[FFmpeg-devel] [PATCH 1/3] avcodec/ass: Faster ff_ass_add_rect()

[Michael Niedermayer]

On Sun, Dec 19, 2021 at 09:00:27PM -0300, James Almer wrote:
> 
> 
> On 12/19/2021 8:56 PM, Michael Niedermayer wrote:
> > Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> > ---
> >   libavcodec/ass.c | 33 +++++++++++++++++++++++++++------
> >   libavcodec/ass.h |  7 +++++++
> >   2 files changed, 34 insertions(+), 6 deletions(-)
> > 
> > diff --git a/libavcodec/ass.c b/libavcodec/ass.c
> > index 725e4d42ba1..06714678722 100644
> > --- a/libavcodec/ass.c
> > +++ b/libavcodec/ass.c
> > @@ -114,17 +114,31 @@ char *ff_ass_get_dialog(int readorder, int layer, const char *style,
> >                          speaker ? speaker : "", text);
> >   }
> > -int ff_ass_add_rect(AVSubtitle *sub, const char *dialog,
> > +int ff_ass_add_rect2(AVSubtitle *sub, const char *dialog,
> >                       int readorder, int layer, const char *style,
> > -                    const char *speaker)
> > +                    const char *speaker, unsigned *nb_rect_allocated)
> >   {
> > -    AVSubtitleRect **rects, *rect;
> > +    AVSubtitleRect **rects = sub->rects, *rect;
> >       char *ass_str;
> > +    uint64_t new_nb = 0;
> > -    rects = av_realloc_array(sub->rects, sub->num_rects+1, sizeof(*sub->rects));
> > -    if (!rects)
> > +    if (sub->num_rects >= UINT_MAX)
> >           return AVERROR(ENOMEM);
> > -    sub->rects = rects;
> > +
> > +    if (nb_rect_allocated && *nb_rect_allocated <= sub->num_rects) {
> > +        new_nb = FFMIN(sub->num_rects + sub->num_rects/16LL + 1, UINT_MAX);
> 
> Isn't this what av_fast_realloc() is for?

No, its what av_fast_realloc_array() would be for but that is not in git yet
I think we should wait for that to become available before changing the
used function (1 change less / less work)

thx

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Republics decline into democracies and democracies degenerate into
despotisms. -- Aristotle
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