[FFmpeg-devel] [PATCH 2/3] avfiltergraph: don't query formats if filter has uninitialized inputs

[Matthieu Bouron]

---
 libavfilter/avfiltergraph.c |   46 ++++++++++++++++++++++++++++++++++++-------
 1 file changed, 39 insertions(+), 7 deletions(-)

diff --git a/libavfilter/avfiltergraph.c b/libavfilter/avfiltergraph.c
index 9d7b956..064e678 100644
--- a/libavfilter/avfiltergraph.c
+++ b/libavfilter/avfiltergraph.c
@@ -202,17 +202,49 @@ static int insert_conv_filter(AVFilterGraph *graph, AVFilterLink *link,
 
 static int query_formats(AVFilterGraph *graph, AVClass *log_ctx)
 {
-    int i, j, ret;
+    int i, j, k, ret;
     char filt_args[128];
     AVFilterFormats *formats, *chlayouts, *packing;
+    int filters_init;
+    int *filters_state = av_calloc(graph->filter_count, sizeof(int));
 
     /* ask all the sub-filters for their supported media formats */
-    for (i = 0; i < graph->filter_count; i++) {
-        if (graph->filters[i]->filter->query_formats)
-            graph->filters[i]->filter->query_formats(graph->filters[i]);
-        else
-            avfilter_default_query_formats(graph->filters[i]);
-    }
+    do {
+        filters_init = 1;
+        for (i = 0; i < graph->filter_count; i++) {
+            int do_query = 1;
+            AVFilterContext *cur = graph->filters[i];
+
+            if (filters_state[i])
+                continue;
+
+            /* Check state of input links */
+            for (j = 0; j < cur->input_count; j++) {
+                AVFilterContext *ifilter = cur->inputs[j]->src;
+
+                for(k = 0; k < graph->filter_count; k++) {
+                    if (ifilter == graph->filters[k]) {
+                        break;
+                    }
+                }
+
+                if (!filters_state[k]) {
+                    do_query = 0;
+                    filters_init = 0;
+                }
+            }
+
+            if (do_query) {
+                filters_state[i] = 1;
+                if (graph->filters[i]->filter->query_formats)
+                    graph->filters[i]->filter->query_formats(graph->filters[i]);
+                else
+                    avfilter_default_query_formats(graph->filters[i]);
+            }
+        }
+    } while (!filters_init);
+
+    av_freep(&filters_state);
 
     /* go through and merge as many format lists as possible */
     for (i = 0; i < graph->filter_count; i++) {
-- 
1.7.10