Tune out

I had grand plans for my Android game. Apart from actually completing it, I was going to fix bugs, and add sound and music.

But my enthusiasm evaporated as fast as it had arrived, and now that I have forgotten the password to my key, it looks even less likely I’ll release new versions.

I did get around to composing a tune for use somewhere in the game. Seeing as it almost certainly never find its way to the game, I may as well dump it here:

I lacked the patience to learn how LilyPond deals with "da capo al fine". Luckily it’s clear where it belongs; this is one of those A-A-B-A melodies.

Another problem was excessive whitespace in the generated PNG image. My older post must have used lilypond-book in its original incarnation, but that was back when I wrote raw icky HTML.

There must be some lilypond option to automatically crop the output, but I found manual labyrinthine. So instead, to produce the above image I ran something like:

$ lilypond --png foo.ly
$ convert -trim -border 8x8 -bordercolor white foo.png foo.png

Other formats: benlynn.ly benlynn.ps benlynn.pdf

Music Players and Game Consoles

Long ago, over a long period of time, I wore out my old MP3 player, a Cowon iAudio X5. First its battery life shortened dramatically. Then after severe mistreatment during a long flight, the headphone jack loosened and became very fussy. Only by pushing the plug in a certain way was I able to achieve stereo sound.

Its condition worsened over time, and the final nail in the coffin was hammered in when, in desperation, I opened it up hoping I could readjust the socket somehow. I wound up breaking a wire.

I could solder it back, but what's the use of bringing it back from the dead if it has a run-down battery and a messed-up audio jack? Besides, I now had a great excuse to shop.

I considered getting another product in the same family, such as the A2, but in the end I took a different direction. Two different directions in fact: I wound up buying two MP3 players to replace my old one.

First, some lessons learned:

• I often just pushed play, and didn't bother fiddling around with the controls. Instead I'd cram it into my pocket, and perform other tasks.
• The built-in battery was annoying, especially when traveling. I'd have to find adapters and/or transformers, or have a computer around. Not to mention carry a strange, easy-to-lose connector and a power cord.
• Its utility greatly decreased with its battery life.
• For some situations it was too big and unwieldy, while for others, such as when reading text files and playing movies, it was too small and unwieldy.

To address some of these concerns, I bought one of those small cheap MP3 player that is little more than a USB SD card reader. It's powered by a single AAA battery, and sports a tiny display and a few buttons. It's perfect for those times when I'm focused on something and want some background music. Instead of playlists, I treat SD cards like CDs, and swap in different cards when I want to change genres.

It's convenient to travel with, due to its low cost and small footprint. Furthermore, AAA batteries are readily available anywhere. As a bonus, it can function as a low-capacity USB thumb drive.

However, there are times when I want to read text files or watch movies on the go, and times when I absolutely must listen to that song right now. I also missed my iAudio's ability to play different music formats, and its ability to run the open source firmware Rockbox.

So on an impulse, I recently picked up a GP2X F-200. It does music and video of various formats, but what really piqued my interest was that it plays games and runs Linux. It has two 200MHZ ARM9 processors, which amuses me because only three desktops ago, my system was a Pentium 200. And in line with my new philosophy, it has an SD card slot and is runs on 2 AA batteries.

I still miss the 20 gigabyte hard drive, FM radio and recording capabilities of my X5, but the GP2X offers more possibilities.

Hello, GP2X F-200
Mainstream gamers no doubt prefer the well-known brands for a hand-held gaming platform, as they have a wide selection of new titles and probably have better build quality. But my priorities are different: I mostly wanted a replacement music and video player, and the GP2X appeals to me thanks to its geek cred.

There is a highly active GP2X development scene. It mostly revolves around simple homebrew games, ports of classics, and emulators, but there are a few commerical games, and some of the freeware offerings are amazingly good.

One such gem is Cave Story, which I found on the bundled CD. I'd never heard of this game before, though it's been available for other platforms for quite some time. As a programmer and amateur game developer, I'm green with envy that one person alone was able to create this marvel.

Soon after my unit arrived, I looked into how the development process works. I followed the Open2x installation instructions at the GP2X wiki (except I placed them in a different directory) but for touchscreen support, afterwards I installed the newest version of the SDL library found on Paeryn's page.

I then set about writing the obligatory "Hello World" program. It's not good enough to print to standard output, because nothing shows up. Instead, I wrote a full-blown SDL program that uses the SDL_ttf library to render a string. Additionally, I had to write a shell script to return to the main menu after the program exits (and also sync the SD card).

• hello2x.tar.bz2

Next I augmented the code to experiment with the touch screen, and the result is a simple drawing program. I'm disheartened by many spurious events, though I have a few ideas on how to clean them up. This must be done if I'm to get the most out of this feature.

• touch2x.tar.bz2

Green circles represent when the stylus was placed on the screen, and red circles represents when it was lifted, corresponding to SDL's MOUSEBUTTONDOWN and MOUSEBUTTONUP events. As can be seen, there are times when it thinks you've lifted the stylus when you haven't, and a fair amount of jitter, usually in the horizontal axis.

ALSA and MIDI

I switched to the ALSA driver from the OSS driver for my Creative Sound Blaster Live! card long ago, but I'm still not used to how MIDI is done. I'll record the relevant commands this time, so I won't have to look them up yet again.

Lately, I've had to manually load the snd_seq kernel module.

Programs I wrote that look at /dev/midi00 should now look at /dev/snd/midiC0D0. The behaviour of this device file differs too: I had to change my code so that it could handle a read() call that returned less than the requested number of bytes.

To play MIDI files on my digital piano, I run pmidi -p 16:0 foo.mid.

To send MIDI events to fluidsynth from my digital piano, I run fluidsynth 2> /dev/null (to get rid of spurious warnings), load a soundfont, then run aconnect 16:0 128:0.

Pi Music

I must have spent most of my life facing one keyboard or another. Over a year ago, while facing a musical kind, I was in a weird whimsical mood and I wrote a tune based on the digits of pi.

It did not surprise me when I discovered I was on a well-beaten path, as a search on Google quickly reveals. After all, many pi-inspired feats have been accomplished, such as setting Edgar Allen Poe's poem "The Raven" to the digits of pi. See also the honourable mention in this ray-tracing competition.

The pi music I found was quite abstract, whereas I want mine to sound more standard. I chose to have the digits 1-7 represent the tones of the C minor scale, altered if necessary, while 8 and 9 wrap around, that is, I encoded 8 and 1 the same way, as well as 9 and 2. Accordingly, I would have treated a 0 as a 7 but the tune ends just before reaching the first 0. (Thus 31 decimal places are encoded, this number fortunately corresponding with the first two digits of pi.)

This is akin to jianpu, a numbered musical notation system which I see in many Chinese books, but have never encountered in the Western world though supposedly it has seem some use in Europe. My scheme differs in that with jianpu, one would normally notate a minor key starting from 6, not 1.

It's a shame jianpu is not more widespread. It is well-suited for quickly and concisely jotting down simple melodies. A blank piece of paper suffices: there is no need to rule a music staff first. Writing numbers and dashes can be done extremely fast and most people are accustomed to this, unlike drawing geometric figures. More sloppiness is tolerated, as it is easier to identify scrawled digits and dashes than it is to figure out which line or space a hastily-scribbled note lies on, or whether a certain dot belongs to a note or was just a slip of then pen. Jianpu is also easy to learn due to its logic and simplicity. (Of course, jianpu performs terribly for even a slightly complex piece.)

(To be precise, jianpu-like notation is in fact employed in Western music. For example, when one writes "C6" to denote a chord, the "6" refers to the sixth note of the major scale.)

I added extra notes in order to produce a repeated motif typical of tunes. Following the digits exactly produces a melody that sounds a little too random for my tastes.

I chose conventional chord progressions. The A section uses a chromatically descending bassline, and the bridge mostly follows the cycle of fifths.

The time signature is 3/4, as this resembles 3.14 superficially. Also, in early (Western) musical notation, this time signature was represented with a circle.

I had intended to post it only once I had made some recordings (ideally after working on Bliss) but I have enough on my plate as it is. Maybe next Pi Day.

Anyway, it feels like an auspicious time to release it, as I happened to have recently released version 0.3.14 of the PBC library. And not too long ago Akira Haraguchi broke the world record after memorizing 100,000 digits of pi.

The lead sheets were created using Lilypond. The Lilypond website convincingly argues that their software automatically produces better sheet music than their major competitors, including commercial ones. It's also easy to integrate its output with HTML:

Incidently, around the same time I also penned a tune that loosely encodes a friend's name, but using a different method:

• Pi: pi.pdf [pi.ps] [pi.ly]
• For a friend: friend.pdf [friend.ps] [friend.ly]

Drums, Engines, Sudoku, Poker Chips, Dodecahedrons

Some links I don't want to forget:

1. Drumkit implemented in Flash
2. Animated Engines.
3. Sudoku at Number-Logic.com: I've lost a lot of time here recently. I only recently discovered these frustrating puzzles, but according to the Wikipedia entry on Sudoku, they've been around since 1979.
4. Poker chip tricks have also been eating up my time of late. Note there are different ways to do poker chips tricks.
5. 12-sided calendar: print and construct your very own dodecahedral calendar.