gst-plugins-good: Revert "Pulsesink: Allow chunks up to bufsize instead of segsize"

[Sebastian Dröge]

On Fri, 2011-04-08 at 21:02 +0300, René Stadler wrote:
> On Fri, Apr 8, 2011 at 3:35 PM, Sebastian Dröge
> <slomo at kemper.freedesktop.org> wrote:
>         Module: gst-plugins-good
>         Branch: master
>         Commit: 11bcac7c9015c4db85514e7837cbd2d0f47b9ff1
>         URL:
>          http://cgit.freedesktop.org/gstreamer/gst-plugins-good/commit/?id=11bcac7c9015c4db85514e7837cbd2d0f47b9ff1
>         
>         Author: Sebastian Dröge <sebastian.droege at collabora.co.uk>
>         Date:   Fri Apr  8 14:35:04 2011 +0200
>         
>         Revert "Pulsesink: Allow chunks up to bufsize instead of
>         segsize"
>         
>         This reverts commit 1e2c1467ae042a3c6bb1a6bc0c07aeff13ec5edb.
>         
>         The commit causes pulsesink to ignore the latency-time
>         baseaudiosink property.
> [...] 
> 
> 
> Hi,
> 
> 
> can you elaborate a bit on this? Strictly speaking, it's not true that
> the property is ignored without the revert, since segsize/latency-time
> is still passed to PA's minreq attribute. Since that is the minimum
> amount of free space that must be available before pulse calls us for
> more data, that should still have a huge effect (if not, there is
> something else wrong in pulsesink).

If a decoder passes large buffers to pulsesink these large buffers will
be written do PA instead of smaller, latency-time-sized parts of the
buffer.

> I haven't measured the wakeup behavior and power consumption of
> pulsesink in a while, so I'm wondering if you have some
> up-to-date empirical data that prompted you to this revert :)

I don't but see the discussion here with Stefan:
https://bugzilla.gnome.org/show_bug.cgi?id=641072

I've reverted the patch yesterday because the conclusion seems to be
that this should be fixed elsewhere and Stefan apparently just forgot to
revert it. I didn't want this to be in the release if it isn't correct
and could cause problems. Nonetheless I agree that something has to be
done to decrease power consumption and wakeups, let's continue that
discussion in the bugreport.


Oh and btw, the patch did cause real problems :) See this bug:
https://bugzilla.gnome.org/show_bug.cgi?id=646999

The change caused underuns, at least with WMA but probably with other
formats too. (Note: WMA frames are very large compared to MP3, e.g.
115200 bytes vs. 9216 bytes in one of my testcases)

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