The One with the Thoughts of Frans

Uw Kinderen — Your Children

2012-02-06T19:37:43Z

I thought this poem by Annie M.G. Schmidt was quite amusing; it also nicely characterizes the prose texts in the bundle from which I took it. The poem’s short, so you’ve got no excuse not to read it — assuming you speak Dutch, of course.

Een sprookje voor het slapen gaan
over de bijtjes en de maan,
over de elfjes teer en fijn,
die Artistiek Verantwoord zijn,
en over ’t zoete bloemenfeetje…
uw kind vindt het wel mooi, een beetje…
maar gooit de elfjes grif terzijde
voor strips met nare blote meiden.
Een kind is al zo gauw tevree:
een overval — een moord of twee.

Kind, huil maar niet, wees maar bedaard:
ik gooi Rie Cramer in de haard.
Hier is de strip, met stromen bloed.
Beng, weer een lijk. Dus wees maar zoet.

From Voeden, verschonen en in de wieg mikken. 2009, Querido.

For the speakers of English among us, I hereby offer you an impromptu translation:

A fairy tale for sleeping soon
about little bees and the moon,
about little elves frail and fine,
of artistically sound design,
and about the sweet flower fairy…
your child thinks it's nice, not very…
but promptly the elves aside it whirls
for comics with nasty naked girls.
A child is easy to entertain:
a robbery — a murder or twain.

Child, don’t cry, just be as if in a daze:
I'll throw Rie Cramer¹ in the fireplace.
Here's the comic, with streams of blood.
Bang, again a corpse. So be good.

1. Rie Cramer is a Dutch author and illustrator of books aimed at little children.

Debian: International Fonts

2012-02-02T20:52:47Z

Ubuntu comes with a large swath of international fonts installed by default, but Debian requires a little more attention. Although I can’t read the languages, I can recognize which script is which. Besides, boxes are just ugly.

East Asian: apt-get install ttf-arphic-uming ttf-wqy-zenhei ttf-sazanami-mincho ttf-sazanami-gothic ttf-unfonts-core (source)
Indic: apt-get install ttf-indic-fonts (source)
All together: apt-get install ttf-arphic-uming ttf-wqy-zenhei ttf-sazanami-mincho ttf-sazanami-gothic ttf-unfonts-core ttf-indic-fonts

These are merely the ones that I missed the most. I may update this post in the future.

Mounting filesystems with fstab

2011-12-23T21:56:24Z

If you’re just switching from Windows and you don’t like to enter passwords every time you want to access your disks, fstab is what you need. Of course it also applies to e.g. ext4 partitions that you didn’t assign a mount point during the installation of your OS, but when you’ve come that far along you probably already know this.

By far the best explanation of fstab I’ve found was on ArchWiki, so I won’t waste my time reiterating what is stated there. I’ll merely try to further clarify a few things that were less immediately obvious to myself and needed a little experimentation.

In many ways fstab is what I always wanted in Windows. For a long, long time I’ve maintained a C partition (dedicated Windows, so I could wipe it without really affecting anything), a D partition (my primary data container), and later, as I added more HDDs, I think I got up to G. There are some hacks available, like NTFS junction points, but they don’t really protect against the fundamental flaw of drive letter assignment compared to the much more sensible mechanism of mount points.

When you mount a partition manually through your GUI, by clicking on it and entering your password, it creates a temporary entry in /etc/mtab; this entry can be used to as a starting point for fstab entries. However, for more reliable partition mounting you need to use UUIDs. You can obtain this using blkid /mnt/sda1, where /mnt/sda1 should be replaced with whatever partition you want to print a UUID for. This command needs to be run as root, i.e. with su or sudo.

# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).

If you prefer to use a GUI, there are some options, but I haven’t tried any of them.

Disk Manager: http://flomertens.free.fr/disk-manager/
PySDM: http://pysdm.sourceforge.net/
fwfstab: http://www.diffingo.com/oss/fwfstab

Why Opera’s XHTML Error Handling Is Superior

2011-12-08T10:58:54Z

I found this old, unfinished post in my drafts. I’m not quite sure when I originally wrote it, but it was over a year ago. Rather than updating the content I decided to publish it as is, as I’m not sure why I didn’t, with a small addendum at the end.

I made a little compilation of the various error messages displayed by browsers upon encountering an XML syntax error. Firefox (Gecko) has the unfriendly looking error on top, Chromium (Webkit) renders the page up to the error, but shows a large error message (albeit not at all useful like in Opera & Fx), and for Opera I included 10.10 and the latest 10.50 pre-alpha build. Note that it’s just the styles behind the error message that changed a bit: the content and helpfulness of the error message is still the same. I’ll run it down a bit more:

Firefox displays an error message that’s only useful if you already know sufficiently much about X(HT)ML, whereas Opera’s error message not only highlights more clearly where parsing failed — although ultimately this difference might just be one of preference. More important, its error message might just helpfully link you precisely where you need to go to learn how to avoid it. When I first started messing about with XHTML back in ’03 or so, I probably would’ve appreciated it if Opera had done that. At the time Opera behaved the same as Fx does now.
Chromium displays an error message that doesn’t even manage to clearly indicate what’s the problem. This compares negatively to Fx and Opera highlighting the &.
Chromium renders the page up to the problem, which may result in a get out of jail free card. The error message doesn’t seem very annoying, but if the error is in the middle of the page it’ll still be in the way. In my sample page it’s at the end, however. (My example page is basically a standard installation of phpGraphy on which I decided to switch to application/xml+xhtml because it claims to be more or less XHTML compliant now — I had to fix all the unclosed meta and link tags first.)
Despite rendering the page, you won’t be able to see the page fully in Chromium. You will with Opera’s reparse as HTML function.

I hope that clarifies why I think Opera’s handling is best, both as a user and as an author.

This blog post is now outdated. You can return to the behavior I hailed by disabling the opera:config#UserPrefs|AutomaticallyreparseXHTMLwithparsingerrorsasHTML option.

Multiple Nationalities

2011-11-21T19:36:36Z

I seem to have missed Donner’s latest brilliant idea for a new law. It seems that the Dutch government is looking to limit the number of people with multiple nationalities to a minimum. In today’s NRC Handelsblad Ulli d’Oliveira wrote a great opinion piece about the matter on page 14. Some highlights:

De rabiate weerzin in delen van het politieke spectrum tegen het verschijnsel van de meervoudige nationaliteit heeft een gevolg dat pas laat aan het licht kwam – dezelfde beperkingen aan het behouden van de oorspronkelijke nationaliteit die aan buitenlandse aspirant-Nederlanders worden opgelegd, gelden voor Nederlanders die een buitenlandse nationaliteit willen aannemen. Een petitie met meer dan vijftienduizend handtekeningen van mensen in het buitenland keert zich tegen deze collateral damage.

…

In het nationaliteitsrecht is het nuttig om politics of identity te onderscheiden van politics of interests. De laatste jaren wordt het Nederlandse nationaliteitsrecht gedomineerd door de vurige wens om aan buitenlanders die Nederlander willen worden eerst de eis te stellen dat ze ideaaltypische Nederlanders zijn geworden. Ze zijn ingeburgerd, spreken de taal, participeren in de samenleving, verdienen behoorlijk, hebben hun startkwalificatie op zak, hebben geen strafblad en zo meer – alsof Nederlandse losers niet bestaan. Deze Nederlandse identiteit mag niet worden bezoedeld door vreemde smetten, zoals een buitenlandse nationaliteit. De identiteit van de would-be-Nederlander moet exclusief Nederlands zijn.

…

Het wetsontwerp houdt geen rekening met burgers. De argumenten van expats zijn verstandig en invoelbaar. Mensen willen settelen in den vreemde zonder hun Nederlanderschap te verloochenen. Om praktische, zakelijke overwegingen nemen ze een vreemde nationaliteit aan, zonder dat ze erover piekeren hun Nederlandse identiteit weg te snijden. Het zijn dezelfde overwegingen die buitenlanders ertoe brengen om Nederlander te willen worden.

Quick, messy, summarizing translation: the dislike in some parts of the political spectrum against multiple nationalities has an unexpected result: the same limitations that apply to aspiring Dutch apply to Dutch people who wish to assume another nationality.

In recent years Dutch politics has been dominated by demanding that foreigners become idealized Dutch people, part of which is being exclusively Dutch.

The law design doesn’t take citizens into account. The arguments made by expatriates are reasonable and can be empathized with. People want to settle in a foreign country without renouncing their Dutch nationality. For practical reasons they assume a foreign nationality without considering cutting off their Dutch identify. These are the same considerations that make foreigners want to assume the Dutch nationality.

I have little to add to that. The whole shebang about multiple nationalities is ludicrous. Perhaps the Dutch municipalities should stop automatically submitting babies born of Moroccan-Dutch parents for Moroccan nationality if it’s truly a problem of such massive scale — although they might’ve stopped it by now, since I think a some Moroccan-Dutch parents sued Amsterdam over this gross misconduct. Nobody will apply for multiple nationalities just for the heck of it.

Mental Conversations

2011-11-13T19:08:21Z

She remembered the day a furniture van from Portland had shown up with a two-thousand-dollar sectional sofa. Scott had been in his study, writing with the music cranked to its usual deafening levels — she could faintly hear Steve Earle singing “Guitar Town” in the house even with the soundproofing — and interrupting him was apt to do another two thousand dollars’ worth of damage to her ears, in Lisey’s opinion. The furniture guys said “the mister” told them she’d let them know where to put the new piece of furniture. Lisey had briskly directed them to carry the current sofa — the perfectly good current sofa — out to the barn, and place the new sectional where it had been. The color was at least a fair match for the room, and that was a relief. She knew she and Scott had never discussed a new sofa, sectional or otherwise, just as she knew Scott would declare — oh yes, most vehemently — that they had. She was sure he’d discussed it with her in his head; he just sometimes forgot to vocalize those discussions. Forgetting was a skill he had honed (emphasis mine).

From Lisey’s Story by Stephen King (p.148 of the 2006 Scribner hardcover).

My wife alleges I do just that.

Skype Call Recorder

2011-11-11T15:02:13Z

Skype Call Recorder delivers on the promise of its name. It records calls, with the participants split into two separate channels if you want — which you do if you want the option of raising or lowering the volume of one participant.

On Critical Thinking

2011-09-19T10:19:31Z

Written in response to someone talking about thinking critically “against the powers that be.”

Given your phrasing, it’s highly improbable that you’re actually talking about critical thinking. One does not think critically against anything. You think critically, period, about everything. Perhaps most important, this includes yourself and your own notions. If you only think critically about (let alone against) others, you’re not thinking critically at all. If you think critically against someone or something, rather than about, you’re just out to find flaws so you can justify your own preconceived notions.

Some Practical, (Extremely) Simple Algebra

2011-08-30T21:01:27Z

Early in secondary school, many of my classmates used to be exasperated by the perceived lack of practical application of the mathematics we had to learn at the time. I never really understood why, because it had clear practical applications, though I admit I also simply thought it was fun. Later on, things like statistics were really boring, but I figured I’d share how the simplest of elementary algebra can help you make financial choices.

Having just moved, we had to decide whether or not to buy a washing machine. Washing machines start at about €400 — they can be obtained used for much less, but last time I picked up a used washing machine for €40 it broke within about a year and it’s just so much trouble trying to fix it or getting yet another used replacement — while laundromats cost about €3-4 per load (+20 cents for detergent). Admittedly the load sizes are slightly larger at the laundromat, but I don’t see that as a good thing: it just makes it harder to carry and dry the laundry.

Washing costs per load for various temperatures in € according to Nibud
temperature/ type of costs	90°C	60°C	40°C
electricity	0.48	0.25	0.15
water	0.10	0.08	0.08
washing powder	0.19	0.19	0.19
depreciation / maintenance	0.48	0.48	0.48
total	1.25	1.00	0.90
total without depreciation	0.77	0.52	0.42

We usually wash on 30 degrees and have an otherwise energy and water efficient washing machine, but I’ll just run with the price for a single wash without depreciation value. I’m not interested in depreciation of the value of the washing machine, since the point is how many times you have to wash to break even compared to the laundromat. Of course a depreciation value could be used for this so that ax = bx should yield a useful conclusion, but that’d be a bit of a roundabout way.

I devised the following simple formula: ax = bx + c, where a is the cost of one load at the laundromat, b is the cost of one load in a self-owned washing machine, and c is the price of a washing machine. x is the break even point of the number of washes required to make it worth your while to buy a washing machine as opposed to utilizing a laundromat.

3.20x = .42x+480 (-.42x)
2.78x = 480
x=480/2.78=173

I haven’t counted the number of times we’ve washed, but if we haven’t surpassed it yet, I bet we’re quite close. We’ve had it for nearly two years and we wash slightly more than once a week on average.

Liberty

2011-07-09T10:23:53Z

Lost now to family, buddies, girlfriend, rabbit hound, society, and himself, this poor young sailor had fallen—not very many miles from Jerusalem—understanding virtually nothing of the situation in the Middle East. He probably believed it involved a struggle between right and wrong, good and evil, freedom and oppression. That was his second mistake. His third mistake was in trusting that even if he didn’t understand the situation, his leaders did. His first—and worst—mistake was blindly doing what he was told to do. Without questioning their methods or their motives, he allowed politicians to make the decisions that led to his early demise.

What is politics, after all, but the compulsion to preside over property and make other people’s decisions for them? Liberty, the very opposite of ownership and control, cannot, then, result from political action, either at the polls or the barricades, but rather evolves out of attitude. If it results from anything, it may be levity.

From Skinny Legs And All by Tom Robbins (p.118 of the May 2003 Bantam trade paperback reissue).

Switching µTorrent from Windows to Linux

2011-06-30T13:16:38Z

A while ago, I wrote about using Wine in order to switch completely to Linux a lot quicker than would be possible if you had to figure out replacements for various pieces of peripheral software. In the case of µTorrent this meant that I could keep on seeding all the torrents I’ve downloaded over the years and not having to set up my RSS feeds and other preferences once more, but it’s not all sunshine. Aside from minor bugs in Wine, it simply uses a lot more memory and sometimes CPU. As an unscientific guestimate, it seems about 5 times as memory hungry as on Windows.

In the not too distant past, fixing this would’ve required a switch to e.g. qBittorrent, but an alpha version of µTorrent Server is now available for Linux. It can do everything normal µTorrent can, but not everything is necessarily available through its default WebUI. Luckily an alternative WebUI is available and I’d highly recommend it over what comes with the µTorrent Server by default. It enables RSS feeds and filters, among other things. I think it’s probably no more than a newer version, so perhaps you can ignore this part of this post if you’re reading this in a few months time.

One thing that doesn’t seem to be mentioned in the documentation anywhere is that you can access the WebUI through http://localhost:8080/gui/.

Now for switching over the data and configuration files. Luckily µTorrent for Linux uses the same data files, so you can easily copy over rss.dat (feeds configuration) and resume.dat (locations of torrents). Of course that won’t fix the problem that directory structures are slightly different on the respective platforms, and I don’t think you can make symbolic links to drive letters except in Wine. That’s where BEncode Editor comes in, as described in an article about moving your µTorrent files. I couldn’t find a similar utility for Linux, but no matter, it works quite well in — drum roll — Wine. I downloaded version 0.7.1.0, the latest at the time of writing.

You should read through the guide I linked, but of course some slight adjustments will have to be made. In my case I did some reorganizing of my HDDs after I hadn’t booted into Windows for a month, but the differences for my torrents weren’t that big. I replaced D:\downloads\torrents\ globally with /media/downloads/torrents/ as outlined in the text. I repeated similar commands for my E:\ and I:\, but of course the specifics will be different for everyone. To finish it off you can replace all instances of \ with /.

Something similar can be done for rss.dat, but I had already adjusted all my filters manually in the µTorrent WebUI.

Assuming you run this command in the directory where you put the µTorrent Server executable, you can run cp /somewhere/uTorrent-for-Windows-folder/*.torrent to copy over all the relevant *.torrent files.

There are some slight inconveniences. For example, you can’t open in folder directly, but you have to navigate there manually or copy the location from the WebUI. However, if you were using Wine you’d already given up on proper integration regardless. I think it’s easier to copy the proper Linux path from the WebUI than to mentally line up Wine drives and directories with real ones.

As one final caveat this method didn’t seem to remember proper times when downloads finished and instead “downloaded” all my torrents at that point in time. I’m sure that could be avoided somehow (perhaps by copying over settings.dat?) but for my purposes it didn’t matter.

More Fun with Screen and SSH with Byobu: Automatic Reattaching

2011-05-31T15:36:57Z

A while ago I wrote about screen, which makes your SSH experience more satisfying. There are some enhancements you can make to screen with .screenrc, but Byobu does more by default than I ever could be bothered to figure out. It seems to come pre-installed on Ubuntu, while aptitude install byubo suffices for Debian.

I thought it’d be even better if screen automatically attached itself when logging in through SSH, and clearly I wasn’t alone in that thought. I made a slight adjustment to the code I found so that Byobu is utilized when available and otherwise regular screen will load. Screen is often installed by default, unlike Byobu, so that way I won’t have to install or compile Byobu to reap the benefits of my custom .bashrc.

# From http://tlug.dnho.net/node/239
# "The following code when added to your .bashrc file will, after logging in via ssh, look for any unattached screen sessions and automatically attach to the first one found. If only attached sessions are found then a list of these will be outputted to std out. Finally, If there are no screen sessions running at all then a new screen session will be created."
if [ $SSH_TTY ] && [ ! $WINDOW ]; then
	SCREENLIST=`screen -ls | grep 'Attached'`
	if [ $? -eq "0" ]; then
		echo -e "Screen is already running and attached:\n ${SCREENLIST}"
	else
		type -P byobu &>/dev/null && byobu -U -R || screen -U -R
	fi
fi
# Optionally adding the following will alter your prompt to let you easily know which window within a screen session you are currently in.
if [ $TERM = "screen" ]; then
	PS1='window ${WINDOW} '$PS1
fi

Time Synchronization: NTP

2011-05-28T07:46:16Z

Today I noticed that my computer clock was running fast, meaning that Debian doesn’t come with some kind of time synchronization enabled by default. Ubuntu doesn’t exactly either, but setting your location seems to take care of it in Ubuntu.

There’s really nothing much to tell here. Debian Wiki has all the instructions lined up already.

Type date to see current date and time
date
Install NTP
aptitude install ntp
Done.
Type ntpq -p to see servers you are syncing with.

Type date again to see if the time changed. You time should be synced in a next minute.

Done.

There’s nothing more to do, though I often like to take a peek at the configuration files and the man pages — the latter is typically a bit too dense unless you already know what you’re looking for. In this case, that would mean man ntpd, man ntp.conf, and, most important, nano /etc/ntp.conf (or whatever your favorite text editor is). It doesn’t look like there’s anything of particular interest, but you might want to replace some of those default Debian server pools with ones geographically closer to you. The easiest way is to check on www.pool.ntp.org, but if e.g. your ISP offers such a service it might be a good idea to use it.

In my case, Belgium didn’t have too many servers, so I made up my own mix of Belgium, the Netherlands, and Europe.

#server 0.debian.pool.ntp.org iburst
#server 1.debian.pool.ntp.org iburst
#server 2.debian.pool.ntp.org iburst
#server 3.debian.pool.ntp.org iburst

server 0.be.pool.ntp.org
server 1.nl.pool.ntp.org
server 2.nl.pool.ntp.org
server 3.europe.pool.ntp.org

Also see how to disable the daemon on battery power. I don’t know how much of a difference that would actually make, but as the Dutch idiom goes, all small bits help.

Unmount Flash Drives & Memory Cards

2011-05-21T11:27:44Z

It seems that Gnome’s safely remove drive feature works just like the equivalent in Windows: not at all. It even displays the exact same useless error message, almost word for word: this device cannot be stopped. Not the slightest hint about why this might be the case.

Following this scenario, on Windows you’d pretty much be stuck shutting down your computer to be sure that no data loss will occur (although workarounds like Unlocker exist, or you can use Process Explorer to figure out the culprit manually). Luckily, on Linux the workaround is a lot easier. Use mount to display information about all currently mounted file systems and umount to, you guessed it, unmount the file system of your choice.

$ mount
[…]
/dev/sde1 on /media/888E-E0E0 type vfat (rw,nosuid,nodev,uhelper=udisks,uid=1000,gid=1000,shortname=mixed,dmask=0077,utf8=1,showexec,flush)
$ umount /dev/sde1

PS I just found out that I’m mistaken, but I already wrote the post and besides, the point that you’re able to do things like this if you want, whereas you’d be stuck in Windows, still stands. It seems that the way Gnome devs envisioned unmounting is not while you’re viewing it in Nautilus by right-clicking, but by right-clicking on the icon on the desktop.

Remote Desktop: Remmina

2011-05-17T13:07:14Z

A quick tip for Ubuntu users: install Remmina instead of (or alongside) the default Vinagre with sudo apt-get install remmina. It’s much better. Not only does it perform better (that is, it doesn’t hog CPU), but it has all the options Vinagre lacks.

Using Wine to Ease Migration from Windows

2011-05-05T21:01:23Z

According to its about page, “Wine lets you run Windows software on other operating systems. With Wine, you can install and run these applications just like you would in Windows.” That sounds like a good enough description to me.

I have some applications that depend on a specific drive letter configuration, so to be truly able to share applications between Wine and Windows I’ll have to set up my drives in Wine just the way they are on Windows. I may write a post later about how to auto-mount Windows partitions.

Setting up drives is incredibly simple: you start the Wine configuration program and go to the drives tab. There you can set up certain directories or mount points to correspond to certain drives for Windows programs, but you don’t even have to use the GUI. The reason this is useful is because you can run your programs like you were on Windows and they wouldn’t know the difference. As far as the programs are concerned they’re reading data from the same location as always. This greatly simplifies my process of switching to Linux. Rather than having to set up replacement programs and configurations I can simply let Wine pretend to my programs that they’re running in the same (drive) configuration as they would on Windows. This way I can switch more completely to Debian without having to exert a lot of effort at once. I can move away from certain programs more slowly, or perhaps not at all.

I found a Gnome to Wine Color Scraper to improve the look of my Wine applications, but the registry file it generated didn’t work for my version of Wine. I enabled the debugging option and had to edit the parts where it speaks of HKEY_USERS\S-1-5-4\. For me the number was different. Check in regedit for specifics.

There are many more things you can do with Wine, including playing a fair amount of Windows-based games. Check the website for more information on compatibility.

Kiwis These Days

2011-04-26T13:38:22Z

Wil Wheaton is always posting conversations he’s had with his wife, so why shouldn’t I?

“You want kiwi?” I asked.

“There is cold?” Mel replied. She doesn’t like fruit that hasn’t been refrigerated, which I take into account unless I happen to forget about it.

“Yes! There’s alway cold kiwi. It’s like a disease. They just jump in the fridge these days. I was walking through the fridge this afternoon—”

“You were walking through the fridge eh?”

“BY!!! By the fridge! And this kiwi suddenly jumped up against me, and I was like, ‘dude wtf are you doing.’ The kiwi was really rude. It said: ‘fuck off, you ass, you’re blocking the road to the fridge.’ So I said ‘chill, kiwi.’ It replied, ‘yeah, that’s what I want to do, Einstein, but you’re keeping me from it.’ I wasn’t going to put up with that, so I said, ‘first apologize for your rudeness or I’ll just let you rot.’ Then it just kind of rolled over like it were one big, giant eye, shrugged — honestly, it did that! — and said, ‘sorry that I bumped into you but I really need to get into the fridge now.’ I opened up the fridge and said ‘alright, but no more shenanigans or I’ll drag you out of there if it’s the last thing I do.’ It jumped right in and let out a big sigh: ‘aaaaaaaaaaaaaaaaaaahhh.’ Then it pulled the fridge closed while muttering something about privacy. So yeah, that’s how kiwis are these days. No respect.”

She didn’t reply verbally, but she pulled… the face.

Lossless Rotation with jhead and jpegtrans

2011-04-24T08:33:50Z

I like my pictures rotated in such a way that I don’t have to depend on application support for them to be displayed correctly. jpegtran (pre-installed on most distros) is a wonderful application with many features, including lossless rotation, but it’s too laborious for my purposes. That’s where jhead comes in.

To install, use apt-get install jhead or sudo apt-get install jhead in Debian and derivatives, as always.

You can simply go into a directory, run a command like the following, and everything will be done automatically for you.

jhead -autorot *.JPG

Of course I wouldn’t run it if you don’t have a backup available. I always keep the pictures around on my camera until I’ve confirmed that all processing was successful and then I still don’t delete them until the adjusted files were also copied to my external HDD in my semi-regular backup regime.

Another utility that can perform the same task is exiftran, but despite being more or less dedicated to this very purpose it’s not even easier to use: I’d expect exiftran *.JPG to default to the equivalent of the jhead -autorot *.JPG command I posted above, but instead you have to use exiftran -ai *.JPG. All other things being equal for my purposes, I decided to go with jhead because it has many more features — although last year I decided that exiv2 is superior to jhead in ease of use for most of those features.

If you’re just looking for the occasional lossless rotation, you could also try the Geeqie image viewer and manager. It integrates calls to exiftran, but beware that you explicitly have to choose the lossless option, as there are also lossy rotate options.

Dolby Digital 5.1 Over S/PDIF With PulseAudio

2011-05-21T15:16:51Z

This post describes how I got Dolby Digital 5.1 output working over S/PDIF on my onboard Realtek chip with other audio sources mixed in. Previously I was only able to achieve either 5.1 output by sending the data stream straight to my receiver, or 2.0 output with everything mixed in. The experiences detailed in this post originate in Debian Squeeze, but if what I wrote is specific to anything, it should be my hardware — not Debian and its derivatives. Before you read on, you might want to check out this forum post instead, which describes a method that didn’t work out for me.

PulseAudio 0.9.22 is required; it won’t work on older versions of PulseAudio. Debian Squeeze comes with ALSA 1.0.23; presumably that’s much less significant. On Debian getting this most recent PulseAudio can be done through the experimental repository.

If you’re on Debian ALSA is already setup, including the required libasound2-plugins, but to get the most recent version of PulseAudio you’ll want to add deb http://ftp.debian.org/debian experimental main to /etc/apt/sources.list, and then type apt-get update && apt-get -t experimental install pulseaudio in a superuser terminal (see the Debian Wiki for more information on the experimental repository). On many other distributions PulseAudio is already setup by default, but just like on Debian Squeeze that’s typically still PulseAudio 0.9.21 at present.

On Ubuntu you’d have to recompile libasound2-plugins yourself because it doesn’t include the a52 ALSA plugin by default. The link in the opening paragraph should describe that process sufficiently.

In the System Log Viewer you can keep an eye on syslog for (error) messages from ALSA as well as PulseAudio.

What follows is my /etc/asound.conf, heavily condensed from Johannes Bauer’s Dolby Digital with Linux and ALSA guide. It works quite nicely (with some minor adjustments), but it will only allow one application to utilize audio at a time. One could utilize PulseAudio for stereo while suspending it (with pasuspender) when you want to play a movie or some such with 5.1 audio, but I’d rather mix everything together in PulseAudio so I don’t have to think about it after the initial setup, just like in Windows.

# Encode AC3 -> Directly on hardware
pcm.Filter_A52Encode {
	type a52
	bitrate 448
	channels 6
}
# Rate Converter to 48kHz, needed for some applications
pcm.a52 {
	type rate
	slave {
        	pcm "Filter_A52Encode"
        	rate 48000
	}
}
# Make last filter the default device
pcm.!default {
	type plug
	slave.pcm "a52"
}

Now that you’ve got the ALSA configuration in order it’s time to make some slight adjustments to /etc/pulse/default.pa or PA won’t detect the possibility for Digital Surround 5.1. According to various sources they had some kind of Digital Surround show up automatically, but I had to explicitly tell PulseAudio about its existence. Adjusted from a comment on Ubuntu bug 348353 (which incidentally is why you need PulseAudio 0.9.22).

load-module module-alsa-sink device=a52 rate=48000 channels=6 tsched=0 sink_properties=device.description=SPDIF sink_name=SPDIF channel_map=front-left,front-right,rear-left,rear-right,front-center,lfe

I initially added this line without the channel_map, but then PulseAudio thought I had something like front-left,front-left-of-center,front-center,front-right-of-center,front-right,lfe, which would be a strange setup indeed.

I’m not quite sure whether the channel map might be more appropriate in /etc/pulse/daemon.conf, where I uncommented default-sample-rate = 48000. I also added the appropriate settings for default-sample-channels = 6 and changed enable-lfe-remixing to yes.

pavucontrol is instrumental in quickly seeing what’s going on and for application-specific volume settings. Not utilizing it would be a disservice for yourself if you’ve chosen to use PulseAudio.

Now that we’ve got all the configuration set up you could reboot the computer, but one of the great things about Linux is that you rarely have to do that other than to load a different kernel.

As user: pulseaudio --kill
As superuser/sudo: /etc/init.d/alsa-utils restart
(As user: pulseaudio -D, but that shouldn’t be necessary)

I utilized the surround test ac3 file from Lynne Music (straight to directory). I played it with mplayer -channels 6 to make sure everything was working correctly and to adjust the channel map. At this point everything was finally working fine for me, but most applications still will not cooperating because they default to ALSA. Again, in Ubuntu this shouldn’t be an issue.

Various adjustments are still required in most applications. For instance, in Totem you have to explicitly set audio output to 5.1 in Edit > Preferences > Audio.
For MPlayer put channels=6 in ~/.mplayer/config (note that if you can’t get PulseAudio to work you could add the equivalents of mplayer -ao alsa:device=spdif -srate 48000 -ac hwac3 file.avi if you so desire).
VLC works fine if Dolby Surround is set to Auto in Tools > Preferences > Audio.

To get the 6 channel output to work in applications that use SDL (Gnash, quite a few games) you’ll need libsdl1.2debian-pulseaudio. This will replace libsdl1.2debian-alsa. Of course this won’t be necessary if your distro is set up with PA by default.

On a separate note, I set PulseAudio up so it can play audio from all kinds of sources (most notably my laptop).

Mouse Jail

2011-04-14T15:50:41Z

One of the applications I like to use on Windows is Mousenitor, which enables advanced mouse control for users with more than one monitor. It was written by a friend. I haven’t yet figured out the best way to trap my mouse on one monitor in Linux, but a little application named Jail offers a rudimentary implementation. It was originally written by Sebastian Marion, but I picked up a slightly modified version from the Ubuntu forums.

If you want to compile it yourself you need to grab apt-get install build-essential libx11-dev libxtst-dev in Debian (and presumably the same for derivatives like Ubuntu). For good order I also uploaded the source, including my compiled x64 binary, to my own server lest the original source code might be deleted. Download jail.tar.xz if you want to test it. Edit .JailSwitch.sh to correspond to your system.

The Gentoo Wiki possibly describes more elegant, but more involved methods to obtain a similar effect. I’ll report back if I can get one of those methods to work successfully, and if they do indeed work more elegantly.