[FFmpeg-devel] [PATCH] lavfi: remove noise libmpcodecs wrapper

[Michael Niedermayer]

On Sat, Apr 06, 2013 at 04:24:15PM +0000, Paul B Mahol wrote:
> On 4/6/13, Michael Niedermayer <michaelni at gmx.at> wrote:
> > On Fri, Apr 05, 2013 at 11:50:01PM +0000, Paul B Mahol wrote:
> >> Native filter have been implemented.
> >>
> >> Even with inline assembly manually enabled, this filter
> >> is significanly slower than native one.
> >>
> >> Optimization to native filter can be added at any time
> >> and there is no reason to keep mp filter just because
> >> it have inline assembly that gets never enabled.
> >
> > noise=all_strength=30
> > 22863845 decicycles in noise, 32 runs, 0 skips
> > the filter shows artifacts (quality is IMHO not acceptable)
> 
> 
> What artifacts?

bright pink pixels
looking at the code i see RAND_MAX in it


> 
> You did not provide full command line (so i can make sure you tested
> same pixel format).

ffplay -i  matrixbench_mpeg2.mpg -vf noise=all_strength=30


> 
> The only difference is not using random().
> 
> >
> > mp=noise=30:30
> > 15285560 decicycles in mpnoise, 32 runs, 0 skips
> >
> > forcing MMX2
> > mp=noise=30:30
> > 2790510 decicycles in mpnoise, 32 runs, 0 skips
> >
> > PS: why does the native filter not handle shorthand notation ?
> 
> What kind of shorthand notation? The one mp=noise use can not
> be done with it.

noise=123
should do something, currently it fails


> 
> >
> > tested using:
> >
> > diff --git a/libavfilter/libmpcodecs/vf_noise.c
> > b/libavfilter/libmpcodecs/vf_noise.c
> > index 3b946e9..606ea66 100644
> > --- a/libavfilter/libmpcodecs/vf_noise.c
> > +++ b/libavfilter/libmpcodecs/vf_noise.c
> > @@ -351,11 +351,11 @@ static int put_image(struct vf_instance *vf,
> > mp_image_t *mpi, double pts){
> >          }
> >  //else printf("dr\n");
> >          dmpi= vf->dmpi;
> > -
> > +START_TIMER
> >          noise(dmpi->planes[0], mpi->planes[0], dmpi->stride[0],
> > mpi->stride[0], mpi->w, mpi->h, &vf->priv->lumaParam);
> >          noise(dmpi->planes[1], mpi->planes[1], dmpi->stride[1],
> > mpi->stride[1], mpi->w/2, mpi->h/2, &vf->priv->chromaParam);
> >          noise(dmpi->planes[2], mpi->planes[2], dmpi->stride[2],
> > mpi->stride[2], mpi->w/2, mpi->h/2, &vf->priv->chromaParam);
> > -
> > +STOP_TIMER("mpnoise")
> >          ff_vf_clone_mpi_attributes(dmpi, mpi);
> >
> >  #if HAVE_MMX
> > diff --git a/libavfilter/vf_noise.c b/libavfilter/vf_noise.c
> > index 8db5329..8782b4a 100644
> > --- a/libavfilter/vf_noise.c
> > +++ b/libavfilter/vf_noise.c
> > @@ -309,11 +309,11 @@ static int filter_frame(AVFilterLink *inlink, AVFrame
> > *inpicref)
> >          }
> >          av_frame_copy_props(out, inpicref);
> >      }
> > -
> > +START_TIMER
> >      for (i = 0; i < n->nb_planes; i++)
> >          noise(out->data[i], inpicref->data[i], out->linesize[i],
> >                inpicref->linesize[i], n->linesize[i], n->height[i], n, i);
> > -
> > +STOP_TIMER("noise")
> >      ret = ff_filter_frame(outlink, out);
> >      if (inpicref != out)
> >          av_frame_free(&inpicref);
> >
> > [...]
> 
> I feared of such kind of "benchmark".
> 
> I tested with "time".

both tests make sense, and if in either case mp is faster then theres
something we can improve
time based benchmarks include alot of interface code that easily
could add a full picture copy ...

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

Awnsering whenever a program halts or runs forever is
On a turing machine, in general impossible (turings halting problem).
On any real computer, always possible as a real computer has a finite number
of states N, and will either halt in less than N cycles or never halt.
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