[FFmpeg-cvslog] [FFmpeg-devel] avfilter: add vmafmotion filter

[Ronald S. Bultje]

Hi,

On Thu, Oct 5, 2017 at 7:52 PM, Michael Niedermayer <michael at niedermayer.cc>
wrote:

> On Sat, Sep 30, 2017 at 03:51:41PM +0000, Ashish Singh wrote:
> > ffmpeg | branch: master | Ashish Singh <ashk43712 at gmail.com> | Sat Sep
> 16 02:35:58 2017 +0530| [148c8e88c43cfbabd6aee9f01ef30942cee9d359] |
> committer: Ronald S. Bultje
> >
> > avfilter: add vmafmotion filter
> >
> > Signed-off-by: Ashish Singh <ashk43712 at gmail.com>
> > Signed-off-by: Ronald S. Bultje <rsbultje at gmail.com>
> >
> > > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=
> 148c8e88c43cfbabd6aee9f01ef30942cee9d359
> > ---
> >
> >  Changelog                   |   1 +
> >  doc/filters.texi            |  14 ++
> >  libavfilter/Makefile        |   1 +
> >  libavfilter/allfilters.c    |   1 +
> >  libavfilter/vf_vmafmotion.c | 365 ++++++++++++++++++++++++++++++
> ++++++++++++++
> >  libavfilter/vmaf_motion.h   |  58 +++++++
> >  6 files changed, 440 insertions(+)
> [...]
> > +static av_cold int init(AVFilterContext *ctx)
> > +{
> > +    VMAFMotionContext *s = ctx->priv;
> > +
> > +    if (s->stats_file_str) {
> > +        if (!strcmp(s->stats_file_str, "-")) {
>
> > +            s->stats_file = stdout;
>
> Using stdout can interfere with the user application using the filter
>
>
> > +        } else {
>
> > +            s->stats_file = fopen(s->stats_file_str, "w");
>
> Opening a filter parameter provided string for writing is a dangerous
> way to output data. It allows one with access to the parameters to
> overwrite any writable file
>
> data should only be output in a safe way
>

The same mechanism is present in ssim/psnr filters. I'm open to any
alternative method you suggest. These are only settable using explicit user
interaction (and are disabled by default) so I don't particularly see the
problem.

Ronald