[FFmpeg-devel] [PATCH v2 1/2] avfilter: add a hflip_vulkan filter

[Paul B Mahol]

On Thu, Nov 18, 2021 at 6:59 AM Wu, Jianhua <jianhua.wu at intel.com> wrote:

> > Andreas Rheinhardt:
> > Wu, Jianhua:
> > > Andreas Rheinhardt wrote:
> > >> Wu Jianhua:
> > >>> The following command is on how to apply hflip_vulkan filter:
> > >>>
> > >>> ffmpeg -init_hw_device vulkan -i input.264 -vf
> > >>>
> > >>
> > hwupload=extra_hw_frames=16,hflip_vulkan,hwdownload,format=yuv420p
> > >>> output.264
> > >>>
> > >>> Signed-off-by: Wu Jianhua <jianhua.wu at intel.com>
> > >>> ---
> > >>>  configure                     |   1 +
> > >>>  libavfilter/Makefile          |   1 +
> > >>>  libavfilter/allfilters.c      |   1 +
> > >>>  libavfilter/vf_hflip_vulkan.c | 276
> > >>> ++++++++++++++++++++++++++++++++++
> > >>>  4 files changed, 279 insertions(+)
> > >>>  create mode 100644 libavfilter/vf_hflip_vulkan.c
> > >>>
> > >>
> > >>> +
> > >>> +static const AVOption hflip_vulkan_options[] = {
> > >>> +    { NULL },
> > >>> +};
> > >>> +
> > >>> +AVFILTER_DEFINE_CLASS(hflip_vulkan);
> > >>> +
> > >>
> > >> What is the point of this class with its empty options?
> > >
> > > The AVFILTER_DEFINE_CLASS needs the hflip_vulkan_options and the
> > > reason why it's NULL is that the most other filters do it like that.
> > >
> >
> > And why do you add an AVClass at all?
> > (The reason that there are some filters with AVClass and empty options
> is a
> > bug in avfilter_init_str() which errors out when given options for a
> filter
> > without AVClass, although it is perfectly fine to set options on a
> filter without
> > AVClass, namely generic AVFilter options (this is important for e.g.
> framesync
> > filters, but not for this filter here).)
> >
>
> Simply I think it is a convention. Yeah. It's not needed at all. I'll
> remove it and update later.
>

Do not do it if it breaks timeline support.

_______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".
>