Intrepid Blog » hack

Unicode to ASCII (1)

Bas Westerbaan — Fri, 19 Jun 2009 13:19:10 +0000

When I want to generate usernames from real names, which can contain non-ascii characters, you can’t simply ignore the unicode characters. For instance, danielle@blaat.org is the right e-mail address for Daniëlle, danille@blaat.org isn’t.

There’s trick. Unicode has got a single code for ë itself, but it has also got a code which (simplified) adds ¨ on top of the previous character. The unicode standard defines a normal form in which (at least) all such characters, which can be, are represented using such modifiers. If you then simply ignore the non-ascii representable codes, you’ll get the desired result.

In python: unicodedata.normalize('NFKD', txt).encode('ASCII', 'ignore').

However, this isn’t the right solution. For instance, in german, one prefers ue as a replacement of ü over u.

GStreamer: accurate duration

Bas Westerbaan — Sun, 19 Apr 2009 13:26:01 +0000

When decoding, for instance, a variable-bitrate MP3, gstreamer reported durations are, to say the least, estimates. I’ve tried to get a better result in a few ways. First off, some files yield a duration tag, but even if you’re lucky and it is there, there are no guaranties about precision. After that I tried seeking to the end (GST_SEEK_END) of the stream and querying the position, which gstreamer didn’t like. Finally, routing the audio into a fakesink, waiting for the end of stream and then querying for the position gives the right result. It’s not the prettiest method, but it works.

This is a Python script that prints the duration of a media to stdout.

Spacing up- and downarrow properly for up- and downsets

Bas Westerbaan — Tue, 24 Mar 2009 22:34:44 +0000

is ugly, but is nice! The solution: prefix \uparrow with \mathopen.

“waiting for x server to begin accepting connections”

Bas Westerbaan — Sun, 29 Jun 2008 17:19:58 +0000

Try DisallowTCP = false under [Security] in /etc/X11/Sessions/Gnome/custom.conf or similar for other window managers. Obviously this isn’t a very desirable solution, emerge --emptytree gnome might do the trick too.

(and obviously this might be just one of the many underlying causes for the very generic symptom of X not accepting connections)

Java crashing on xcb_xlib_unlock.

Bas Westerbaan — Mon, 17 Dec 2007 22:34:31 +0000

When Java applications crash on linux with xcb_xlib_unlock: Assertion `c->xlib.lock' failed you should upgrade to libxcb-1.1 and add LIBXCB_ALLOW_SLOPPY_LOCK=1 to the environment.