EZDefinition.com: VideoLAN Howto

     1.1 What is the VideoLAN project ?
     1.2 About this Howto
     1.3 Legal notice
     1.4 The documentation of the project
     1.5 Requirements
        1.5.1 The skills
        1.5.2 The VideoLAN Client
        1.5.3 The VideoLAN Server and mini-Server
        1.5.4 Get a streamable MPEG file
        1.5.5 The VideoLAN Channel Server
        1.5.6 The Network
     1.6 The mailing-lists

2. Overview of the existing streaming solutions

     2.1 Unicast
        2.1.1 What is unicast and why use it ?
        2.1.2 Network hardware required
        2.1.3 Server configuration
           2.1.3.1 (TT
           2.1.3.2 (TT
        2.1.4 Client configuration
     2.2 Broadcast
        2.2.1 What is broadcast and why use it ?
        2.2.2 Network hardware requirements
        2.2.3 Server configuration
           2.2.3.1 (TT
           2.2.3.2 (TT
        2.2.4 Client configuration
     2.3 Multicast
        2.3.1 What is multicast and why use it ?
        2.3.2 Network hardware required
        2.3.3 Server configuration
           2.3.3.1 (TT
           2.3.3.2 (TT
        2.3.4 Client configuration
     2.4 Unicast IPv6
        2.4.1 Basics
        2.4.2 Server configuration
        2.4.3 Client configuration

3. Using channel tools

     3.1 Multicast and miniVLCS
        3.1.1 Building miniVLCS
        3.1.2 miniVLCS configuration
        3.1.3 Run mini-vlcs
        3.1.4 (TT
     3.2 Broadcasting and VLANserver + VLANbridge
        3.2.1 Overview
        3.2.2 The two versions of the tools
        3.2.3 Installation and configuration of the VLAN solution
           3.2.3.1 mini VLAN Server
           3.2.3.2 vlb-linux
        3.2.4 (TT

4. Video On Demand

     4.1 Overview
        4.1.1 What is Video On Demand ?
        4.1.2 Hardware required
        4.1.3 Design of the VOD solution
     4.2 VOD with VideoLAN
        4.2.1 On the server
        4.2.2 On the client
        4.2.3 Client launched by a Web browser
        4.2.4 Using a channel tool for VOD

5. Designing a complete VideoLAN solution

     5.1 The VideoLAN Servers
     5.2 The VideoLAN Channel Servers
        5.2.1 Multicast solution
        5.2.2 VLANs solution

6. Conclusion

Introduction

1.1. What is the VideoLAN project ?

VideoLAN is a complete software solution for video streaming, developed by students at the Ecole Centrale Paris and contributors from all over the world, under the General Public License (GPL). It has been designed for streaming MPEG 1 and MPEG 2 videos on local area networks (LAN), but it can be extended to metropolitan or wide area networks (MAN, WAN), thanks to the multicast technology.

The VideoLAN solution includes a server, which can stream video from various sources (file, DVD, satellite and MPEG 2 encoder), a client, which can receive, decode and display MPEG 1 and MPEG 2 streams and, if necessary, a channel server which tells automatically to the client the parameters needed to receive the stream.

Here is an illustration of the complete VideoLAN solution :

          DVD --->-                 Unicast/Broadcast/Multicast
                    \                           ---
          File --->--     --------            /     \            --------
                     |->-| Server |=====>====|  LAN  |---->-----| Client |
       Satellite ->--    | (VLS)  |           \     /           | (VLC)  |
                    /     --------              ---              --------
         MPEG2 -->-                              ^
        encoder                                  |
                                                 v
                                          ----------------
                                         | Channel Server |
                                         |    (VLCS)      |
                                          ----------------

More details about the project can be found on the VideoLAN Web site.

1.2. About this Howto

This Howto is designed to explain how to use the complete VideoLAN solution. It presents the different possibilities of VideoLAN and which configuration you should adopt depending on the configuration of your network.
1.3. Legal notice

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation ; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts. The text of the license can be found on .

1.4. The documentation of the project

There are four main documents :

the VideoLAN Quickstart,
this VideoLAN HOWTO,
the VideoLAN Server user guide,
the VideoLAN Client HOWTO.

The up-to-date version of these documents can be found on the VideoLAN Web Site.

1.5. Requirements

1.5.1. The skills

Basic skills on Linux and Network should be enough.

1.5.2. The VideoLAN Client

The VideoLAN Client (vlc) works on many platforms : Linux, Windows, Mac OS X, BeOS, *BSD, Solaris, iPaq, QNX. It can read MPEG 1, MPEG 2 and MPEG 4 / DivX files from a hard disk or a CD-ROM drive, read DVDs and VCDs. But the most important function is that it can read MPEG 1, MPEG 2 and DVDs streamed on a network. vlc requires at least a Pentium 400Mhz with 32MB of RAM.

1.5.3. The VideoLAN Server and mini-Server

The VideoLAN Server (vls) can read videos from :

an MPEG 1 or MPEG 2 file stored on a hard drive or on a CD,
a DVD located in a local DVD drive or copied on a hard drive,
a satellite card,
an MPEG encoding card ;

and stream it on the network.

A Pentium 100 MHz with 32 MB of memory should be enough to send one stream on the network. When streaming a lot of videos stored on a hard drive, the actual limitation is not the processor but the hard drive and the network connection.

vls works under Linux, Solaris and Windows. Currently, the Windows vls version of is only able to stream a video from a file.

The VideoLAN mini-Server (vlms) is only capable of streaming an MPEG file. vlms works on Linux only. It is easier to install and configure than vls and should be used mainly for testing purposes.

1.5.4. Get a streamable MPEG file

vls and vlms can stream MPEG 1 or MPEG 2 files that meet two critera :

the file must be MPEG PS (Program Stream) or MPEG TS (Transport Stream), that contain video and audio multiplexed. vls and vlms can't stream MPEG ES (Elementary Stream), i.e. a file with only audio or video.

     In order to know if an MPEG file is MPEG PS, MPEG TS or MPEG ES,
     read the file with vlc and look at the messages (with the interface
     : Click on "View" and "Messages", or use the command line "vlc -v")
     and look for a line :

module: locking demux module `mpeg_XX'

If XX = ps or XX = ts, then your file is MPEG PS and MPEG TS respec tively , and you may be able to stream it. If XX = es, then your file is MPEG ES and is not streamable.

2. the sequence header of the video must repeat itself regularly,

     which is often the case with MPEG 2, but very rare with MPEG 1.
     There is no easy way to know if the sequence header is repeated
     regularly.

     Files with a .vob extension are normally MPEG 2 files and files
     with .mpg or .mpeg extension or usually MPEG 1 files.

You can download this streamable MPEG 2 PS file for your tests : .

1.5.5. The VideoLAN Channel Server

The VideoLAN Channel Server (vlcs) is the central architecture that manages the network. There are different versions of vlcs for different kinds of networks. For example, if your network supports multicast, you will use mini-vlcs. If your network doesn't support multicast but supports VLANs, you should use mini VLAN Server. vlcs works on Linux only.

1.5.6. The Network

You will need a network, which can be as small as one ethernet 10 / 100 Mbit/s switch or hub, and as big as the whole Internet ! See if your network supports "multicast". The bandwidth needed is :

6 to 9 Mbit/s for a DVD,
3 to 4 Mbit/s for an MPEG 1 stream, an MPEG 2 stream (from a
satellite or an MPEG 2 encoding card).

1.6. The mailing-lists

If you have problems using VideoLAN, and if you don't find the answer to your problem in the ``documentation'', please look at the online archive of the mailing-lists. There are 3 english-speaking mailinglists for the users :

vlc@videolan.org for the questions on vlc,
vls@videolan.org for the questions on vls and vlms,
vlcs@videolan.org for the questions on vlcs and the network.

The mailing lists above also have their equivalent for the developers (they also receive the commit mails) :

vlc-devel@videolan.org for the development of vlc,
vls-devel@videolan.org for the development of vls and vlms,
vlcs-devel@videolan.org for the development of vlcs and the network
tools.

If you want to subscribe or unsubscribe to the mailing-lists, please go to the VideoLAN Web Site

2. Overview of the existing streaming solutions

In this section, we assume that :

a VideoLAN Client (vlc) is installed on all the client machines.
Please, refer to the VideoLAN Quickstart or the VideoLAN Client HOWTO for the installation instructions.
a VideoLAN Server (vls) or a VideoLAN mini-Server (vlms) is
installed on a machine. Please, refer to the VideoLAN Quickstart or the VideoLAN Server user guide.
you have the knowledge and the passwords to configure your network
hardware (such as switches and routers).

2.1. Unicast

2.1.1. What is unicast and why use it ?

Unicast is a simple protocol : the packets are sent directly from one machine to another. With VideoLAN, this mean that the source IP address is the one for the server machine, and the destination IP address is the one for the client machine. With unicast, the stream can go through routers without any problem.

Unicast should be used when you want to send the stream to one client machine only. It is also used for ``Video on Demand''.

2.1.2. Network hardware required

No special feature or configuration of your network hardware is required.

The only problem is the bandwidth. As explained in the ``introduction'' , an MPEG 1 or 2 stream needs between 3 and 9 Mbit/s. So a 10 Mbit/s Ethernet network should be enough. 100 Mbit/s would be needed if you want to stream several videos at the same time or stream one big DVD stream (a DVD stream can go up to 11 Mbit/s if there are many languages, subtitles and multiple angles).

2.1.3. Server configuration

You can either use vlms or vls to do unicast.

2.1.3.1. vlms

vlms can only stream valid MPEG PS files stored on a hard drive.

You can download this streamable MPEG 2 PS file for your tests : .

In the example below, the IP address of the client machine is 10.0.0.2. The name of the MPEG file is called MPEG_file_name.

Run vlms :

% vlms -d 10.0.0.2 MPEG_file_name

If you want the server to stream the file continuously, you can use the -l option :

% vlms -d 10.0.0.2 -l MPEG_file_name

or if you want to send it 3 times use the option -n 3 :

% vlms -d 10.0.0.2 -n 3 MPEG_file_name

2.1.3.2. vls

Modify the configuration file vls.cfg by adding the following :

       BEGIN "Channels"
          net1 = "network"
       END

       BEGIN "net1"
           Domain = "Inet4"
           Type = "unicast"
           DstHost = "10.0.0.2"
           DstPort = "1234"
       END

Then, restart vls and start to stream a video to "net1".

2.1.4. Client configuration

On the client, run vlc with this command line :

% vlc udp:

You can also use the interface :

% vlc

and then click on "Net" and select "UDP".

2.2. Broadcast

2.2.1. What is broadcast and why use it ?

Broadcast is a very dirty method to stream video : the stream is sent to all the machines of a subnet at the same time. With VideoLAN, this means that the source IP address is the IP address of the server, and the destination IP address is the broadcast IP address of the subnet. Broadcast is considered a dirty method because all the machines of the subnet receive the stream, even the machine that don't want to watch the stream. It creates a lot of pollution on the network and some devices don't like to receive too much broadcast.

So broadcast should be used to stream video to multiple clients at the same time only if your network hardware doesn't support multicast (see ``next subsection'').

2.2.2. Network hardware requirements

No special feature or configuration of your network hardware is required. It only needs to have the necessary bandwidth, as for unicast.

2.2.3. Server configuration

You can either use vlms or vls to do broadcast.

2.2.3.1. vlms

In the example below, the broadcast IP address of the subnet is 10.0.0.255. The name of the MPEG file is called MPEG_file_name.

Run vlms :

% vlms -d 10.0.0.255 MPEG_file_name

If you want the server to stream the file continuously, do :

% vlms -l -d 10.0.0.255 MPEG_file_name

2.2.3.2. vls

Modify the configuration file vls.cfg by adding the following :

       BEGIN "Channels"
          net1 = "network"
       END

       BEGIN "net1"
           Domain = "Inet4"
           Type = "broadcast"
           DstHost = "10.0.0.255"
           DstPort = "1234"
       END

Then, restart vls and start to stream a video to "net1".

2.2.4. Client configuration

On the client, run vlc with this command line :

% vlc udp:

You can also use the interface :

% vlc

and then click on "Net" and select "UDP".

2.3. Multicast

2.3.1. What is multicast and why use it ?

When you use unicast or broadcast, you can encounter the following problems :

with unicast, when a lot of clients want to receive the stream, the
network interface of the server becomes saturated. So the number of clients is very limited, especially when the stream is big.
with broadcast on a LAN, the number of clients are not limited
because all the machines of the subnet receive the stream, with only one stream going out of the network interface of the server. But the machines that do not want to receive the stream are polluted and some devices do not like to receive huge broadcasts. If you want to send several streams at the same time, the network becomes oversaturated.

The above problems are why the multicast protocol was invented. With multicast, the packets are sent on the network to a multicast IP group which is designated by its IP address. Multicast IP addresses belong to the Class D : 224.0.0.0 -> 239.255.255.255.

The machines can join or leave a multicast group by sending a request to the network. The request is usually sent by the kernel of the operating system. Linux (if the option "IP multicast" in the category "Networking options" is activated in the configuration of the kernel), Windows (at least 98, 2000 and XP) and MacOS X support multicast. The vlc takes care of asking the kernel of the operating system to send the join request.

The network devices do everything necessary to keep in memory which machine belongs to which group and forwards the stream to the client. It is possible for one client to belong to several groups.

Below is a scenario given as an example :

vls sends a stream to the multicast IP address 239.255.12.42. Client n°1 and n°2 already joined the multicast group and receive the stream.