[FFmpeg-devel] [PATCH 07/10] avfilter/vf_nlmeans: Move ff_nlmeans_init into a header

[Hendrik Leppkes]

On Fri, May 13, 2022 at 11:01 AM Soft Works <softworkz at hotmail.com> wrote:
>
>
>
> > -----Original Message-----
> > From: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
> > Sent: Friday, May 13, 2022 10:27 AM
> > To: Soft Works <softworkz at hotmail.com>; FFmpeg development discussions
> > and patches <ffmpeg-devel at ffmpeg.org>
> > Subject: Re: [FFmpeg-devel] [PATCH 07/10] avfilter/vf_nlmeans: Move
> > ff_nlmeans_init into a header
> >
> > Soft Works:
> > >
> > >
> > >> -----Original Message-----
> > >> From: ffmpeg-devel <ffmpeg-devel-bounces at ffmpeg.org> On Behalf Of
> > >> Andreas Rheinhardt
> > >> Sent: Tuesday, May 3, 2022 8:38 AM
> > >> To: ffmpeg-devel at ffmpeg.org
> > >> Cc: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
> > >> Subject: [FFmpeg-devel] [PATCH 07/10] avfilter/vf_nlmeans: Move
> > >> ff_nlmeans_init into a header
> > >>
> > >> This removes a dependency of checkasm on lavfi/vf_nlmeans.o
> > >> and also allows to inline ff_nlmeans_init() irrespectively of
> > >> interposing.
> > >>
> > >> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
> > >> ---
> > >
> > > [..]
> > >
> > >> +
> > >> +static av_unused void ff_nlmeans_init(NLMeansDSPContext *dsp)
> > >> +{
> > >> +    dsp->compute_safe_ssd_integral_image =
> > >> compute_safe_ssd_integral_image_c;
> > >> +    dsp->compute_weights_line = compute_weights_line_c;
> > >> +
> > >> +    if (ARCH_AARCH64)
> > >> +        ff_nlmeans_init_aarch64(dsp);
> > >
> > > Hi Andreas,
> > >
> > > the above breaks compilation for me:
> > >
> > > 1>libavfilterd.lib(libavfilter_vf_nlmeans.obj) : error LNK2019:
> > unresolved external symbol ff_nlmeans_init_aarch64 referenced in
> > function ff_nlmeans_init
> > >
> > > The reason is that I'm (obviously) not compiling stuff from the
> > > libavfilter\aarch64 subfolder.
> > >
> > > It might need an #ifdef ?
> > >
> > > I haven't taken a deeper look at it, though.
> > >
> > > Thanks,
> > > softworkz
> > >
> > >
> >
> > That surprises me: The earlier code did exactly the same; in fact,
> > using
> > if (ARCH_*) is our typical check for arches in dsp-init code.
>
> I looked at this a bit further. It seems that the VS project
> generation tool that I'm using is creating dummy definitions
> for such cases. In the previous workspace it had generated
>
> void ff_nlmeans_init_aarch64(NLMeansDSPContext *dsp) {return;}
>
> in a separate code file for being able to work with the ffmpeg
> code in VS without modifying any of the code.
>
> Now that you have moved that code to a header file, this logic
> doesn't work anymore.
>

Nevermind my previous comment then, perhaps external tools should be
updated if they somehow work around our need for DCE (which is well
documented).

- Hendrik