lavfi: split frame_count between input and output.

AVFilterLink.frame_count is supposed to count the number of frames
that were passed on the link, but with min_samples, that number is
not always the same for the source and destination filters.
With the addition of a FIFO on the link, the difference will become
more significant.

Split the variable in two: frame_count_in counts the number of
frames that entered the link, frame_count_out counts the number
of frames that were sent to the destination filter.

1 files changed, 3 insertions, 3 deletions

diff --git a/libavfilter/vf_zoompan.c b/libavfilter/vf_zoompan.c
index 7a71503168..136d6c83fd 100644
--- a/libavfilter/vf_zoompan.c
+++ b/libavfilter/vf_zoompan.c
@@ -149,7 +149,7 @@ static int output_single_frame(AVFilterContext *ctx, AVFrame *in, double *var_va
     var_values[VAR_PDURATION] = s->prev_nb_frames;
     var_values[VAR_TIME] = pts * av_q2d(outlink->time_base);
     var_values[VAR_FRAME] = i;
-    var_values[VAR_ON] = outlink->frame_count + 1;
+    var_values[VAR_ON] = outlink->frame_count_in + 1;
     if ((ret = av_expr_parse_and_eval(zoom, s->zoom_expr_str,
                                       var_names, var_values,
                                       NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
@@ -235,8 +235,8 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *in)
     s->var_values[VAR_IN_H]  = s->var_values[VAR_IH] = in->height;
     s->var_values[VAR_OUT_W] = s->var_values[VAR_OW] = s->w;
     s->var_values[VAR_OUT_H] = s->var_values[VAR_OH] = s->h;
-    s->var_values[VAR_IN]    = inlink->frame_count + 1;
-    s->var_values[VAR_ON]    = outlink->frame_count + 1;
+    s->var_values[VAR_IN]    = inlink->frame_count_out + 1;
+    s->var_values[VAR_ON]    = outlink->frame_count_in + 1;
     s->var_values[VAR_PX]    = s->x;
     s->var_values[VAR_PY]    = s->y;
     s->var_values[VAR_X]     = 0;