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        <channel>
                <title>Petter Reinholdtsen - Entries tagged nice free software</title>
                <description>Entries tagged nice free software</description>
                <link>http://people.skolelinux.org/pere/blog/</link>

        
        <item>
                <title>OpenALPR, find car license plates in video streams - nice free software</title>
                <link>http://people.skolelinux.org/pere/blog/OpenALPR__find_car_license_plates_in_video_streams___nice_free_software.html</link>
                <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/OpenALPR__find_car_license_plates_in_video_streams___nice_free_software.html</guid>
                <pubDate>Wed, 23 Dec 2015 01:00:00 +0100</pubDate>
                <description>&lt;p&gt;When I was a kid, we used to collect &quot;car numbers&quot;, as we used to
call the car license plate numbers in those days.  I would write the
numbers down in my little book and compare notes with the other kids
to see how many region codes we had seen and if we had seen some
exotic or special region codes and numbers.  It was a fun game to pass
time, as we kids have plenty of it.&lt;/p&gt;

&lt;p&gt;A few days I came across
&lt;a href=&quot;https://github.com/openalpr/openalpr&quot;&gt;the OpenALPR
project&lt;/a&gt;, a free software project to automatically discover and
report license plates in images and video streams, and provide the
&quot;car numbers&quot; in a machine readable format.  I&#39;ve been looking for
such system for a while now, because I believe it is a bad idea that the
&lt;a href=&quot;https://en.wikipedia.org/wiki/Automatic_number_plate_recognition&quot;&gt;automatic
number plate recognition&lt;/a&gt; tool only is available in the hands of
the powerful, and want it to be available also for the powerless to
even the score when it comes to surveillance and sousveillance.  I
discovered the developer
&lt;a href=&quot;https://bugs.debian.org/747509&quot;&gt;wanted to get the tool into
Debian&lt;/a&gt;, and as I too wanted it to be in Debian, I volunteered to
help him get it into shape to get the package uploaded into the Debian
archive.&lt;/p&gt;

&lt;p&gt;Today we finally managed to get the package into shape and uploaded
it into Debian, where it currently
&lt;a href=&quot;https://ftp-master.debian.org//new/openalpr_2.2.1-1.html&quot;&gt;waits
in the NEW queue&lt;/a&gt; for review by the Debian ftpmasters.&lt;/p&gt;

&lt;p&gt;I guess you are wondering why on earth such tool would be useful
for the common folks, ie those not running a large government
surveillance system?  Well, I plan to put it in a computer on my bike
and in my car, tracking the cars nearby and allowing me to be notified
when number plates on my watch list are discovered.  Another use case
was suggested by a friend of mine, who wanted to set it up at his home
to open the car port automatically when it discovered the plate on his
car.  When I mentioned it perhaps was a bit foolhardy to allow anyone
capable of placing his license plate number of a piece of cardboard to
open his car port, men replied that it was always unlocked anyway.  I
guess for such use case it make sense.  I am sure there are other use
cases too, for those with imagination and a vision.&lt;/p&gt;

&lt;p&gt;If you want to build your own version of the Debian package, check
out the upstream git source and symlink ./distros/debian to ./debian/
before running &quot;debuild&quot; to build the source.  Or wait a bit until the
package show up in unstable.&lt;/p&gt;
</description>
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        <item>
                <title>listadmin, the quick way to moderate mailman lists - nice free software</title>
                <link>http://people.skolelinux.org/pere/blog/listadmin__the_quick_way_to_moderate_mailman_lists___nice_free_software.html</link>
                <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/listadmin__the_quick_way_to_moderate_mailman_lists___nice_free_software.html</guid>
                <pubDate>Wed, 22 Oct 2014 20:00:00 +0200</pubDate>
                <description>&lt;p&gt;If you ever had to moderate a mailman list, like the ones on
alioth.debian.org, you know the web interface is fairly slow to
operate.  First you visit one web page, enter the moderation password
and get a new page shown with a list of all the messages to moderate
and various options for each email address.  This take a while for
every list you moderate, and you need to do it regularly to do a good
job as a list moderator.  But there is a quick alternative,
&lt;a href=&quot;http://heim.ifi.uio.no/kjetilho/hacks/#listadmin&quot;&gt;the
listadmin program&lt;/a&gt;.  It allow you to check lists for new messages
to moderate in a fraction of a second.  Here is a test run on two
lists I recently took over:&lt;/p&gt;

&lt;p&gt;&lt;blockquote&gt;&lt;pre&gt;
% time listadmin xiph
fetching data for pkg-xiph-commits@lists.alioth.debian.org ... nothing in queue
fetching data for pkg-xiph-maint@lists.alioth.debian.org ... nothing in queue

real    0m1.709s
user    0m0.232s
sys     0m0.012s
%
&lt;/pre&gt;&lt;/blockquote&gt;&lt;/p&gt;

&lt;p&gt;In 1.7 seconds I had checked two mailing lists and confirmed that
there are no message in the moderation queue.  Every morning I
currently moderate 68 mailman lists, and it normally take around two
minutes.  When I took over the two pkg-xiph lists above a few days
ago, there were 400 emails waiting in the moderator queue.  It took me
less than 15 minutes to process them all using the listadmin
program.&lt;/p&gt;

&lt;p&gt;If you install
&lt;a href=&quot;https://tracker.debian.org/pkg/listadmin&quot;&gt;the listadmin
package&lt;/a&gt; from Debian and create a file &lt;tt&gt;~/.listadmin.ini&lt;/tt&gt;
with content like this, the moderation task is a breeze:&lt;/p&gt;

&lt;p&gt;&lt;blockquote&gt;&lt;pre&gt;
username username@example.org
spamlevel 23
default discard
discard_if_reason &quot;Posting restricted to members only. Remove us from your mail list.&quot;

password secret
adminurl https://{domain}/mailman/admindb/{list}
mailman-list@lists.example.com

password hidden
other-list@otherserver.example.org
&lt;/pre&gt;&lt;/blockquote&gt;&lt;/p&gt;

&lt;p&gt;There are other options to set as well.  Check the manual page to
learn the details.&lt;/p&gt;

&lt;p&gt;If you are forced to moderate lists on a mailman installation where
the SSL certificate is self signed or not properly signed by a
generally accepted signing authority, you can set a environment
variable when calling listadmin to disable SSL verification:&lt;/p&gt;

&lt;p&gt;&lt;blockquote&gt;&lt;pre&gt;
PERL_LWP_SSL_VERIFY_HOSTNAME=0 listadmin
&lt;/pre&gt;&lt;/blockquote&gt;&lt;/p&gt;

&lt;p&gt;If you want to moderate a subset of the lists you take care of, you
can provide an argument to the listadmin script like I do in the
initial screen dump (the xiph argument).  Using an argument, only
lists matching the argument string will be processed.  This make it
quick to accept messages if you notice the moderation request in your
email.&lt;/p&gt;

&lt;p&gt;Without the listadmin program, I would never be the moderator of 68
mailing lists, as I simply do not have time to spend on that if the
process was any slower. The listadmin program have saved me hours of
time I could spend elsewhere over the years.  It truly is nice free
software.&lt;/p&gt;

&lt;p&gt;As usual, if you use Bitcoin and want to show your support of my
activities, please send Bitcoin donations to my address
&lt;b&gt;&lt;a href=&quot;bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b&amp;label=PetterReinholdtsenBlog&quot;&gt;15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b&lt;/a&gt;&lt;/b&gt;.&lt;/p&gt;

&lt;p&gt;Update 2014-10-27: Added missing &#39;username&#39; statement in
configuration example.  Also, I&#39;ve been told that the
PERL_LWP_SSL_VERIFY_HOSTNAME=0 setting do not work for everyone.  Not
sure why.&lt;/p&gt;
</description>
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        <item>
                <title>S3QL, a locally mounted cloud file system - nice free software</title>
                <link>http://people.skolelinux.org/pere/blog/S3QL__a_locally_mounted_cloud_file_system___nice_free_software.html</link>
                <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/S3QL__a_locally_mounted_cloud_file_system___nice_free_software.html</guid>
                <pubDate>Wed, 9 Apr 2014 11:30:00 +0200</pubDate>
                <description>&lt;p&gt;For a while now, I have been looking for a sensible offsite backup
solution for use at home.  My requirements are simple, it must be
cheap and locally encrypted (in other words, I keep the encryption
keys, the storage provider do not have access to my private files).
One idea me and my friends had many years ago, before the cloud
storage providers showed up, was to use Google mail as storage,
writing a Linux block device storing blocks as emails in the mail
service provided by Google, and thus get heaps of free space.  On top
of this one can add encryption, RAID and volume management to have
lots of (fairly slow, I admit that) cheap and encrypted storage.  But
I never found time to implement such system.  But the last few weeks I
have looked at a system called
&lt;a href=&quot;https://bitbucket.org/nikratio/s3ql/&quot;&gt;S3QL&lt;/a&gt;, a locally
mounted network backed file system with the features I need.&lt;/p&gt;

&lt;p&gt;S3QL is a fuse file system with a local cache and cloud storage,
handling several different storage providers, any with Amazon S3,
Google Drive or OpenStack API.  There are heaps of such storage
providers.  S3QL can also use a local directory as storage, which
combined with sshfs allow for file storage on any ssh server.  S3QL
include support for encryption, compression, de-duplication, snapshots
and immutable file systems, allowing me to mount the remote storage as
a local mount point, look at and use the files as if they were local,
while the content is stored in the cloud as well.  This allow me to
have a backup that should survive fire.  The file system can not be
shared between several machines at the same time, as only one can
mount it at the time, but any machine with the encryption key and
access to the storage service can mount it if it is unmounted.&lt;/p&gt;

&lt;p&gt;It is simple to use.  I&#39;m using it on Debian Wheezy, where the
package is included already.  So to get started, run &lt;tt&gt;apt-get
install s3ql&lt;/tt&gt;.  Next, pick a storage provider.  I ended up picking
Greenqloud, after reading their nice recipe on
&lt;a href=&quot;https://greenqloud.zendesk.com/entries/44611757-How-To-Use-S3QL-to-mount-a-StorageQloud-bucket-on-Debian-Wheezy&quot;&gt;how
to use S3QL with their Amazon S3 service&lt;/a&gt;, because I trust the laws
in Iceland more than those in USA when it come to keeping my personal
data safe and private, and thus would rather spend money on a company
in Iceland.  Another nice recipe is available from the article
&lt;a href=&quot;http://www.admin-magazine.com/HPC/Articles/HPC-Cloud-Storage&quot;&gt;S3QL
Filesystem for HPC Storage&lt;/a&gt; by Jeff Layton in the HPC section of
Admin magazine.  When the provider is picked, figure out how to get
the API key needed to connect to the storage API.  With Greencloud,
the key did not show up until I had added payment details to my
account.&lt;/p&gt;

&lt;p&gt;Armed with the API access details, it is time to create the file
system.  First, create a new bucket in the cloud.  This bucket is the
file system storage area.  I picked a bucket name reflecting the
machine that was going to store data there, but any name will do.
I&#39;ll refer to it as &lt;tt&gt;bucket-name&lt;/tt&gt; below.  In addition, one need
the API login and password, and a locally created password.  Store it
all in ~root/.s3ql/authinfo2 like this:

&lt;p&gt;&lt;blockquote&gt;&lt;pre&gt;
[s3c]
storage-url: s3c://s.greenqloud.com:443/bucket-name
backend-login: API-login
backend-password: API-password
fs-passphrase: local-password
&lt;/pre&gt;&lt;/blockquote&gt;&lt;/p&gt;

&lt;p&gt;I create my local passphrase using &lt;tt&gt;pwget 50&lt;/tt&gt; or similar,
but any sensible way to create a fairly random password should do it.
Armed with these details, it is now time to run mkfs, entering the API
details and password to create it:&lt;/p&gt;

&lt;p&gt;&lt;blockquote&gt;&lt;pre&gt;
# mkdir -m 700 /var/lib/s3ql-cache
# mkfs.s3ql --cachedir /var/lib/s3ql-cache --authfile /root/.s3ql/authinfo2 \
  --ssl s3c://s.greenqloud.com:443/bucket-name
Enter backend login: 
Enter backend password: 
Before using S3QL, make sure to read the user&#39;s guide, especially
the &#39;Important Rules to Avoid Loosing Data&#39; section.
Enter encryption password: 
Confirm encryption password: 
Generating random encryption key...
Creating metadata tables...
Dumping metadata...
..objects..
..blocks..
..inodes..
..inode_blocks..
..symlink_targets..
..names..
..contents..
..ext_attributes..
Compressing and uploading metadata...
Wrote 0.00 MB of compressed metadata.
# &lt;/pre&gt;&lt;/blockquote&gt;&lt;/p&gt;

&lt;p&gt;The next step is mounting the file system to make the storage available.

&lt;p&gt;&lt;blockquote&gt;&lt;pre&gt;
# mount.s3ql --cachedir /var/lib/s3ql-cache --authfile /root/.s3ql/authinfo2 \
  --ssl --allow-root s3c://s.greenqloud.com:443/bucket-name /s3ql
Using 4 upload threads.
Downloading and decompressing metadata...
Reading metadata...
..objects..
..blocks..
..inodes..
..inode_blocks..
..symlink_targets..
..names..
..contents..
..ext_attributes..
Mounting filesystem...
# df -h /s3ql
Filesystem                              Size  Used Avail Use% Mounted on
s3c://s.greenqloud.com:443/bucket-name  1.0T     0  1.0T   0% /s3ql
#
&lt;/pre&gt;&lt;/blockquote&gt;&lt;/p&gt;

&lt;p&gt;The file system is now ready for use.  I use rsync to store my
backups in it, and as the metadata used by rsync is downloaded at
mount time, no network traffic (and storage cost) is triggered by
running rsync.  To unmount, one should not use the normal umount
command, as this will not flush the cache to the cloud storage, but
instead running the umount.s3ql command like this:

&lt;p&gt;&lt;blockquote&gt;&lt;pre&gt;
# umount.s3ql /s3ql
# 
&lt;/pre&gt;&lt;/blockquote&gt;&lt;/p&gt;

&lt;p&gt;There is a fsck command available to check the file system and
correct any problems detected.  This can be used if the local server
crashes while the file system is mounted, to reset the &quot;already
mounted&quot; flag.  This is what it look like when processing a working
file system:&lt;/p&gt;

&lt;p&gt;&lt;blockquote&gt;&lt;pre&gt;
# fsck.s3ql --force --ssl s3c://s.greenqloud.com:443/bucket-name
Using cached metadata.
File system seems clean, checking anyway.
Checking DB integrity...
Creating temporary extra indices...
Checking lost+found...
Checking cached objects...
Checking names (refcounts)...
Checking contents (names)...
Checking contents (inodes)...
Checking contents (parent inodes)...
Checking objects (reference counts)...
Checking objects (backend)...
..processed 5000 objects so far..
..processed 10000 objects so far..
..processed 15000 objects so far..
Checking objects (sizes)...
Checking blocks (referenced objects)...
Checking blocks (refcounts)...
Checking inode-block mapping (blocks)...
Checking inode-block mapping (inodes)...
Checking inodes (refcounts)...
Checking inodes (sizes)...
Checking extended attributes (names)...
Checking extended attributes (inodes)...
Checking symlinks (inodes)...
Checking directory reachability...
Checking unix conventions...
Checking referential integrity...
Dropping temporary indices...
Backing up old metadata...
Dumping metadata...
..objects..
..blocks..
..inodes..
..inode_blocks..
..symlink_targets..
..names..
..contents..
..ext_attributes..
Compressing and uploading metadata...
Wrote 0.89 MB of compressed metadata.
# 
&lt;/pre&gt;&lt;/blockquote&gt;&lt;/p&gt;

&lt;p&gt;Thanks to the cache, working on files that fit in the cache is very
quick, about the same speed as local file access.  Uploading large
amount of data is to me limited by the bandwidth out of and into my
house.  Uploading 685 MiB with a 100 MiB cache gave me 305 kiB/s,
which is very close to my upload speed, and downloading the same
Debian installation ISO gave me 610 kiB/s, close to my download speed.
Both were measured using &lt;tt&gt;dd&lt;/tt&gt;.  So for me, the bottleneck is my
network, not the file system code.  I do not know what a good cache
size would be, but suspect that the cache should e larger than your
working set.&lt;/p&gt;

&lt;p&gt;I mentioned that only one machine can mount the file system at the
time.  If another machine try, it is told that the file system is
busy:&lt;/p&gt;

&lt;p&gt;&lt;blockquote&gt;&lt;pre&gt;
# mount.s3ql --cachedir /var/lib/s3ql-cache --authfile /root/.s3ql/authinfo2 \
  --ssl --allow-root s3c://s.greenqloud.com:443/bucket-name /s3ql
Using 8 upload threads.
Backend reports that fs is still mounted elsewhere, aborting.
#
&lt;/pre&gt;&lt;/blockquote&gt;&lt;/p&gt;

&lt;p&gt;The file content is uploaded when the cache is full, while the
metadata is uploaded once every 24 hour by default.  To ensure the
file system content is flushed to the cloud, one can either umount the
file system, or ask S3QL to flush the cache and metadata using
s3qlctrl:

&lt;p&gt;&lt;blockquote&gt;&lt;pre&gt;
# s3qlctrl upload-meta /s3ql
# s3qlctrl flushcache /s3ql
# 
&lt;/pre&gt;&lt;/blockquote&gt;&lt;/p&gt;

&lt;p&gt;If you are curious about how much space your data uses in the
cloud, and how much compression and deduplication cut down on the
storage usage, you can use s3qlstat on the mounted file system to get
a report:&lt;/p&gt;

&lt;p&gt;&lt;blockquote&gt;&lt;pre&gt;
# s3qlstat /s3ql
Directory entries:    9141
Inodes:               9143
Data blocks:          8851
Total data size:      22049.38 MB
After de-duplication: 21955.46 MB (99.57% of total)
After compression:    21877.28 MB (99.22% of total, 99.64% of de-duplicated)
Database size:        2.39 MB (uncompressed)
(some values do not take into account not-yet-uploaded dirty blocks in cache)
#
&lt;/pre&gt;&lt;/blockquote&gt;&lt;/p&gt;

&lt;p&gt;I mentioned earlier that there are several possible suppliers of
storage.  I did not try to locate them all, but am aware of at least
&lt;a href=&quot;https://www.greenqloud.com/&quot;&gt;Greenqloud&lt;/a&gt;,
&lt;a href=&quot;http://drive.google.com/&quot;&gt;Google Drive&lt;/a&gt;,
&lt;a href=&quot;http://aws.amazon.com/s3/&quot;&gt;Amazon S3 web serivces&lt;/a&gt;,
&lt;a href=&quot;http://www.rackspace.com/&quot;&gt;Rackspace&lt;/a&gt; and
&lt;a href=&quot;http://crowncloud.net/&quot;&gt;Crowncloud&lt;/A&gt;.  The latter even
accept payment in Bitcoin.  Pick one that suit your need.  Some of
them provide several GiB of free storage, but the prize models are
quite different and you will have to figure out what suits you
best.&lt;/p&gt;

&lt;p&gt;While researching this blog post, I had a look at research papers
and posters discussing the S3QL file system.  There are several, which
told me that the file system is getting a critical check by the
science community and increased my confidence in using it.  One nice
poster is titled
&quot;&lt;a href=&quot;http://www.lanl.gov/orgs/adtsc/publications/science_highlights_2013/docs/pg68_69.pdf&quot;&gt;An
Innovative Parallel Cloud Storage System using OpenStack’s SwiftObject
Store and Transformative Parallel I/O Approach&lt;/a&gt;&quot; by Hsing-Bung
Chen, Benjamin McClelland, David Sherrill, Alfred Torrez, Parks Fields
and Pamela Smith.  Please  have a look.&lt;/p&gt;

&lt;p&gt;Given my problems with different file systems earlier, I decided to
check out the mounted S3QL file system to see if it would be usable as
a home directory (in other word, that it provided POSIX semantics when
it come to locking and umask handling etc).  Running
&lt;a href=&quot;http://people.skolelinux.org/pere/blog/Testing_if_a_file_system_can_be_used_for_home_directories___.html&quot;&gt;my
test code to check file system semantics&lt;/a&gt;, I was happy to discover that
no error was found.  So the file system can be used for home
directories, if one chooses to do so.&lt;/p&gt;

&lt;p&gt;If you do not want a locally file system, and want something that
work without the Linux fuse file system, I would like to mention the
&lt;a href=&quot;http://www.tarsnap.com/&quot;&gt;Tarsnap service&lt;/a&gt;, which also
provide locally encrypted backup using a command line client.  It have
a nicer access control system, where one can split out read and write
access, allowing some systems to write to the backup and others to
only read from it.&lt;/p&gt;

&lt;p&gt;As usual, if you use Bitcoin and want to show your support of my
activities, please send Bitcoin donations to my address
&lt;b&gt;&lt;a href=&quot;bitcoin:15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b&amp;label=PetterReinholdtsenBlog&quot;&gt;15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b&lt;/a&gt;&lt;/b&gt;.&lt;/p&gt;
</description>
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                <title>ReactOS Windows clone - nice free software</title>
                <link>http://people.skolelinux.org/pere/blog/ReactOS_Windows_clone___nice_free_software.html</link>
                <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/ReactOS_Windows_clone___nice_free_software.html</guid>
                <pubDate>Tue, 1 Apr 2014 12:10:00 +0200</pubDate>
                <description>&lt;p&gt;Microsoft have announced that Windows XP reaches its end of life
2014-04-08, in 7 days.  But there are heaps of machines still running
Windows XP, and depending on Windows XP to run their applications, and
upgrading will be expensive, both when it comes to money and when it
comes to the amount of effort needed to migrate from Windows XP to a
new operating system.  Some obvious options (buy new a Windows
machine, buy a MacOSX machine, install Linux on the existing machine)
are already well known and covered elsewhere.  Most of them involve
leaving the user applications installed on Windows XP behind and
trying out replacements or updated versions. In this blog post I want
to mention one strange bird that allow people to keep the hardware and
the existing Windows XP applications and run them on a free software
operating system that is Windows XP compatible.&lt;/p&gt;

&lt;p&gt;&lt;a href=&quot;http://www.reactos.org/&quot;&gt;ReactOS&lt;/a&gt; is a free software
operating system (GNU GPL licensed) working on providing a operating
system that is binary compatible with Windows, able to run windows
programs directly and to use Windows drivers for hardware directly.
The project goal is for Windows user to keep their existing machines,
drivers and software, and gain the advantages from user a operating
system without usage limitations caused by non-free licensing.  It is
a Windows clone running directly on the hardware, so quite different
from the approach taken by &lt;a href=&quot;http://www.winehq.org/&quot;&gt;the Wine
project&lt;/a&gt;, which make it possible to run Windows binaries on
Linux.&lt;/p&gt;

&lt;p&gt;The ReactOS project share code with the Wine project, so most
shared libraries available on Windows are already implemented already.
There is also a software manager like the one we are used to on Linux,
allowing the user to install free software applications with a simple
click directly from the Internet.  Check out the
&lt;a href=&quot;http://www.reactos.org/screenshots&quot;&gt;screen shots on the
project web site&lt;/a&gt; for an idea what it look like (it looks just like
Windows before metro).&lt;/p&gt;

&lt;p&gt;I do not use ReactOS myself, preferring Linux and Unix like
operating systems.  I&#39;ve tested it, and it work fine in a virt-manager
virtual machine.  The browser, minesweeper, notepad etc is working
fine as far as I can tell.  Unfortunately, my main test application
is the software included on a CD with the Lego Mindstorms NXT, which
seem to install just fine from CD but fail to leave any binaries on
the disk after the installation.  So no luck with that test software.
No idea why, but hope someone else figure out and fix the problem.
I&#39;ve tried the ReactOS Live ISO on a physical machine, and it seemed
to work just fine.  If you like Windows and want to keep running your
old Windows binaries, check it out by
&lt;a href=&quot;http://www.reactos.org/download&quot;&gt;downloading&lt;/a&gt; the
installation CD, the live CD or the preinstalled virtual machine
image.&lt;/p&gt;
</description>
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        <item>
                <title>Video DVD reader library / python-dvdvideo - nice free software</title>
                <link>http://people.skolelinux.org/pere/blog/Video_DVD_reader_library___python_dvdvideo___nice_free_software.html</link>
                <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Video_DVD_reader_library___python_dvdvideo___nice_free_software.html</guid>
                <pubDate>Fri, 21 Mar 2014 15:25:00 +0100</pubDate>
                <description>&lt;p&gt;Keeping your DVD collection safe from scratches and curious
children fingers while still having it available when you want to see a
movie is not straight forward.  My preferred method at the moment is
to store a full copy of the ISO on a hard drive, and use VLC, Popcorn
Hour or other useful players to view the resulting file.  This way the
subtitles and bonus material are still available and using the ISO is
just like inserting the original DVD record in the DVD player.&lt;/p&gt;

&lt;p&gt;Earlier I used dd for taking security copies, but it do not handle
DVDs giving read errors (which are quite a few of them).  I&#39;ve also
tried using
&lt;a href=&quot;http://people.skolelinux.org/pere/blog/Ripping_problematic_DVDs_using_dvdbackup_and_genisoimage.html&quot;&gt;dvdbackup
and genisoimage&lt;/a&gt;, but these days I use the marvellous python library
and program
&lt;a href=&quot;http://bblank.thinkmo.de/blog/new-software-python-dvdvideo&quot;&gt;python-dvdvideo&lt;/a&gt;
written by Bastian Blank.  It is
&lt;a href=&quot;http://packages.qa.debian.org/p/python-dvdvideo.html&quot;&gt;in Debian
already&lt;/a&gt; and the binary package name is python3-dvdvideo. Instead
of trying to read every block from the DVD, it parses the file
structure and figure out which block on the DVD is actually in used,
and only read those blocks from the DVD.  This work surprisingly well,
and I have been able to almost backup my entire DVD collection using
this method.&lt;/p&gt;

&lt;p&gt;So far, python-dvdvideo have failed on between 10 and
20 DVDs, which is a small fraction of my collection.  The most common
problem is
&lt;a href=&quot;https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=720831&quot;&gt;DVDs
using UTF-16 instead of UTF-8 characters&lt;/a&gt;, which according to
Bastian is against the DVD specification (and seem to cause some
players to fail too).  A rarer problem is what seem to be inconsistent
DVD structures, as the python library
&lt;a href=&quot;https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=723079&quot;&gt;claim
there is a overlap between objects&lt;/a&gt;.  An equally rare problem claim
&lt;a href=&quot;https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=741878&quot;&gt;some
value is out of range&lt;/a&gt;.  No idea what is going on there.  I wish I
knew enough about the DVD format to fix these, to ensure my movie
collection will stay with me in the future.&lt;/p&gt;

&lt;p&gt;So, if you need to keep your DVDs safe, back them up using
python-dvdvideo. :)&lt;/p&gt;
</description>
        </item>
        
        <item>
                <title>Free Timetabling Software - nice free software</title>
                <link>http://people.skolelinux.org/pere/blog/Free_Timetabling_Software___nice_free_software.html</link>
                <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Free_Timetabling_Software___nice_free_software.html</guid>
                <pubDate>Sat, 7 Jul 2012 09:50:00 +0200</pubDate>
                <description>&lt;p&gt;Included in &lt;a href=&quot;http://www.skolelinux.org/&quot;&gt;Debian Edu /
Skolelinux&lt;/a&gt; is a large collection of end user and school specific
software.  It is one of the packages not installed by default but
provided in the Debian archive for schools to install if they want to,
is a system to automatically plan the school time table using
information about available teachers, classes and rooms, combined with
the list of required courses and how many hours each topic should
receive.  The software is

&lt;a href=&quot;http://lalescu.ro/liviu/fet/&quot;&gt;named FET&lt;/a&gt;, and it provide a
graphical user interface to input the required information, save the
result in a fairly simple XML format, and generate time tables for
both teachers and students.  It is available both for
&lt;a href=&quot;http://lalescu.ro/liviu/fet/download.html&quot;&gt;Linux, MacOSX and
Windows&lt;/a&gt;.&lt;/p&gt;

&lt;p&gt;This is &lt;a href=&quot;http://lalescu.ro/liviu/fet/features.html&quot;&gt;the
feature list&lt;/a&gt;, liftet from the project web site:&lt;/p&gt;

&lt;p&gt;&lt;ul&gt;

  &lt;li&gt;FET is free software, licensed under the GNU GPL v2 or later.
    You can freely use, copy, modify and redistribute it &lt;/li&gt;
        
  &lt;li&gt;Localized to en_US (US English, default), ar (Arabic), ca
    (Catalan), da (Danish), de (German), el (Greek), es (Spanish), fa
    (Persian), fr (French), gl (Galician), he (Hebrew), hu
    (Hungarian), id (Indonesian), it (Italian), lt (Lithuanian), mk
    (Macedonian), ms (Malay), nl (Dutch), pl (Polish), pt_BR
    (Brazilian Portuguese), ro (Romanian), ru (Russian), si (Sinhala),
    sk (Slovak), sr (Serbian), tr (Turkish), uk (Ukrainian), uz
    (Uzbek) and vi (Vietnamese) (incompletely for some languages)
    &lt;/li&gt;
        
  &lt;li&gt;Fully automatic generation algorithm, allowing also
    semi-automatic or manual allocation&lt;/li&gt;
        
  &lt;li&gt;Platform independent implementation, allowing running on
    GNU/Linux, Windows, Mac and any system that Qt supports &lt;/li&gt;
        
  &lt;li&gt;Flexible modular XML format for the input file, allowing editing
    with an XML editor or by hand (besides FET interface)&lt;/li&gt;
        
  &lt;li&gt;Import/export from CSV format&lt;/li&gt;
        
  &lt;li&gt;The resulted timetables are exported into HTML, XML and CSV
    formats &lt;/li&gt;
        
  &lt;li&gt;Flexible students structure, organized into sets: years, groups
    and subgroups. FET allows overlapping years and groups and
    non-overlapping subgroups. You can even define individual students
    (as separate sets)&lt;/li&gt;
        
  &lt;li&gt;Each constraint has a weight percentage, from 0.0% to 100.0%
    (but some special constraints are allowed to have only 100% weight
    percentage)&lt;/li&gt;
        
  &lt;li&gt;Limits for the algorithm (all these limits can be increased on
    demand, as a custom version, because this would require a bit more
    memory):
    &lt;ul&gt;
      &lt;li&gt;Maximum total number of hours (periods) per day: 60&lt;/li&gt;
      &lt;li&gt;Maximum number of working days per week: 35&lt;/li&gt;
      &lt;li&gt;Maximum total number of teachers: 6000&lt;/li&gt;
      &lt;li&gt;Maximum total number of sets of students: 30000&lt;/li&gt;
      &lt;li&gt;Maximum total number of subjects: 6000&lt;/li&gt;
      &lt;li&gt;Virtually unlimited number of activity tags&lt;/li&gt;
      &lt;li&gt;Maximum number of activities: 30000&lt;/li&gt;
      &lt;li&gt;Maximum number of rooms: 6000&lt;/li&gt;
      &lt;li&gt;Maximum number of buildings: 6000&lt;/li&gt;
      &lt;li&gt;Possibility of adding multiple teachers and
          students sets for each activity.  (it is possible
          also to have no teachers or no students sets for an
          activity)&lt;/li&gt;
      &lt;li&gt;Virtually unlimited number of time constraints&lt;/li&gt;
      &lt;li&gt;Virtually unlimited number of space constraints&lt;/li&gt;
    &lt;/ul&gt;&lt;/li&gt;

  &lt;li&gt;A large and flexible palette of time constraints:
    &lt;ul&gt;
      &lt;li&gt;Break periods&lt;/li&gt;
      &lt;li&gt;For teacher(s):
        &lt;ul&gt;
          &lt;li&gt;Not available periods&lt;/li&gt;
          &lt;li&gt;Max/min days per week&lt;/li&gt;
          &lt;li&gt;Max gaps per day/week&lt;/li&gt;
          &lt;li&gt;Max hours daily/continuously&lt;/li&gt;
          &lt;li&gt;Min hours daily&lt;/li&gt;
          &lt;li&gt;Max hours daily/continuously with an activity tag&lt;/li&gt;

          &lt;li&gt;Respect working in an hourly interval a max number of
            days per week&lt;/li&gt;
        &lt;/ul&gt;&lt;/li&gt;
      &lt;li&gt;For students (sets):
        &lt;ul&gt;
          &lt;li&gt;Not available periods&lt;/li&gt;
          &lt;li&gt;Begins early (specify max allowed beginnings at second hour)&lt;/li&gt;
          &lt;li&gt;Max gaps per day/week&lt;/li&gt;
          &lt;li&gt;Max hours daily/continuously&lt;/li&gt;
          &lt;li&gt;Min hours daily&lt;/li&gt;
          &lt;li&gt;Max hours daily/continuously with an activity tag&lt;/li&gt;

          &lt;li&gt;Respect working in an hourly interval a max number of
            days per week&lt;/li&gt;
        &lt;/ul&gt;&lt;/li&gt;
      &lt;li&gt;For an activity or a set of activities/subactivities:
        &lt;ul&gt;
          &lt;li&gt;A single preferred starting time&lt;/li&gt;
          &lt;li&gt;A set of preferred starting times&lt;/li&gt;
          &lt;li&gt;A set of preferred time slots&lt;/li&gt;
          &lt;li&gt;Min/max days between them&lt;/li&gt;
          &lt;li&gt;End(s) students day&lt;/li&gt;
          &lt;li&gt;Same starting time/day/hour&lt;/li&gt;
          &lt;li&gt;Occupy max time slots from selection (a complex and
            flexible constraint, useful in many situations)&lt;/li&gt;
          &lt;li&gt;Consecutive, ordered, grouped (for 2 or 3 (sub)activities)&lt;/li&gt;
          &lt;li&gt;Not overlapping&lt;/li&gt;
          &lt;li&gt;Max simultaneous in selected time slots&lt;/li&gt;
          &lt;li&gt;Min gaps between a set of (sub)activities&lt;/li&gt;
        &lt;/ul&gt;&lt;/li&gt;
    &lt;/ul&gt;&lt;/li&gt;

  &lt;li&gt;A large and flexible palette of space constraints:
    &lt;ul&gt;
      &lt;li&gt;Room not available periods&lt;/li&gt;
      &lt;li&gt;For teacher(s):
        &lt;ul&gt;
          &lt;li&gt;Home room(s)&lt;/li&gt;
          &lt;li&gt;Max building changes per day/week&lt;/li&gt;
          &lt;li&gt;Min gaps between building changes&lt;/li&gt;
        &lt;/ul&gt;
      &lt;/li&gt;
                
      &lt;li&gt;For students (sets):
        &lt;ul&gt;
          &lt;li&gt;Home room(s)&lt;/li&gt;
          &lt;li&gt;Max building changes per day/week&lt;/li&gt;
          &lt;li&gt;Min gaps between building changes&lt;/li&gt;
        &lt;/ul&gt;
      &lt;/li&gt;
      &lt;li&gt;Preferred room(s):
        &lt;ul&gt;
          &lt;li&gt;For a subject&lt;/li&gt;
          &lt;li&gt;For an activity tag&lt;/li&gt;
          &lt;li&gt;For a subject and an activity tag&lt;/li&gt;
          &lt;li&gt;Individually for a (sub)activity&lt;/li&gt;
        &lt;/ul&gt;
      &lt;/li&gt;

      &lt;li&gt;For a set of activities:
        &lt;ul&gt;
          &lt;li&gt;Occupy a maximum number of different rooms&lt;/li&gt;
        &lt;/ul&gt;
      &lt;/li&gt;
    &lt;/ul&gt;
  &lt;/li&gt;
&lt;/ul&gt;&lt;/p&gt;

&lt;p&gt;I have not used it myself, as I am not involved in time table
planning at a school, but it seem to work fine when I test it.  If you
need to set up your schools time table, and is tired of doing it
manually, check it out. 

A quick summary on how to use it can be found in
&lt;a href=&quot;http://marvelsoft.co.in/wp/2012/03/generate-timetable-for-state-cbse-icse-igcse-schools-free/&quot;&gt;a
blog post from MarvelSoft&lt;/a&gt;.  If you find FET useful, please provide
a recipe for the Debian Edu project in the
&lt;a href=&quot;http://wiki.debian.org/DebianEdu#Howtos&quot;&gt;Debian Edu HowTo
section&lt;/a&gt;.&lt;/p&gt;
</description>
        </item>
        
        </channel>
</rss>