Veejay HOWTO

Matthijs van Henten ( )
Niels Elburg ( )
v1.0, 30 March 2003
v1.1, 22 June 2003
v1.2, 26 August 2003
v1.3, 9 November 2003
v1.4, 24 May 2004
v2.0, 25 July 2004
v2.1 27 January 2005
v2.2 22 April 2005

This document describes how to use veejay, a visual 'music' instrument for Linux/GNU

1.1 Disclaimer
1.2 Acknowledgements
1.3 Audience and Intent
1.4 Revision History
1.5 New versions of this document
1.6 Feedback
1.7 Distribution Policy
2. About veejay
2.1 Features
2.2Hardware configuration
3. Installation
3.1 Dependencies
3.2 Installing veejay
3.3 Setting up multicast
4. Using Veejay
4.1 Terminology and limitations
4.2 VIMS
4.3 The keyboard interface
4.4 Recording video
4.5 Streaming video
4.6 Other utilities
5Popular packages
5.3The MJPEG Tools
6.Other Resources
6.1Web Sites
6.2 Mailing Lists

8.GNU Free Documentation License

1. Introduction

1.1 Disclaimer

No liability for the contents of this documents can be accepted. Use the concepts, examples and other content at your own risk. As this is a new edition of this document, there may be errors and inaccuracies, that may of course be damaging to your system. Proceed with caution, and although this is highly unlikely, the authors do not take any responsibility for that.
All copyrights are held by their respective owners, unless specifically noted otherwise. Use of a term in this document should not be regarded as affecting the validity of any trademark or service mark.
Naming of particular products or brands should not be seen as endorsements.
You are strongly recommended to take a backup of your system before major installation and backups at regular intervals.

1.2 Acknowledgements

The following peope have been helpful in getting this HOWTO done:

1.3 Audience and Intent

This document is targeted at the Linux user interested in learning a bit about veejay and trying it out.

1.4 Revision History

Version 1.0

First version for public release
Version 1.1
Updated Howto to match version 0.4.0. Revised chapters 2.2,4.4, 5.3 and 6
Version 1.2
Updated Howto to match version 0.4.6. Revised chapter 2.1,2.2,3.3
Version 1.3
Updated Howto to match version 0.5.3.
Version 1.4
Updated Howto to match version 0.5.9
Version 2.0
Partial re-write to match version 0.6
Version 2.1
Updated Howto to match version 0.7.2
Version 2.2
Updated Howto to match version 0.8

1.5 New versions of this document

You will find the most recent version of this document at
If you make a translation of this document into another langauge, let us know and we'll include a reference to it here.

1.6 Feedback

We rely on you, the reader, to make this HOWTO usefull. If you have any suggestions, corrections , or comments , please send them to us ( ), and we will try to incorporate them in the next revision. Please add 'HOWTO veejay' to the Subject-line of the mail.
Before sending bug reports or questions, please read all of the information in this HOWTO, and send detailed information about the problem.
If you publish this document on a CD-ROM or in hardcopy form, a complimentary copy would be appreciated. Mail us for our postal address. Also consider making a donation to the Veejay Project to help support free video editing software in the future.

1.7 Distribution Policy

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. A copy of this license is included in the section entitled "GNU Free Documentation License".

2. About Veejay

Veejay is a visual instrument and realtime video sampler. It allows you to 'play' the video like you would play a Piano and it allows you to record the resulting video directly to disk for immediate playback (video sampling).

Thus, Veejay can be operated live by using the keyboard (which is 100% user definable) and remotely over network (both unicast and multicast) using an inhouse message system that allows mapping of various protocols on top of it, like OSC (OpenSoundControl).

Veejay is beeing developed in the hope it will be usefull for VJ's, media artists and other interested users that want to use Free Software for their performances and/or video installations.

As of version 0.8 Veejay comes with a graphical user interface GVeejay. You can use GVeejay to connect (and switch) to any Veejay on the network , alternativly it can launch a veejay locally on your machine.
Use GVeejay to customize keyboard mappings and save the configuration file.
Gveejay supports hot switching between multiple running instances of veejay, simply disconnect and connect to another veejay.

2.1 Features





2.2 Hardware configuration

Veejay requires at least a linux kernel 2.4.x, 2.6.x or later, a lot of diskspace and a fast CPU. Depending on the speed of your machine, your milage may vary. See the list below for a few systems veejay was reported to work on:

Video Editing requires a lot of diskspace, make sure you you have enough diskspace available for your project. If you are going to use the recording functions, make sure you have sufficient free disk space available.Otherwise you are quite safe, veejay does not change your original video or fill your harddisk with needless temporary files. Neither does it waste your resources (unless you fill the effect chain with a lot of effects)

3. Installation

3.1 Dependencies

Before you install Veejay, you should install the following software packages. Although none of them is required, Veejay will be much less usable without them.

On newer distributions, some of the listed software is already installed but you may be missing the -devel- packages! (especially on redhat, suse and debdian systems!!)

You can find the websites of these projects in Other Resources.

3.2 Installing veejay

Verify that the PKG_CONFIG_PATH variable is set to the directory containing files like jack.pc and directfb.pc to include them in the build process.

$ echo $PKG_CONFIG_PATH   
If nothing is set, do something like
$ export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig
Decompress and untar the file by typing:
$ tar -jxvf veejay-0.8.x.tar.bz2
Change to the directory containing veejay's source's:
$ cd veejay-0.8.x

$ ./configure
On completion it will summarize the results of the ./configure script, which could look like this:
configure:  Veejay 0.8.0 build configuration :
configure:  Compiler flags: -march=pentium4 -mcpu=pentium4 -fno-common -O2 -fomi
t-frame-pointer -malign-double -mfpmath=sse -Wall -Wunused 
configure:  Architecture: i686 
configure:    x86  
configure:     MMX     enabled     : true
configure:     MMX2    enabled     : false
configure:     SSE     enabled     : true
configure:     SSE2    enabled     : true
configure:     3DNOW   enabled     : false
configure:     CMOV    enabled     : true
configure:     Nasm    enabled     : true
configure:    Platform: Linux
configure:  Required dependencies:
configure:   - POSIX Threads (pthread)       : true
configure:  Optional dependencies
configure:   - video4linux                   : true
configure:   - SDL support                   : true
configure:   - DirectFB support              : false
configure:   - AVI MJPEG playback/recording  : true (always)
configure:   - libDV (digital video) support : true
configure:   - JPEG support                  : true 
configure:   - jack                          : false
configure:   - xml c library for gnome       : true
configure:   - freetype support              : true
configure:    - GVeejay UI
configure:      share : ${prefix}/share/veejay

Now, you can start building veejay
$ make
Followed by
# make install

3.3 Setting up multicast

Multicast is a technology that reduces network traffic by simultaneously delivering a single stream of information to any interested recipient.

To enable multicast in Veejay, you must have enabled IP multicast in your kernel configuration.

Finally you need to add a multicast route :

for 1 ethernet device:
# route add -net netmask dev eth0

for > 1 
# route add -net netmask gw dev eth1

Next, Veejay can be started with the commandline flags -M/--multicast-osc and/or -V/--multicast-vims

4. Using Veejay

Veejay uses by default a SDL window to play a video file or video stream, all the keybinding in veejay depend on SDL; if you move your mouse over to the SDL windows to focus it , you can press the keys explained in 4.3 The keyboard interface.
To use veejay in commandline style interface mode, see 4.2 sayVIMS.
You must no longer provide a video file to use with veejay; it will run in dummy mode by using the '-d' commandline parameter:

$ veejay -d

4.1 Terminology and limitations

Veejay has a number of playback modes, each playback mode is unique and defines more or less a different functionality:

Also, note that veejay runs in only 1 resolution at a time (depending on the video dimensions of the first loaded movie). All movies loaded must have identical properties, otherwise veejay will not start. This limitation is also valid when streaming video from veejay to another veejay.

Playback modes in veejay

Mode Description Navigation Looping Speed Effect Chain
Plain Default mode, playback of video Yes No Yes No
Sample Sample mode, playback of video samples. Yes Yes Yes Yes
Tag Tag mode, playback of video streams No No No Yes

4.2 VIMS

Use the command 
$ veejay -u -n |less

to dump all VIMS messages.

1.1 Message Format

A message is described as:

	  :  ; 


	099:0 0;

The action identifier is a 3 digit number describing a Network Event  
The colon is used to indicate the start of the Argument List and must be given. 

The Argument List is described by a printf() style formatted template 
which describes the number and type of arguments to be used. 

The semicolon must be given to indicate the end of this message

1.2 Bundled Messages

A message bundle is a special message that contains an ordered list of at least 1 or more messages. Each message is executed from left to right (first in, first out) while parsing the bundle.   


	5032|BUN:002{361:0 3 56 230 93 0;361:0 4 1 7;}|
	5033|BUN:003{361:0 3 56 230 93 0;361:0 4 1 7;361:0 5 1 7;}|
	5034|BUN:003{361:0 3 56 230 93 0;361:0 4 1 7;361:0 5 1 8;}|

A message bundle is described as:

	 BUN:  { 
		 :  ;
		 :  ;

The token 'BUN:' indicates the start of a messaage bundle, the first 3 digit numeric value represents the total number of messages in the bundle. The '{' symbol indicates the start of a message block and is ended with '};' or just '}'. 

1.3 Format of an Action File/Attaching Keys to Bundles

	<501 - 599> |  |

The contents of some action file can be :


The message bundle BUN sends '355' for clear effect chain.
This message bundle is attached to action identifier 516.

A key is attached to this function trough using the GUI (GVeejay)
or by using: 


	"083:516   ;"

The message bundle can be attached to a key , for example 'SHIFT + A' by sending 
	083:516 97 3;

Which attaches bundle '516' to SDL key '97' using a modifier '3', which is SHIFT. 

Modifiers: 0 = none, 1 = alt , 2 = ctrl,  3 = shift
Keys     : see SDLkeysym.h somewhere in include/SDL/

If the number 0 is used for an event number, a given key combination can be
unset (wiped) :

	083:0 97 3;

Alternativly, you can bind keys to any action identifier. The complete
list can be viewd by typing veejay -u |less or with Gveejay. 

	083:20 97 0 4;

The example above sets key 'a' to 'change video speed to 4'

General  description of VIMS messages

Some reserved numbers:

	clip id		0	:	select currently playing clip	
	clip id		-1	:	select highest clip number 
        chain entry	-1      :   	select current chain entry 
	stream id 	0	:	select currently playing stream 
	stream id 	-1	:	select highest stream number
	key modifier	        :	0 = normal, 1= alt , 2 = ctrl, 3 = shift
	frame		-1	:	use highest possible frame number (usually num video frames)
	playback mode   	:	0 = clip, 1 = stream, 2 = plain
	data format     	: 	yv16 (yuv 4:2:2 raw) , mpeg4, divx, msmpeg4v3,
					div3, dvvideo, dvsd, mjpeg, i420 and yv12 (yuv 4:2:0 raw)
	loop type		:  	0 = no looping, 1 = normal loop, 2 = pingpong (bounce) loop


sayVIMS is a commandline utility distributed with the veejay package, it allows you to give short commands in interactive mode

$ sayVIMS -i -h localhost -p 3490

Typing '?' followed by pressing ENTER gives the list of command below:
  vi [file]           Open video4linux device 
  fi [file]           Open Y4M stream for input 
  fo [file]           Open Y4M stream for output 
  av [file]           Open (almost any) video file using FFmpeg 
  mc [address] [port] Open a multicast UDP video stream 
  pr [hostname][port] Open a unicast TCP video stream
  cl [file]           Load cliplist from file 
  cn [n1] [n2]        New clip from frames n1 to n2 
  cd [n]              Delete clip n1 
  sd [n]              Delete Stream n1 
  cs [file]           Save cliplist to file 
  es [file]           Save editlist to file 
  ec [n1] [n2]        Cut frames n1 - n2 to buffer 
  ed [n1] [n2]        Del franes n1 - n2  
  ep [n]              Paste from buffer at frame n1 
  ex [n1] [n2]        Copy frames n1 - n2 to buffer 
  er [n1] [n2]        Crop frames n1 - n2 
  al [file]           Action file Load 
  as [file]           Action file save 
  de                  Toggle debug level (default off) 
  be                  Toggle bezerk mode (default on) 
Also, you can send messages in VIMS format (or files, containing VIMS messages )

For example, add the Pixelate effect on the Effect Chain of the current playing stream or clip:
sayVIMS -h localhost -p 3490 "361:0 0 150 3;"

Last but not least, sayVIMS can parse files containing VIMS messages.
See the test/examples directory of the package for a list of perl scripts that output a VIMS script.
sayVIMS -f advocate.vims -h localhost -p 3490

Alternativly, you can start a secundary veejay and stream from peer to peer in uncompressed video:
$ veejay -d -p 5000

$ sayVIMS -h localhost -p 5000 "245:localhost 3490;"

(press 'F7' in veejay to display the stream, prob. stream 7)
Or for multicast:
$ veejay -V -p 5000 -n -L movie1.avi

$ veejay -d 

$ sayVIMS -h localhost -p 3490 "246: 5000;"

$ veejay -d -p 4000

$ sayVIMS -h localhost -p 4000 "246: 5000;"

Or, if you want to play a XVID movie (or any other compressed format that is not I frame only):
$ sayVIMS -h localhost -p 3490 "244:/tmp/my-XVID-movie.avi;"

4.3 The keyboard interface

Here is a quick overview for the most used default keys, if applied in order you will end up with a newly created video sample looping in some way (depending on how many times you press the asterix key)

Some keyboard bindings

Description SDL key In plain english
Set the starting position of a new sample SDLK_LEFTBRACKET Left bracket
Set ending position and create a new sample SDLK_RIGHTBRACKET Right bracket
Select and play sample 1 SDLK_F1 F1
Set playback speed to 3 SDLK_d d
Change looptype SDLK_KP_MULTIPLY asterix on numeric keypad
Play backward SDLK_KP_4 Cursor left on numeric keypad
Play forward SDLK_KP_6 Cursor right on numeric keypad
Skip 1 second SDLK_KP_8 Cursor up on numeric keypad
Switch playmode to Plain SDLK_KP_DIVIDE Divide on numeric keypad
Print information about sample SDLK_HOME Home

The function keys F1...F12 can be used to select sample 1 ... 12, use the keys 1...9 to select a sample range 1-12 ... 108-120 and press one of the F-keys to play that sample.

Use ESC to switch between samples and streams. Press ESC again to switch back to the sample playmode
You can create new input streams by using the console interface or by using GVeejay.
All new input streams (and samples) are auto numbered.

4.4 Recording video

You can record video to a new clip , by using the stream- or clip recorder functions.
For example, to record a new clip from a playing clip in MJPG format:

Record 100 frames and start playing new clip when ready:
130:100 1;
Record the whole clip and dont start playing new clip when ready:
130:0 0;
If your Effect Chain is very CPU demanding , consider disabling audio and using the commandline parameter -c 0 to disable sync correction.

It is possible to start veejay headless and have it write all video data to a (special) file for further processing.

Refer to chapter 5.3 for some examples.

4.5 Streaming video

You can create an input stream to read video coming from a video4linux device, from a pipe or from a network socket (both unicast and multicast).

4.5.1 video4linux

To open a video4linux device use gveejay or type the command:

$ sayVIMS 240:0 1;
The selector '240' tells veejay to open a video4linux device, the first argument '0' indicates the device number (i.e. /dev/video0) and the last argument '1' indicates the video in port of your capture card (in this case composite).
Veejay will create a new stream see chapter 4.4 for activating the stream.

4.5.2 pipe

Veejay supports reading video data from a pipe (FIFO) by means of an input stream.
The only supported transport format is yuv4mpeg (yuv 4:2:0). When playing YUV 4:2:2 the video stream will be sampled to YUV 4:2:0 and vice versa
You can create the input stream by typing the command
$ sayVIMS 243:/tmp/stream.yuv;

4.5.3 network

To get frames from another running veejay, use the command:
$ sayVIMS 245: ;
For example, sayVIMS 245:localhost 5000;

If you want to send the same video to multiple running veejays accross the network, you can save bandwith by starting the veejay you wish to use as server with the -V option.
You can use the -V option to start an optional multicast frame sender.
First, you need a multicast route in your routing table. See chapter 3.3 for a short introduction or consult a howto that disuccess setting up multicast for your operating system.

$ veejay -V -p 5000
Start another veejay, and use this command:
$ sayVIMS "246:5000;" 
To create a new input stream. Start more veejays and use sayVIMS with the -p option to give it a port offset number.

4.6 Other utilities

Currently there are 4 extra utilities yuv2rawdv , rawdv2yuv , sayVIMS and any2yuv included in the veejay package for encoding a Y'CBCR 4:2:0 stream to raw DV and vice versa.

yuv2rawdv takes input from STDIN and outputs to STDOUT, we illustrate this with a few examples.

When loading yuv2raw dv without parameters you will see:

This program reads a YUV4MPEG stream and puts RAW DV to stdout
Usage:  yuv2rawdv [params]
where possible params are:
    -v num    Verbosity [0..2] (default 1)
    -l num    Clamp Luma (default 0)
    -c num    Clamp Chroma (default 0)
If you use the clamp parameters, it will clip (not scale!) a pixel into a valid range, the resulting video could be for example a bit darker if the input stream has values for Luminance exceeding the maximum of 235.
See the table below for all valid ranges.


Channel Range (Clamp) Byte range (no clamping)
Y (Luminance) 16 - 235 0 - 255
Cb (Chroma Blue) 16 - 240 0 - 255
Cr (Chroma Red) 16 - 240 0 - 255

To convert a yuv4mpeg file to rawdv (the yuv4mpeg file needs to be compatible with the digital video format properties)
$ cat yuv4mpeg-file.yuv | yuv2rawdv | playdv

To convert a yuv4mpeg file to rawdv with luminance and chroma information clipped to a valid range:
$ cat yuv4mpeg-file.yuv | yuv2rawdv -l 1 -c 1 | playdv

rawdv2yuv takes input from STDIN and outputs to STDOUT, we illustrate this with a few examples.
This program reads a raw DV stream from stdin and puts YV12/I420 to stdout
Usage:  rawdv2yuv [params]
where possible params are:
   -v num     Verbosity [0..2] (default 1)
   -x         Swap Cb/Cr channels to produce IV12 (default is I420)
   -n num     Norm to use: 0 = NTSC, 1 = PAL (default 1)
   -q         DV quality to fastest (Monochrome)
   -h         Output Half frame size
   -c num     clip off  rows of frame (for use with -h)
              must be a multiple of 8

If you want to convert a full PAL/NTSC dv frame to half PAL YCbCr (I420 or YV12) you can give the command:
$ cat raw.dv | rawdv2yuv -h | yuvplay

You can use the -c parameter to clip the width of the video frame.
$ cat raw.dv | rawdv2yuv -h -c 8 | yuvplay

The resizer in rawdv2yuv uses a best neighbour interpolation algorithm for downsizing.

any2yuv takes input from STDIN and puts YV12/I420 to stdout:
This program reads anything from stdin and puts YV12/I420 to stdout
Usage:  any2yuv [params]
where possible params are:
   -v num     Verbosity [0..2] (default 1)
   -x         Swap Cb/Cr channels to produce IV12 (default is I420)
   -n num     Norm to use: 0 = NTSC, 1 = PAL (default 1)

sayVIMS can be used to send commands or files to batch-process to veejay
Usage: sayVIMS [options] [messages]
where options are:
 -p             Veejay port (3490)
 -h             Veejay host (localhost)
 -g			    Veejay multicast address (
 -f   Send contents of this file to veejay
 -c             Colored output (geek feature)

Messages to send to veejay must be wrapped in quotes
You can send multiple messages by seperating them with a whitespace

5 Popular Packages

Usefull software (in no apparant order):

Please refer to Other Resources to find the project's website

5.1 The MJPEG Tools

The Mjpeg tools are a set of tools that can do recording of videos and playback, simple cut-and-paste editing and the MPEG compression of audio and video under Linux. You can use the EditLists from this package in veejay and vice versa
Here are a few examples for processing video data:

1. Start veejay headless:

$ mkfifo /tmp/special_file
$ veejay /video/video.avi -O3 -o /tmp/special_file

Encoding it to DV avi type 2 (if video dimensions match either full PAL or NTSC)
$ cat /tmp/special_file | yuv2rawdv -v 2 > rawdv

Encoding it to MJPEG file 'video-mjpeg.avi'
$ cat /tmp/special_file | yuv2lav -v2 -f 0 -I 0 -q 90 -o video-mjpeg.avi
Encoding veejay output to MJPEG file:
$ veejay movie1.avi -o stdout -O3 | yuv2lav -f 0 -I 0 -q 90 -o movie1-mjpeg.avi

5.2 Transcode

Transcode is a Linux video Stream Processing Tool, it can convert between different types of video formats

Encode a file to mjpeg with no audio and rescale the output video to 352x288:

$ transcode -i input_file.avi -o new_mjpeg_file.avi -y mjpeg,null -Z352x288

6. Other Resources

Here you will find the websites of the packages veejay requires as well as packages you can use in combination with veejay.

6.1 Web Sites

Packages you need

Usefull software

6.2 Mailing Lists

There is a mailing list for veejay which is hosted by Sourceforge. The address is

6.3 Veejay developer's lounge

Veejay's developer lounge provides a ticket system for you , the user, to report any problem or feature requests. The ticket system allows us to keep track of problems.
Also, the developer lounge hosts a subversion code repository where you can find the 'on the bleeding edge' source codes of veejay.
Many thanks to jaromil (author of FreeJ/Muse) and the Dyne Foundation for providing these tools

7. Credits

End of the Veejay HOWTO. (You can stop reading here.)

8. GNU Free Documentation License

GNU Free Documentation License

Version 1.1, March 2000

Copyright (C) 2000 Free Software Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed.


The purpose of this License is to make a manual, textbook, or other written document "free" in the sense of freedom: to assure everyone the effective freedom to copy and redistribute it, with or without modifying it, either commercially or noncommercially. Secondarily, this License preserves for the author and publisher a way to get credit for their work, while not being considered responsible for modifications made by others.

This License is a kind of "copyleft", which means that derivative works of the document must themselves be free in the same sense. It complements the GNU General Public License, which is a copyleft license designed for free software.

We have designed this License in order to use it for manuals for free software, because free software needs free documentation: a free program should come with manuals providing the same freedoms that the software does. But this License is not limited to software manuals; it can be used for any textual work, regardless of subject matter or whether it is published as a printed book. We recommend this License principally for works whose purpose is instruction or reference.


This License applies to any manual or other work that contains a notice placed by the copyright holder saying it can be distributed under the terms of this License. The "Document", below, refers to any such manual or work. Any member of the public is a licensee, and is addressed as "you".

A "Modified Version" of the Document means any work containing the Document or a portion of it, either copied verbatim, or with modifications and/or translated into another language.

A "Secondary Section" is a named appendix or a front-matter section of the Document that deals exclusively with the relationship of the publishers or authors of the Document to the Document's overall subject (or to related matters) and contains nothing that could fall directly within that overall subject. (For example, if the Document is in part a textbook of mathematics, a Secondary Section may not explain any mathematics.) The relationship could be a matter of historical connection with the subject or with related matters, or of legal, commercial, philosophical, ethical or political position regarding them.

The "Invariant Sections" are certain Secondary Sections whose titles are designated, as being those of Invariant Sections, in the notice that says that the Document is released under this License.

The "Cover Texts" are certain short passages of text that are listed, as Front-Cover Texts or Back-Cover Texts, in the notice that says that the Document is released under this License.

A "Transparent" copy of the Document means a machine-readable copy, represented in a format whose specification is available to the general public, whose contents can be viewed and edited directly and straightforwardly with generic text editors or (for images composed of pixels) generic paint programs or (for drawings) some widely available drawing editor, and that is suitable for input to text formatters or for automatic translation to a variety of formats suitable for input to text formatters. A copy made in an otherwise Transparent file format whose markup has been designed to thwart or discourage subsequent modification by readers is not Transparent. A copy that is not "Transparent" is called "Opaque".

Examples of suitable formats for Transparent copies include plain ASCII without markup, Texinfo input format, LaTeX input format, SGML or XML using a publicly available DTD, and standard-conforming simple HTML designed for human modification. Opaque formats include PostScript, PDF, proprietary formats that can be read and edited only by proprietary word processors, SGML or XML for which the DTD and/or processing tools are not generally available, and the machine-generated HTML produced by some word processors for output purposes only.

The "Title Page" means, for a printed book, the title page itself, plus such following pages as are needed to hold, legibly, the material this License requires to appear in the title page. For works in formats which do not have any title page as such, "Title Page" means the text near the most prominent appearance of the work's title, preceding the beginning of the body of the text.


You may copy and distribute the Document in any medium, either commercially or noncommercially, provided that this License, the copyright notices, and the license notice saying this License applies to the Document are reproduced in all copies, and that you add no other conditions whatsoever to those of this License. You may not use technical measures to obstruct or control the reading or further copying of the copies you make or distribute. However, you may accept compensation in exchange for copies. If you distribute a large enough number of copies you must also follow the conditions in section 3.

You may also lend copies, under the same conditions stated above, and you may publicly display copies.


If you publish printed copies of the Document numbering more than 100, and the Document's license notice requires Cover Texts, you must enclose the copies in covers that carry, clearly and legibly, all these Cover Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on the back cover. Both covers must also clearly and legibly identify you as the publisher of these copies. The front cover must present the full title with all words of the title equally prominent and visible. You may add other material on the covers in addition. Copying with changes limited to the covers, as long as they preserve the title of the Document and satisfy these conditions, can be treated as verbatim copying in other respects.

If the required texts for either cover are too voluminous to fit legibly, you should put the first ones listed (as many as fit reasonably) on the actual cover, and continue the rest onto adjacent pages.

If you publish or distribute Opaque copies of the Document numbering more than 100, you must either include a machine-readable Transparent copy along with each Opaque copy, or state in or with each Opaque copy a publicly-accessible computer-network location containing a complete Transparent copy of the Document, free of added material, which the general network-using public has access to download anonymously at no charge using public-standard network protocols. If you use the latter option, you must take reasonably prudent steps, when you begin distribution of Opaque copies in quantity, to ensure that this Transparent copy will remain thus accessible at the stated location until at least one year after the last time you distribute an Opaque copy (directly or through your agents or retailers) of that edition to the public.

It is requested, but not required, that you contact the authors of the Document well before redistributing any large number of copies, to give them a chance to provide you with an updated version of the Document.


You may copy and distribute a Modified Version of the Document under the conditions of sections 2 and 3 above, provided that you release the Modified Version under precisely this License, with the Modified Version filling the role of the Document, thus licensing distribution and modification of the Modified Version to whoever possesses a copy of it. In addition, you must do these things in the Modified Version:

A. Use in the Title Page (and on the covers, if any) a title distinct from that of the Document, and from those of previous versions (which should, if there were any, be listed in the History section of the Document). You may use the same title as a previous version if the original publisher of that version gives permission. B. List on the Title Page, as authors, one or more persons or entities responsible for authorship of the modifications in the Modified Version, together with at least five of the principal authors of the Document (all of its principal authors, if it has less than five). C. State on the Title page the name of the publisher of the Modified Version, as the publisher. D. Preserve all the copyright notices of the Document. E. Add an appropriate copyright notice for your modifications adjacent to the other copyright notices. F. Include, immediately after the copyright notices, a license notice giving the public permission to use the Modified Version under the terms of this License, in the form shown in the Addendum below. G. Preserve in that license notice the full lists of Invariant Sections and required Cover Texts given in the Document's license notice. H. Include an unaltered copy of this License. I. Preserve the section entitled "History", and its title, and add to it an item stating at least the title, year, new authors, and publisher of the Modified Version as given on the Title Page. If there is no section entitled "History" in the Document, create one stating the title, year, authors, and publisher of the Document as given on its Title Page, then add an item describing the Modified Version as stated in the previous sentence. J. Preserve the network location, if any, given in the Document for public access to a Transparent copy of the Document, and likewise the network locations given in the Document for previous versions it was based on. These may be placed in the "History" section. You may omit a network location for a work that was published at least four years before the Document itself, or if the original publisher of the version it refers to gives permission. K. In any section entitled "Acknowledgements" or "Dedications", preserve the section's title, and preserve in the section all the substance and tone of each of the contributor acknowledgements and/or dedications given therein. L. Preserve all the Invariant Sections of the Document, unaltered in their text and in their titles. Section numbers or the equivalent are not considered part of the section titles. M. Delete any section entitled "Endorsements". Such a section may not be included in the Modified Version. N. Do not retitle any existing section as "Endorsements" or to conflict in title with any Invariant Section.

If the Modified Version includes new front-matter sections or appendices that qualify as Secondary Sections and contain no material copied from the Document, you may at your option designate some or all of these sections as invariant. To do this, add their titles to the list of Invariant Sections in the Modified Version's license notice. These titles must be distinct from any other section titles.

You may add a section entitled "Endorsements", provided it contains nothing but endorsements of your Modified Version by various parties-for example, statements of peer review or that the text has been approved by an organization as the authoritative definition of a standard.

You may add a passage of up to five words as a Front-Cover Text, and a passage of up to 25 words as a Back-Cover Text, to the end of the list of Cover Texts in the Modified Version. Only one passage of Front-Cover Text and one of Back-Cover Text may be added by (or through arrangements made by) any one entity. If the Document already includes a cover text for the same cover, previously added by you or by arrangement made by the same entity you are acting on behalf of, you may not add another; but you may replace the old one, on explicit permission from the previous publisher that added the old one.

The author(s) and publisher(s) of the Document do not by this License give permission to use their names for publicity for or to assert or imply endorsement of any Modified Version.


You may combine the Document with other documents released under this License, under the terms defined in section 4 above for modified versions, provided that you include in the combination all of the Invariant Sections of all of the original documents, unmodified, and list them all as Invariant Sections of your combined work in its license notice.

The combined work need only contain one copy of this License, and multiple identical Invariant Sections may be replaced with a single copy. If there are multiple Invariant Sections with the same name but different contents, make the title of each such section unique by adding at the end of it, in parentheses, the name of the original author or publisher of that section if known, or else a unique number. Make the same adjustment to the section titles in the list of Invariant Sections in the license notice of the combined work.

In the combination, you must combine any sections entitled "History" in the various original documents, forming one section entitled "History"; likewise combine any sections entitled "Acknowledgements", and any sections entitled "Dedications". You must delete all sections entitled "Endorsements."


You may make a collection consisting of the Document and other documents released under this License, and replace the individual copies of this License in the various documents with a single copy that is included in the collection, provided that you follow the rules of this License for verbatim copying of each of the documents in all other respects.

You may extract a single document from such a collection, and distribute it individually under this License, provided you insert a copy of this License into the extracted document, and follow this License in all other respects regarding verbatim copying of that document.


A compilation of the Document or its derivatives with other separate and independent documents or works, in or on a volume of a storage or distribution medium, does not as a whole count as a Modified Version of the Document, provided no compilation copyright is claimed for the compilation. Such a compilation is called an "aggregate", and this License does not apply to the other self-contained works thus compiled with the Document, on account of their being thus compiled, if they are not themselves derivative works of the Document.

If the Cover Text requirement of section 3 is applicable to these copies of the Document, then if the Document is less than one quarter of the entire aggregate, the Document's Cover Texts may be placed on covers that surround only the Document within the aggregate. Otherwise they must appear on covers around the whole aggregate.


Translation is considered a kind of modification, so you may distribute translations of the Document under the terms of section 4. Replacing Invariant Sections with translations requires special permission from their copyright holders, but you may include translations of some or all Invariant Sections in addition to the original versions of these Invariant Sections. You may include a translation of this License provided that you also include the original English version of this License. In case of a disagreement between the translation and the original English version of this License, the original English version will prevail.


You may not copy, modify, sublicense, or distribute the Document except as expressly provided for under this License. Any other attempt to copy, modify, sublicense or distribute the Document is void, and will automatically terminate your rights under this License. However, parties who have received copies, or rights, from you under this License will not have their licenses terminated so long as such parties remain in full compliance.


The Free Software Foundation may publish new, revised versions of the GNU Free Documentation License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. See

Each version of the License is given a distinguishing version number. If the Document specifies that a particular numbered version of this License "or any later version" applies to it, you have the option of following the terms and conditions either of that specified version or of any later version that has been published (not as a draft) by the Free Software Foundation. If the Document does not specify a version number of this License, you may choose any version ever published (not as a draft) by the Free Software Foundation.

ADDENDUM: How to use this License for your documents

To use this License in a document you have written, include a copy of the License in the document and put the following copyright and license notices just after the title page:

    Copyright (c)  YEAR  YOUR NAME.
    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 the Invariant Sections being LIST THEIR TITLES, with the
    Front-Cover Texts being LIST, and with the Back-Cover Texts being LIST.
    A copy of the license is included in the section entitled "GNU
    Free Documentation License".

If you have no Invariant Sections, write "with no Invariant Sections" instead of saying which ones are invariant. If you have no Front-Cover Texts, write "no Front-Cover Texts" instead of "Front-Cover Texts being LIST"; likewise for Back-Cover Texts.

If your document contains nontrivial examples of program code, we recommend releasing these examples in parallel under your choice of free software license, such as the GNU General Public License, to permit their use in free software.