Duplo

Update: due to wide-spread changes in the MPD git repository, this patch no longer applies and builds correctly.  You can still play with the shout MP3 plugin by cloning my shiny-new git repository at: http://git.musicpd.org/encoded/mpd.git See the comments section below for information about configuration changes.  The plugin is currently on the roadmap for the 0.14.0 release, so keep your fingers crossed.

I’ve updated my patch so that it can be applied against the current MPD git repository.  Hopefully it will be rolled into MPD for the 0.14.0 release.  The patch has been improved to do better configuration-time checking for the lame library.  I also found a bug where I wasn’t setting the bit rate properly if constant bit rate was requeted.

I’m hoping to roll this out to Mildred soon.

Here’s the link:  0001-Creation-of-shout_mp3-audio-output-plugin.-Basicall.patch

MPD is a great little project that collects, organizes, and plays your music files for you.  You can connect to MPD and listen to your music in a great number of ways.  You can even stream your music out as your own radio station (Mildred makes use of this functionality).

I’ve always thought it odd that MPD would stream in Ogg, but not MP3.  Don’t get me wrong, I’m a big fan of open standards and all, but MP3 is just so dominant, that I was surprised MP3 streaming hadn’t been implemented.  Add to that the stupid inability of Apple’s iTunes to stream Ogg and well, it motivated me.  I sat down and hacked together a MPD plugin that allows you to stream MP3 to your shoutcast server from MPD.

Source patches for the plugin are available here:  http://kill-0.com/patches/shout_mp3.patch

It’s rough around the edges, but it does work.  You can even play it in iTunes.

Enjoy!

Voyeur is a very small bit of ruby code that I’ve written to display updates to your MPD stream via Growl.

You can find it here:  http://kill-0.com/voyeur/

You start and stop it as you would a daemon, ie $ ./voyeur start and ./voyeur stop. As an added bonus, you can send it a HUP signal, and it will immediately display the current track information or status. Here’s a screen shot:

I was having all sorts of problems upgrading Mildred to Rails 2.1.  A lot of the errors I was seeing were like the following:

ArgumentError in 'TracksController downloading a track by admin should not be a redirection'
wrong number of arguments (0 for 1)
/Users/ewollesen/src/mildred/app/models/track.rb:52:in `title'
/Users/ewollesen/src/mildred/app/models/track.rb:52:in `filename'
/Users/ewollesen/src/mildred/app/controllers/tracks_controller.rb:49:in `download'
./spec/controllers/tracks_controller_spec.rb:82:

It took me a good while to figure out what was going on. The error was strange because as far as I knew, title was a database attribute in the Album model, which was a descendant of ActiveRecord. There shouldn’t have been any arguments required. Indeed, firing up my debugger and running track.album.read_attribute(:title) returned the expected result of “Test Album 1″. I was very puzzled.

I realized that my title method was being overridden, but by what? I started feeding the title method random arguments in the hopes of learning something new. It wasn’t long before I got lucky:

(rdb:1) e track.album.title("x")
NoMethodError Exception: undefined method `content_tag' for #<Album:0x3d5bbfc>

That tipped me off as to what was overriding my title method. The content_for is part of a pattern I use to set a view’s title in the layout via a method called title in my ApplicationHelper. This made me think of how in Rspec 1.1.4, a Helper module is no longer included by default. I popped over to my application_helper_spec.rb and found something similar to this:

require File.dirname(__FILE__) + '/../spec_helper'

include ApplicationHelper

describe "ApplicationHelper" do

This needed to be changed to:

require File.dirname(__FILE__) + '/../spec_helper'

describe "ApplicationHelper" do

  include ApplicationHelper

Then all was well. Whew. Just to be sure I didn’t run into this sort of thing again, I went ahead and made sure that all of my other Helper specs followed this paradigm.

This is the second time I’ve run into an issue where RSpec had overridden some seemingly random method in some seemingly random object. I guess there’s a lot of magic in there that I don’t have my head wrapped around yet. I just wish it were easier to spot!