ContentedLife

No, it’s not really my DJing that’s script-powered, but over the last couple of years that I’ve been doing regular net radio shows, I have written a number of Perl scripts to help with some of the more tedious aspects of the job, particularly related to the posting of the MP3 archives and tracklists of those shows (and my occasional promo mixes) on quextal.com, but also for the broadcasting process itself.

In fact one of the first scripts I wrote was to assist with the fact that I broadcast (using darkice on my Linux box) on different stations, necessitating having multiple different configurations for darkice. What began as a one-liner to do the equivalent of darkice -c /path/to/darkice/configs/$1.cfg then expanded to do things like shut down certain daemons before broadcasting, and start them again afterwards, as my elderly PC would occasionally struggle to cope with the demands of running two MP3 encoders if it was also dealing with a large incoming mail or a disk-heavy cronjob.

I then tired of hitting reload on the server stats page to keep an eye on my listener count, so now I have a script which fetches that page every couple of minutes, parses the relevant number out of it, and shows it with a timestamp, so I have a full record of how many were tuned in at each point of the show, what the peak was etc.

Scripts followed to automate filling in the ID3 tag, and renaming darkice’s output spool name into a standard format prior to uploading it to the site.

quextal.com is a WordPress-based site with a heavily customised skin and a couple of extra plugins, nothing too fancy. After writing the first few posts by hand, I came up with a simple template-driven script which would simply wrap my plain-text tracklist of the show in some HTML to make it look a bit prettier for the site. This evolved so that it would read the metadata from the MP3 (eg filesize, bitrate, length in minutes and seconds) and put that info in there as well.

After a while I decided to have my online tracklists in table format rather than just reproducing what I write in plain text. So this meant adapting the script to split up each entry in the tracklist for the separate columns. I had the prescience to choose a roughly standardised format for my plain text tracklists anyway — at its simplest, it’s just “Artist – Title” or “Artist – Title – Label” — but over time it’s evolved a number of variations to deal with, for example, marking out who played which track when I have a guest in. I sensed it was time to create a separate library (Perl module) to parse tracklists into separate information, and a number of my scripts now use this.

Just this year I expanded the templating script into a more complex system which interfaces directly with the WordPress API. It determines which radio station the broadcast was on (which is in the filename), searches for some of my past mixes for that station on the site, and offers a selection of their post titles so I can choose one (eg with, or without, a guest DJ, as applicable) on which to base the default title for the new one, helping to keep the title format consistent. Both my current regular shows feature the number of the show in the title – the script will automatically increment this, be it in ordinary numerals or Roman numerals. Appropriate tags are chosen automatically, and any additional words for the article can be added before the script posts it directly to the site via the API.

Why stop there? Since my Tracklist library conveniently gives me information about the artists and labels played in each show, the script now also creates a Custom Field entry for each. I don’t really know why I’ve done that… just a vague sense that it might be useful at some point in the future. For now, a slight tweak at the WordPress end provides A-Z lists of artists and labels for each mix at the end of the article. At some point, if so desired, it should make it easier to search for all the mixes containing a specific artist or label…

Most recently, the thing I was finding particularly time-consuming was to fill in the label for each tune, which information I often don’t have handy during the show when I’m writing down the track. So now I have a couple of scripts to help with that. The first just looks for the “artist – title” string in all my previous tracklists and copies the label info from there if it finds it. The second, which is a work in progress, attempts to automate looking up the track details on the sites where I do most of my tune shopping, and screen-scraping the label from there.

Curiously, the net effect of all this automation has not really made it significantly quicker or easier to post a mix, compared to when I first started out and was doing it all by hand. What it has done is escalated the amount and quality of information I’m putting up, its consistency and reliability, while taking about the same amount of time and effort. Obviously that doesn’t include the effort required to write the scripts… but that’s not effort. That’s fun. It’s been a whole series of interesting little coding tasks… which of course is the main reason I did it.

I’ve become quite a fan of this sound device since I got it about a year ago.

For its price, the sound quality is excellent. It’s fairly packed with features, has a good range of options for input and output connectivity, plus MIDI. And it works flawlessly, out of the box, with Linux — no special setup or drivers required, ALSA knows what it is and how to deal with it in any mode.

The same is true of Mac OS, but only in the basic mode which restricts you to 16-bit 44.1kHz I/O – a driver is required for Advance mode to get up to 24-bit 96kHz support (either in, or out – we’ll come to this under Limitations). This driver can be downloaded free from the Edirol website, and seems to work fine on my new unibody Macbook Pro with OSX 10.6 Snow Leopard, though I haven’t used it extensively on there yet.

I guess it probably works in Windows too, but I wouldn’t know anything about that

The sound quality (for what I’ve used it for anyway) is very good. It’s stacked with features, and quite versatile… within certain limits.

First we’ll take a quick look at the features packed into this gadget, which is information you could probably find elsewhere but I include for ease of reference, and after that we’ll get to discussing those limitations in more detail.

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Unlike many webmail providers, Google don’t allow you to upload your folders from your old mail system in mbox format and import them. This is a pretty basic feature if you ask me, they really should.

There are a number of alternative ways. GMail does support fetching from other mail servers via POP3 (but not IMAP, another strange omission), so if your mail is all in your inbox at the old place that might work, but mine is organised into several folders, and I want to keep that organisation damnit!

Needless to say, someone has written a nice piece of software to do the job; in this case Mark Lyon’s GML. I was about to give this a whirl, but while I was waiting for the requisite Python lib to install, I found a much simpler way… click to read on…

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Updated: 2007/07/27 – New section on LEDs. Update on mixxx SVN.

In case any of you who have read my review of the M-Audio Xponent are thinking of getting one and wondering “but will it work under Linux?”, the short answer is a resounding Yes!… except for the LEDs, so far. More on that later.

I use Debian unstable with a hand-rolled kernel. YMMV, of course, but the chances are that if you’re using any modern distro you’ll be fine. In fact you may not even have to manually insert the kernel modules if you have a working udev setup, you might just be able to plug’n'play.

Full details below the cut, as they say…

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I’ve been using BackupPC to take offsite backups of all my machines over the network for over a year. It seemed to work well enough and, it seemed, would always email me if it hadn’t been able to backup a certain machine for a few days.

Yesterday I discovered that it has not done a successful backup of one of my machines since March! I just suddenly noticed on the status screen that instead of a table of 8 backups (2 full and 6 incr), only 3 were shown — 2 full, both dating back to March, and 1 “partial” from the day before yesterday. Looking at the logs I see this:


2006-07-24 06:00:05 full backup started for directory /data/work; updating partial 678
2006-07-24 06:20:28 full backup started for directory /home; updating partial 678
2006-07-24 06:20:34 Got fatal error during xfer (fileListReceive failed)
2006-07-24 06:20:39 Backup aborted (fileListReceive failed)
2006-07-24 06:20:39 Saved partial dump 678


Exactly the same thing has been happening every day for the past 4 months. Backuppc didn’t email to tell me. It’s email system was definitely working because during that time it did mail me about a machine that was offline for a while. So it appears it doesn’t bother to send mail to notify you of a failed backup!

I had no idea what might be causing this. It just started out of the blue, having worked flawlessly before March. It only affected one machine. The configuration had not changed. It always failed on /home but was apparently ok with /data/work.

Something weird in /home? To find out, I set tar loose on it:

$ cd /home; tar cf - . >/dev/null
tar: ./jammin/.gxine/socket: socket ignored
tar: ./jammin/.kde/kdeinit-\:0: socket ignored
tar: ./sarah/.totem.sarah: socket ignored
tar: ./sarah/.xine/session.0: socket ignored
$

Surely not. Surely it couldn’t be something as trivial as a couple of stale socket files causing my backup to fail? Well, I’m not using any of those programs, so I deleted the sockets, and told backuppc to start a full backup. What do you know — it worked.

So is it that it doesn’t like sockets? Or has the poor thing got confused by the funny characters in the filename of that KDE one? I’ll test this out at a later date when my backups have recovered.

There are three major failings by BackupPC here. One, failing over a simple socket or dodgy filename, and not giving much clue why. The second, not bothering to email when a backup fails halfway through. But most concerning of all is that it kept trying to add to the same partial backup, instead of starting a new one — so I no longer have 2 weeks’ worth of incrementals even for the part of the backup that succeeded. Every day, yesterday’s backup was being overwritten by today’s. If I needed to recover a version of a file in /data/work from 2 days ago, I couldn’t. That sucks.

This has made me realise something. Quis custodiet ipsos custodes?. Why am I relying on *one* backup solution? It’s a SPOF, and it has quite spectacularly F’d. I still want to find out why, and ideally fix it, but I’m also going to start setting up something else alongside. Since backuppc is server-driven, the alternative should be client-driven. All recommendations welcome. The two major requirements are that it must support ssh, and be bandwidth-efficient because I’m backing up over ADSL.
All the client machines run Linux.

I just had a very strange experience. I hooked up my new Sony Ericsson K750i mobile phone via USB to my PC (running Linux 2.6.11 Debian unstable). And it just worked. I didn’t have to faff around with the USB driver as I’d had to for my Treo 600 a year ago. It just thought for a while, dumped several KB of its thoughts into syslog (I probably selected a debugging option when I built the kernel), and *ping* the memory stick in the phone appeared as /dev/sda. I just had to mount /dev/sda1 (vfat), and there it was.

Almost disappointing.

The phone is very nice, btw. Screen is good, mp3 playback is very good (even with the supplied earbuds — even through the speaker is not bad), camera is alright (for a phone). Organiser is rubbish: you can’t set up events without a time, or recurring events like birthdays, and the bold font used to identify dates with appointments in calendar view is barely different from the normal font. Sometimes I think I should just go back to a paper diary…