[MPlayer-dev-eng] [PATCH] af_scaletempo

[Robert Juliano]

On Fri, Sep 14, 2007 at 01:21:30AM -0400, Rich Felker wrote:
> Read what Reimar said. You don???t have to do any divisions in the inner
> loop. Instead do them outside. No need for float which is bad anyway
> because it needs alternative non-float code to support machines
> without hardware float.
> 
> Rich

ROTFL, thanks for implying that I'm idiot who doesn't read
the posts I respond to and could use basic computer science
explained to me.

Show me benchmarks.
Show me code.
Show me respect.

BTW, I more than read what Reimer says, I try his suggestions,
and he's 0 for 2 on optimization suggestions, so far.  Even
so, I respect him because often he's spot on, yet humble enough
to encourage testing his suggestions.

Ok, SUM(MAX_INT * MAX_INT) easily overflows.  Yeah, I could
use 64-bit ints to avoid dividing so often, but would that
be faster than the float version.  Not on my system.  It's
slower even with no division at all.

I can only benchmark on systems I have access to.  On my
system, the float version is 150x realtime, and the int
version with the division is 80x realtime, plenty fast enough
either way.  On old, slow systems this whole calculation can
be skipped entirely and still produce decent results.

My priority, when it comes to performance, is to add some
sort of QoS option.  I haven't settled on a way to do this,
so it's not included yet.

If someone else wants to optimize it for some other system,
they are more than welcome.  I can't without the hardware and
a devkit.

I'm more than open to suggestions, but give me some respect.
Show me code.  I'm not to found of over-generalizations.
Send patches, that I can respect.

ciao,
robert