Starting Encoding Profiles

Two weeks without reporting, but here I am. I spent this time with implementing the proposed interface, which I did all in glade format and I can easily edit it. Also, the project is detecting format - oh, I spent some hours implementing my own pipeline with decodebin to get info from files in the input and just later I found gst.extend.discoverer... ok, now I have more experience with pipelines, and I'm working in the xml format - I really don't know for now how can I represent the pipelines for themselves, as they need some processing power. For an example, to encode to mp3 I can use id3mux or id3v2mux, but to choose one I need to tell to try each. I saw the method of Banshee, using S-expression, is very useful but I would like to use only XML, just not sure exactly how.

A way that I was thinking is like:
<element id="audioconvert" type="required">
<element id="lame" type="required">
<property id="bitrate" type="optional">
<property id="vbr" type="">
<if expression="vbr!=0"> <!-- vbr!=0 need to use html encoded chars -->
<property>
</property>
</if>
<if expression="vbr != 0">
<element id="xingmux" type="optional">
<element id="id3v2mux" type="optional">
<else>
<if expression="exist(id3v2mux)">
<element id="id3v2mux" type="optional">
<elif expression="exist(id3mux)">
<element id="id3mux type=">
</element>
</elif>

Suggestions?

update: I corrected the XML code which was not appearing.

Encoding Profiles

Reporting my GSoC work, last week I worked in the encoding profiles idea (http://gstreamer.freedesktop.org/wiki/EncodingProfiles), deriving it from Banshee's Audio Profile, which is a very nice profile system for transcoding audio files. I'm putting at my project wiki all issues that I'm having to create an example XML of this generalized media profile, which supports video, audio and, why not, images later. With this profile I hope to ease user creation of any kind of transcode operation, according to its need or to an application need.

I'm also comparing some transcoder applications at my project wiki too. If you know any other open source application that I didn't cited at wiki, please just leave a comment there to I analyze it and check if I can get anything to help me on my project!

Now this week I'll delay Encoding Profiles to do, as a Stefan's suggestion, a python script to dump possible configurations for codecs and themselves from registry, so any example script that does something like this is welcome too!