Re: [Rhythmbox-devel] New plugin: Pitch/Speed Shifting

[Jonathan Matthew <jonathan d14n org>]

On Wed, Oct 28, 2009 at 12:42 AM, Sean McNamara <smcnam gmail com> wrote:

[not ignoring specifics of this plugin this time]

> Hello,
>
> I have started work on a new plugin for Rhythmbox. I have written it
> in Vala, and developed it on / tested it against a Fedora 12 Beta
> x86_64 system with Rhythmbox 0.12.5 and Vala 0.7.7.
>
> The current project status is that it works on my system, and the
> primary features I wanted are implemented and functional. There is no
> tarball release; instead, use git:
> http://tiyukquellmalz.org/cgit/rbpitch <--- CGit web ui.
> git clone git://tiyukquellmalz.org/rbpitch <--- git command to check
> out the source.
>
> First, pictures are worth a thousand words. Here are some screenshots
> -- I couldn't get window borders to show up, but each screenshot is of
> a toplevel window.
>
> Addition to Rhythmbox Shell is visible in a red box (the box is not
> rendered in the GUI): http://tiyukquellmalz.org/rbpitch-icon.png
>
> Clicking the icon in the rb shell pops up this window. First, with the
> sliders in the default position:
> http://tiyukquellmalz.org/rbpitch-ui-1.png
> Second, with the sliders moved around a bit:
> http://tiyukquellmalz.org/rbpitch-ui-2.png

The problem here is that the useful range for the sliders is around
50% to 150%, but that's only 10% of the total range. I'd suggest
making the sliders longer, and making them non-linear. The difference
between 100% and 110% is far more important than the difference betwen
300% and 310%, but they're currently represented by the same amount of
space on the slider.

> Now that I am happy with the functionality of the plugin, my new goal
> is to help it reach the largest audience possible. I have chosen the
> most favorable license possible by using the same one as the Rhythmbox
> core, and I offer my help and perpetual maintainership of this plugin.
> The RB maintainers can choose to help me reach the largest audience
> possible, or not -- either way, I am still happy using the plugin
> myself. I do believe it is of some general use, and there is precedent
> for other media players including this functionality by default.

Now that I've fixed the playback pipeline filter functionality so you
can add and remove filters without changing playback state (mostly),
the main obstacle for this plugin is that the 'pitch' element doesn't
appear to do timestamping, duration queries, or position queries
properly, so the playback position slider advances at one second per
second regardless of the actual rate. I haven't actually tried seeking
but I'm guessing there are likely to be problems there too.