Re: [Banshee-devel-list] GStreamer Equalization support

[Aaron Bockover <abockover novell com>]

Hey Alexander, Ivan,

First, "great work" to both of you - it's good to see some folks can
dedicate some time to this.

Since there is now again active work on this, I would like to step in
and more actively monitor your progress and provide feedback where I
may. You guys are certainly doing well and on the right track, so my
only real goal will be to facilitate getting the highest quality work
into trunk as soon as possible.

That said, I'd like this discussion to take place directly on the bug so
history is best preserved and thoughts are not lost. Ivan, would you
please move your comments here to the bug?

Thanks!

--Aaron


On Wed, 2007-04-25 at 13:28 +0100, Ivan N. Zlatev wrote:
> On 4/25/07, hixon alexander mediati org <hixon alexander mediati org> wrote:
> > I actually started a bit of hacking on the equalizer component a few
> > weeks back (see attached patch on
> > http://bugzilla.gnome.org/show_bug.cgi?id=426562).
> >
> Cool I am not alone out there. A few comments on your patch to follow.
> 
> * EqualizerSupported and EqualizerBandCount
> 
> When I was initially hacking on the equalization abock said he would
> like to have as an optional interface that a MediaEngine can
> implement, so IEqualizer was born (and if it is not implemented there
> is no equalization support).
> 
> * nband-equalizer
> 
> > My GStreamer code is fairly messy, and your implementation is much,
> > much cleaner. However, I would have liked to see equalizer-nbands,
> > rather than equalizer-10bands, since it may be possible later to have
> > equalizers with an adjustable number of frequency bands.
> > g_object_set(G_OBJECT(engine->equalizer), "num-bands", 10, NULL); can
> > be used to emulate the current implementation.
> >
> 
> Initially I implemented the equalizer support for my Xine media engine
> and for Helix. They both have different number of bands and different
> ranges of gains. So it was decided to have a fixed 10 band equalizer
> with fixed frequencies and all the media engines should adapt to that.
> 
> * Preference Loading
> 
> > My code also has the added functionality to load preset values from
> > the last session, enable/disable the equalizer, as well as hiding the
> > menu item depending on if the GStreamer element can be found.
> >
> 
> My personal opinion is that EqualizerView and EqualizerPresetComboBox
> (and everything in the Equalizer.GUI namespace) are purely UI
> controls, so they should not have the preference loading logic or any
> other logic. All the logic should be in EqualizerManager.
> 
> > Hopefully the best bits of both patches can be merged, and then
> > possibly work on the preamp started.
> 
> If you are okay with it, you can merge the following with my patch and
> we can continue discussing any further issues:
> 
>   * fill in the amplifier related methods in gst-playback with the amp code
>   * schema modifications
> 
> Regards.
> 
> P.S: There is a bug GstChildProxy, which yesterday was fixed in CVS. I
> haven't yet tried if the equ works now (I don't have CVS of
> gstreamer). I think i might have to change the code to pass gdouble
> instead of a GValue as well.
>