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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> Marco Ballesio
[mailto:gibrovacco@gmail.com] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Monday, October 11, 2010
12:46<br>
<b><span style='font-weight:bold'>To:</span></b> Discussion of the development
of GStreamer<br>
<b><span style='font-weight:bold'>Subject:</span></b> Re: [gst-devel] possible
optimisations in pad_push mutex handling</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><snip/><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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<p class=MsoNormal style='margin-bottom:12.0pt'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'>> P.S. it appears the
penalty decreases when buffers have bigger sizes,<br>
> as already shown from Felipe.<o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>That's not what that test showed, it showed that the more buffers you<br>
push per second, the more CPU you consume, which is rather obvious.<o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><br>
<font color=navy><span style='color:navy'>> </span></font>well, not for me
;). In a perfect world the algorithm should increase in complexity wrt<font
color=navy><span style='color:navy'><o:p></o:p></span></font></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>></span></font> the quantity of data,
and not depending on how it's<font color=navy><span style='color:navy'> </span></font>partitioned.
The algorithm should<font color=navy><span style='color:navy'><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 color=navy face="Times New Roman"><span
style='font-size:12.0pt;color:navy'>></span></font> be O(1) in this terms,
and my patch tends to proof this.<font size=2 color=navy face=Arial><span
style='font-size:10.0pt;font-family:Arial;color:navy'><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Wim is correct (it’s not the actual size
of the buffers, but their frequency that matters), but I think your point is
that it doesn’t mean there’s not still an issue to be addressed? Ideally,
GStreamer to have no overhead, but it doesn’t (and nothing will). I
think the key point is that the per-buffer overhead is *<b><span
style='font-weight:bold'>significant</span></b>*, for your application, so you’re
interested in looking at ways to reduce it.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>We also have scenarios where GStreamer
overhead is significant (i.e. handling lots of compressed streams on a server
platform), so there’s broader interest in trying to reduce overhead. However,
since we also modify running pipelines, we’re very interesting in that functionality
continuing to work.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><snip/><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Matt<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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