnight]

http://www.azureuswiki.com/index.php/Sequential_downloading_is_bad

[ilnar]

hm, yes, I've already understood the problem before.

Abuse of sequential download isn't good idea.

But in theory, in particular cases, when there are enough seeders with high upload speed and not many leechers probably it works.

I understand decision to don't implement sequential downloading. It's reasonable to avoid global low efficiency by price of some ocassionaly helpfull feature.

I found it was actually discussed before http://forum.utorrent.com/viewtopic.php?id=44927

[Switeck]

For example, videos are around 700-800 kbits and bandwidth is around of 1.5-2 Mbit/s.

Ugh! I bet your UPLOAD isn't over 800 kilobits/second...so even if it was implemented, you may be able to watch while viewing but you'll screw the chances of others doing the same!

It is precisely for when there's a bandwidth crunch that a feature such as this should NOT be made!

And even if there's LOTS of seeds, it's still very hostile to the torrent swarm -- meaning you could put enough of a drain on the seeds that others cannot reach the same download speeds. Lots of seeds are seeding many torrents at once, resulting in their average upload speed per torrent being 1 KB/sec...or less! So even if you could upload fast enough to make up for the seed-drain you're likely causing, your actions would be choking out the spread of "rare" pieces.

Even the issue of piece size can be a problem...if it's 1 MB or larger, you'd have to get whole pieces AND verify them by hashing them before they're "safe" for viewing. So a downloader needs both a read ahead of a couple megabytes to handle completed pieces AND an additional read ahead so short bandwidth "hiccups" don't cause it to fall behind playback speeds.

Such "peers" become immensely bad sharers, because if most peers are doing this...they end up having NOTHING to share with each other and have to keep hitting the seed/s for more pieces of the torrent. This means the seeds have to supply to the torrent swarm at MULTIPLE TIMES the playback speed or the system cannot be sustained at playback speed for most! It takes fewer than 1 out of 4 peers doing this on even an "average torrent" (with multiple seeds) before it "poisons" the whole swarm into disproportionally demanding from the seeder/s. Many seeders quit before they reach 4-to-1 share ratios, but that's what's needed to keep sequential downloaders supplied.