Hi Ruby,
you are pinpointing two important issues regarding offering online access to
video files:
1) The video files, in wmv format are too large. As a result, downloading
takes a long time for users and the process weighs on the available
bandwidth (both at the user and server side)
2) An infrastructure might be unable to offer more than a certain number of
simultaneous downloads.
Using
a streaming server & video player is primarily a solution for the
first issue. To offer new video's through your streaming server &
player, the files first need to be converted to a "streaming format",
for instance FLV (Flash Video).
Flash Video files can be delivered in several different ways:
- "Streamed via RTMP"
to the Flash Player using the Flash Media Server, VCS,
ElectroServer, Wowza Pro, WebORB for .NET or the open source Red5
server.
- "Progressive download via HTTP". This method uses ActionScript to
include an externally hosted Flash Video file client-side for
playback.
However, unlike streaming using RTMP, HTTP "streaming" does not
support real-time broadcasting. Streaming via HTTP requires a custom
player and the injection of specific Flash Video metadata containing
the exact starting position in bytes and timecode of each keyframe.
Using this specific information, a custom Flash Video player can
request any part of the Flash Video file starting at a specified
keyframe.
You can determine a fixed bitrate for the converted movies. This will mean
that resolution and quality will be scaled down. An example bitrate is
600kb/sec (this is equal to 75kB/sec ... virtually any client broadband
connection is able to view the files fluently.
The biggest advantage for users, is that they are able to start viewing
immediately, and that they are not required to wait until the full movie is
downloaded. In addition to that, they are able to "jump" to a certain point
on the video's timeline, and streaming will continue from there.
To make the bridge to the second issue: multiple users viewing
simultaneously always has an impact on the bandwidth, available to your
server. But by using a streaming server & viewer, the bandwidth requirements
per client are fixed, while with normal downloading, one client could
"drain" the bandwidth with very high download speeds.
To make this clear through an example:
If your server has a 100mbit bandwidth connection, you are able to support
170 simultaneous viewers. However, if you would offer the videos as
downloadable files, and if you have users with 8mbit connections, this would
mean that you would only be able to serve 12 clients, who are fully using
their own 8mbit connections.
If you are interested in implementing a streaming solution for your DSpace,
@mire offers a DSpace add-on module for streaming video (and audio), please
see http://atmire.com/audiovisual.php. Several streaming servers and players
are possible but the most common setup is using a flash video player and the
Adobe Streaming Server (for Flash video).
with best regards,
Bram Luyten & Lieven Droogmans
@mire NV
Romeinse Straat 18
3001 Heverlee
Belgium
+32 2 888 29 56
http://www.atmire.com - Institutional Repository Solutions
http://www.togather.eu - Before getting together, get [EMAIL PROTECTED]
On Tue, Nov 25, 2008 at 7:37 AM, <[EMAIL PROTECTED]> wrote:
>
> Hi!
>
> We would like to upload video files that are produced for the department
> and
> ideally we would like to archive into the Institution's established DSpace
> instance.
>
> The department's IT people are concerned that the size of the video files
> could
> cause a major problem with the government's internet traffic (eg cause an
> outage), especially if too many people attempt to access at the same time.
> We
> currently have one video file on DSpace which is in .wmv format. The .wmv
> format is not seen as being compact enough to minimise the impact of video
> files
> (in DSpace) on the government Internet.
>
> A suggestion from our IT person has been "streaming HTML" as it has a small
> footprint which would make it ideal for this exercise. I don't know what
> streaming HTML is and if it is recommended to work with DSpace.
>
> Is there someone out there who can enlighten me as to what streaming HTML
> is and
> if it will work in archiving video files in DSpace?
>
> Thanks very much.
>
> Ruby Lindberg
> Electronic Services Librarian
> Northern Territory Department of Health & Community Services
> Northern Territory Government
> www.nt.gov.au/health
> PO Box 40596, Casuarina, NT
>
> 0811
>
> Building 4, Royal Darwin Hospital, TIWI, NT 0810
> [EMAIL PROTECTED]
> Ph: +61 8 8922 7913
> Fax: +61 8 8922 7777
>
> Librarian on Call (DHCS staff)
> Library Catalogue
> eLibrary a new service replacing CROC for DHCS staff - login using your
> ePass
> username and password
>
>
>
>
> "You can't direct the wind but you can adjust the sails."
> P Please consider our environment before printing this e-mail
>
>
> -------------------------------------------------------------------------
> This SF.Net email is sponsored by the Moblin Your Move Developer's
> challenge
> Build the coolest Linux based applications with Moblin SDK & win great
> prizes
> Grand prize is a trip for two to an Open Source event anywhere in the world
> http://moblin-contest.org/redirect.php?banner_id=100&url=/
> _______________________________________________
> DSpace-tech mailing list
> DSpace-tech@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/dspace-tech
>
-------------------------------------------------------------------------
This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
Build the coolest Linux based applications with Moblin SDK & win great prizes
Grand prize is a trip for two to an Open Source event anywhere in the world
http://moblin-contest.org/redirect.php?banner_id=100&url=/
_______________________________________________
DSpace-tech mailing list
DSpace-tech@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/dspace-tech
