Archive for March, 2009

Open Source Document Licensing

Thursday, March 19th, 2009

I’m currently preparing a technical college lecture. The slides for the lecture should become open source. To reduce my overhead I want to use existing source (mainly pictures) from wikipedia.

Open source licensing should really make it easier to re-use material in other open source projects. As far as I can tell the current mess with different documentation licenses does not achieve that goal.

Sad fact: To understand what is possible with the current licensing is nearly as time-consuming as re-creating the material from scratch. So I’ve chosen to document what I’ve learned here, so others may have a faster learning curve and can contribute their experience.

In addition I hope for comments from people involved in the licensing jungle to comment on my views here.

Typically wikipedia pictures come in three license variants, see the Wikipedia Copyrights page, the german version Wikipedia Lizenzbestimmungen has specific sections on picture use:

Some pictures are dual-licensed under GFDL and CC-BY-SA.

Since the GFDL typically is used with a version-upgrade clause, e.g., "Version 1.2 or any later version published by the Free Software Foundation", upgrade to a later version of the license by the user is possible. This is typically not the case with CC-BY-SA.

I’ve decided that CC-BY-SA version 3.0 best fits my license requirements. The GFDL with its front-cover, back-cover and invariant sections is too complicated and CC-BY-SA is much clearer concerning reuse and remix of the material.

One problem I’m having is that when "performing" my slides (thats the term CC-BY-SA is using for e.g. using the slides in a presentation) I want to use either my company logo or I’m forced to use the logo of the teaching institution I’m working for. So I’ve come up with the following addition to the pointer of the licensing terms:

When performing this work (e.g. teaching using these slides) you may use your company and/or teaching institution logo in the header of each slide without putting the logo under the license above. When distributing derived works, make sure you distribute the document without the company or teaching institution logo.

So I’m specifically allowing to use a logo in the header of each slide when performing. I hope this is compatible with the CC licensing terms.

The next problem I’m facing is reuse of pictures. Pictures licensed under a CC-BY-SA license (also earlier than 2.5) shouldn’t pose a problem, because CC-BY-SA explicitly distinguishes derivative work and collective work. Collective work is defined as (cited from version 2.5 of CC-BY-SA as that is the relevant version for most pictures on Wikipedia):

"Collective Work" means a work, such as a periodical issue, anthology or encyclopedia, in which the Work in its entirety in unmodified form, along with a number of other contributions, constituting separate and independent works in themselves, are assembled into a collective whole. A work that constitutes a Collective Work will not be considered a Derivative Work (as defined below) for the purposes of this License.

So I guess my use of the unmodified pictures in slides is collective work not derivative work. That means I can use CC-BY-SA pictures from wikipedia in a CC-BY-SA document that uses these pictures similar to the usage of pictures in Wikipedia articles, even if the version of the CC-BY-SA license is not the same.

The question if I can use pictures licensed unter GFDL in my slides licensed under CC-BY-SA is still not fully clear for me. Since the pictures typically contain the license-version upgrade clause mentioned above, I could use version 1.3 of the GFDL that includes permission to relicense the work under the CC-BY-SA license under specific circumstances — but my interpretation of that clause allows this only for Wikipedia, not for me as a user of the content on Wikipedia.

Putting my work under a dual-license (CC-BY-SA + GFDL) is also not a solution because this effectively constitutes relicensing of the used content.

So the question remains if I can use GFDL pictures in CC-BY-SA slides and if this is permitted by the GFDL. The GFDL has one paragraph (7) on "aggregation with independent works":

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, is called an "aggregate" if the copyright resulting from the compilation is not used to limit the legal rights of the compilation’s users beyond what the individual works permit. When the Document is included in an aggregate, this License does not apply to the other works in the aggregate which are not themselves derivative works
of the Document.

So, hmm, are my slides a "compilation with other separate and independent documents or works" — probably yes. Are they in a "in or on a volume of a storage or distribution medium"? Hard to say. My "copyright resulting from the compilation [provided it is a compilation in the sense of GFDL] is not used to limit the legal rights of the compilation’s users beyond what the individual works permit". So I guess I can use these pictures without the GFDL applying to my document (I want to use the CC-BY-SA).

Thats my due diligence investigation before using this material.

But I’m not a lawyer.

Howto get Asterisk with mISDN V2 and Linux Call Router running on debian lenny

Monday, March 9th, 2009

Update 2009-03-31: provide signed archive with archive key, add udev rules, add /etc/modules entries, add amd64.
Update 2009-04-05: typos fixed

This is a short howto how I built the debian patches and how you can — as a user — install everything needed for mISDN version 2 and Linux Call Router (LCR) with asterisk chan_lcr running on debian lenny.

I’m providing debian packages for Kernel (v, an updated zaptel (debian lenny zaptel doesn’t compile with newer kernels and zaptel wctdm uses some settings for analogue phones that don’t work with german and austrian phone like the “R”-key or optional pulse dialling), finally I’m providing a slightly patched asterisk for larger buffer sizes when playing long tones, LCR and misdnv2user packages originally built by Joerg Dorchain. My misdnv2user is the same as Joergs. The lcr package contains my bug-fix for DTMF digits A-F (also in Joergs packages now) which don’t work in upstream LCR version 1.3 and an updated /etc/init.d/lcr for querying the status of lcr.

I’m also providing source packages, except for the kernel — the kernel is stock configured for use of mISDN. The kernel was built using debians make-kpkg from the kernel-package debian package. And the config used for building the kernel is in the binary package.

I hope I can contribute something in order to get mISDN V2 and LCR into debian… in the meantime others may want to uses these on debian stable.


apt-get install vim less ssh ntp
apt-get install python-dev openbsd-inetd postfix madplay

Add following lines to /etc/apt/sources.list:

deb lenny main
deb-src lenny main

If you want to avoid warnings about an untrusted archive key from apt, you should import the following archive key. Save the key to a file and then issue the command
apt-key add file

Version: GnuPG v1.4.9 (GNU/Linux)


Then install:

apt-get update
apt-get install linux-headers- linux-image- 
    asterisk zaptel lcr zaptel-modules-

If you’re on the amd64 architecture, you should replace i686 in the packages above with amd64.

and optionally (for misdn_info):

apt-get install misdnv2user

Edit /etc/default/asterisk and set RUNASTERISK=yes. Then make several directories (should be done by a future version of the lcr package):

mkdir /var/run/lcr
chown asterisk.asterisk /var/run/lcr
mkdir /var/log/lcr
chown asterisk.asterisk /var/log/lcr

I’ve also made a start-script for lcr (for use as /etc/init.d/lcr) ,
downloadable at
this probably should also be part of the lcr package.

Config file examples used for lcr — these pass
everything to asterisk. File /etc/lcr/interface.conf:

portnum 0

portnum 1

portnum 2

portnum 3

I’m using a Beronet 4 port ISDN card, your config will probably differ: This system only expects incoming calls and needs to check on which line a call comes in. So I distinguish all external interfaces as separate interfaces of LCR. I also need to check an interface by calling out via that interface, you probably would want to make all external ports a trunk by grouping them into one LCR interface.

And the routing config needs to match your interface definition. This config will pass all calls — if asterisk is running — to asterisk. If asterisk isn’t running, I’m calling a test application (untested). The context in asterisk will be the interface name. Again, if you’re using a trunk here, be sure to match the routing config with your interface config. /etc/lcr/routing.conf:

remote=asterisk interface=Ext1 : remote application=asterisk
remote=asterisk interface=Ext2 : remote application=asterisk
remote=asterisk interface=Int1 : remote application=asterisk
remote=asterisk interface=Int2 : remote application=asterisk
default                        : efi

Update /etc/modules to include the following lines (the command appends the lines between cat and EOF):

cat >> /etc/modules << EOF
mISDN_core debug=0x0
mISDN_dsp debug=0x0 options=0x0
hfcmulti debug=0x0

Linux udev must be configured to correctly set the user for the isdn device(s):

cat > /etc/udev/rules.d/91-isdn.rules << EOF
ACTION!="add|change", GOTO="permissions_end"

KERNEL=="mISDN*",       GROUP="dialout"


After a reboot asterisk and lcr should be running.


Getting kernel:


For compilation (zlib isn’t checked by make-kpkg!):

apt-get install kernel-package bzip2 libncurses5-dev zaptel-source 
    zlib1g-dev fakeroot

Compile Kernel:

tar xvf linux-2.6.28.tar.bz2
cd linux-2.6.28
zcat ../patch- | patch -N -p1 | less 2>&1
cp /boot/config- .config
make oldconfig
make menuconfig # just to be sure

For amd64:

make-kpkg --append-to-version -amd64 --revision --us 
    --uc --initrd --rootcmd fakeroot binary > m.out 2> m.err

For i686:

make-kpkg --append-to-version -i686 --revision --us 
    --uc --initrd --rootcmd fakeroot binary > m.out 2> m.err

The following doesn’t seem to work although zaptel is installed:
probably need to unpack /usr/src/zaptel.tar.bz2 into
/usr/src/modules/zaptel (tar file contains modules directory!)
this would save us from the m-a a-i step below. amd64:

make-kpkg --append-to-version -amd64 --revision --us 
    --uc --initrd --rootcmd fakeroot modules > mo.out 2> mo.err
cd ..

For i686:

make-kpkg --append-to-version -i686 --revision --us 
    --uc --initrd --rootcmd fakeroot modules > mo.out 2> mo.err
cd ..

Make a debianized zaptel for new kernel:

apt-get install devscripts libnewt-dev quilt libusb-dev asciidoc
svn checkout zaptel
apt-get source zaptel-source
cp zaptel/kernel/ztdummy.* zaptel-1.4.11~dfsg/kernel
cd zaptel-1.4.11~dfsg
# Add "Fix compilation for newer kernels"
dch -i
cd ..
dpkg -i zaptel-source_1.4.11~dfsg-3.1_all.deb
m-a a-i zaptel

The following installs my patched asterisk, I’m modifying some buffer sizes because I want to play long tones (I’m generating a faked modem guard-tone that is needed in a project). You probably won’t need the patches asterisk, but it won’t hurt to install it. The create-patches script is available from

apt-get install libreadline5-dev libgsm1-dev libssl-dev libtonezone-dev 
    libvpb-dev autotools-dev libsqlite-dev libspeex-dev libspeexdsp-dev 
    graphviz libcurl4-openssl-dev doxygen libpopt-dev libopenh323-dev   
    libiksemel-dev libradiusclient-ng-dev freetds-dev libvorbis-dev     
    libsnmp-dev libc-client2007b-dev libcap2-dev libpq-dev unixodbc-dev 
apt-get source asterisk
scp ralf@bee:checkout/own/config/asterisk/create-patches .
cd asterisk-
sh ../create-patches
# Hunk #1 succeeded at 25 (offset 3 lines).
# Add " local buffer-size patches"
# and new version-number 1:
dch -i # add comment
dpkg-buildpackage -rfakeroot
cd ..

For mISDNuser and chan_lcr I’m using Joerg Dorchains packages with my added patches for DTMF codes A-F.

sane snapscan and epson 3590 photo + rpm weirdness

Friday, March 6th, 2009

I’ve recently upgraded to debian lenny. Unfortunately after this upgrade my epson 3590 scanner stopped working. After some googling around I managed to find an rpm package with the binary firmware image. But the package converter alien would not let me convert the file, the message was

Unpacking of 'iscan-firmware-' failed at /usr/share/perl5/Alien/Package/ line 155.

After some more searching I found debian bugs 518348 and 509444 of which the latter contains a workaround: Seems that the rpm format changed to a compressed format that can be unpacked with lzma. Now unpacking was possible — after all I was only interested in the firmware file — and now my scanner is working again… For the record, unpacking was done as follows:

mkdir iscan-firmware-
rpm2cpio iscan-firmware-
| lzma -d | (cd iscan-firmware-;
cpio --extract --make-directories
--no-absolute-filenames --preserve-modification-time)