[FFmpeg-devel] [PATCH] lavfi/avfilter.c: Correct guess_status_pts to account for differing link timebases.

[Thomas Mundt]

2017-10-06 10:01 GMT+02:00 Nicolas George <george at nsup.org>:

> Le quartidi 14 vendémiaire, an CCXXVI, Sasi Inguva a écrit :
> > Signed-off-by: Sasi Inguva <isasi at google.com>
> > ---
> >  libavfilter/avfilter.c | 16 ++++++++--------
> >  1 file changed, 8 insertions(+), 8 deletions(-)
>
> You are right, this change is needed. Thanks for spotting it and the
> patch.
>
> >
> > diff --git a/libavfilter/avfilter.c b/libavfilter/avfilter.c
> > index 58917ed445..ec7dfc0bd3 100644
> > --- a/libavfilter/avfilter.c
> > +++ b/libavfilter/avfilter.c
> > @@ -427,19 +427,19 @@ int ff_request_frame(AVFilterLink *link)
> >      return 0;
> >  }
> >
>
> > -static int64_t guess_status_pts(AVFilterContext *ctx, int status)
> > +static int64_t guess_status_pts_from_src(AVFilterLink *link, int
> status)
>
> I would prefer if you just added a "AVRational time_base" parameter.
> With this version, the code has "link->" indirections all over the
> place, that lowers the readability.
>
> >  {
> >      unsigned i;
> >      int64_t r = INT64_MAX;
> >
> > -    for (i = 0; i < ctx->nb_inputs; i++)
> > -        if (ctx->inputs[i]->status_out == status)
> > -            r = FFMIN(r, ctx->inputs[i]->current_pts);
> > +    for (i = 0; i < link->src->nb_inputs; i++)
> > +        if (link->src->inputs[i]->status_out == status)
> > +          r = FFMIN(r, av_rescale_q(link->src->inputs[i]->current_pts,
> link->src->inputs[i]->time_base, link->time_base));
> >      if (r < INT64_MAX)
> >          return r;
> > -    av_log(ctx, AV_LOG_WARNING, "EOF timestamp not reliable\n");
> > -    for (i = 0; i < ctx->nb_inputs; i++)
> > -        r = FFMIN(r, ctx->inputs[i]->status_in_pts);
> > +    av_log(link->src, AV_LOG_WARNING, "EOF timestamp not reliable\n");
> > +    for (i = 0; i < link->src->nb_inputs; i++)
> > +      r = FFMIN(r, av_rescale_q(link->src->inputs[i]->status_in_pts,
> link->src->inputs[i]->time_base, link->time_base));
> >      if (r < INT64_MAX)
> >          return r;
> >      return AV_NOPTS_VALUE;
> > @@ -458,7 +458,7 @@ static int ff_request_frame_to_filter(AVFilterLink
> *link)
> >          ret = ff_request_frame(link->src->inputs[0]);
> >      if (ret < 0) {
> >          if (ret != AVERROR(EAGAIN) && ret != link->status_in)
> > -            ff_avfilter_link_set_in_status(link, ret,
> guess_status_pts(link->src, ret));
> > +            ff_avfilter_link_set_in_status(link, ret,
> guess_status_pts_from_src(link, ret));
> >          if (ret == AVERROR_EOF)
> >              ret = 0;
> >      }
>

It would be great if this fix will find its way into FFmpeg 3.4.

Thank you,
Thomas