lavfi/mp=decimate: fix off-by-one logic in diff_C() x loop

[ffmpeg] / libavfilter / avfiltergraph.c

diff --git a/libavfilter/avfiltergraph.c b/libavfilter/avfiltergraph.c
index a5517fc5e09c48f37f97d5d13cebbcee765460cd..7ab1124f29748f0ce7354779829324e2a5ba5daa 100644 (file)
--- a/libavfilter/avfiltergraph.c
+++ b/libavfilter/avfiltergraph.c
@@ -34,6 +34,7 @@
 
 #include "libavutil/audioconvert.h"
 #include "libavutil/avassert.h"
+#include "libavutil/common.h"
 #include "libavutil/log.h"
 
 static const AVClass filtergraph_class = {
@@ -629,7 +630,7 @@ static void swap_channel_layouts_on_filter(AVFilterContext *filter)
 
     for (i = 0; i < filter->nb_outputs; i++) {
         AVFilterLink *outlink = filter->outputs[i];
-        int best_idx, best_score = INT_MIN, best_count_diff = INT_MAX;
+        int best_idx = -1, best_score = INT_MIN, best_count_diff = INT_MAX;
 
         if (outlink->type != AVMEDIA_TYPE_AUDIO ||
             outlink->in_channel_layouts->nb_channel_layouts < 2)
@@ -678,6 +679,7 @@ static void swap_channel_layouts_on_filter(AVFilterContext *filter)
                 best_count_diff = count_diff;
             }
         }
+        av_assert1(best_idx>=0);
         FFSWAP(uint64_t, outlink->in_channel_layouts->channel_layouts[0],
                outlink->in_channel_layouts->channel_layouts[best_idx]);
     }