Re: [Rhythmbox-devel] Gapless/crossfade playback in svn trunk

["Christophe Dehais" <christophe dehais gmail com>]

On 4/1/07, Jonathan Matthew <jonathan kaolin wh9 net> wrote:
> On Sat, Mar 31, 2007 at 01:53:02PM +0200, Christophe Dehais wrote:
> > Hello,
> >
> > Just tested the new backend, here is some feedback:
> >
> > * I experience lag (about 1sec) in skip / go back / play / pause actions
>
> This is a known problem that I'm not sure I'll be able to fix entirely.
>
> > * Position slider behavior is not as reliable as in the standard
> > backend: sometimes it doesn't show the actual position, and when
> > crossfade is activated the end of the song is hardly reacheable
> > (because it has jsut skipped to the next song)
>
> If you could clarify when it doesn't show the actual position, how badly
> it gets it wrong, etc., that would be helpful.  The way the crossfading
> player backend does position queries tends to show up bugs in GStreamer
> plugins that just using playbin doesn't (it sometimes ends up querying
> decoders rather than sinks), so it's possible that problems with the
> song position will be media type specific.
>
> We probably need to do something more intelligent with regard to track
> changes while the user is moving the position slider.

Well again, I talked a bit quickly. The problem is most significant
with networked tracks (daap, network share). With local tracks, there
is a little back-and-forth motion but it's merely noticeable.

A video is worth thousand words:
http://kris.dehais.free.fr/gapless-backend/out.ogg
The network buffer is 1024kb and crossfade duration is 6 seconds. A
smaller buffer size doesn't improve the behavior.

In earlier version of RB, there was this inacurrate seeking behavior
with remotely served tracks. And then it was solved, starting with
version I don't remember exactly (around 9.4 / 9.6 ?).


> > * it crashes when playing mpc files : Rhythmbox-ERROR **: file
> > rb-player-gst-xfade.c: line 2088 (preroll_stream): assertion failed:
> > (stream->src_blocked)
> > aborting...
>
> Bug #424734; if you can reliably reproduce this, attaching gstreamer
> debug output (GST_DEBUG=*:4) to the bug would be most helpful.  I
> suspect this is a bug in the musepack decoder plugin.

Ok I commented  on bug #424734. Not handling mpc files is a problem
with my gstreamer installation (It does since I recently updated to
gstreamer CVS), but with the standard backend RB warns whereas here it
crashes.


Christophe