Commit 01c2a2bfa4 for ffmpeg

commit 01c2a2bfa46a79eab35b60a83794a9730ebe6c3b
Author: Michael Niedermayer <michael@niedermayer.cc>
Date:   Tue Sep 22 21:31:24 2026 +0200

    avfilter/vf_xfade: keep the rescaled transition duration nonzero

    Found during review of the fix for #22273

diff --git a/libavfilter/vf_xfade.c b/libavfilter/vf_xfade.c
index d2da541ffe..8371fdf5ad 100644
--- a/libavfilter/vf_xfade.c
+++ b/libavfilter/vf_xfade.c
@@ -2099,8 +2099,9 @@ static int config_output(AVFilterLink *outlink)

     s->start_pts = s->inputs_offset_pts = AV_NOPTS_VALUE;

-    if (s->duration)
-        s->duration_pts = av_rescale_q(s->duration, AV_TIME_BASE_Q, outlink->time_base);
+    s->duration_pts = av_rescale_q(s->duration, AV_TIME_BASE_Q, outlink->time_base);
+    if (!s->duration_pts)
+        s->duration_pts = 1;

     switch (s->transition) {
     case CUSTOM:     s->transitionf = s->depth <= 8 ? custom8_transition     : custom16_transition;     break;