Re: Introducing Muine, Rhythmbox in 2.8 and other things

[Jorn Baayen <jbaayen gnome org>]

On Sat, 2004-05-08 at 15:35 +0100, Gustavo J. A. M. Carneiro wrote:
> A Sex, 2004-05-07 ās 22:10, Ronald Bultje escreveu:
> 
> > "Changing streams is relatively slow, it usually takes ~ 1 second, whereas
> > this is more or less instant using xine-lib. This has a major impact on
> > the user experience."
> > 
> > If you want to know a possible way to fix this: you would basically need
> > to "queue up" the next/previous song to prevent this. The GStreamer model
> > focusses on playback of a single media stream. Playlists are basically on
> > the border of GStreamer's core scope, probably right outside it. Queueing
> > up means that you already create a pipeline element (or whatever
> > descendant of that you use in Muine) of another song, if possible with a
> > queue between the decoder (or the autoplugger) and the audio sink element.
> > Set the left part (before the queue) to playing, and possibly wait for the
> > 'full' signal on the queue. Then set back to pause (saves CPU cycles). Set
> > back to playing if you change songs. Now, the transition will be instant.
> > 
> > It probably sounds hackish. Sorry for that. I don't think there's an easy
> > solution. Autoplugging just isn't fast enough yet... :-(.
> 
>   How about just keeping the same pipeline, and merely changing the
> location attribute of the vfs source element?
> 
>   OK, I realize this will fail if one changes from a mp3 to vorbis
> file.  So instead of this, we would keep a set of cached pipelines, one
> for each MIME type encountered so far, and simply switch pipeline and
> file location as needed.  It probably isn't as instantaneous/smooth as
> xmms with cross-fading plugin, but should be a lot faster than 1 second.
>   Well, I really know very little of GStreamer programming, so forgive
> any technical errors.

Exchanging decoder elements would be a bit better than this, and it's
actually what we used to do in Muine - worked pretty well. We stopped
doing that when we made the switch to using GstPlay. This brings me to
an idea for GstPlay- what about being able to pass along a mime type
hint (as Muine could easily cache mime types)? 


Jorn