scratch team mailing list archive

[Amos Blanton <amos@xxxxxxxxxxxxxxx>]

Thanks for working on this Derek. Myself and all the other Scratchers
running Linux are very grateful to have benefited from your stubbornness! :)

Your approach makes sense to me. One minor additional point in favor of a
Gst plugin-- I would imagine that in future versions of PA the interface to
gstreamer would figure prominently in testing / the QA process. They'd be
more likely to invest resources to find / fix something that breaks the
interface with gstreamer (and thereby breaks all the apps that depend on it)
than something that just breaks Scratch. So I can imagine some benefit to
being on that bandwagon.

However - time and resources are scarce and precious! So it seems like
trying to fix the PA plugin is the best approach. And who knows - maybe PA
will get stable enough that they won't break the plugin again? One can
dream...

On Thu, Feb 4, 2010 at 8:27 PM, Derek O'Connell <doc@xxxxxxxxxxxxxxxxx>wrote:

> Hi all, I have been updating myself on PA issues. Last time I looked
> (~December) Lennart Poettering had disappeared on holiday while quite a
> few people were having problems on Karmic with the Simple_API (which I
> use in the Scratch plug-in). The problem boils down to default latency
> being ~2s, much too long for most app's, and not easily controlled via
> Simple_API (my attempts failed at least). The volume meter set a low
> latency in order to display the current sound level/s so that's why
> things improved for other app's when it was running.
>
> The problems were created by an internal change to the PA API
> (supposedly one single flag setting!) between 9.04 / 9.10 and the good
> news is that it's impact is at least now recognised. There seems to be
> some new suggestions about how to get around the problem, including a
> patch to set latency via an env var. So tomorrow I will see how far I
> can get with them. The bad news is there seems to be new problems
> introduced by the version of PA to be used in Lucid. Fingers crossed
> they get sorted soon.
>
> Re GStreamer, the hope was/is that a GSt based plugin for Scratch would
> avoid these issues but thinking about it there is no guarantee since GSt
> itself relies on plugin's to interface with whatever sound server is in
> use. On Ubuntu that will still be PA out-of-the-box. PA can of course be
> shut down and bypassed but the ideal solution is one that avoids forcing
> what may be *novice* users from having to reconfigure their system just
> to run Scratch (auto shutdown/start-up of PA is not an option for other
> reasons). So it makes sense to me to concentrate on working around
> current PA issues before considering GSt, although GSt is still
> attractive for the other options it brings to the table, as well as
> isolating Scratch from specific sounds systems, ie, more platform/distro
> independence.
>
> Btw, I don't claim to be an expert on any of the above, more like too
> stubborn to know when to give up ;-) So if anyone else has expertise/
> info/ advice I'm happy to hear it.
>
> -D
>
>
>


-- 
_____
Amos