[FFmpeg-devel] [PATCH] vf_overlay: add logic for avoiding overlaying frames with PTS > main frame PTS

[Paul B Mahol]

On 1/10/12, Stefano Sabatini <stefasab at gmail.com> wrote:
> On date Tuesday 2012-01-10 00:30:12 +0000, Paul B Mahol encoded:
>> On 1/10/12, Stefano Sabatini <stefasab at gmail.com> wrote:
>> > Also add debug logging messages for helping tracking down similar
>> > issues.
>> >
>> > Fix trac ticket #467.
>> > ---
>> >  libavfilter/vf_overlay.c |   41
>> > +++++++++++++++++++++++++++++------------
>> >  1 files changed, 29 insertions(+), 12 deletions(-)
>> >
>> > diff --git a/libavfilter/vf_overlay.c b/libavfilter/vf_overlay.c
>> > index 062783e..9600061 100644
>> > --- a/libavfilter/vf_overlay.c
>> > +++ b/libavfilter/vf_overlay.c
>> > @@ -25,6 +25,8 @@
>> >   * overlay one video on top of another
>> >   */
>> >
>> > +/* #define DEBUG */
>>
>> Is this really needed?
>
> It's handy for me since I need just a few keystrokes for
> enabling/disabling it. Also it shows that there is debug code in the
> file.
>
>> > +
>> >  #include "avfilter.h"
>> >  #include "libavutil/eval.h"
>> >  #include "libavutil/avstring.h"
>> > @@ -75,7 +77,7 @@ typedef struct {
>> >      uint8_t overlay_rgba_map[4];
>> >      uint8_t overlay_has_alpha;
>> >
>> > -    AVFilterBufferRef *overpicref;
>> > +    AVFilterBufferRef *overpicref, *overpicref_next;
>> >
>> >      int main_pix_step[4];       ///< steps per pixel for each plane of
>> > the
>> > main output
>> >      int overlay_pix_step[4];    ///< steps per pixel for each plane of
>> > the
>> > overlay
>> > @@ -144,6 +146,8 @@ static av_cold void uninit(AVFilterContext *ctx)
>> >
>> >      if (over->overpicref)
>> >          avfilter_unref_buffer(over->overpicref);
>> > +    if (over->overpicref_next)
>> > +        avfilter_unref_buffer(over->overpicref_next);
>> >  }
>> >
>> >  static int query_formats(AVFilterContext *ctx)
>> > @@ -302,22 +306,33 @@ static void start_frame(AVFilterLink *inlink,
>> > AVFilterBufferRef *inpicref)
>> >      AVFilterBufferRef *outpicref = avfilter_ref_buffer(inpicref, ~0);
>> >      AVFilterContext *ctx = inlink->dst;
>> >      OverlayContext *over = ctx->priv;
>> > +    av_unused AVFilterLink *outlink = ctx->outputs[0];
>> >
>> >      inlink->dst->outputs[0]->out_buf = outpicref;
>> >      outpicref->pts = av_rescale_q(outpicref->pts,
>> > ctx->inputs[MAIN]->time_base,
>> >                                    ctx->outputs[0]->time_base);
>> >
>> >      if (!over->overpicref || over->overpicref->pts < outpicref->pts) {
>> > -        AVFilterBufferRef *old = over->overpicref;
>> > -        over->overpicref = NULL;
>> > -        avfilter_request_frame(ctx->inputs[OVERLAY]);
>> > -        if (over->overpicref) {
>> > -            if (old)
>> > -                avfilter_unref_buffer(old);
>> > -        } else
>> > -            over->overpicref = old;
>> > +        if (!over->overpicref_next)
>> > +            avfilter_request_frame(ctx->inputs[OVERLAY]);
>> > +
>> > +        if (over->overpicref && over->overpicref_next &&
>> > +            over->overpicref_next->pts <= outpicref->pts) {
>> > +            avfilter_unref_buffer(over->overpicref);
>> > +            over->overpicref = over->overpicref_next;
>> > +            over->overpicref_next = NULL;
>> > +        }
>> >      }
>> >
>> > +#ifdef DEBUG
>>
>> Use av_dlog() instead.
>> > +    av_log(ctx, AV_LOG_DEBUG, "main_pts:%"PRId64" main_pts_time:%f",
>> > +           outpicref->pts, outpicref ->pts *
>> > av_q2d(outlink->time_base));
>> > +    if (over->overpicref)
>> > +        av_log(ctx, AV_LOG_DEBUG, " over_pts:%"PRId64"
>> > over_pts_time:%f",
>> > +               over->overpicref->pts, over->overpicref->pts *
>> > av_q2d(outlink->time_base));
>> > +    av_dlog(ctx, "\n");
>> > +#endif
>
> Fixed.

Looks fine to me.