[FFmpeg-cvslog] lavfi/vf_decimate: do not compare the first frame to itself.

[Nicolas George]

ffmpeg | branch: master | Nicolas George <george at nsup.org> | Sat Oct 24 19:43:55 2015 +0200| [962727acb4e3c4dff856b48460ddcf747fcfda93] | committer: Nicolas George

lavfi/vf_decimate: do not compare the first frame to itself.

This is a waste of computing power and will result to 0,
making it always dropped.
Use maximum difference values instead.

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=962727acb4e3c4dff856b48460ddcf747fcfda93
---

 libavfilter/vf_decimate.c |    9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/libavfilter/vf_decimate.c b/libavfilter/vf_decimate.c
index cd374c3..8b950b4 100644
--- a/libavfilter/vf_decimate.c
+++ b/libavfilter/vf_decimate.c
@@ -167,9 +167,12 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *in)
     if (in) {
         /* update frame metrics */
         prv = dm->fid ? dm->queue[dm->fid - 1].frame : dm->last;
-        if (!prv)
-            prv = in;
-        calc_diffs(dm, &dm->queue[dm->fid], prv, in);
+        if (!prv) {
+            dm->queue[dm->fid].maxbdiff = INT64_MAX;
+            dm->queue[dm->fid].totdiff  = INT64_MAX;
+        } else {
+            calc_diffs(dm, &dm->queue[dm->fid], prv, in);
+        }
         if (++dm->fid != dm->cycle)
             return 0;
         av_frame_free(&dm->last);