@@ -186,8 +186,17 @@ static int config_input(AVFilterLink *inlink)

     s->start_duration = av_rescale(s->start_duration, inlink->sample_rate,

                                    AV_TIME_BASE);

+    if (s->start_duration < 0) {

+        av_log(ctx, AV_LOG_WARNING, "start duration must be non-negative\n");

+        s->start_duration = -s->start_duration;

+    }

+

     s->stop_duration  = av_rescale(s->stop_duration, inlink->sample_rate,

                                    AV_TIME_BASE);

+    if (s->stop_duration < 0) {

+        av_log(ctx, AV_LOG_WARNING, "stop duration must be non-negative\n");

+        s->stop_duration = -s->stop_duration;

+    }

     s->start_holdoff = av_malloc_array(FFMAX(s->start_duration, 1),

                                        sizeof(*s->start_holdoff) *