[Rhythmbox-devel] rhythmdb.xml standards / registry

[Alice Wonder <alicewonder shastaherps org>]

Hello list,

I hope this list is the right one.

I am currently considering writing a plugin to meet a need I have that
it appears rhythmbox does not currently have a solution for. Podcasts
where I do not want to subscribe to the feed.

The reason I don't want the feed, I don't want every episode in the
podcast but it can be difficult to tell the topic of the podcast from
the feed. Sometimes the title is descriptive but often it is not. I
prefer to manually download the ones I want based upon the blog or web
page.

Additionally sometimes episodes are poorly encoded and sound extremely
distorted via fluendo mp3 decoder. In those cases I often can fix it by
decoding it with lame (resulting in a bunch of complaints but a wav file
that sound decent) and re-encoding it.

Additionally sometimes the volume is just way too low and I want to
normalize the audio before listening to it so that I don't have to futz
with the volume control.

The solution I came up with - when tagging with xiph comments, the
following three comments:

PODCAST=The Name of the Podcast
EPISODE=57
PODCAST_RSS=http://example.net/feed.rss

The latter two are optional. EPISODE should be a non-negative integer
*except* for an addendum that corrects a factual mistake. e.g. if the
podcaster made a factual mistake in above episode 57, a correction could
be pushed as EPISODE=57a

EPISODE=0 is same as no EPISODE and used for things like an audio
description.

For ID3v2 the first two tags could be TXXX frames and the third a WXXX
frame.

-=-

The plugin - when Rhythmbox imports an audio with non-empty PODCAST tag,
it does not show up in the main music pane but rather in a new pane
similar to the current Podcast pane but obviously called something else
(e.g. OCDcast ;) so they don't end up in random playlists, etc.

That pane will allow sorting by PODCAST title and EPISODE within the
podcast. And if the audio files defines a PODCAST_RSS should allow the
user to optionally subscribe to it, adding the podcast to the existing
Podcast plugin.

For those three tags to mean anything to Rhythmbox they need to be
recorded in the rhythmdb.xml file upon import.

Will this require defining a new type attribute for entry nodes? Looking
at my own rhythmdb.xml file I see type="podcast-feed" and I see
type="song"

I'm guessing the easiest way to have these audio files not show up in my
music is to use a new type, is there some kind of a registry that can be
used to avoid conflicts? I'd like to just type="podcast" but if that
would interfere with something already using that type, I should pick
something else.

Within the entry node itself, I'm hoping I can use a podcast node for
the value of the PODCAST xiph comment, an episode node for the value of
the EPISODE comment, and an rss node for the value of the PODCAST_RSS
comment.

Again is there a registry for this? I see that the main rhythmdb node
has a version attribute. If I can get away without needing to use an
xmlns:namespace that would be preferable. But by get away, I mean not
break a standard.

Thanks for any suggestions.

Oh and the reason I don't want to use tracknumber for episode is because
I have seen podcasts where a series within the podcast uses an album
name for each episode in the specific series and then uses tracknumber
to indicate which number in the series the audio corresponds with.
Keeping episode separate from tracknumber and the podcast name separate
from album name keeps that freedom.

Thanks,

Alice Wonder