Thursday 10th June 2010 - Weekly Report 03

[David Williams <redache googlemail com>]

Hi Everyone,

Here's my third weekly report which you can find at [0] as well as below.

This week I’ve been toying with the Source Element and have managed to
get it working correctly (finally!) and I’ve also started working on
search and replace on the model and tidying things up. I haven’t done
as much as I’d like this week but it took a while to realise how
simple the solution to the Source Element issue was (a len() fixed
it). Sometimes it’s hard to see the simplest things. I’m also getting
a strange bug with the Bus messages that causes the pipeline to crash
if I have it listen for error messages, I haven’t debugged the
GStreamer pipeline yet, but I bet that there is something throwing an
error that isn’t fatal or noticeable. I want to get the Source Element
perfect because it’ll be relied on to work every time someone clicks
play in the Score Editor.

The Test GUI works quite well, although changing the key/time sig
doesn’t work after the initial selection, which is what I’ll be doing
to test my search and replace and why I’ve started working on it. I’ve
been pushing every so often to my Jokosher branch on Launchpad. Once I
have search and replace working correctly I’ll begin work on modifying
Jokoshers current GUI with a GTK Notebook, which will be the
foundation of the Score Viewer.

If you want to run the code in the branch you need to do the following:

- Grab the MusicXML2Midi plugin from Elleo’s blog.
- Branch the source from Launchpad
- Navigate to the Score Editor folder (which if you branched in your
home directory would be
~/MusicXMLEditor/jokosher/Jokosher/ScoreEditor)
- Run PlayMusicXML.py. This is the GUI that connects everything
together (Excuse the poorly commented code for that file).

You should see the following:

http://redache.files.wordpress.com/2010/06/xmledit.png

It’s not the prettiest thing in the world but it does its job as well
as you'd hope.

A couple of caveats:

1. Pressing play without saving something first will lead to Gstreamer
dying and the program will have to be restarted if you want sound.
2. Changing the Key/Time Signature won't work after the first time as
there's no functionality to do that yet.

I'll also update the live.gnome.org wiki with the build instructions.

[0] - http://redache.wordpress.com/2010/06/10/weekly-report-no-3-feel-the-source/

Thanks for reading,

David Williams,
Extending Jokosher with a Musical Notation Editor.