diff --git a/libavfilter/avfilter.c b/libavfilter/avfilter.c
index 8d5702a0c8..d2e9ba47ef 100644
--- a/libavfilter/avfilter.c
+++ b/libavfilter/avfilter.c
@@ -997,6 +997,14 @@ int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
             av_log(link->dst, AV_LOG_ERROR, "Sample rate change is not supported\n");
             goto error;
         }
+
+        frame->duration = av_rescale_q(frame->nb_samples, (AVRational){ 1, frame->sample_rate },
+                                       link->time_base);
+#if FF_API_PKT_DURATION
+FF_DISABLE_DEPRECATION_WARNINGS
+        frame->pkt_duration = frame->duration;
+FF_ENABLE_DEPRECATION_WARNINGS
+#endif
     }
 
     link->frame_blocked_in = link->frame_wanted_out = 0;