[FFmpeg-devel] [RFC][PATCH] ffplay: factorize subtitle rendering code to a private filter

[wm4]

On Tue, 3 Mar 2015 15:03:19 +0100
Lukasz Marek <lukasz.m.luki2 at gmail.com> wrote:

> On 3 March 2015 at 14:16, wm4 <nfxjfg at googlemail.com> wrote:
> 
> > On Tue, 3 Mar 2015 13:17:12 +0100
> > Lukasz Marek <lukasz.m.luki2 at gmail.com> wrote:
> >
> > > On 17 February 2015 at 03:27, Marton Balint <cus at passwd.hu> wrote:
> > >
> > > >
> > > >
> > > > On Sat, 14 Feb 2015, Clément Bœsch wrote:
> > > >
> > > >  On Sat, Feb 14, 2015 at 02:08:15AM +0100, Marton Balint wrote:
> > > >>
> > > >>> Signed-off-by: Marton Balint <cus at passwd.hu>
> > > >>> ---
> > > >>>  Makefile                         |   1 +
> > > >>>  doc/ffplay.texi                  |   4 +
> > > >>>  ffplay.c                         | 336
> > +++++-------------------------
> > > >>> -------
> > > >>>  libavfilter/Makefile             |   1 +
> > > >>>  libavfilter/vf_ffplay_subtitle.c | 347
> > ++++++++++++++++++++++++++++++
> > > >>> +++++++++
> > > >>>  libavfilter/vf_ffplay_subtitle.h |  38 +++++
> > > >>>  6 files changed, 434 insertions(+), 293 deletions(-)
> > > >>>  create mode 100644 libavfilter/vf_ffplay_subtitle.c
> > > >>>  create mode 100644 libavfilter/vf_ffplay_subtitle.h
> > > >>>
> > > >>>
> > > >> This is not the correct way of doing it.
> > > >>
> > > >> The proper way is to integrate subtitles within lavfi. If you want to
> > work
> > > >> toward this, feel free to ask for more details, but it's not trivial.
> > > >>
> > > >> (and no, this patch is not an improvement in the correct direction,
> > sorry)
> > > >>
> > > >>
> > > > What would be an improvement in the right direction? I see little
> > chance
> > > > that I will work on subtitles in lavfi, but if there is a
> > better/preferred
> > > > way to change ffplay to support subtitles in the filter chain without
> > > > waiting for the whole subtitles-in-libavfilter infrastructure, I may be
> > > > interested in working toward that.
> > > >
> > >
> > > Just random guess, but for now you could implement this filter in
> > > ffplay_sub_filter.c (or something) and register it from ffplay. So code
> > of
> > > ffplay itself is  cleaner and libavfilter is not spoiled.
> > > When this all suff Clement is talking about is done then it can be pushed
> > > further.
> > >
> > > I like this patch because some time ago I ported ffplay to ios and
> > removing
> > > this code was annoying.
> >
> > API users can't add new filters from the "outside".
> 
> 
> Isn't it allowed (and enough) to call avfilter_register with own filter?
> If not then I,m surprised TBH.

No. While the register function is public, you'd need to use private
APIs to actually implement the filter.