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, 2 insertions, 2 deletions

diff --git a/libavfilter/vf_perspective.c b/libavfilter/vf_perspective.c
index 287db68845..d590cfa48d 100644
--- a/libavfilter/vf_perspective.c
+++ b/libavfilter/vf_perspective.c
@@ -135,8 +135,8 @@ static int calc_persp_luts(AVFilterContext *ctx, AVFilterLink *inlink)
     double (*ref)[2]      = s->ref;
 
     double values[VAR_VARS_NB] = { [VAR_W] = inlink->w, [VAR_H] = inlink->h,
-                                   [VAR_IN] = inlink->frame_count  + 1,
-                                   [VAR_ON] = outlink->frame_count + 1 };
+                                   [VAR_IN] = inlink->frame_count_out + 1,
+                                   [VAR_ON] = outlink->frame_count_in + 1 };
     const int h = values[VAR_H];
     const int w = values[VAR_W];
     double x0, x1, x2, x3, x4, x5, x6, x7, x8, q;