[MPlayer-dev-eng] [PATCH] faster lavcresample

[Michael Niedermayer]

On Sun, Jun 13, 2010 at 02:16:05PM +0200, Dan Oscarsson wrote:
> While writing my patches to make a-v-sync use pts and vsyncs, I found
> that changing speed disrupts normal processing quite a lot. Changing
> speed takes a lot of CPU. Analysing I found that lavcresample is about a
> 1000 times slower than scaletempo to initialise. While lavcresample is
> complex and I have not spent much time on it, I found that af_init calls
> af_reinit twice. To reduce CPU time needed to initialise a speed change
> using lavcresample by half, the attached patch makes lavcresample on
> recalculate its tables each time its parameters change. So calling it
> twice with same parameters only results in one table calculation.

why is af_reinit() called twice?

Iam not against your change to af_lavcresample.c, it actually looks ok
but maybe we could fix the root of the 2x call.

Also making av_resample_init() faster is welcome, the problem likely
is the speed of bessel() and the number of calls to it.
init is likely also a much bigger issue for fpu-less systems

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Why not whip the teacher when the pupil misbehaves? -- Diogenes of Sinope
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