Tim Hatch

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Playing Back Letterbox as Widescreen in OSX-X 28 Feb, 2006

I have always been annoyed at how letterbox content displays on my widescreen PowerBook (aka SlowBook Pro), with black borders on all four sides. I was playing back some clips last night, to include Fear of Girls and got frustrated enough that I looked it up. Here's what to do to play back Google Videos with their proper zoom, using FoG as the guinea pig:

# cd ~/Movies
# wget http://tinyurl.com/dgfey -O FearofGirls.flv
# /Applications/mplayer FearofGirls.flv -vf crop=320:180

Yes, that's deceptively simple. The mplayer binary is from mplayerosx on SourceForge (missing most of the gui, but fullscreen and +/- for audio sync work as advertised).

That tinyurl simply points to the url you can find in the source of a Google Video page (look for the string vp.video or use the google video link decoder). In this case, the expanded version is:


Python Compile-time Optimization 27 Feb, 2006

I was asked earlier today if Python did any sort of compile-time optimizations, and the only ones I could think of were strings concatenated without an addition operator. Making sure this is correct, I fired up the interpreter:

>>> from dis import dis
>>> dis(lambda: 'a' 'b')
  1           0 LOAD_CONST               1 ('ab')
              3 RETURN_VALUE
>>> dis(lambda: 'a' + 'b')
  1           0 LOAD_CONST               1 ('a')
              3 LOAD_CONST               2 ('b')
              6 BINARY_ADD
              7 RETURN_VALUE

The most important thing to get out of this is that chr(0) is not equivalent to "\0", even though they are functionally identical. You need to optimize things like this yourself.

>>> dis(lambda: chr(0))
  1           0 LOAD_GLOBAL              0 (chr)
              3 LOAD_CONST               1 (0)
              6 CALL_FUNCTION            1
              9 RETURN_VALUE        
>>> dis(lambda: "\0")
  1           0 LOAD_CONST               1 ('\x00')
              3 RETURN_VALUE        
>>> chr(0)
>>> "\0"

Link: Yet Another Image Replacement Technique 27 Feb, 2006

Everybody seems to have come up with their own image replacement technique for css, but this one at least seems simple. img Image Replacement via someplace I forget.

Project Euler 27 Feb, 2006

There's a website (gasp) that has posted a number of interesting-to-me math-related programming problems (wow, that's a mouthful). Most of them are solvable in your choice of language, though flexible languages may make it easier. My favorite that I've tried so far: #25. “What is the first term in the Fibonacci sequence to contain 1000-digits?

Project Euler, via some python thing.

Link: Aargh. 27 Feb, 2006

Aargh likelihood based on Google results for various powers of 'a' and 'r'. Via jwz. Yeah, some of you know I’ve been sitting on this one for a while.

Link: Vader Theme Remixed 27 Feb, 2006

Heavy Ammunition Project’s Vader Theme Remixed. Via jwz.

Link: Microsoft iPod 27 Feb, 2006

This is the first of several links I’m posting tonight. What if Microsoft Redesigned the iPod Box. Via photomatt.

In da Hood 27 Feb, 2006

I'm just back from chem lab.

“We need some ice. Where's the ice?”
“In the trashcan. And not in the figuritive sense that Shakespeare would have meant, had he said that. In the literal trashcan over there, on the floor.”
“When you need the chemicals, they're over there, in da hood.”

Dear Lazyweb 26 Feb, 2006

How does one get utf-8 working in PERL and Subversion on OSX-X?

I've had some interesting results with trying to get Unicode working consistently on my Mac. Python is the only app that uses locale that seems to like the language string en_US.utf-8. Others, to include PERL, PHP, and Subversion all warn "falling back to 'C' locale." I initially thought most things would support utf-8 but ended up making wrappers for those programs to temporarily set $LANG.

I've tried regenerating certain locales as described in the utf-8 howto, but I think this had issues resolving fink's /sw/ prefix and wrote the files in the wrong location.

A class after mine 26 Feb, 2006

I have a chemistry class at 8 in the morning, three days a week. Directly after this class ia a TAMS class. I know this because their discussions range mostly involve Linux topics like “Did you get DRI working last night?”

PHP sqlwrap for psuedo-bound parameters 20 Feb, 2006

If only PHP had iterators, and exceptions backported to php4, the world would be a better place. At least that’s what I tell myself. I use a couple of wrappers to make things more palatable, although they’re, in a sense, leaky abstractions.

function sqlwrap() {
    $params = func_get_args();
    $q = array_shift($params);
    array_walk($params, 'esc');
    $query = vsprintf($q, $params);
    return $query;

function esc(&$s) {
        $s = "'".addslashes($s)."'";

This allows you to pretend you’re binding parameters, ala:

$qh = mysql_query(sqlwrap(
    "SELECT * FROM somedb
     WHERE username=%s or userage>%d", "bob", 23))
    or die("Query Error");

While this does not seem immediately productive to some, imagine that magic_quotes_gpc are disabled (as they ought to be!), this pushes the escaping function over to the database layer by saying “this is a string, deal with it.” One peeve I have about PHP (which I promptly fix via php.ini) is that magic_quotes_gpc affects all data, assuming that they go straight to the database and not to the screen, like, ever. You can safely pass things straight from $_REQUEST into the second parameter and beyond of sqlwrap, it handles escaping for you.

If you need to put literal in there that shouldn’t be escaped, then put them directly into the query string before passing it to sqlwrap. In this way, the abstraction is not terribly leaky, and you retain control over things when you need it. I haven’t included support for LIKE queries’ escaping, that’s something that really ought to have a human touch to deal with correctly. (Strip ‘%’ and ‘?’ from params, then use sqlwrap on the resulting sanitized string.) In this way, you get all the benefits of bound parameters, except speed.

What Makes PHP Popular 20 Feb, 2006

There has been a bit of discussion about whether PHP is “good” per se, and I think this post just about sums it up:

PHP can be used or abused, just like perl. The abuse is what makes it popular :)

PHP Everywhere

On Bashing PHP 20 Feb, 2006

Wow, there has been an awful lot of response to this post, requiring substantial updates, so I went ahead and redid the whole post to incorporate them. I wasn’t aware that this would be automagically linked from the referenced post, and was not expecting so many rude comments. Let me please note that if you have snide remarks, my email is tim@timhatch.com. Unsigned comments will not be published, period.

Overall, my experience is not that php is great or not great, simply that it is both efficient and adequate for what it is billed as: a hypertext preprocessor. As long as you don’t expect organizational miracles to come from its use, it’s not bad. Expecially when coupled with something like Apache’s mod_rewrite.

Tim Bray previously posted an article “On PHP” which summed up my basic opinions on the issue as well. PHP is easy to use. PHP is better that some alternatives (see Perl) in terms of understanding what something was supposed to do, although it’s not terribly good in being able to reuse it.

PHP is not designed around modules. It has no real concept of namespaces, although you can use classmethods as kind of a hack around this. Even then, you ought to keep a singleton around (in the global namespace) if you intend to keep around faux-module-level variables. This is something that IMO Python has gotten right very early on. Simply set $PYTHONPATH before running the script or modify sys.path while running, and that’s where it will start looking for packages. This makes it very easy to set up development environments, whereas PHP requires a modification to the systemwide php.ini in order to alter the include paths.

In one comment, unsigned and thus not published, someone mentioned the ability to use php_value in .htaccess files. This is a workaround for include paths, but doesn’t work when run from the console.

I claimed that there was no acceptable PHP debugger, and was subsequently pointed to three, one of which looks like it would work nicely. Although not on NetWare, because nothing works on NetWare.

I claimed that Perl’s DBI and Python’s PyDBO de facto standard database layers were better than PHP’s, mainly because a good one doesn’t exist for php. One person pointed me to PDO, "included in PHP5.1," and another mentioned ADODB. ADODB does not behave on NetWare, and seems to be finicky on other OSes. When I code, it’s simultaneously for Win32-Apache2.0-PHP4, MacOSX-Apache1.3-PHP4, GentooLinux-Apache2.0-PHP4, DebianLinux-Apache1.3-PHP4, and RollYourOwnLinux-Apache2.0-PHP5CGI (from source). ADODB is used by a number of projects, including Gallery, which is the slowest php webapp I’ve ever used.

Exceptions are nice in PHP5, as would be PDO, but as you can see from the previous list, my supported platforms are (for the most part) PHP4. This is why I’ve ended up writing a lot of wrappers myself, to avoid writing ugly code over and over (instead writing it once, then not having to look at it again).

Will I continue to use PHP in my everyday life? Yes, I certainly will. Why? Because I can get things done in it. In the short term, I think that’s what matters.

Disk Inventory X 20 Feb, 2006

Disk Inventory X (Filelight for OSX, on steroids) via Mark Looks at Neat Stuff

RSS Enclosures Length 20 Feb, 2006

After some interest was revived in my feeds, I checked into adding enclosures, even though my current reader (NetNewsWire Lite) doesn’t use them. One thing I am stuck on is that I’m sure I saw somewhere online that used length="", and I can’t find whether that is incorrect or not. The spec says that it’s required but not whether it must contain useful data. If I’m linking to an image on another server, I suppose I could just grab it once and check the size. (hmm, if I’m doing that, how about an md5 attribute on the enclosure element?)

Brokeback to the Future 18 Feb, 2006

Brokeback to the Future trailer mashup. Via Ned Bachelder.

Up With Cavemen 17 Feb, 2006

This ad from Geico came out in the student paper here (NT Daily) earlier this week. I haven't found a good scan online so I'm posting it too.


The reverse side of the flyer is a regular ad.

Random Slashdot Wisdom 16 Feb, 2006

I usually print it out and staple it to a squirrel. Then I set the squirrel free, because information wants to be free, and so do squirrels with paper stapled to them.

Kothan, on storing previously-written code

MySQL on OS-X 14 Feb, 2006

I began installing MySQL on my laptop today to better facilitate making a real backend for my website that can handle more than the ~160 posts I have now (I never thought I would keep it even this long), and found a couple of nifty hints for getting things working on OS-X with minimal headache.

  • The packages from MySQL AB work quite well.
  • If you have sql complaining about the mysql version, just downgrade the passwords:

For those of you trying to use MySQL with PHP, the way they have you set the password here doesn't work. The solution can be found later in the document, but it seems appropriate to add it here because it can save some heartache later on. If you have PHP 4 or older, and MySQL 4.1 or newer, you have to use 16-bin encription, as PHP 4 does not support mysql at 32-bit.

After some digging it turns out the fix is EASY. Just use OLD_PASSWORD('yourpasswordhere') instead of PASSWORD('yourpasswordhere')

MySQL 5.0 Reference: Securing Initial Accounts

Now I just need to get some sort of mysqlsync command (like rsync but for sql). That's a project for another day

No Air Banding 13 Feb, 2006

So, I was watching Scrubs last week and thought this was so hilarious I wanted to print out a copy for myself. Sadly though, a Google search for "No Air Banding" didn't come up with any hits (sad face).

This has now been remedied.
No Air Banding

Update: If you're interested in printing it out, here's a pdf with the paths as vector art.

Apparently chemistry does not involve hazardous fluids 09 Feb, 2006

I’m in a general chemistry class this semester at UNT, and all the students in the lab needed to buy safety glasses. The ones sold by the chemistry fraternity, and condoned for use by the chemistry department contain the following disclaimer:

It will not provide protection against sever impact hazards or hazardous fluids.

Just thought that was worth mentioning.

Subliminal Spam Messages 09 Feb, 2006

Indeed, umbrella defined by short order cook ignore abstraction of power drill.And go deep sea fishing with the dark side of her cashier.buzzard boogie bonbon from.

Making Perl "Less Bad," Part 3 08 Feb, 2006

Yep, I'm still working on Perl. Here's a few pointers that had nontrivial solutions:

  • IO::Socket::SSL for Windows. Just run ppm install url-to-ppd to install from here. Also required the rather oddly named Net_SSLeay.pm.ppd.
  • Python to Perl and PHP to Perl guides, lacking a few things that I found helpful. strlen($s) in PHP is length($s) in Perl. sub x ($$;$) {} creates a sub that has two required parameters and one optional one, and sub x ($\@) {} is how you make a "one or more parameters is required" prototype.

Link: Fear of Girls 07 Feb, 2006

Neat little video about tabletop gamers. I can't believe I found this before K8. Via Dana Myers

PERL: Peculiar and Arbitrary 07 Feb, 2006

Shouldn't listjoin { $a + $b } be illegal? It should be, because $a and $b are global variables, and the purpose of strict 'vars' is to forbid the use of unqualified global variables.

But actually, there's no problem here, because strict 'vars' makes a special exception for $a and $b. These two names, and no others, are exempt from strict 'vars', because if they weren't, sort wouldn't work either, for exactly the same reason. We're taking advantage of that here by giving listjoin the same kind of syntax. It's a peculiar and arbitrary exception, but one that we're happy to take advantage of. (emphasis mine)

Seven Useful Uses of local

Nikon Raw mode on the CP995 02 Feb, 2006

CP995 has a raw mode, but it's not that great, and requires tricking the camera into thinking it's back for service. Photos remaining are shown wrong, and it's really slow, and doesn't automatically do whitebalance correction. What more could you ask for, really?

Anyway, the reason I'm posting this is to collect a number of steps into one reasonably coherent post in case I ever find the time to experiment with it again.

First off, you need cpixraw (run as administrator) to enable the mode in the camera. From then on, whenever you take a photo (even with Basic quality!), another .JPG file will be saved. This contains the raw data, however there aren't many tools to read it. You need raw2nef, dcraw, and netpbm to make tiffs out of them.

mkdir tif; for f in *.JPG; do
    raw2nef $f;
    dcraw -w -t 5 -c -4 `echo $f| sed -e 's/.JPG/.nef/'` | \
    pnmtotiff > tif/`echo $f | sed -e 's/.JPG/.tif/'`;